Yak 18T Flight Operations Manual

6.4. Engine Starting............................................................................................... 31 6.5. Engine Warm-up............................................................................................. 32 6.6. Taxiing to the holding point ............................................................................. 33 Yak 18T Flight Operations Manual Page 3 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 6.7. Engine Run-up ............................................................................................... 34 S ECTION 7 - F LYING ................................................................................................ 36 7.1. Take-off Preparation ....................................................................................... 36 7.2. Take-off and Climb ......................................................................................... 36 7.3. Cross-Wind Take-Off....................................................................................... 37 7.4. Climbing ........................................................................................................ 38 7.5. Engine Overheating (During the Climb)............................................................. 38 7.6. Horizontal Flight ............................................................................................. 39 7.7. Chips in Oil..................................................................................................... 40 S ECTION 8 – AEROBATIC F LIGHT MANOEUVRES ........................................................... 41 8.1 Steep Turn: 45° of bank................................................................................... 41 8.2 Steep Turn: 60° of bank................................................................................... 42 8.3 Figure Eight .................................................................................................... 43 8.4 Combat Turn ................................................................................................... 44 8.5 Diving............................................................................................................. 44 8.6 Steep Climb/Zoom ........................................................................................... 44 8.7 Spiral.............................................................................................................. 45 8.8 Slipping .......................................................................................................... 45 8.9 Slow/Barrel Rolls ............................................................................................. 46 8.10 Flick/Snap Rolls ............................................................................................. 46 8.11 Half-roll......................................................................................................... 47 8.12 Normal Loop.................................................................................................. 47 8.13 Half-Loop and Half-Roll .................................................................................. 48 8.14 Aircraft Behaviour at Large Angles of Attack and Stall ....................................... 49 S ECTION 9 - S PINS .................................................................................................. 51 9.1. Entry into spin................................................................................................ 51 9.2. Spin Recovery ................................................................................................ 52 9.3. Recovery from an Inverted Spin....................................................................... 53 9.4. Unintentional Snap or Fall into Spin .................................................................. 53 S ECTION 10 - L ANDING ........................................................................................... 55 10.1. Descent and Landing Preparation ................................................................... 55 10.2. Planning the approach................................................................................... 55 10.3. Going Around ............................................................................................... 56 10.4. Landing........................................................................................................ 56 10.5. Crosswind Landing ........................................................................................ 57 10.6. Engine Shutdown.......................................................................................... 57 S ECTION 11 - S PECIAL CASES IN FLIGHT .................................................................... 59 11.1. Pilot Actions in case of Engine Failure ............................................................. 59 11.2. Pilot Actions in case of Pressure Drop ............................................................. 59 11.2.1. Engine Failure and the Primer ..................................................................... 59 11.2.2. Pilot Actions in case of drop in Engine Oil Pressure........................................ 60 11.3. Pilot Actions in case of drop in Fuel Pressure and Non-Uniform Fuel Consumption ...........................................................................................................................60 11.4. Pilot Actions in case of Engine Vibration .......................................................... 60 11.5. Pilot Actions in case of Propeller Over-speeding ............................................... 61 11.6. Pilot Actions in case of in-flight Fire ................................................................ 61 11.7. Pilot Actions in case of Forced Landing ........................................................... 61 11.8. Pilot Actions in case of Emergency Undercarriage Extension ............................. 62 11.9. Pilot Actions in case of Emergency Flap Extension............................................ 62 11.10. Landing with the Flap Retracted ................................................................... 63 11.11. Pilot Actions in case of Brake Failure ............................................................. 63 11.12. Pilot Actions in case of Radio Station Failure .................................................. 63 11.13. Pilot Actions in case of Generator Failure....................................................... 63 11.14. Pilot Actions in case of Converter Failure ....................................................... 64 11.15. Pilot Actions in case of Speed Indicator Failure .............................................. 64 11.16. Pilot/Crew Actions in case of a Emergency Bailout.......................................... 64 11.17. Pilot Actions for Engine Hand Starting ........................................................... 65 Yak 18T Flight Operations Manual Page 4 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 11.18. Special Feature of the Power Unit at low ambient temperatures ...................... 66 S ECTION 12 - O PERATION OF S YSTEMS AND E QUIPMENT ............................................... 67 12.1 Radio Station................................................................................................. 67 12.2 Radio Compass .............................................................................................. 67 12.2.1 General Information .................................................................................... 67 12.2.2 Pre-flight radio compass switching-in, tuning and checking ............................. 67 12.2.3 Radio Compass Usage in Flight..................................................................... 68 12.2.3.1 Compass System ............................................................................... 70 12.2.3.2 Pre-Flight Compass Switching-on ........................................................ 70 12.2.3.3 Troubles and failures of the Gyro-magnetic Compass ............................ 71 12.2.3.4 Magnetic Compass............................................................................. 72 12.2.3.5 Gyro-horizon ..................................................................................... 72 12.2.4 The Heating and Ventilation System ............................................................. 77 12.2.5 Aneroid and diaphragm actuated instruments and the pitot static systems ....... 77 12.2.6 Operational Limitations ................................................................................ 78 12.2.7 Light Facilities............................................................................................. 79 I NDEX ................................................................................................................... 81 Yak 18T Flight Operations Manual Page 5 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Introduction This manual is to be used as a general guide for owners and pilots to understand and become familiar with Yak 18T Flight Operations. Flying acquaintances can also make use of it as an initial education prior to practical experience. This document is based on two versions of translated Russian flight operations manuals. They were brought together in this single document with diagrams and images where appropriate. The main purpose of this guide is to present the reader with pertinent information, experiences and wisdom about the Yak 18T. If you have information that should be included in this manual, either identified as an obvious omission or as a useful enhancement, then kindly contact Alex Berry by email at alexberry@yak-aviation.com. This document is up for review by Yak 18T owners and pilots. The Yak 18T aircraft was initially designed for training Aeroflot pilot cadets. It was purposely designed and manufactured as a robust but flexible 4-seat touring aircraft with the added bonus of aerobatic capabilities. In recent times, many of these aircraft have been brought back to life via a complete overhaul both mechanically and cosmetically, with custom paint schemes, up rated engines and executive leather interior being commons options. For these reasons, and many more, the Yak 18T is a serious contender for the discerning pilot who is seeking both aerobatic capability and, with extended fuel tanks, good touring capacity. The 18T is worthy of all due consideration, especially when value for money is a key factor in the decision to purchase a recently overhauled aircraft. The 18T is considered a complex aircraft; it has a 360HP 9-Cylinder M-14P radial engine with both Retractable Gear and Variable Pitch Propeller, clearly not your average PA-28 or C172. The engine demands care and respect like any other engine, but it may be somewhat different to what you are used to, or what you trained in. However, do not let this dissuade until you have all the facts and have had a much closer look at this charismatic type. Many modifications for the 18T are currently available. For example, the engine can be up rated to 400HP, the propeller can be exchanged for a 3-blade German MTV-9 240/250 (amongst others), inverted fuel and oil systems, extended wing tip and extended wing tanks can also be fitted. This manual does not however take into account the majority of these modifications – although we would be happy to incorporate these sections should they become available. This manual contains instructions on Yak 18T piloting technique and general flight operations on the ground and in-flight. The checks in this guide also assume that only one person is present, the Pilot-in-Command (PIC). Disclaimer This flight operations manual is for guidance purposes only and has not been officially approved by Yakovlev or any other authority. It is not “a” or “the” definitive guide to Yak 18T Flight Operations and no claim is made to this effect. The originator of this document will not be held responsible for any action taken as a result of information presented herein. Your support and assistance with the content and accuracy of this manual will no doubt aid all Yak 18T owners in continuing to conduct safe and informed flights. Yak 18T Flight Operations Manual Page 6 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 1 – Background Information This section contains a brief background that was largely extracted from an article by A. Dugin (Smolensk) titled “YAK 18T. LIFE GOES ON”. 1.1. Introduction The 25th anniversary of the first Yak 18T take-off at the Smolensk Aircraft Manufacturing Plant was celebrated on May 25th, 1999. Today, the Yak 18T is the most popular general aviation aircraft in the Commonwealth Independent States (CIS) countries. It is well-known to all aviators of the CIS countries, developed by the Yakovlev Design Bureau and followed the Yak-18U, Yak-18A, Yak-18P, Yak-18PM and Yak-18PS. The 18T was the final modification in the Yak-18 family. The two-seater basic aircraft Yak-18 (1946) was put into production in 1947-1955 at the Arsenyevsk and Kharkov Aircraft Manufacturing Plants as well as in China. 3,752 and 379 aircraft were built in the USSR and China respectively. The Yak-18U (1953) is an improved two-seater trainer. During the period of 1954-1957 960 Yak- 18U were put out at Arsenyevsk Aircraft Manufacturing plant. The Yak-18-A (1957) was produced from 1957 till 1961 at Arsenyevsk Aircraft Manufacturing Plant (927 aircraft) and 1,796 planes were made in China. In 1961-1962, 125 aircraft were put out at Arsenyevsk Aircraft Manufacturing Plant. The Yak-18PM (1966) is aerobatic. In 1970-1972, 25 aircraft were produced in Arsenyevsk. The Yak-18PS (1970) is aerobatic too but there is no information about the number of aircraft produced (according to Russian Publishing Company Kodeks and KONVERSULT Consulting Company database). 1.2. Purpose At first, the Yak 18T was designed to be multi-purpose. That's why the Ministry of Timber Industry and the Ministry of Public Health ordered 300 aircraft each (unfortunately their requests were not met). According to the USSR Council of Soviet Ministers (SOVMIN), the Yak 18T became a trainer for the Civil Aviation schools, so that the production program was intended only for the Ministry of Civil Aviation. For ten years the Smolensk Aircraft Manufacturing Plant sent its output to Aktubinsk, Buguruslanovsk, Kirovograd, Krasnokutsk, and Sasovsk Civil Aviation schools. The Yak 18T’s were not delivered to the DOSAAF (semi-military organisations) airclubs. Only a "go-ahead" Ivanovsk airclub managed to get 10 aircraft. All-in-all 536 Yak 18T were produced in Smolensk for the period of 1973-1983, including experimental and prototypes. In 1974 an ambulance aircraft was built. Its purpose was to transport a patient on a stretcher with the escort of a doctor. But the series production of this configuration was not organized. Also, versions of an aircraft with ski and floating landing gears were being developed at the Yakovlev Design Bureau. But everything was in vain. Nothing came out of it. The schools mastered the Yak 18T well while using it. All the shortcomings of the design were eliminated and improved according to 217 bulletins. But in 1988 according to the decree of the Ministry of Civil Aviation (MCA) of the USSR all the aircraft were taken out of operation and subjected to discarding, even though the aviation industry produced nothing comparable to replace the Yak 18T. Absolute nonsense! For example, in Kirovograd plant, a team of workers, having completed the up-dating according to the bulletins, as it had been planned, signed their names in the logbook of the aircraft, which next morning was carried away for good. All aircraft fleet was replaced by the An-2 at the schools. Yak 18T Flight Operations Manual Page 7 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. The students had to study the nuts and bolts of training flights "in a Kamaz instead of Zhyguli" (which means dump truck and automobile respectively) was a witty remark of one of the pilot instructors. Part of the worn off Yak 18T was utilized. But after the interference of a newly created USSR Federation of Amateur Aviators, DOSAAF workers and motorcar enthusiasts were held to ransom aircraft for the depreciated cost. The nimblest managed to get the condemned for scrap-iron aircraft for 500…800 soviet roubles each or even for nothing. Thanks to such a decision more than 200 aircraft became privately owned property. As for the YAK 18T, it turned out to be the first popular General Aviation aircraft in the CIS countries. But, unfortunately, it is almost the only one up to the present day. 1.3. Collapse of the Iron Curtain After the "iron curtain" collapsed, this aircraft attracted the attention of foreign countries. Apparently, the aircraft participation in widely advertised flights of the crews of the Russian Federation of Amateur Aviators to the USA and Australia boosted its popularity. The aircraft were taken abroad in different ways. That's why at the present time the habitat of the aircraft spread to various countries from Bulgaria to New Zealand. In 1993, the Smolensk Aircraft Manufacturing Plant resumed Yak 18T production. Although the rigging was made afresh, the aircraft structure did not change. Outwardly the second- generation aircraft differs by symmetrical installation of two footboards (footboards of the first-generation aircraft were mounted only on the left side). Little changes also occurred in the equipment make-up. The ARK-9 was replaced by the ARK-15M. The Ulyanovsk Civil Aircraft Academy (UCAA), the former Civil Aviation Centre of the Council of Mutual Economic Assistance, became the biggest customer of the second-generation aircraft. Having got their bearings, the UCAA supervisors made a decision to get involved in primary training and bought 15 Yak 18T in Smolensk. And here is the result: if other schools go on using the An-2 as a trainer, and have been handing over certificates about completing the theoretical course instead of pilot license, in Ulyanovsk the students fly as much as they are supposed to. 1.4. The Aircraft The aircraft fuselage is mainly of riveted structure. Glue-welded joining of stringers and skin is used in the rear part. The wing is two-spar, cantilevers are mounted to the centre-section by the joint of the "lug-plug" type with four bolts each. The wing centre-section is made as a one-piece unit with a fuselage and the wingspan is 3.6m (11ft). That puts certain limitations on ground transportation. Along the whole span of the centre-section to the lower berth of the rear spar, the landing dashboard is hanging. The frame of the wing and tail unit is all- metal. Wing panels, ailerons, fin, stabilizer, elevator and rudder have aircraft cotton fabric ÀÌ-93 skin, which is called ‘percale’ in Russia, although these are different materials that can be used. The cabin is four-seat. Along the cabin sides there are two car-type doors from 850 to 1250mm in size, equipped with an emergency fault mechanism that allows the doors to be jettisoned in an emergency. In the first row there are two armchairs, adjustable vertically and horizontally with the mechanism of shoulder belts tightening. There is a passenger couch in the second row. Behind it there is an upper baggage rack and under it is quite a substantial baggage compartment. The hatch of the baggage compartment is to the left side of the board of the fuselage. The hatch lid opens up. And when it is closed, it is held by a pintle lock. Access to the lock-knob is from the cabin side with a rack-back position of the couch. There is a heating system, in which the outward air is heated from a heat exchanger of the engine exhaust and comes into the cabin. The system insures the windshield blower of the canopy. The air-cooling system ensures the cabin pressurization under the velocity head Yak 18T Flight Operations Manual Page 8 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. influence (air intakes are located on both sides of the fuselage and on the canopy upper frame). Left windshield is provided with an electric drive windshield wiper. The service ceiling is 5,520m (16,730 ft). But as oxygen system is not available on-board, it is not permitted to fly higher than 4,000m (13,120 ft) as it is stated later in this Flying Operations Manual (FOM). The power plant consists of the M-14P engine and a variable-pitch propeller V530TA-D35 with an rpm governor R-2. It is completely identical to the propeller group of the Yak-52s, except for some little differences in engine mounting. The tricycle-equipped landing gear with the nose strut is retractable. The front strut wheel is castor. The main landing gear wheels have block brakes. All landing gears are of telescopic type with a oleo-pneumatic shock-strut (AMG-10 oil and nitrogen). The double action shock struts are used in the Yak 18T. They ensure overcoming of the unpaved runway roughness with a smaller loading for frame construction. The tire pressure is 3 kgpcm² (61lbpsq.ft). A skilled pilot can turn the aircraft around practically on one wheel. The turning radius equals the landing gear tread width. A parking brake system is provided for the Yak 18T. In the case of the main system failure, the emergency system can perform all the functions except for the M-14P start. The capacity of a main air system cylinder is 12l (3.2 gal), the emergency one is 3l (0.8 gal). During the flight the air system is recharged from the AK-50T compressor, mounted on the engine. 1. Propeller 2. M-14P engine 3. Oil tank 4. Pilot chair 5. Radio equipment 6. Landing light 7. Fuel tank 8. Retractable landing gear The fuel (standard version) is distributed in two main tanks with the capacity of 95l (25 gal) each and in the service tank with the capacity of 3.5l (0.9 gal). The fuel is fed by gravity from the main tanks to a service tank, located in wing panels. The service tank is mounted lower than the main ones. The fuel is fed from the service tank, mounted on the engine by the 702K rotary pump. Before the engine start-up a fuel priming pump is used for priming its cylinders and the 702K fuel pump. The fuel to be used is B-91/115 gasoline, GOST (State All- Yak 18T Flight Operations Manual Page 9 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Union standard) is 1012-72. But Voronezh Mechanichal plant is going to use the automobile AI-92 gasoline for the M-14P operation in the nearest future. The oil system ensures oiling and cooling of rubbing surfaces of the engine parts as well as the P-2 regulator pump. The MS-20 oil of GOST 21743-76 is used in it. The oil circulation in the system is forced by the MN-14 gear pump, mounted on the engine. The oil tank is mounted on frame No 0. Its capacity is 24 l (6.35 gal). The air-oil cooler 2281-2-0 of a tubular type is mounted on the right side of the center-section of the front spar. Its air intake is located in the wing leading edge flap. To make the engine start-up easy in winter the system of oil thinning by gasoline is provided. The Yak 18T inherited the ability to perform a full complement of aerobatics from the early aircraft of the "T" family. There is only one point to pay attention to. The standard oil system design doesn't provide the engine oiling during the inverted flight. That's why the FOI forbids its performing. The fuel and oil consumption doesn't exceed 45 lph (12 galph) and 1 lph (0.26 galph) respectively at the second cruising regime. Three power supply systems are used on the Yak 18T. They are: a direct-current of a voltage of 28V, an alternate single-phase current of a voltage of 115V with frequency of 400 Hz and alternate three-phase current of the voltage of 36V and frequency of 400 Hz. The primary system is a direct-current system with the GSR-3000M generator and the 20NKBN-25UZ storage battery. The sources of alternate current are the PO-250A (115V) and the PT-200Ts (36V) converters. 1.5. The Fuel System 1 - oil dilution valve 10 - fuel drain valve 2 - P-1B fuel pressure transmitter 11 - vent pipe 3 - oil feed pipe 12 - check valve 4 - main fuel tank 13 - 740400 hand primer pump 5 - service tank 14 - fill hoses 6 - main fuel tank 15 - bypass pipeline Yak 18T Flight Operations Manual Page 10 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 7 - filler 16 - fuel fire shut-off valve 8 - fuel quantity transmitter 17 - fuel filter 9 - overflow and vent line 18 - overflow and vent line of a service tank The standard complete set of aircraft instrumentation consists of the GMK-1AE compass system (CS), the AGD-1K gyro horizon, the EUP-53U turn indicator, the UC-450K airspeed indicator, the VD-10K altimeter, the VR-10MK VSI rate-of-climb indicator, the AM-10K accelerometer, the AchC-1 aircraft clock, the KI-13K magnetic compass, the SSKUA-1 angle- of-attack warning system. 1.6. The Control Panel 1 - engine start button 12 - US-450 speed indicator 23 - EUP-53U indicator 2 - 2M-80 air system gauge 13 - 1122-B horizon indicator 24 - TUE-48 temperature indicator 3 - AM-1OK accelerometer 14 - VR-1MK rate-of climb indicator 25 - TTsT-1 temperature indicator 4 - landing gear warning light 15 - MV-1bV pressure vacuum gauge 26 - SBES-2077B fuel quantity indicator 5 - PM1-1 magneto switch 16 - ground break-down control button 27 - ARK-15 control panel 6 - hand primer pump product No 740400 17 - VD-1OK altimeter 28 - KM-8 compensator 7 - T6-U2 signal panel 18 - SSLUA-1 system indicators 29 - fuel emergency shut-off cock handle 8 - GMK-1AE control panel 19 - UKZ-1 indicator 30 - Baklan-5 control desk 9 - 20 - PTE-1 tachometer indicator 31 - landing gear emergency release cock 10 - SPU-9 control panel 21 - VA-Z voltammeter 32 - electrical system charging cock 11 - YGR-4UK indicator 22 - AchS-1K clock 33 - AZRGK-2 break-down signalling The radio equipment consists of the Baklan-5 radio compass and the MRP-56P station and the SPU-9 intercom. The radio navigational equipment includes the ARK-15M automatic marker receiver. The RV-5 low-altitude radio altimeter and the Os-1 device for automatic landing were additionally installed on five aircraft for Kirovograd flying school some years ago. But Soviet GPS for the Yak 18T was unclaimed. So the aircraft of such a complete set haven't been produced any more. For the night flights and in conditions of low visibility the red highlight of the dashboard and the control panel is provided. Besides the navigation lights and the MSL-3 signal beacon, the exterior lighting equipment includes the LFSM 28-200-landing/taxi light. Yak 18T Flight Operations Manual Page 11 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 2 - Technical Information This section contains some technical information about the performance, dimensional characteristics and standard equipment of the Yak 18T. 2.1 Performance Engine 360HP, M-14P Engine starting system Pneumatic Cylinders 9, Radial, Star-type/single layer Cubic capacity 10 litres (1.1l per cylinder) Cooling system Air Weight (dry) 214kgs ±2%, 471lbs ±2% Max engine speed 101% Empty weight 2,728lbs, 1,240kg Gross weight 3,630lbs, 1,650kg Average cruise 200km/h, 108kts, 124mph Top speed (sea level) 262km/h, 141kts, 162mph Max. IAS (straight and level flight) 300km/h, 162kts, 186mph Max. IAS (straight and level flight with bumpiness) 360km/h, 194kts, 224mph Max. IAS (in a dive) 460km/h, 248kts, 285mph Range, 193litres (std. no reserve) 760km, 470miles, 3hrs 45mins Range, 193litres (+30mins reserve) 660km, 410miles, 3hrs 15mins Range, 193litres (+45div. + 30mins reserve) 510km, 315miles, 2hrs 30mins Range, 320litres (ext. no reserve) 1,250km, 775miles, 6 hrs 20mins Range, 320litres (+30mins reserve) 1,150km, 714miles, 5 hrs 50mins Range, 320litres (+45div. + 30mins reserve) 1,000km, 620miles, 5 hrs 5mins Ground run 1,221ft, 370m Ground roll 1,155ft-1,551ft, 350m-470m Service ceiling (with supplemental oxygen) 16,400ft, 5,000m Service ceiling (without supplemental oxygen) 13,120ft, 4,000m The ranges above are based on an approximate average burn rate of 50 litres per hour of flight at 200km/h i.e. Cruise I. Monitor the fuel burn rate of your particular aircraft against these figures (it may be more or slightly less) and always err on the side of caution. Also note the additional ground run and roll distances based on take-off weight, fuel load, C of G, runway slope, icing conditions etc. Never conduct flights purely based on the figures stated above. 2.2 Dimensional Characteristics of the Yak 18T Yak 18T Flight Operations Manual Page 12 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 2.2.1 General Data Length 8.39m ±1.6cm (27’6”) Height 3.4m (11’1”) LG wheel track 3.12m ±2cm (10’2”) LG wheel base at rest 195.5cm ±0.6cm Tyre size (braked wheel tyres of main undercarriage legs) 50*15cm Tyre size (nose undercarriage leg) 40*15cm Distance from tip of propeller blade to the ground (at parking position with compressed shock struts and wheel tires) 16cm Pitch angle at rest 2° 2.2.2 Wing Section Klark YH Area, Span 18.8m², 11.16m (36’7”) Length of mean aerodynamic chord 1.74m (5’8”) Aspect ratio 6.6 Dihedral (along ¼ chord line) 7°20’ Angle of wing setting 2° Ailerons area 1.92m² Aileron deflection (up/down) 22°-1° / 15°-1° Landing split flap area 1.6m2 Deflection angle of the landing split flap 50° +3° / -1°30’ 2.2.3 Horizontal Tail Area 3.185m² Span 3.54m (11‘7”) Elevator area (incl. trim tab) 1.235m² Dihedral 0° Elevator deflection (up/down) 25° -1°30’ / 25° -1°30’ Elevator trimmer deflection (up/down) 20° +3°40’ / 20° -1°15’ 2.2.4 Vertical Tail Area 1.7m² Rudder area 0.982m² Rudder deflection (left/right) 27°-1° / 27°-1° 2.2.5 Engine Conditions Engine Condition Power nr. Ground (HP) Crankshaft Speed Supercharger pressure, mm mercury column Specific fuel consumption g/l, s.hr Take-off regime 360-2% (reduced) 99-4% ground 99+1-2% air Po+125±15 285-315 Nominal I 290-2% (reduced) 82%-84% Po+95±15 280-310 Nominal II 240-2% (reduced) 70% Po+75±15 265-300 Cruise I 0.75 of the measured power at Nominal II 64% 735±15 (absolute) 210-230 Cruise II 0.6 of the measured power at Nominal II 59% 670±15 (absolute) 215-235 Idling ≤ 26% 1. Higher power limit and boost pressure behind the supercharger at take-off, Nominal I and II is not limited 2. 99.4% of the crankshaft rotational speed corresponds to 2900rpm 3. Time of continuous engine operation in the take-off regime must not exceed 5mins at peak rpm conditions are 1min at rest conditions Maximum engine speed (rpm) 101% Idling (26%) to take-off regime engine acceleration capacity at V=0, H=0 does not exceed 3 seconds Maximum over-speeding at acceleration application in flight (duration does not exceed 1 second and time during service life – 30 minutes) 109% Yak 18T Flight Operations Manual Page 13 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 2.3 Fuel Specification and Octane Number Petrol B-91/115 Gost 1012-72 (octane number ≥ 91) 2.4 Carburettor Symbol AK-14P Type Pressure carburettor, without float Inlet temperature +10°C - +45°C 2.5 Fuel Pressure in front of Carburettor At operating conditions 0.2-0.5 kgf/cm² At minimum rpm at least 0.15 kgf/cm² 2.6 Petrol Pump Symbol 702 ML Type Lobe rotary pump Number per engine 1 2.7 Fine Filter Symbol 8D 2.966.064 Type Sump, gravity filter Filtration fineness 36-40μm 2.8 Oil Grade For flight and winter ops. MC-20 or MK-22 (Gost 10103-49) 2.9 Oil Consumption At Cruise I (g/l sec/hr) ≤ 8 (during 1st overhaul) 2.10 Oil Pressure At operating conditions 4-6 kgf/cm² At minimum rpm (in the main line) ≥1 kgf/cm² (Measured through a special pipe connection at the oil pump) 2.11 Oil Inlet Temperature Recommended 50°C - 65°C Minimum permissible 40°C Maximum during long term operations 75°C Maximum temperature in first 15mins operation 85°C 2.12 Cylinder Head Temperature Recommended 140°C - 190°C Minimum permissible for engine normal operation 120°C Minimum for continuous operation 140°C Maximum for continuous operation 220°C 2.13 Magnetos Symbol M9-25M Type Four-spark, shielded Number in the engine 2 2.14 Spark Plugs Symbol CD-49CMM Number per cylinder 2 Ignition sequence 1-3-5-7-9-2-4-6-8 Yak 18T Flight Operations Manual Page 14 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 2.15 Propeller Symbol V530TA-D35 Type Variable-pitch tractor Action Direct Direction of action Left Diameter 2.4m (7’10”) Blades 2 Minimum blade angle at 1000mm radius 14°30’±10’ Maximum blade angle at 1000mm radius 14°30’±10’ Range of blade rotation 20°±40’ Weight 40kg+2% (88lbs+2%) 2.16 Main Flight Performance at Standard Conditions Maximum indicated horizontal airspeed 262km/h, 141kts 162mph Maximum service ceiling 13,120ft, 4,000m As standard oxygen equipment is not available in the aircraft, flights at altitudes above 4,000m (13,120ft) are PROHIBITED. In order to avoid the engine overheating, the climb to 3,000m (9,900ft) should be made at Nominal II (70%) conditions - • V(limit) = 170km/h (91kts) at ambient temperature near the ground up to +20°C • V(limit) = 180km/h (97kts) at ambient temperature near the ground over +20°C Climb from 3000m and higher is allowed to be performed at Nominal I conditions V(limit) = 165km/h (89kts). Time to climb to an extreme high altitude is ≤35 minutes. 2.17 Airfield Performance Take-off Weight Rotation Speed Take-off Run Take-off Distance to 10m (33ft) Length of Aborted Flight Touch- down Velocity with Flap Landing Run Landing Distance from 15m (50ft) At mean conventional bearing power of soil 8-9 kgf/cm² 1,650kg 135km/h 370m 670m 850m 130km/h 470m 790m 1,510kg 125km/h 265m 540m 650m 120km/h 390m 690m 3,637lbs 73kts 1,214ft 2,198ft 2,789ft 70kts 1,542ft 2,592ft 3,329lbs 67kts 870ft 1,772ft 2,132ft 65kts 1,279ft 2,264ft At mean conventional bearing power of soil 4-5 kgf/cm² 1,650kg 125km/h 500m 920m 700m 125km/h 350m 650m 1,510kg 120km/h 455m 830m - 124km/h 350m 610m 3,637lbs 67kts 1,640ft 3,018ft 2,297ft 67kts 1,148ft 2,132ft 3,329lbs 65kts 1,493ft 2,723ft - 67kts 1,148ft 2,001ft Landing without the extended split flap is permitted in the following cases: • at headwind speed of less than 10m/s (19kts/22mph) • at crosswind • in case of faulty flap extension mechanism • in the cases where the pilot possesses adequate skill • in the case of aircraft ditching Yak 18T Flight Operations Manual Page 15 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 3 – Operational Limitations 3.1. Flying Limitations Maximum allowable indicated airspeed at diving 300km/h 162kts Maximum allowable indicated airspeed at turbulence (210-250km/h recommended) 300km/h 162kts Maximum allowable indicated airspeed for undercarriage and flap extension 200km/h 108kts Indicated stalling airspeed at braking with flying weight of 1570kg – 1620kg when the engine is at idling conditions Clean: Flap extended: Nominal I Clean: Take-off regime (gear down/flap): 120-123km/h 112-114km/h 102-105km/h 97km/h 64-66kts 60-61kts 55-56kts 52kts 3.2. Operational Loading At take-off weight of 1,500kg +6.4 / -3.2 At take-off weight of 1,650kg +5 / -2.5 3.3. Crosswind Components Maximum permissible headwind velocity at take-off and landing 15m/s (29kts/33mph) Maximum allowable crosswind speed at 90° runway angle at take-off 12m/s (23kts/26mph) Maximum allowable crosswind speed at 90° runway angle at landing 10m/s (19kts/22mph) Maximum allowable headwind speed when landing without the extended split flap 10m/s (19kts/22mph) 3.4. Weight and Balance Data 1. Aircraft empty weight allowance is ±1% 2. Empty aircraft c.g. position tolerance is ±1% (MAC – mean aerodynamic chord) 3. The undercarriage extension displaces the centre-of-gravity forwards by 0.5%-0.7% MAC 4. In the initial training version, the crew weight includes two parachutes C-4. Assumed weight of the parachute is 12.5kg 5. One of every five mass-production aircrafts feature the wiring and attachment fittings for the OSB-1 and PB-5 radio stations. When these stations are installed, the mass of the Versions Trainer version Initial training Take-off Weight 1,650kg (3,638lbs) 1,510kg (3,329lbs) Total load 438kg (966lbs) 303kg (668lbs) Fuel 100kg (220lbs) 100kg (220lbs) Equipment 338kg (745lbs) 203kg (447lbs) Crew – including: Pilot (1/2 persons) 80kg (176lbs) 185kg (408lbs) Cadets (3 persons) 240kg (529lbs) - Equipment without crew: Seat cushions 5 - Parachutes - 25 Oil 18 18 Aircraft empty weight 1,217kg (2,683lbs) 1,217kg (2,683lbs) Centre-of-gravity (c.g.) position, %MAC (mean aerodynamic chord) - At take-off, RG retracted - At landing, RG extended with 10% fuel and 50% oil - Empty, RG extended - Permissible CG position range, %MAC 24.5 23.4 18.5 13.0-26.0 19.5 17.8 18.5 13.0-20.5 Yak 18T Flight Operations Manual Page 16 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. aircraft becomes increased by 10kg and the CG position of the aircraft becomes displaced 0.5-0.6 %MAC aft ward. The OSB-1 and PB-5 stations are installed only in the advanced training version aircrafts. In this case the take-off mass of the empty aircraft is increased by 25kg. The CG position of the aircraft shits 1.6-2.3 %MAC aft ward. For aircrafts not equipped with SARPP-12K flight data recorder the mass of the aircraft decreases by 10kg and the CG position of the aircraft shits 0.3-0.5 %MAC forward. 3.5. Other Limitations • Due to the fact that the aircraft does not feature regular oxygen equipment, flights at altitudes more than 4,000m are prohibited • In the trainer version, the number of the crewmembers should not exceed four persons • As parachutes are not employed in the trainer version, it is PROHIBITED to make aerobatic manoeuvres. However, in the initial training version with a crew of two persons equipped with emergency parachutes, all elementary and advanced manoeuvres can be performed • Prolonged inverted flight and return (backward) flying is strictly PROHIBITED • Night training flights from non-lighted runways is prohibited • Take-off is prohibited if the quantity of available fuel is less than 60litres. In the case of illumination of the RESERVE 30litres (Oct. 30l) light annunciator the aircraft is allowed to fly not more than 40-45mins. Flights in the circuit should be performed with LG extended. The minimum sub-soil strength for taxiways and runway is 4 kgf/cm² Yak 18T Flight Operations Manual Page 17 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 4 - Pre-flight Inspection A quick review of your logbook will make it obvious how long ago it was that you flew in a Yak 18T. Whether you are the sole owner or a shareholder, you should always treat the aircraft with critical and suspect eyes. Whether you were the last to fly just yesterday or not, always perform an unrushed formal pre-flight inspection. The number of AAIB reports indicating inadequate pre-flights is unnecessary and avoidable. It takes 15-30minutes to do a good pre-flight; the best advice is to know what to look for and CHECK PROPERLY. The following suggested pre-flight inspection is targeted at the pilot who is travelling alone – hence the structure of the checks and the engine starting procedures. The process of conducting the pre-flight inspection for those with willing and able assistance will no doubt be improved. In any case, it is recommended that you take full responsibility for all of the checks, allocating only insignificant tasks to others until you are convinced of their competence. 4.1. Preliminary Pre-Flight Actions The following steps should be carried out prior to beginning the inspection, make sure that all covers and protective caps i.e. pitot cover, propeller cover, oil cooler stop, cockpit cover, aileron and rudder gust tabs are removed. 1. at dusty aerodromes the parking area of the aircraft must be HOSED 2. REMOVE any wing and tail tie-downs 3. in winter make sure that the aircraft is CLEANED from snow, ice and frost 4. if parked on grass, REMOVE any mud and grass from the undercarriage – also, check for unwanted items in the undercarriage recesses 5. REMOVE any items (typically grass and hay) located in the oil-cooling unit at the front of the starboard wing near the cowling 6. LEAVE the chocks under the main wheels and ensure that fire extinguishing aids are close to the aircraft in the event of a fire 7. CHECK that there are no PEOPLE, SUBJECTS or VEHICLES NEARBY capable of obstructing the propeller Ensure that all precautions are taken to prevent against spontaneous folding of the undercarriage, the engine occasional start, cut-in of individual electric units and extension of the split flap. For this purpose check the following – 8. SWITCH the BATTERY-GROUND SUPPLY to the OFF position 9. ENSURE that all switches and cut-outs on the panel are switched OFF 10. CHECK that the magneto switch is SET to 0 position OFF 11. CHECK that the undercarriage lever is in the DOWN position and locked with a detent. If no detent is available, advise all assistants and passengers of the importance not to touch this lever 12. ENSURE that the flap lever is in the NEUTRAL position 13. in winter time, check that the gills are CLOSED (remember to check visually that the gills are actually closed when you think they are) 14. ENSURE that the oil cooler is CLOSED (remember to check visually that the oil cooler shutter is closed when you think it is) 15. CHECK that the carburettor heat is OFF While in the cockpit, it is advisable to do a quick instrument check of the fuel contents – 16. SWITCH the BATTERY-GROUND SUPPLY to the ON position Yak 18T Flight Operations Manual Page 18 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 17. SWITCH the ENGINE INSTRUMENTS to the ON position 18. NOTE the reading of BOTH tanks from the fuel contents gauge 19. SELECT and hold the switch for the LEFT fuel tank contents and wait for the gauge to stabilise and note the reading 20. SELECT and hold the switch for the RIGHT fuel tank contents and wait for the gauge to stabilise and note the reading 21. COMPARE the individual readings with the total fuel contents and that of the expected contents (i.e. as stated in the engine log book) 22. unless full-fuel is required, avoid deciding on this basis if the aircraft needs additional fuel until you have VISUALLY checked the contents of each tank, just in case the gauges are inaccurate 23. SWITCH the circuit breaker ENGINE INSTRUMENTS to the OFF position 24. SWITCH the circuit breaker BATTERY-GROUND SUPPLY to the OFF position 25. if additional fuel is required then inform the ground staff now 26. NOTE: all switches should be OFF It is now advisable to perform a very quick check of the ANE (air navigation equipment). To do this, perform the following actions and remember that battery power is limited and will not last long; a quick check is all that is necessary to ensure that the lighting facilities function correctly - 27. SWITCH the BATTERY-GROUND SUPPLY to the ON position 28. SWITCH the ANE switches to the ON position 29. get out of the cockpit and CHECK the port side wing tip ANE light 30. move around to the front of the aircraft and CHECK the landing/navigation light on the port wing 31. while moving around to the starboard wing tip, CHECK the landing position lights on the front and main undercarriage 32. CHECK the starboard side wing tip ANE light 33. while moving to the rear, CHECK the anti-collision beacon 34. while moving to the port side, CHECK the rear tail ANE and then enter the cockpit 35. SWITCH the ANE switches to the OFF position 36. SWITCH the BATTERY-GROUND SUPPLY to the OFF position 37. NOTE: all switches should be OFF 4.2. Relevant Documentation Before the equipment is inspected, the pilot-in-command must look through the flight logbook to check whether any reported defects (detected during previous flights) have been eliminated. It is important to get to know what kind of works/repairs have been performed on the aircraft by technical personnel. If a group manages the aircraft then seek information about the maintenance schedule and if action needs taking – ACT! From this point on, you the pilot-in-command become responsible for the readiness of the aircraft for flight - Have you got valid and appropriate Aviation Insurance? Do you have copies of your C of A and C of R with you? Do you need a Permit to Fly? Is it valid? Taking passengers? Yak 18T Flight Operations Manual Page 19 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Are you ready to brief them? Have you got the prerequisite flying experience? CHECK! 4.3. Performing the Inspection 4.3.1. Pre-flight Checks Checking the Fuel and Oil 38. The amount and grade of the available fuel and oil must be CHECKED and REPLENISHED if necessary. The pilot-in-command must be sure that the fuel deposit is discharged and is free of mechanical additives and water and in wintertime ice crystals Checking the Oil 39. The oil contents are checked by the means of a dip-yoke attached to the oil cap on top of the cowling. First CHECK the oil by climbing on the starboard wing, edging forward avoiding the oil cooler until you can comfortably remove the oil filler cap without losing your footing. If you are quite a heavy individual or are uncomfortable with this approach, find some step-ladders and climb from either side of the cowling – it’s safer this way 40. REMOVE the cap, undo, remove and check the dip-yoke and ENSURE that the oil contents are in the range of 12-14 litres for ordinary flight (>8litres for aerobatic flight). The standard oil level reading is 18 litres. The total oil tank volume is 30litres 41. ADD the correct grade of oil as required by using a funnel being careful not to spill the oil during the process 42. Once satisfied with the oil contents, ensure that you REPLACE the dip-yoke and cap correctly and SECURELY. CHECK that the dip-yoke cap is held tight under the edges of the oil filler tab and then tighten 43. When refitting the oil cap on top of the cowling, ENSURE that the cap is placed correctly and that the screw ‘clicks’ into place to fasten the cap correctly 44. NOTE the quantity of oil and the amount added in the engine log book Checking the Fuel Deposit Yak 18T Flight Operations Manual Page 20 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 45. To drain and INSPECT the fuel contents, move underneath the fuselage to identify the fuel drain cap (only 1 fuel drain on a Yak 18T). This is located aft of the cowling, just in front of the split flap 46. Carefully UNSCREW the locking screws and allow the fuel cap to open on its hinge. Note, use the right tool and avoid using excessive force when opening the cap as this will decrease the life of the screw heads 47. Use a reasonably large clear container (unlike the usual test-tube like drainers). HOLD the container beneath the drain and PUSH the release valve to allow the fuel contents to fill the container 48. CHECK that the fuel is free from mechanical admixtures, sediments, water, ice crystals and is of the correct colour (i.e. blue). It is quite normal to drain 200ml-300ml of fuel 49. If unsatisfied with the fuel contents, RE-DRAIN and RE-CHECK. If you are in doubt, err on the side of caution and seek additional advice – do not rely on hope. We all know that the carburettor can become blocked and hence stop the engine at a critical time 50. REPLACE the fuel cap and as before, carefully lock the securing screws in place without using excessive force Visual Fuel Inspection 51. With a full tank reading, the fuel level in the tanks must be BELOW the edges of the tank fillers by at least 3cm. The total capacity of the fuel tanks is 193litres (more for those 18T’s with extended wing or wing-tip tanks) 52. REMOVE the fuel cap and fuel lock on the port wing (similar to when checking the oil) 53. REMOVE the inner fuel filter and then use a fuel dip-yoke (if available, visually if not) to MEASURE the contents of the tank. Note: with extended wing tanks, it is not possible to gain an accurate measure of the tank contents by visual inspection due to the wing dihedral 54. REPLACE the fuel filter and lock and ensure it is correctly positioned and SECURE (similar to oil) even if you are awaiting additional fuel 55. REPLACE the fuel cap and lock the screws in the correct position Performing the Walk Around Yak 18T Flight Operations Manual Page 21 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 56. Perform the walk around SLOWLY; take your time. If you are in a rush, then think about the implications of missing something vital and then ask yourself what is more important? The diagram below suggests a route for the walk around. By all means design your own, but whatever you decide, ensure that the walk around covers everything that is vital and once you have adopted a route, stick to it and improve it. AVOID the complacent ‘quick-random-check’ syndrome. Perform the external inspection of the aircraft with the following checks – 57. CHECK that the air valve inside the port-side cowling has been released and that no air is present by opening the valve. Do not over tighten this value 58. CHECK the engine cowling to make sure that no damage is present and that the cowl fasteners and cover plates are shut and secured correctly (slits of the fasteners should coincide with marks on the cowling) 59. CHECK the spinner/hub, ensure that all of the screws are secure, especially on either side of the propeller blades where they meet the spinner 60. CHECK the propeller blades and the blade counterweights for stone chips on the reverse side and other damage and cracks Yak 18T Flight Operations Manual Page 22 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 61. CHECK propeller blade setting according to setting marks 62. CHECK for leakage of petrol and oil 63. CHECK the undercarriage and fixture of the undercarriage extension signal lights, be sure that the tyre casing of the nose undercarriage leg is not damaged, the tyre pressure is a standard one (15-20mm tyre deflection), the damper conditions is proper (no mixture leakage) and camber of the shock- absorber strut is normal, a visible portion of the stem should de equal to 173- 187mm 64. CHECK whether tyre casings of the main undercarriage legs, grounding springs and signal lights fixtures of the undercarriage lowering are proper, the tyre pressure is standard (25-30mm deflection) and the sag of the shock- absorber struts is equal, the visible portion of the stem should be 204- 234mm Main Undercarriage Example Undercarriage Front Undercarriage 65. CHECK the centre-wing section from below 66. unlike the diagram below, make sure that the landing split flap is raised and fits TIGHTLY and that no fuel or oil leakage is present Yak 18T Flight Operations Manual Page 23 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 67. CHECK the starboard wing and look for damage of the wing skin and fillets 68. CHECK the state of the air intake, oil cooler and cells 69. CHECK for oil leakage and the proper condition of the extended undercarriage position indicator and state and fastening of the position lights 70. CHECK that the ailerons are good and joint couplings are proper, and that the clamps are taken off and the aileron can be freely deflected 71. at ambient temperatures of less than -5°C, CHECK whether a shutter is installed on the radiator cells 72. CHECK the starboard side of the fuselage, ensure that the cabin glazing, fuselage skin and radio station aerial are not damaged. Also check that the security of attachment to the fuselage is proper 73. CHECK along the top of the fuselage to the point where the tail fin joins the fuselage, looking for signs of stress and any disfiguration or panel movement 74. INSPECT the tail unit for external defects 75. ENSURE that the horizontal and vertical stabilisers and their fillets are free from mechanical damage 76. CHECK that the hinge joints of the elevator and rudder are serviceable and are properly greased, see whether cramps are proper 77. CHECK fastening of bracing struts, case of the elevator and rudder deflection 78. CHECK the elevator trimmer is operational by winding it lock-to-lock and then SET it back to the NEUTRAL position. It is possible for the elevator trimmer wire to come off of its spindle. If you anticipate that this is the case during the winding, cease to test the trimmer as this will only make the corrective action more difficult 79. CHECK that the flashing anti-collision beacon and tail position lights are not defective 80. INSPECT the port side of the fuselage, CHECK its skin, see whether the locks of the luggage compartment and board hatches are closed, secure and fastened to the fuselage. The luggage compartment lock is renowned for looking locked but not actually being locked – check this is not the case by firmly pushing the luggage compartment from the inside behind the rear seat Yak 18T Flight Operations Manual Page 24 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 81. CHECK the radio-altimeter aerial, radio compass and marker aerials are not damaged 82. CHECK state of glazing, the cabin door and door hinges. Water has been known to creep down into the slim cabin door pockets. If this is the case, remove the water before continuing 83. CHECK the port wing, check the state of the wing skin and presence of fillets, condition of an aileron and joint couplings. See whether cramps are withdrawn and the fastening is proper 84. INSPECT the state of pitot-static tube PST, see whether the pitot cover is removed and the undercarriage extended position indicator is sound and that the landing light is not damaged The pilot should check the following prior to entering the cockpit - 85. that the cockpit is FREE from foreign objects, the seats are INTACT and mechanisms of the door latches are PROPER. The door locks can become difficult to close properly RESOLVE before you get to the point of doing your power checks 86. the state of the SAFETY HARNESSES and the mechanism of fitting the shoulder straps is secure and operational 87. the presence of PARACHUTES in both front seat pans, checking that the parachutes have been repacked according to regulations (4 if carrying passengers, remembering weight and balance checks) 88. the presence of LIFE-JACKETS in both front seat pans if crossing water (4 if carrying passengers) 89. the presence of a LIFE-RAFT on the rear shelf or on an appropriate seat if crossing water 90. CLEANLINESS and the condition of the glass cockpit windows being intact. Clean both inside and outside if necessary 91. if passengers are to be carried, the pilot may now allow them to the enter the cockpit, providing them with clear instructions as to what to do to install themselves and fasten the RESTRAINTS, LIFE-JACKETS and PARACHUTES where appropriate 92. the pilot must then CHECK that all passenger restraints are correct and that no items are trapped outside when the cabin door when it is closed 93. the pilot is now obliged to provide the first part of the pre-flight PASSENGER BRIEFING, giving the passengers plenty of time to understand and question the talking procedure, take-off, enroute and landing processes, exit procedures and priority and noises to expect. If appropriate, ask one or more of your passengers some questions too and ask them to keep a good look out to the port or starboard side/s Yak 18T Flight Operations Manual Page 25 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. After entering the cockpit, the pilot should proceed as follows – 94. PUT feet on the rudder pedals under the pedal belts and, if necessary, ADJUST the seat so as to be able to fully deflect the rudder pedals and the yoke to their full extent 95. CHECK to be sure of easy and positive action of the yokes and rudder pedals and of the correctness of the controls and ailerons for FULL AND FREE deflection 96. CHECK whether the parachute spring hook is attached to the pull ring on the seat pan 97. CHECK to ensure that the seat harness release is intact 98. FASTEN waist and shoulder straps and press yourself to the seat back and tighten waist straps in the buckles. By means of a handle of the tightening mechanism retract and lock the shoulder straps and then tighten the buckles – ensure that you can still REACH all necessary instruments 99. CONNECT the radio communications headsets 100. CHECK whether the cockpit's doors are closed and properly clamped in the locked position with by the latch and the lock 101. CHECK for the proper state of the flight and navigation instruments as well as other instruments, SET the altimeter pointer to zero and check whether the altimeter barometric pressure corresponds to the actual value at the aerodrome level pressure at a given moment (with a difference of not more than +1.5mm of Hg.) 102. CHECK clock reading, wind it up and SET the correct time and reset the counter Yak 18T Flight Operations Manual Page 26 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Check the engine controls – 103. CHECK the motion of the thrust lever from idle to fully open 104. CHECK the action of the pitch control lever 105. CHECK that the carburettor heat control lever can be easily moved (after checking stop heating by placing the lever fully upwards) 106. CHECK the opening and closing of the cowling gills and radiator shutters, ENSURE that the control wiring does not jam and that the cowling gills and radiator shutters are closed and open when you expect them to be – CHECK VISUALLY: do not expect that everything is fine just because the control levers feel normal. If the gills are not opening and closing freely, then it is possible to loosen the equipment by squirting aviation lubricant in the cowling joints on the front of the cowling, being careful not to disconnect the small springs connected to some of the gills 107. ENSURE that the FUEL SHUT-OFF VALVE is pushed as far forward as it will go. i.e. fuel is not cut off 108. Now OPEN the air system valve by turning it fully to the left and – a. CHECK air pressure in the main and emergency cylinders which must be 50 ±5 kgf/m² b. PROPER functioning of the landing split flap-operating mechanism (its extension and retraction) and CHECK the proper state of the warning light. To do this, move the flap lever to the position RETRACT (counter pressure is to be created) and then to the EXTEND position and control the flap extension by means of a red indicator FLAP EXTENSION on the panel which will LIGHT UP at this moment. Then RETRACT the flap, to do it SET the flap lever to the position RETRACT and on making sure it has been retracted from a red indicator light FLAP EXTENSION which will go OUT on the panel, place the flap lever in the NEUTRAL position. c. NOTE: if the air pressure is low, you may omit this step for now, until the engine is operational and the air pressure is being recharged 109. CHECK air-tightness of the braking system, fully apply the brakes and ENSURE that no noise or hissing of air can be heard. Leave the brakes in the ON position and continue the checks in the next section 5.1 Start Preparation Yak 18T Flight Operations Manual Page 27 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 5 – Engine Start Preparation The following text provides an overview of Hydraulic shock – if you have not read it before, you are urged to read it entirely before continuing. If you have read it before, it is still worth reading it as a reminder. 5.1. Hydraulic Lock/Shock Avoidance This section kindly provided courtesy of Richard Goode Aerobatics (www.russianaeros.com) The importance of preventing hydraulic lock can never be underestimated. The consequences are at best expensive, at worst – catastrophic! One fatal accident was caused by hydraulic lock, leading to total engine failure and a subsequent stall/spin. 5.2. What is Hydraulic Lock/Shock? In the normal functioning of the internal combustion engine, the piston moves towards the top of the combustion chamber. (To avoid confusion we should realise that we are talking about the lower three cylinders on the M-14P, and therefore this is effectively at the bottom, at least in relation to the ground!) If, however, a proportion of the combustion chamber is filled with a liquid – in this case oil, which is incompressible - something must give. If the engine is turning with any degree of inertia – even being pushed through by the air-starter (although hand pulling cannot cause problems), the weakest part of the entire assembly is the connecting rod. Thus, when we attempt to start an engine with oil in the bottom of the combustion chamber, and it certainly doesn’t need to be full, this will initially increase the compression and, at its extreme, simply results in the piston being unable to progress further, hence the connecting rod bending and shortening. If you have any doubts about oil descending in these engines, you only have to see the amount of smoke following a start-up to realise that every engine has a fair amount of oil in the cylinders – but we of course are talking about more than that. A fundamental cause is that the pistons are made from an aluminium alloy to a very high coefficient of expansion. This means that, as it heats up, it expands to a much larger size and, in order to tolerate this, when cold it is quite significantly smaller than the piston bore, allowing oil in the engine to drain past the pistons, through the piston rings, and then down into the bottom three cylinders. The other issue is that the M-14P has a dry sump, i.e. a separate oil tank, from which oil is sucked to feed the engine, and to which it is returned by the scavenge pump. Normally a valve prevents oil from the tank, which is of course higher than the engine, descending into the engine unless the oil pump is turning. However, this can become stuck, even by a small piece of dirt, and particularly over a period of time the entire contents of the oil tank can migrate into the engine and, inevitably, will end up in the lowest place – the lower cylinders. 5.3. The Consequences Once the connecting rod has bent, it is inevitable that it will ultimately break, although amazingly engines often continue to run with a bent connecting rod for a number of hours. In the shorter term however, the bottom piston ring (of course, with inverted cylinders, the one furthest away from the ground), comes very close to the end of the cylinder at the bottom of its stroke, i.e. geographical top). With a bent connecting rod it is quite likely that the final oil-control piston ring will jump out of the cylinder. Then of course, when the piston is forced back into the cylinder, the piston ring will break, which initially will lead to high oil Yak 18T Flight Operations Manual Page 28 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. consumption, and almost inevitably to pieces of the ring being found in the front oil-filter, with an indication also from the chips-in-oil. If nothing is done at this stage, the connecting rod will break. The consequences of this can be truly dramatic, in one case the main crankcase bolts shot forward not only through the gills (quite easily), but also right through the passing propeller blade! It is also quite likely that mechanical mayhem on this scale could cause the engine to seize totally, and if this happens suddenly it will very likely tear itself out of the frame, with a consequent problem of a quite serious shift of C of G to the rear. 5.4. What can be done? The obvious answer is to not start the engine with oil in the bottom cylinders. What one should realise, however, is that there is oil not only in the cylinders, but also in the three bottom intake-tubes. An examination of the engine will show you that a tail-wheeled aircraft (e.g. Yak-50 or Sukhoi) will have a much higher tendency to collect oil in these tubes than a nose-wheeled aircraft. For this reason those owners who think that merely by turning the propeller through 20 or whatever blades before starting, they are totally avoiding hydraulic lock are deluding themselves. Certainly this will dislodge oil already in the cylinders, but it will do nothing to remove the oil in the intake tubes, which immediately after starting, is sucked into the engine, then possibly causing hydraulic lock. For this reason the designers put drain plugs in the three bottom cylinders, as well as thoughtfully providing a special spanner with which to remove these plugs. The problem with this is that it does take some time to remove the lower engine cowl and drain these intake tubes. However, you ignore this at your peril. Thus, for the original operators of these aircraft, as soon as an aircraft had not been used for a day or so, it was absolutely routine to undo the cowls and drain oil out of these intake tubes. Few of us however have our trained mechanic to do this before flying, and all too often it is neglected. A final way of minimising the problem is to ensure that every engine is run for at least 30 seconds at 60% before shutting down (remembering of course that the engine should not be shut down at above 1500 cylinder head temperature), which will scavenge excess oil from the engine into the oil tank, as well as get rid of oil in the supercharger, which is after all, the oil that ultimately drains into the intake tubes. 5.5. Other Solutions Given the reluctance of the average pilot in the West to spend more than a couple of minutes with an aircraft before flying, it is inevitable that people have been thinking of ways of banishing hydraulic lock. Sergio Dallan method Sergio Dallan, an Italian Sukhoi owner and an exceptional engineer, pondered the problem at length, and his solution comes in two parts: i) A master oil-tap at the bottom of the oil tank, which is (thankfully) connected to a warning light and an external visual signal, whereby after flight the oil supply is switched off and therefore cannot drain out of the oil tank. Hopefully of course the oil is switched on again before starting. ii) A clear window on the gearbox inspection plate enabling the propeller to be turned after shutting down to the position whereby the crankshaft throw is in its highest position. In this way oil cannot drain through the crankshaft and then slowly leak out of the big-end bearings and then into the lower cylinders. Yak 18T Flight Operations Manual Page 29 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. The system is good, but is not cheap (US$1,000), as well as taking a day and a half to install, and the slight possibility arising of starting with the oil still switched off. Manifold drains The next obvious way of combating the problem is a system whereby pipes are attached in the three lower manifold drain plugs, which then either go to individual drains or, more commonly, collect together into one larger pipe, and then into a fuel-drain type tap, which is opened after flight - oil slowly trickles through it, and before flight it is shut. This is an excellent system, although most of the systems I have seen incorporate small-bore pipes, which certainly would not allow oil in sufficient quantities to pass through when cold. There is also the need to shut the drain tap before the next flight. Vedeneyev System Vedeneyev are of course the original designers of the engine, and they have developed an ingenious, and fully automatic system whereby, after shutdown, oil drains from the three lower intake tubes into a container fitted to the bottom of the engine, which, on start up, is sucked slowly into the supercharger, and then into the cylinders and burnt. This system has the advantage of being totally automatic, as well as providing extra lubrication around the engine during the critical start-up period. Prototypes of it are now flying successfully, and it is hoped that the system can be offered on a commercial basis within a few months. Again however it is not a simple modification and the existing oil sump, i.e. the large green part of the engine you see projecting from between the lower cylinders, needs to be removed and machined. 5.6. Conclusion Check that the engine was previously run for at least 30 seconds at 60% before being shutting down. Turn the engine thoroughly through before every start and notice any oil coming out of the exhausts – even if you have only left the aircraft for half an hour (being aware of the engine temperature before turning is important to avoid it starting by itself). Drain the intake tubes if you have left the aircraft for more than a day, or fit one of the systems above which will drain them for you. If you have failed to start the engine after the second attempt and engine priming was conducted, then pull through the propeller to remove any excess fuel from the cylinders. Yak 18T Flight Operations Manual Page 30 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 6 – Engine Start At ambient temperatures of +5°C or less, the engine must be warmed-up from an airfield heater, to a cylinder head temperature of at least 30°C. In this case, it should be quite easy to turn the engine propeller through by hand. If the ambient temperature is between +5°C-10°C and if the oil in the engine and oil system is diluted with petrol then the engine can be started having not been warmed-up. The engine can either be started from the aircraft accumulator or from the airfield power source. CAUTION • DO NOT turn the propeller when the engine is hot i.e. > 100°C (lower to be safer) • DO NOT fill petrol up above the amount specified, as it can wash oil off the cylinder walls and cause a score of the pistons or can be accumulated in the bottom cylinders and also contribute to a hydraulic shock • DO NOT fill the petrol up through exhaust branch pipes and spark-plug ports 6.1. Prior to Starting the Engine • CHECK that the propeller pitch lever is placed in the FINE PITCH position • SET the thrust lever to the position corresponding to 1/3rd of fully open equivalent to approx. 28-38% engine rpm • ENSURE that the fuel cut-off valve is in the open position i.e. FULLY FORWARD • at ambient temperatures below zero, SET the carburettor heat control lever (adjusts air getting into the carburettor) to the ON position (i.e. fully downwards) 6.2. Avoiding Hydraulic Shock • CHECK that the engine was shutdown using the correct procedure i.e. run at 60% for at least 30 seconds at the correct temperature setting – if not, it is advisable to drain the bottom three cylinders for hydraulic shock avoidance • TURN the propeller through until the oil that may drip from the exhausts ceases completely. This may take several revolutions • Now WAIT for the oil to stop dripping completely and then turn the propeller through a few more times looking for signs of further oil expulsion from the cylinders and repeat if necessary 6.3. Engine Priming • TURN propeller (3-4 revolutions); during the propeller turning, SET the primer MOTOR PRIMING to the CYLINDER position and fill up 2-3 primers of petrol into the engine cylinders in summer and 3-5 primers in winter time. • GOOD ADVICE, but this is a tad difficult if you are on your own! Prime the cylinder, turn the propeller, prime the cylinder, turn the propeller, prime the cylinder and turn the propeller. Laborious but necessary and “Yes”, you do need to get in and out of the cockpit each time. Also, if you are on wet and muddy ground, you need to think about cabin cleanliness too • Now SET the MOTOR PRIMING primer to the FUEL LINE position and GENERATE the fuel pressure in front of the carburettor to 0.2 to 0.5 kgf/cm² • NOTE: this pressure will drop with time and may need to be restored prior to start – DO NOT over prime more than 0.5kgf/cm² • upon completion, SET the primer back to the CYLINDER position ready to provide additional fuel into the cylinders upon starting (i.e. the primer should be pulled out) Yak 18T Flight Operations Manual Page 31 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. 6.4. Engine Starting To start the engine, the pilot should proceed as follows - • have a good look round and check for any PEOPLE, ANIMALS or VEHICLES that may have unexpectedly approached the aircraft • even if your aircraft does not have the small windows at the front of the cockpit, it is still advisable to open the cockpit door, look around and announce loudly “CLEAR OF PROPELLER” and listen carefully for any response • once happy, close the cabin door and fit your safety harness securely • SWITCH the BATTERY-GROUND SUPPLY to the ON position • SWITCH the circuit breakers IGNITION, UNDERCARRIAGE WARNING, ENGINE INSTRUMENTS, ELECTRIC TURN INDICATOR and GYRO-HORIZON to the ON positions • TURN the start button-casing counter clockwise until the red mark is pointing north. The starter button is now live and the engine is now ready to be started • LOOK AROUND AGAIN for any PEOPLE, ANIMALS or VEHICLES • PRESS the START button as far as it will go. Duration of a continuous depression should not exceed 3 seconds • after the propeller has been turned through 3-5 turns, switch the MAGNETOS ON by setting the switch to 1+2 position. To provide a more successful start of the engine after the first flashes, feed additional fuel into the cylinders with the help of the primer (which was intentionally left out in the previous steps) • DURING start, if flashes appear in the cylinders, it is allowed to continue the engine starting procedure by displacing the thrust lever forwards and backwards in the range of revolutions, corresponding to 28%-60%, a throttle retard and accelerate rate is 2-3 seconds • after STABLE ENGINE OPERATION has been obtained, RELEASE the start button and SET the thrust lever to the position corresponding to 38%-41%, while simultaneously observing the oil pressure and the pressure gauge readings • after the engine start, LOCK the priming pump handle by setting it to the centre position. MOVE the start button clockwise to the locked position, cut in the generator and warm-up the engine • If the engine fails to be started after two attempts, stop the starting and identify the reason CAUTION • Prior to re-starting, observing all precautions (e.g. engine temperature) pull the propeller through manually by 4-8 full revolutions to remove fuel and oil from the cylinders which has remained there after a previous start (if it was performed with priming) in order to avoid hydraulic shock • If during 15-20 seconds after the engine has been started, OIL PRESSURE does not reach a value of 1.0 kgf/cm2, SHUTDOWN the engine and locate the cause Yak 18T Flight Operations Manual Page 32 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Now that the engine has started, pay particular and frequent attention to the engine and oil temperatures and pressures and CHECK the following – • that the undercarriage warning (three green indicators) lights come on, and check the proper state of red lights by pressing the test button • that the elevator trimmer control (when the trimmer is in the NEUTRAL position, a yellow/green indicator light TRIM NEUTRAL on the panel is ON • the state of electric instruments (check whether the pointers are SET to their initial down positions) • the serviceability of the fuel level indicator, the total amount of fuel in the tanks and fuel amount in the left and right tanks separately • note the amount of fuel that was added (if any) and compare against what is now indicated • the voltage of the airborne accumulator under load, to do it cut in the ANE (AHO) circuit breaker on the panel for 10-15 seconds, press the voltmeter button-voltage value should be at least 24V and is likely to stabilise at 27V-29V. The image obviously shows 0 • prepare and check the flight-control and navigation equipment and the radio instruments of the aircraft as well as the interior cabin lighting facility, if night flights are to be performed 6.5. Engine Warm-up • Warm-up the engine at the crankshaft speeds of 41%-48% until the oil temperature at the engine inlet is increased. As fast as the oil temperature increases, accelerate the engine up to 44%-48% in summer and 51% in winter time and perform the engine warm-up at these conditions until temperature of at least 120°C of the cylinder heads is reached and the oil temperature not less than 40°C at the engine inlet is obtained Yak 18T Flight Operations Manual Page 33 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. • The engine is considered to be warmed-up, if the temperature of the cylinder heads is not less than 120°C, the oil temperature across the engine inlet is not below 40°C and the temperature of air getting into the carburettor is not less than +10°C • Once satisfied with the raising oil pressure and temperature, during the remaining period of the engine warm-up, proceed with the provision of the second half of your passenger BRIEFING • After the engine has been warmed-up, ALTER the propeller PITCH by moving it twice from fine to coarse i.e. high to low • With the help of the thrust lever DECELERATE the engine to minimum rpm • CHECK again to ensure, that the cockpit doors are safely enclosed and locked with the catch • UNLOCK the undercarriage lever by moving the latch to the left • SET rudder pedals and the yoke to the NEUTRAL position 6.6. Taxiing to the holding point • REQUEST ATC taxi clearance to the hold. Upon clearance, have a good LOOK around and RELEASE the brakes After having received taxi-clearance, the pilot must proceed as follows – • APPLY the brakes and accelerate the engine up to 64%-68%. At this speed the aircraft should be HELD on the brakes and in position • During taxi, perform the differential brake checks but do this SPARINGLY. The braking system of the Yak 18T can OVERHEAT with a prolonged application of the braking mechanism, thus resulting in a complete brake failure on one or both sides of the system. However, it must be noted that one can taxi reasonably well WITH MINIMUM BRAKE USE • DECELERATE the engine to minimum rpm and ensure that no obstacles in the taxiing direction are present, release the brakes and accelerate the engine smoothly to the extent SUFFICIENT for the aircraft to start motion and proceed taxiing. At night and if visibility is poor or reduced at day time, switch on lower beam and, if required, the upper beam of the land/taxi lamp • Time of the land/taxi lamp switching-on should not exceed 5 minutes. During taxiing, hold the yoke in the NEUTRAL position, use brakes smoothly and as short duration pulses. Note: it may be necessary to deflect the yoke • The speed of taxiing on a natural surfaced runway should not exceed 15km/h, on a concrete runway not more than 30km/h • Perform taxiing at a slow speed, observing maximum care if the ground is slush-covered or rough, the terrain is unknown and obstacles are present nearby. If taxiing on grass, beware that uneven ground can push the nose wheel into the air, sometimes quite high, so taxi at what you might think to be too slow a speed on all suspected uneven ground • During taxiing at low engine crankshaft speeds, it is advisable to switch off the maximum number of the power consumers except for the radio station, flashing beacon and ANE Yak 18T Flight Operations Manual Page 34 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. and at night - to avoid discharging of the airborne accumulator due to prolonged taxiing which is not sufficient enough to charge the accumulator 6.7. Engine Run-up • Carry out the engine checks with the cowling gills and the radiator shutter CLOSED. Prior to acceleration, SET the controls to the NEUTRAL position and BRAKE the wheels • Run-up the engine to Nominal II, by pushing the throttle lever fully forwards and by increasing the propeller pitch simultaneously. In so doing, the readings of the engine control instruments should be as follows – Crankshaft speed 70% Supercharger pressure (boost pressure) Po+75±15mm of Hg Oil pressure 4-6 kgf/cm² Petrol pressure 0.2-0.5 kgf/cm² Oil temperature at the engine inlet 40-75°C Cylinder head temperature ≤ 190°C Carburettor inlet air temperature ≥ +10°C • The engine must run steadily and without shaking or abnormal vibration. To avoid engine overheating as a result of insufficient airflow, the engine should NOT be operated continuously on the ground at the Nominal Rating conditions. CHECK the correct functioning of the magnetos and spark plugs – • SET the propeller to the FINE PITCH position • USING the thrust lever SET a speed of 64%-70% • SWITCH one magneto off for 15-20 seconds and compare the drop in rpm with the previous setting • SWITCH both magnetos ON for 20-30 seconds (usually much quicker), until the initial speed is recovered • SWITCH the second magneto OFF and compare the drop in rpm with the previous setting and note the difference in drops between both magneto checks • SWITCH both magnetos ON • The engine crankshaft speed (rpm) drop when one magneto is operating should not exceed 3% • If the drop does exceed 3%, repeat the procedure until normal operation is achieved. If after prolonged magneto tests a drop is still found to be more than 3%, one is advised to shutdown the engine and seek further advice • APPLY carburettor heat and CHECK for a drop in engine rpm CHECK the correct operation of the generator – • SET the engine conditions to IDLING • using the thrust lever SET the crankshaft speed to 57%-58% • from extinguishing the GENERATOR FAILURE light, make sure that the generator has been connected to the aircraft electrical wiring system • CHECK the voltage being produced by the aircraft through the electrical wiring system via the voltmeter by pushing the voltage check button, its reading must be 27V-29V • SWITCH ON the power consumers required for the flight - converter, radio altimeter, radio compass, intercom system, VHF radio station, gyro-horizon inverted, compass system, gyro-horizon and the flashing beacon and for night flights, the air navigation equipment and the landing/taxi light CHECK for the correct functioning of the propeller and rpm governor. To do this, proceed as follows – Yak 18T Flight Operations Manual Page 35 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. • using the thrust lever SET a speed of 70% with the propeller's position SET to FINE PITCH • SHIFT the propeller pitch lever to the COARSE PITCH position (fully backwards), in this case the crankshaft speed will be reduced to approximately 53% • SHIFT the propeller pitch lever to the FINE PITCH position (fully forwards), the crankshaft speed will increase up to the initial value of 70%. Notice a short-term oil pressure drop at the engine inlet. Up to 2 kgf/cm² is allowed with a subsequent recovery during 8-11 seconds CHECK for the correct operation of the propeller and rpm governor at the equilibrium speeds, for this purpose proceed as follows – • using the thrust lever SET a speed of 70% with the propeller SET to a FINE PITCH position • using the propeller pitch lever SET a speed of 64% • by MOVING the thrust lever smoothly back and forth but not against the stop, make sure that the engine crankshaft speed remains UNCHANGED • the engine speed can be increased or decreased by 2-4% respectively via an abrupt forwards and backwards motion of the thrust lever. It’s equilibrium rpm will then be restored in 2-3 seconds. CHECK the engine during 20-30 seconds. To do this, perform the following procedures – • SET the propeller control lever to the position FINE PITCH forwards to the fine-pitch stop (decrease the propeller pitch completely) • SHIFT the thrust lever smoothly forwards against the stop The readings of the engine control instruments must be as follows – Crankshaft rational speed 95%-99% Supercharger pressure Po+125±15mm of Hg Petrol pressure 0.2-0.5 kgf/cm² Engine inlet oil temperature 40°C-75°C Oil pressure 4-6 kgf/cm² Cylinder head temperature ≤ 220°C Carburettor inlet air temperature ≥ +10°C CHECK the engine running at minimum speed (rpm) with the propeller SET at fine pitch and the thrust lever SET fully backwards. The engine should run steadily, the instruments readings must be as follows - Engine speed (rpm) ≥ 26% Oil pressure ≥ 1.0 kgf/cm² Petrol pressure ≥ 0.15 kgf/cm² To prevent the spark plugs from getting FOULED, the duration of the engine running at minimum rpm should NOT EXCEED 5 minutes. Also note that the low voltage generator light is expected to illuminate. CHECK engine acceleration response. For 2-3 seconds put the thrust lever smoothly from the idling stop fully forwards against the stop, in this case the propeller pitch lever must be in the position FINE PITCH. Transition from the minimum speed (rpm) to the take-off regime should be performed smoothly during 3 seconds. To provide the normal acceleration response, the temperature of the cylinder heads should be at least 120°C and the oil temperature at the engine inlet must be not less than 40°C NOTE: the pilot can TEST of the engine acceleration response in flight. This should be performed at an IAS of 160km/h Yak 18T Flight Operations Manual Page 36 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. Section 7 - Flying 7.1. Take-off Preparation Prior to requesting clearance for take-off, hold the aircraft with the brakes ON and carry out the following checks – • CHECK the proper state of the gyro-horizon. The aircraft is cleared for take-off only if the gyro-horizon is OPERATIONAL (i.e. actually operational for at least 3 minutes) • CHECK that the compass reading CORRESPONDS to the take-off heading (when was the last time the compass was re-aligned?) • CHECK that the landing split flap is RETRACTED • CHECK propeller pitch is SET to the FINE PITCH position (i.e. fully forward) • CHECK for full and free DEFLECTION of the yoke and rudder pedals • CHECK elevator trim is NEUTRAL position (a yellow/green light TRIM NEUTRAL on the panel should be ON) • CHECK that the cut-outs, switches and circuit breakers on the switch board required for the flying mission fulfilment are ON • in case of possible carburettor icing or ice formation in winter, SWITCH the carburettor heat ON LOOK around and on making sure that it is clear and that no unexpected aircraft are approaching, REQUEST a clearance for take-off. 7.2. Take-off and Climb Upon receiving the appropriate form of take-off clearance, enter the runway and TAXI along a straight line 3-5m in order to SET the nose wheel straight and over the take-off line, holding the brakes ON. Immediately place the engine into the Nominal I regime. Hold the aircraft with the brakes ON and check readings of the instruments controlling the engine operation. The instrument readings must be as follows – • cylinder head temperature 140°C-190°C • recommended inlet engine oil temperature 50°C-65°C (at least 40°C and not over 75°C) and fuel pressure 0.2-0.5 kgf/cm²) • oil pressure 4-6 kgf/cm² • the engine must run without undue VIBRATION or SHAKING • SWITCH ON the warning indicator DANGEROUS SPEED On making sure that the engine OPERATES PROPERLY, CLEARANCE has been given and NO OBSTACLES are present on the runway, you may TAKE-OFF by selecting the engine TAKE-OFF regime • SET the CLOCK to the ON position • RELEASE the BRAKES and by a smooth moving of the thrust lever SET it to the take-off regime, i.e. fully forward • DURING the take-off run, keep the yoke in the NEUTRAL position, compensate for the turns that may be necessary by gradually deflecting the rudder • when the IAS has reached 80-90km/h, smoothly pull the yoke backwards in order to RAISE the nose wheel to the take-off position (10-15 cm off the ground) and hold Yak 18T Flight Operations Manual Page 37 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. this position until the aircraft rotates naturally upon the increase in airspeed. NOTE: DO NOT raise the nose wheel too high. The aircraft typically ROTATES as follows – • with take-off weight 1,650kg IAS of 135km/h • with take-off weight 1,500kg IAS of 125km/h • what have you calculated it to be, given your load? • After rotation, INCREASE IAS to 160-170km/h for a gradual climb. NOTE: just after rotation, with the airspeed rising, the aircraft tends to quickly increase the pitch- up angle, be ready to COMPENSATE for this with the trim • You may have been trained to take-off in a different way, i.e. as above, but upon rotation, level the nose to the horizon at about 30ft, with the undercarriage still down, so as to gain the maximum amount of airspeed without climbing and then to perform the climb out upon sufficient IAS. If you HAVE been trained in this way then fine, if not, continue with the gradual climb approach. Do not attempt this approach UNTIL you have received SUFFICIENT TYPE TRAINING. Also be aware that this approach may infringe your local circuit procedures so CHECK first • At an altitude of at least 10m (~35ft) RETRACT the undercarriage. To do this, perform the following procedure – • MOVE the undercarriage lever to the RETRACT/UP position, take care NOT to retard the lever to the NEUTRAL position • CHECK that the undercarriage has RETRACTED by noting the illumination of the RED indicator lights on the undercarriage display panel • CHECK that the undercarriage has RETRACTED by noting that the port wing, cowling and starboard wing undercarriage indicator SIGNALS have lowered into the airframe • once SATISFIED that the lights and indicators are correct and that the undercarriage has been retracted, SET the undercarriage lever to the NEUTRAL position By the time the undercarriage has been retracted and an altitude of ~300ft has been achieved, ALTER the engine conditions from the take-off regime to the Nominal I regime for the climb to circuit height – • ACHIEVE a crankshaft rotational speed of 82%-84% by first reducing the propeller pitch and then by reducing the throttle to achieve the desired rpm. This action is to be carried out swiftly The climb is to be performed – • at IAS of 170km/h at ambient temperatures up to +20°C • at IAS of 180km/h at ambient temperatures over +20°C • carry out the usual 500ft CHECKS CAUTION • CONTINUOUS engine running in the take-off regime is NOT to exceed 5 minutes 7.3. Cross-Wind Take-Off • The peculiar feature of this take-off is the necessity to DEFLECT the yoke into WIND from the very beginning of the take-off run Yak 18T Flight Operations Manual Page 38 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. • This enables us to maintain a UNIFORM load on the main undercarriage wheels and to PREVENT banking during the take-off run • A trend to the upwind turn should be COMPENSATED by sufficient rudder deflection • As the speed increases and the aileron rolling power gets stronger, the yoke is gradually pulled to the NEUTRAL position so as to PREVENT the aircraft lifting on one wheel and placing undue stress on the other undercarriage leg • When an IAS of 100km/h has been achieved, as above, by a smooth pulling of the yoke backwards, lift the front wheel to take-off position. The crosswind take-off speed MUST be 5-10km/h HIGHER than that of a usual take-off • The direction after rotation and while climbing is kept by following your PLANNED flight course • NOTE: observe the cross-wind limitations of this aircraft 7.4. Climbing To prevent the engine from overheating, after you have achieved circuit height, perform the rest of the climb at the Nominal II regime with the engine SET at 70% and IAS at – • 170km/h at ambient air temperature up to 20°C • 180km/h at ambient air temperature over +20°C While climbing - • TAKE the load off the yoke by using the trimmer and check readings of the engine instruments • CONSTANTLY observe the engine temperatures and that they fall within the recommended limits - Crankshaft rational speed 70% (Nominal I) Petrol pressure 0.2-0.5 kgf/cm² Engine inlet oil temperature engine inlet oil temperature 50°C-65°C (maximum oil temperature 75°C, maximum allowable temperature during a long-term engine operation or not more than 15 minutes is 85°C) Oil pressure 4-6 kgf/cm² Cylinder head temperature cylinder head temperature 140°C-190°C (maximum cylinder head temperature during continuous engine operation is 220°C) Carburettor inlet air temperature ≥ +10°C Climbing from 3000m can be performed in the Nominal I regime with an IAS of 165km/h 7.5. Engine Overheating (During the Climb) If, while climbing, the temperature regime of the engine EXCEEDS the permissible limits with the cowling gills and the radiator shutters fully OPEN, the pilot should CEASE to climb, level out and increase the flight speed to REDUCE the severity of the engine conditions. To DECELERATE the engine, first reduce the boost pressure using the thrust lever and then REDUCE the engine speed rpm using the propeller pitch lever. If the measures taken do not result in the temperature reduction, the pilot should plan to END THE FLIGHT and INFORM ATC of the conditions and depending on the actual situation, land at the planned alternate airfield. WARNINGS • Deliberate flights into known icing conditions are PROHIBITED. If the aircraft enters into an icing zone, the pilot must SWITCH on the CARBURETTOR HEATING, CABIN HEATING, CLOCK and change direction and/or the flight altitude Yak 18T Flight Operations Manual Page 39 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. • Training flights into cloud are NOT allowed. In the cases of inadvertent IMC, the pilot must level out by a smooth pulling of the yoke and continue to pilot the aircraft relying on the gyro-horizon and electrical turn indicator. The pilot must compare the readings of the – • gyro-horizon and electrical turn indicator and make sure that there is NO banking or turn • gyro-horizon and the VSI indicator and make sure that the aircraft is flying HORIZONTALLY The pilot should CONTINUE instrument flying and perform a 180° turn using a maximum 15° angle of bank and SET a descent of 2-3m/s to break out of the clouds • Flying OVER 4000m can be performed only if OXYGEN equipment is available on board 7.6. Horizontal Flight When performing circuit flights (undercarriage up or down) it is advisable to maintain an IAS of 170-180km/h. CHECK for normal engine running conditions during horizontal flight, these are the same for flight planning. • After climbing to a specified level, SET the speed and engine boost pressure according to the engine regime selected. At normal conditions during horizontal flight, the engine instruments should read as follows – Fuel pressure 0.2-0.5 kgf/cm² Engine inlet oil temperature 50°C-65°C Oil pressure 4-6 kgf/cm² 1.0kgf/cm² at minimum rpm Cylinder head temperature 140°C-190°C Carburettor inlet air temperature ≥ +10°C • During warm weather, carburettor heat must be SWITCHED OFF as a high temperature of air coming into the carburettor causes a DECREASE in the engine POWER and therefore engine efficiency • In all cases of horizontal flight in conditions of increased humidity with the air temperature becoming lower than +10°C, carburettor heating must be SWITCHED ON • In-flight fuel consumption is to be monitored by using the fuel level indicators for both tanks and the clock. When the RESIDUAL FUEL red light on the panel is illuminated, it means that 30litres of fuel remains in the tanks, this amount will be sufficient for a MAXIMUM OF 40-45 minutes of flying. See below! • Aircraft onwards of No.0604 have an improved emergency fuel capacity monitoring system that provides a separate remaining fuel warning in the main fuel tanks. When the remaining fuel reaches 15litres, the fuel quantity low warning lights come on FUEL RIGHT or FUEL LEFT. This applies to HA-YAV • Controlled changes to in-flight engine power is recommended as followings - a) to reduce power (conditions) - • DECREASE the boost pressure • DECREASE the engine crankshaft rotational speed to the specified one • ADJUST the boost pressure b) to increase power (conditions) – Yak 18T Flight Operations Manual Page 40 of 82 Disclaimer: This manual is to be used as a reference only, it is based on translated Yak 18T Flight Operations Manuals and has not been approved by the Yakovlev Design Bureau or any other authority. • INCREASE the engine speed rpm to the specified one • INCREASE the boost pressure To AVOID oil thickening in the propeller hub cylinder during prolonged flight in steady conditions with low ambient air temperatures, it is necessary to shift the propeller pitch from a fine pitch to a coarse one at regular intervals (i.e. every 25-30 minutes) using the propeller pitch lever, changing the engine rpm within the 55%-67% limits. One can monitor the correct operation of the Generator by checking the GENERATURE FAILURE red light on the annunciator panel or by using the voltage level tester on the voltmeter gauge. 7.7. Chips in Oil In flight, if the CHIPS IN OIL red light illuminates on the annunciator panel, the pilot is obliged to END THE FLIGHT IMMEDIATELY and to INTENSIFY control of the aircraft. SPECIAL attention should be paid to the oil pressure and temperature at the engine inlet. If the pressure drops or the oil temperature rises, INFORM ATC about it and land at the nearest aerodrome or on the nearest emergency landing ground. It is PROHIBITED to perform any flight if the CHIPS IN ENGINE red light is illuminated before take-off. This problem must be eliminated before flight.