Instructions for Continued Airworthiness H36 Dimona

Play in the automatic mating fixture can be adjusted with set screws in the female side of the fixture. 3.2 AIRBRAKE DRIVE FIXTURE AND WHEEL BRAKES The two airbrake levers are connected together beneath the seat by a torque tube. Control cables connect this tube to another torque tube mounted on the aft bulkhead. This torque tube extrudes left and right from the fuselage butt rib and connects automatically to a mating torque tube in the wing structure. Outboard in the wing four drive lugs are attached to the airbrake flap itself. The entire system is spring loaded in the “RETRACT” position and the brakes are retracted by releasing the lever in the cockpit. The cable who connects the torque tubes are adjustable thru turnbuckles. Attached to the aft torque tube is a drive arm, which actuates the brake cylinder. From the master cylinder, a “T” fitting and tubing provide fluid pressure to each wheel brake assembly. The brake fluid reservoir is attached to the rear bulkhead and should be checked daily to ensure the fluid quantity is adequate. The parking brake is incorporated into the master cylinder and is actuated by a push-pull Bowden cable. 3.3 TRIM UNIT The trim for the elevator controls is accomplished thru two springs, attached to the elevator push-pull tube. The positioning of the trim lever located on the middle console is secured by a spring loaded locking teeth. Adjustment of the trim force can only be made by changing the trim springs. The trim force is adjusted at the factory, during manufacture. Correct trim forces can be measured when the trim lever is in the middle, neutral position. These forces are: Pressure required, full forward: 30 N +5 N full aft: 40 N + 5 N -6- Aileron and Elevator Controls in Fuselage -7- Rudder and Tail Wheel steering Controls Elevator Controls in vertical Fin -8- Airbrake Controls and Parking Brake -9- Aileron Controls in the Wing —10— 3.4 FUEL SYSTEM The aircraft is equipped with a 80 1 fuel tank, constructed from fuel resistant Polyester fibreglass. The tank is installed between the main and rear bulkheads. The fuel tank cover, when secure, is the floor of the baggage compartment. The filler cap for the tank is outboard on the left side of the aircraft and is connected to the tank by a cast rubber neck assembly. The tank vent is a part of the fuel quantity sending unit and passes thru the fuselage lower skin, parallel to the drain fitting to the exterior of the aircraft. The fuel tank cap is NOT vented. The entire tank assembly is grounded by a copper net impregnated within the Polyester fabric. This grounding net is connected to the entire ground system in the aircraft with static grounding cables. CAUTION When working within the tank area, insure that the static grounding cables have been secured after the tank has been completed. Also check the static ground cable on the filler neck/flange assembly! The bottom of the tank contains the fuel quantity sending unit, which is connected electrically to the fuel quantity gauge. Also, in the tank bottom is a “finger filter’ installed to hinder dirt and foreign matter. From the filter assembly a short hose is connected to the drain, which goes thru the fuselage floor to the exterior of the aircraft. In the normal “tail down” attitude this is the lowest part of the fuel system, and should water or dirt be in the fuel, it will be drained off at this point. From the fuel drain, a copper fuel line goes forward to the fuel shut-off valve, located in the middle console. CAUTION The fuel shut-off valve should only be closed in the event of an engine fire or during maintenance on the fuel system. The risk of attempting a take-off with a closed valve is too evident. From the fuel shut-off valve the fuel line continues forward to the firewall and the installed fuel filter. The filter element is replaceable (Purolator No. GF—140/1, Limbach No. 17.20.180). The filter body is a part of the electrical fuel pump. From the electrical fuel pump a fire retardant fuel line goes to the engine-driven fuel pump and further to the two carburetors. In the engine-driven pump another fuel screen filter is installed. To remove the fuel tank , the fuel tank cover and the cover of the brake fluid reservoir is first removed. Also the filler neck must be disconnected. Place a container under the aircraft and open the drain To accelerate the draining, a hand pump or electrical pump may be used thru the filler neck. CAUTION When de-fuelling always ensure the aircraft and pump are grounded, and a fire extinguisher is readily at hand!. When the tank is empty, disconnect the wires to the fuel quantity indicator. Tilt the tank and disconnect the drain hose. Then tilt it upside down and lift from the aircraft. Hereby the canopy must be held half-closed by a second person. Installation is a reverse of the removal procedures. Don’t forget the static ground wires. -11- Fuel System .Schematic -12- 3.5 POWER PLANT The engine in the DIMONA is a Limbach L 2000 EB 1.C. The engine is of opposed cylinder arrangement, 4 cycle, and delivers 80 hp rated power. The lubrication is wet sump. The engine is installed in the nose of the aircraft and is direct drive. The propeller is a Hoffmann HO-V 62R/Ll60T or. L 160 BT . The propeller has three pitch positions and is mechanically actuated. The engine is installed within the fuselage on traverse members, fore and aft. On each corner of the traverse assemblies are “Silent Blocks” which serve as shock mounts to negate engine vibration. The “Silent Blocks” are installed at a 45EoB angle to permit optimum dampening. Within the dampener blocks are steel lugs to prevent excessive movement of the power plant assembly. These lugs also act as restrainers, should the rubber mount be damaged. The fuselage structure is so designed, that the stringers, on which the dampeners are attached, carry the load thru the entire fuselage. This type of engine installation has several distinct advantages. a. Engine movement is restricted b. Vibration and noise in the cockpit area is reduced c. In the event that an emergency landing is performed, the fuselage structure absorbs the impact loading and not the engine or engine mount. The fireproof bulkheads in the engine compartment are providing safety for the cockpit in the event of fire and protect the forward structure as well. 1. Engine removal; The engine must be removed for overhaul or repair. a. Loosen and remove the four screws on the engine cowling, remove cowling. b. Remove lower air vent grill. c. Remove Positive (+) cable from battery and the following electrical cables with their respective cable numbers: Starter cable Nr.2 Ground cable Nr. 3, Cylinder head temperature cable Nr. 6, Oil temperature Nr. 7, Ignition Ground Nr. 9, Oil Pressure and Oil Pressure Warning Nr. 10 and 11, Voltage Regulator Nr. 15. d. Fuel shut-off valve close. Then disconnect fuel line from the exit side of the electrical fuel pump. e. Air Filter on right carburetor, remove. f. Heater hose on heater distribution box, remove. g. Bowden cables on choke and heater valve, loosen (Bug nut fitting). h. Throttle cable on combining throttle rod, disconnect. i. Tachometer cable, disconnect. j. Propeller pitch change cable, disconnect. k. Turnbuckles on V-form tensioner beneath the engine, loosen. 1. Four bolts between Silent Blocks and Stringers, remove. m. Engine assembly, with exhaust, accessories and Propeller can now be lifted from the fuselage. -13- 2. Engine Installation The engine installation is a reverse of steps a. thru m. NOTE When the engine is reinstalled, the engine will hang slightly left (20). After the engine is replaced in the fuselage, the two turnbuckles should be pulled up, until they are tight. All bolts are either safetied with wire or Nylon insert nuts. Engine compartment Nylon nuts should be only used once! Attention should be paid to proper safetied bolts or nuts! -14- Engine Component Description 1. Crankcase 11. Induction Manifold (L/H) 2. Propeller Flange 12. Carburetor (L/H) 3. Crankcase Breather 13. Starter 4. Oil Cooler 14. Magneto 5. Cylinder 15. Generator 6. Cylinder Head 16. Carburetor Actuating Shaft 7. Oil Filler neck 17. Carburetor (R/H) 8. Oil Pump with Angle Drive 18. Induction Manifold (R/H) 9. Engine Driven Fuel Pump 19. Induction Pipe (R/H) 10. Induction Pipe (L/H) 20. Manifold Equalizer Hose 21. Oil Dip Stick The Carburetors installed on the Limbach engine are Stromberg Zenith 150 CD-3. These carburetors are called equal or constant speed carburetors. The pre-positioning of the carburetor flapper valve regulate the amount of suction (intake) being produced by the engine thru the intake manifold. To balance this suction the piston in the carburetor body ascends or descends (depending on flapper valve position) within the under pressure chamber. This piston (membrane ) movement moves the fuel needle with it. The fuel/air mixture is therefore in balance, hence the term “equal pressure” carburetors. -15- a. Idle System; The carburetor does not have a separate idle system. When the piston (Membrane) is in the idle position, i.e. fully closed, the fuel needle provides sufficient by-pass fuel to retain the desired idle speed. b. Main System; When the engine is running the following events take place when the throttle is opened. As the flapper valve opens, the outside pressure (atmospheric) is greater than the internal pressure (mani- fold). Thus the piston assembly in the carburetor chamber, due to pressure in the dome rises. This movement increases fuel flow thru the tapered fuel needle, the engine accelerates until the pressures atmospheric/manifold are equal. The closing of the throttle is in effect a reverse of acceleration. At all times the airflow thru the carburetor throat is constant, hence the term “constant speed or equal pressure c. Acceleration System; A rapid opening of the flapper valve would cause a excessive mixture. To prevent this, the piston is contained in an oil bath, creating a hydraulic dampening action. The oil viscosity is an important function of the dampening action and only “ZENITH” original oil should be used. d. The carburetor membrane should be inspected every 100 hours (see inspections). To perform this inspection it is not necessary to remove or adjust the carburetor. Perform the following steps to accomplish the inspection: 1. Screw cap, No. 64, with piston rod and piston, Remove. 2. Spring 63, Remove 3. For mounting screws 4, remove 4. Pressure Piston 9, Membrane 8, extract, CAREFULLY! Pay attention not to bend the needle! 5. Check the membrane for cracks or tears. 6. Should the membrane be defective, remove the screws 6 and separate the membrane holder 7 from the membrane. Replace the membrane with a new one. 7. Re-assembly is a reverse of steps 1-5. Prior to closing the screw cap, fill the cavity with ZENITH oil to within 10 mm of the top. -16- Carburetor Stromberg Zenith 150 CD-3 64 Screw Cap with piston rod and piston 63 Spring 4 Screws, retaining 9 Pressure Piston 8 Membrane 6 Screws, Retaining 7 Membrane Holder e. Replacing Float Chamber Needle, and adjusting Float level. 1. Remove the carburetor from the engine. a. Remove float chamber cover, lift out float b. Immerse Float in hot water to check for buoyancy. If not water tight, replace float. c. Float needle can be removed by un-screwing, and a new needle inserted. d. Proper Float level can be measured from the float chamber (without cover). From the top of the float chamber to the tapered top of the float should be 16.5 mm. The two floats should be the same height. If not carefully bend the float tabs to parallel the floats. -17- 2. Testing newly installed float and/or needle. a. Reinstall Carburetor, install air-filter. Set idle speed by idle set screw 24 until 600-700 RPM is obtained with a warm engine. 3. Engine Inspection after sudden stoppage. a. Remove engine. Engine should be returned to the manufacturer for inspection. The checking of the propeller flange does not indicate an torque warping within the engine or damage to the engine case studs. 4. Spare Parts; Spare parts for the Limbach Engine should be obtained either directly from the Limbach Co. or from Hoffmann Flugzeugbau. 3.6 Electrical System: In the following description, all numbers in brackets can be equated to the similar numbers on the wiring diagram. The current producing side of the system is a Lead-Acid Battery and an Engine driven Generator. Two battery types, 16 or 28 Ampere hour Capacity can be installed. The battery had a central venting system, to provide overboard venting of corrosive gases. The Generator (7) can be of two types, 22 or 40 Ampere hour units. The both Generators are AC current Generators and the current is converted to DC by DC Diodes. The Voltage Regulator (8) is a transistor Regulator. To separate the current from the system an main switch (2) is installed. With the exception of the Starter, all electrical components are backed up with a Fuse or Circuit Breaker. The E-T-A Circuit Breakers operate on the over-temp principal. The Main Fuse (4), when switched off, breaks the circuit between the Buss Bar and the Battery. Generator Voltage (7) goes thru a 25 Ampere Fuse (5) to Buss. The Voltage Regulator has it’s own Fuse (10). The electrical circuit is designed to provide the Voltage Regulator current when switched on. Normally in the Glider mode undesired current loss would occur, and possibly deaden the Battery. However, when the engine is shut down and the oil pressure sinks below 0.5 bar, the warning contact on the oil pressure switch (12) and the Current Relay (9) closes. Thus the current to the Voltage Regulator is switched off and no current loss occurs. NOTE When trouble shooting the system for electrical faults, remember that current is switched off to the Voltage Regulator when the engine is not running! To provide a cockpit check instrument, a Voltmeter (11) is installed in lieu of an Ammeter. This instrument offers a more precise evaluation of current being produced. With the engine NOT RUNNING it should show 12-l3VDC. After the engine is started, it should or can climb to l4VDC. When the engine has warmed up it should remain at l4VDC. Should this not take place then the Battery has no charge or a fault within the charging system exists. If the voltage shown is to high, then the problem lies within the Voltage Regulator and severe damage to the battery may occur. Engine performance instruments are installed to monitor the powerplant system. They are: Electric Oil Pressure (15/17), Electric Oil temperature (16/18) Electric fuel Quantity Gauge (14/13) and Cylinder-head Temperature Indicator (24/25/26/27). The technical function of the above is basically the same. The transmitters produce a certain resistance, and the indicators provide a readout of the resistance value. The only instrument not connected to the wiring circuit is the Cylinder-head Temperature unit. Using a thermocouple, it produces its own current and resistance. The unit is very sensitive and loose connectors or chaffed wiring can lead to immediate erroneous readings. -18- NOTE Should the Thermocouple wiring be damaged, it cannot be spliced. It must be replaced, to retain its’ original resistance value! To increase fuel flow, especially for starting the engine, an electrical fuel pump is installed (19). The pump is an electromagnetic pump with membrane. The pump is activated by a separate switch. The Limbach engine is equipped with either Slick (4230) or Bendix (54RN21) Magnetos. The magneto is rendered inactive by shorting it to ground. It is very important to insure a good connection between Magneto and switch and that the switch is properly grounded. CAUTION When the grounding cable is removed from the magneto or switch, the magneto is HOT and the engine can fire if the prop is turned. Never leave a HOT magneto un-attended! The wiring bundles in the DIMONA are arranged to prevent chafing or abrasive contact. Guide tubes, PVC tubes, clamps and ty-raps are used for this. By repairs or modifications, care must be taken not to expose wire bundles to possible damage. All connectors are crimp type. A few exceptions are soldered connections, made by the manufacturer. An isolated connector has more strength than the wire itself, when the proper crimping tools are used. Do not attempt to repair a broken wire when the proper crimping tools are not available! The circuit breakers and Fuses operate on a Thermal Overload. They have an absorption capacity of 200 Amperes, then they switch automatically to OFF. They cannot be reset until the defective system cools below the 200 Amp. heat range. Do not continue to reset a popped circuit breaker. The circuit breaker is telling you something-s wrong! The installed fuses have the same Ampere rating as the circuit breakers. The fuse board is connected to the circuits by approved connectors. In the right instrument panel are the Main fuse, 25 Amp., Generator fuse 25 Amp., Engine Instrument fuses and Voltage Regulator fuse. Switches installed in the DIMONA are single pole, single, throw type. They have the capacity of 20 Amp., 28 VDC. The ignition switch is either JAN-ST 40A or MS 35058-22. These two switches cannot be replaced by switches with another specification, due to grounding values! Antennas are installed at the factory. VOR antenna is behind the rear fuselage bulkhead, ADF and OME/Transponder antennas under the fuselage between Firewall bulkhead and Main spar bulkhead. The Radio loudspeaker is installed in the canted console between the seats. When installing a speaker, the Rovings on this console should not be damaged or modified! In the canted console is installed a tube, assigned for wires. -19- The following electrical components and respective part numbers are installed as standard equipment on the H 36 DIMONA. Nomenclature Part Number 1. Battery with central venting 51612 or 52815 2. Battery main switch, Bosch 0 341 001 001 3. Starter, Fiat, 12 Volt, 130 Amp. npn 4. Main fuses, 25 Amp., E-T-A 2-5700-KlO-DD-25A 5. Generator fuse, E-T-A 2-5700-Kl O-DD-25A 6. Starter Button, Bosch 0 343 003 001 7. Generator, Ducellier, 14 VDC/22 Amp. or 7532 Generator, Motorola, 14 VOC/40 Amp. 9 AL 2696 G 8. Regulator, Electrical Current, Wehrle or DU 506/ l4VDC Regulator, Electrical Current, Motorola (Transistor) 9 RH 7013 9. Relay, Bosch, 12 VDC 0 332 204 150 10. Circuit Breaker, E-T-A- 2-5700-Kl 0-1 0056A Circuit Breaker, E-T-A 2-5700-Kl 0-1003 .5A 11. Voltmeter, Motometer (or VDO) 685.002.1002 12. Oil Pressure Switch (component of oil press. transmitter) npn 13. Fuel Quantity Transmitter (in Tank), Motometer or VDO 608 001 1055 14. Fuel Quantity Indicator, Motometer (or VDO) 609 003 1012 15. Oil Pressure Indicator, Motometer (or VDO) 644 001 1002 16. Oil Temperature Indicator, Motometer (or VDO) 641 011 1010 17. Oil Pressure Transmitter, VDO 360 081 030 002 18. Oil Temperature Transmitter, Motometer (or VDO) 642 0091021 19. Fuel Pump, Electric, Hardi E 65 20. Circuit Breaker, E-T-A, 3.5 or 6 Amp. Same as 10 21. Switch, APR 20-631 n/2 20 Amp., 28V Wiring Diagram *) Grounded on case by installation Unmarked wires are AN 16 22. Switch, Ignition, JAN Type ST 40 or MS 350058-22 23. Magneto, Slick or Bendix Refer to Limbach 24. Cylinder-head Temperature Indicator, Westach 2A1-2 25. Equalizing Thermo Element (included with Westach) 26. Element, Heat Transfer (for Spark plug) Included with 24 -20- Electrical Cable Marking 1. Positive terminal battery to Main Switch 2. Main Switch to Starter 3. -Ground C-) Engine Mount to Negative Pole Battery C-) 4. Ground Engine Mount to Firewall (Regulator) 5. Fuel Quantity Transmitter 6. Cylinder Head Temperature Transmitter 7. Oil Temperature Transmitter 8. Starter Relay 9. Ignition Ground Wire 10. Oil Pressure Transmitter 11. Oil Pressure Warning Contact 12. Electric Fuel Pump 13. Generator Regulator, Current 14. Generator Regulator to Relay 15. Regulator to Generator, Field 16. Generator to Generator Fuse, 25 Amp. 17. Main Switch to Main Fuse, 25 Amp. 18. Radio Speaker 19. Transmitting Button(s), Pilot’s Control Stick 20. Position Lights (includes positions 20 thru 24) 25. Anti Collision Light Wire Sizes 1 to 3: AN 4 Wire, 22 mm2 5, 7, 8, 10 to 15, 20 to 25: AN 16 Wire, 1.2 mm2 4, 16, 17: AN 10 Wire, 5.3 mm2 Permitted Loading on AN 16 Wire: Wire Length in m 30 15 6 3 Current (Amp.) 1 2 5 10 Anti Collision Light is usually installed on the upper side of the fuselage or of the Horizontal fin. Care should be used not to install it in the immediate vicinity of the VOR antenna. The antenna should not be installed on the vertical fin, since a cable disconnect will be necessary each time the aircraft is disassembled. The light is switched thru a toggle switch installed on the switch panel. Position lights are switched thru toggle switch (fused) on the switch panel. If position lights are not installed at the factory, information concerning the installation and the necessary wiring and routing are available from Hoffmann Flugzeugbau. Electrical circuit loading: 1. Current for Engine instruments 0.3 A 2. Current for Voltage Regulator max. 1.5 A 3. Electric Boost Pump, max. 1.0 A 4. Starter, max. 130.0 A 5. Lighting (Whelen Strobe) 1.7 A 6. Position Lights, max. 5.0 A -21- When ordering Avionics, pay attention to the current requirements. The Generator delivers 22 Amp. and the sum of all required current above, less Starter is 9.1 Amp. To maintain a safety factor, no more than 17 Amp. are available to compensate for Voltage drop and current surges. Most Avionics today will not consume the available current, however, the Transmitter of a VHF Radio may. It is highly recommended that a reliable Avionics shop be consulted when installing Avionics, after the Aircraft has been delivered from the Factory. The smaller battery is rated for 10 hours gliding with one radio receiver on and an electric Variometer operating. If flight planning is such that position lights, Anti Collision Light or other avionics are to be used, then the larger battery must be installed. General rules for working on electrical components: Turn the main switch off and disconnect the Negative Battery cable. With this done, a short circuit is impossible. Repair procedures set forth in FAA 43.13-la are to be followed. Approved material is to be used (AN, MS or NAS). Soldered joints are not acceptable. Wire must have the original material area The maximum Voltage loss within the system is 0.5 VDC. Consequently when the Battery is fully charged, the lowest reading in the system should be 13.5 VDC. CAUTION Before removing or disconnecting the battery, insulate the rudder cable. If this is not done, a short circuit with the rudder cable may happen Pitot Static System: By removing the glare shield, covering the instrument panel, access can be gained to all flight instruments. Instrument lines and hoses should be checked for security and damage. Installed within the vertical fin are the pitot and compensation tubes. Under no circumstances should they be blown into. Severe instrument damage will result! To check the pitot system for function, place a short length of surgical tubing (18”) over the pitot tube. Tie the other end shut. Slowly roll the tubing up toward the pitot tube. The air trapped in the tube will compress and produce an effective reading on the airspeed indicator. -22- The following schematic illustrates the pitot static system as installed in the DIMONA. 1. Altimeter 6. Static port (blue) 2. Air speed 7. Pressure (green) 3. Rate of Climb and Decent 8. Compensation Tube (red) 4. Compensation nozzle 9. Equalizing Bottle (0.45 1) 5. Pitot / Static Tube -23- Hoffmann Maintenance and H 36 DIMONA Inspections 4. MAINTENANCE & INSPECTIONS Table of Contents Paragraph Page 4.1 General --------------------------------------------- - 24 4.2 Inspection checklists for 50/100/500 hours ---------- 25 4.3 Inspection Criteria ------------------------------------- 30 4.4 Test Flights ---------------------------------------------- 33 4.5 Special Inspections ------------------------------------- 34 —24— Hoffmann Maintenance and H 36 DIMONA Inspections 4.1 GENERAL The performance of Inspections on the H 36 DIMONA is easily done. The aircraft requires no special tools or fixtures to complete all items on the checklist. Our experience is that one mechanic can perform the 100 hr inspection in less than one day, providing the aircraft has been maintained to standards. The use of two persons can expedite the work and two will be needed for a few minutes to pull and fold the wings, should that be necessary. The outer surface of the DIMONA has been sprayed with a two component paint to provide a lasting finish. The only care needed to protect the gloss finish is periodic washing with warm water and a mild detergent. We suggest that once a year (more often, if the aircraft is not fully hangared) a good automotive wax be applied and hand polished. This not only protects the finish, but improves the aerodynamic qualities of the aircraft, especially the wing upper surfaces. Extra copies of the DIMONA check list should be made from the blank master copy that is sent with the aircraft documents package. The reduced size copy in the handbook can be used for reference. We suggest, that accurate records, especially the inspection and test flight sheets, so that work performed or faults discovered, can be evaluated. It will also provide a perspective buyer an opportunity to review your efforts in maintaining your aircraft and will always influence a sale. A short comment on TBO (Time between overhauls): You will probably use the DIMONA in its dual roles, one as a glider and one as powered aircraft. Don-t forget to remember that engine time may not be the same as airframe time. The hourmeter in the cockpit will record engine time only. The pilot in command should determine the hours flown in the glider mode. -25- 4.2 INSPECTION CHECKLIST FOR 50-100-500 HOUR INSPECTIONS: A. Powerplant: 1. Start engine and run until temperatures are in green range. Shut down engine. 2. Remove engine outlet air grill and clean 3. Inspect grill and engine cowling for security and damage. 4. Remove wiring from spark plug tips and remove spark plugs 5. Perform compression test on all four cylinders (differential pressure check). Nr. 1: …………. Nr. 2 ……………. Nr. 3: …………. Nr. 4: ………….. 6. Remove sump plug and drain engine oil 7. Check oil screen for metal particles, wash oil screen in solvent bath and dry. 8. Oil temperature, oil pressure fittings, check for security and oil seepage 9. clean oil cooler and check for security and leaks. 10. Replace sump plug, re-fill engine with 2,5 ltr. oil 11. Clean engine (solvent or degreaser) 12. Check valve clearance (cold), replace cylinder head valve gaskets. 13. Remove air filter and clean by compressed air. Blow air from inner surface to outer surface. 14. Replace air filter element with new element 15. Check fuel lines from carburetor, fuel pump and fuel filter for security and damage. 16. Replace fuel filter element with new element 17. Replace float needle in carburetor 18. Clean filter in engine driven fuel pump 19. Drain fuel, remove finger filter and check for dirt and condition. Look also Pos. 11 and 14 (Fuselage) 20. Check carburetor membranes 21. Check flapper valve play in carburetor throat. If play exceeds 0.8 mm. repair by bushing or replace. 22. Check oil level in carburetor dome. Add original “Zenith lube oil” if necessary. 23. Check carburetor, choke, heater and air bowden flex cables for ease of movement. Lubricate if necessary with light oil. 24. Check engine mounting bolts and Silent blocks for security, safety and damage. 25. Check V-wire brace beneath engine for security. If cables are loose, re-tighten. 26. Check Generator belt for security and condition. Replaced frayed belt. 27. Check ignition timing (Refer to Limbach handbook) 28. Inspect magneto points. Replace if worn. 29. Check ignition harness for security, abrasion and porosity. Replace cracked or damaged harness. 30. Electrical and connectors md. battery, check for security, damage and corrosion. 31. Clean spark plugs and reset gap (0.4 mm). Replace plugs after 200 Engine hours. 32. Check exhaust system for blow by, cracks and security. 33. Remove heater shroud and check for cracks, hot spots, corrosion and damage. 34. Check engine case for oil seepage or cracks 50 100 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -26- 35. Check engine breather for blockage. If blocked, remove and clean. 36. Check cylinder air baffles for security and condition. 37. Check firewall for security and, where bulkhead fittings pass thru, for sealing. 38. Check combining hose between carburetors for security and porosity. 39. Check battery for damage and security. Check water/acid level. If low add distilled water. B. Propeller: 1. Remove propeller spinner and check for condition. 2. Inspect the four thrust rods for condition, grease rods and mating surface of plate with Calypsol H 442 or equivalent grease. 3. Check propeller blades for installation and security. Check function of pitch change system. 4. Check pitch stops for ease of function. 5. Check pitch change lever for security and function. 6. Check prop flange bolts with torque wrench. Prop flange nuts should not turn with 45 Nm force. 7. Check propeller blade cuff for cracks. If cracks are longer than 0.1 mm wide, notify manufacturer. 8. Check propeller blade paint and leading edge shield for cracks 90* to blade length. If such cracks exist, notify manufacturer. 9. Check leading edge shield for 900 cracks, security and condition. Such damage, including de-bonding or separation should be reported immediately to manufacturer. 50 100 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -27- C. Cockpit area: 1. Check cockpit canopy for security and damage, frame and latching unit for function. 2. Check seat belts for security and damage. Check mounting/attaching bolts for security. 3. Check trim unit for damage and function. 4. Check rudder pedals for security, free movement and function. should the occasion arise, lubricate. 5. Check control stick for freedom of movement and function. Check 0-position in reference to ailerons. 6. Check airbrake lever for function and positioning. Check wheel brakes for function when airbrake lever is in full up. 7. Check that installed replaceable fuses have the proper Amp. rating. 8. Check instrument markings for legibility. 9. Check all control knobs and handles for security and proper color coding. l0. Check all switches, circuit breakers, instruments and fuel shut-off valve for security and function. ll. Check seat adjustment unit for condition and security. 12. Check safety on main bolts for security 13. Check main bolts for smoothness of operation. Should bolts bind, check for burrs and lubricate. 50 100 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -28— D. Fuselage: 1. Check exterior skin of aircraft for security and damage. 2. Check ailerons for function and security. 3. Check aileron outboard controls (thru plastic window) for function and security. 4. Check airbrakes for proper seat and safeties. 5. Remove horizontal stabilizer assy. and check’ mounting fittings for security and corrosion. Check rod end bearings for cracks 6. Cheek elevator attachments for function and security 7. Check elevator drive for function, security and corrosion. 8. Check rudder mounts and cables for function and security. 9. Check tail wheel for function and security. Check tire for tread wear and proper inflation. l0. Remove rudder and lubricate hinge bushings. Drain static pitot system from water. ll. Remove baggage compartment floor. Check: a. Rudder cables, rudder cable drive b. Aileron bellcranks c. Airbrake drive. Check all above for function, security and corrosion. 12. Remove baggage compartment panel on aft bulkhead. inspect the following: a. Control cables b. Turnbuckles and springs in tail wheel steering Check all above for function, security and corrosion. 13. Check brake fluid reservoir for security and proper fluid level. 14. Check fuel lines and tank assy. for security and leaks. 15. Check static ground wires and outboard installed electrical units, ie. lights for function and security. 16. Check pitot static, TEK nozzle and antenna units for condition and security. 17. Check moisture drain holes and vents for stoppages 18. Check placards and markings. 19. Remove wings and check airbrake drive-lubricate 20. Check aileron drive in butt rib-wing/fuselage for function- lubricate 21. Lubricate remaining points in lube diagram. 22. Re-install wings. 50 100 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -29- Hoffmann Maintenance and H 36 DIMONA Inspections E. Landing Gear 1. Clean landing gear 2. Check landing gear for cracks, un-bonding or deformity 3. Check landing gear mounting bracket for proper seating 4. Check brake pucks for condition and wear. 5. Check tires for condition, check tire tread for cuts, abrasion and porosity. 6. Check tire pressure. 7. Check wheels, especially rim bead for cracks or damage 8. Check brake lines for security and condition F. General 1. Check manufacturers service bulletins for compliance as required. 2. Check ad notes for compliance. 3. Perform test flight for completion of inspection. 50 100 500 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 NOTES Motorglider H 36, Reg. Nr. ____________ has had a 50/100/500 hour inspection performed in accordance with this checklist. Total time airframe: Total time engine: Date ___________________ Mechanics signature ________________________ -30- 4.3 Inspection criteria A. Cabin/Cockpit; the main and rear two plexiglass panels should be inspected for cracks and pressure cracks (which may be induced by heat or distortion of the frame). Should a crack, completely thru the plexiglass be found, refer to Ch 8/8.6 repair of plexiglas canopy. The locking mechanism should fit tightly, but pot bind. The connecting rods to the locking pins should not be deformed or bent. The canopy ejection unit must function smoothly and not bind in any position. B. Seat belts; the seat belts, when inspected must not have any worn or frayed edges. The belt should be inspected for dry-rot or sharp bends/creases, from being jammed under seat cushions. Crack on the painted surfaces of the seat belt mounting brackets may indicate metal fatigue on the fitting itself, and should be closely inspected. C. Trim unit; the trim unit in its positioning must move smoothly without b4nding. When the elevator is, fully applied (up or down) the unit must remain in its selected position. The condition of the toothed locking plate and its mounting screws should be inspected for security. D. Rudder pedals; the pedal adjustment must function smoothly. The guide tubes and the locking hooks, for adjustment must be lightly lubricated. The bowden cable should be lightly lubricated with a light oil. The cable itself must not have any nicks or loops. The cables in the adjustment (pedal ) guides should be inspected for wear. Should the cables indicate broken strands, the cables must be replaced. E. Control sticks; both sticks must be free to move in all directions and contact the stops. The stick position should be checked for neutral by holding and aileron flush with the wing and inspect the sticks positions. One stick should be held tightly and the other stick moved to check for excessive play between the two control sticks. F. The airbrake lever is rigged properly when the stick can move about 10 mm, before the airbrakes begin to activate. Another rigging check is made when the airbrake lever is fully applied. The 3irbrakes should be in their fully extended position just before the lever hits the seat pan stop. Fully extended airbrakes should have 75* of pitch. With airbrake lever extended check the function of the parking brake. If necessary, adjust the bowden cable to the parking brake actuating lever. G. Replaceable fuses; the values of the replaceable fuses are marked on the fuse bodies. Should a question arise, refer to the wiring diagram for the exact values. H. Instrument markings; the instrument markings are illustrated in the flight handbook. Markings should be clear and easy to read. If for some reason, markings have been placed on the outer surface of the glass face, a slip mark must be applied to insure that the glass alignment remains correct. I. Seat adjustment; the track for seat adjustment should be easy and free to move. The rack assembly in the seat back should be serviced at all times and the seat back should not slip out of the desired position without actuating the adjustment assembly (Optional equipment) J. Main bolt safety pin. The safety pin must be easy to install. Check pre-stress and readjust if needed. -31- K. Main locking bolts; When the mounting lever is in the middle of travel, the locking bolts should close without binding. This ease of movement should occur regardless that the wings are installed or not. Should the lever bind, that indicates a small burr, dirt or improper lubrication on the bolts. By wing ‘installation, the wing should never be unsupported when the bolts are half-way installed. This will cause improper loading on the bolt assemblies and bend them. Should this occur, it will be impossible to lock the bolts and the aircraft will not be airworthy. A bent locking bolt cannot be straightened, but must be replaced. L. Fuselage; repairs of small nicks, scratches, and holes are easily done. Further repair information can be found in chap 8, repair supplement. M. Ailerons; The ailerons are fastened to the wing by piano hinge. The hinge holes are pre- stamped. Should an extra hole or two be found in the band assy, that is not drilled through. the wing assembly, it does not mean a rivet has been left out. It is normal. N. Hardware; All bolts used in the DIMONA are aircraft standard and are safetied against loosening by the use of Nylon insert nuts. All push—pull tubes are safetied with jam nuts. Bolts should be checked for corrosion. 0. Airbrake drive unit; the airbrake torque tubes, within the drive box are safetied with nylon insert nuts. There should be not play between the torque tubes. P. Empennage fittings; all three mounting bolts for the horizontal fin are safetied with nylon insert nuts. The fitting must be firmly seated with no play. Areas indicating rust formation should be cleaned with a fine grit emery paper and re-primed. The safety pin, that is installed on the lower leading edge of the horizontal fin should snap upward, from spring loading. When not, clean and lubricate the spring. Q. Drive Fork; The drive fork in the upper vertical fin must be free from play, both fore and aft and sideward. The fork assembly should not be bent or deformed. R. Rudder; The rudder is held in place by two bolts at the top and a set screw at the bottom. The rudder cables are secured by two set screws in the lower rudder bearing plate. All three mounting screws are safetied with lockwire. When checking these safeties, also check the condition of the rudder cables and the nicopress sleeves on the cables. S. Tail wheel steering; when the rudder Is held firmly, and the :all wheel turned, a positive spring load must be felt. Play in the assembly indicates a loose cable or a defective spring. A further check is to elevate the aft fuselage, turn the tail wheel, and insure it returns to a neutral position, when the rudder Is brought to neutral T. Rudder; removal of’ the rudder is found in chapter 8 repair supplement. U. The rudder cables should be checked for frayed or broken strands. Should this occur the cables should be changed. In addition, the cables have a TBO from 1000 hours or 5 years see chapter 10, replacement schedules. The two turnbuckles, when properly installed and rigged should have 2 cm. Free movement (rudder) when the cables are installed. -32- V. Brakes; The brake fluid should maintain a constant level. Should the level decrease, check the brake pucks for wear. If they are good condition, inspect the brake system for seepage or leaks. The brake pucks can be worn down to 2 mm thickness. Replace worn pucks with cleaveland Nr. 066-00200 linings. Remove the two wire safeties and the two screws Nr. 18. The two pressure plates Nr. 12 & 15 can be removed and the worn pucks removed by drilling out the rivets. New pucks are delivered with rivets and these can be easily installed. When replacing brake pucks, all four should be replaced at the same time to Insure even wear. W. Latching-hooks; Check function and free - moving of additional metal fitting. Check function and fixing of springs in hooks. Inspect fixing of tie bar ( hexagon nuts and washers ) and check tie bar for corrosion. 1. Brake cylinder 2. Brake piston 4. Guide pins 8. Bleed nipple 9. Bleed screw 11. Brake line fitting 12./15. Pressure plate 13.. Brake pucks 16. Fixture plate 18. Fixture bolts All four Brake pucks should be replaced at the same time! X. Fuel tank; the copper grounding net should not be torn, broken or deformed. The connecting wire to the aircraft grounding system must be intact. The mounting screws for the fuel quantity system should be checked for looseness. The lower side should be checked for leaks or seepage, especially the drain fitting. Y. Airbrake drive couplings; the automatic couplings at the butt rib (male/female) should be checked for wear. An inside/outside caliper is suitable for this. Neither fitting should show excessive wear or deformity. -33- 4.4 Test flights: The following test flight work sheet should be filled out after each required inspection, or when a repair is performed that requires a test flight. Item Test flight Work sheet Performance as specified Yes No 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26 27 28. 29. 30. 31. Fuel quantity Indicator Anti Collision Lights Navigation Lights Avionics (VOR, ADF, VHF, XPDR, MKR, COMM) Electric Boost Pump Starter Starting with cold engine Oil Pressure Indicator Voltmeter, Generator, Charging Rate Tachometer Cylinder-head Temperature Brakes, Parking Brake Oil Temperature Indicator Taxiing Propeller function, ground test Take-off Airspeed Indicator Altimeter, QNH-function Rate of climb Indicator, TEK Magnetic Compass Propeller, Flight check-climb/cruise positions Cruise configuration, trim required Slow speed, stall configuration Airbrakes Heater, Outside Air Glider configuration, Propeller function/feather Landing configuration Landing Shut down fuel shut-off valve, check Open fuel shut-off valve Re-start with warm engine Pilot in command Signature, Date -34— 4.5 Special Inspections: Special inspections for the DIMONA are not required, except for the following: 1. Hard Landing; Should the aircraft have a hard landing, especially on a hard surface airfield, the following inspection should be performed: a. Inspect landing gear where gear mates into fuselage. Inspect for cracks and deformity of gear legs and fuselage sides. Inspect mating surfaces of gear assy for damage. Inspect tires for cuts or damage. Inspect tail wheel assy for damage and attachment to fuselage structure. b. Check antennas (if installed) beneath fuselage for security and damage. 2. Propeller strike; A prop strike can occur either on the ground, as a result of contacting the ground or an object or in the air, from a bird. The actions taken are the same. a. If such a strike occurs on the ground, shut down engine and return aircraft to parking. Under no circumstances continue to run the engine or attempt to fly to the next airfield for maintenance. Measurement of the propeller flange for out-off-round will only indicate the condition of the prop flange and not the condition of the engine bearings or torsion stress on the crankshaft. Remove engine and inspect components for damage. b. If a strike occurs in the air, shut down engine, feather propeller and continue in glider mode. Land as soon as practical. Perform maintenance as in par. 2a above. -35- Hoffmann Rigging H 36 DIMONA 5. RIGGING Table of contents Paragraph Page 5.1 Rigging Diagram for Elevator and Dihedral ------------------- 36 52 Rigging Diagram for Ailerons, Rudder and Wing Sweep - 37 5.3 Weights and Moments of Control Surfaces ------------------- 38 -36- 5.1 RIGGING DIAGRAM FOR ELEVATOR AND DIHEDRAL: The following diagram illustrates the values from a factory rigged aircraft. The wing supports should be placed at the inboard portion of the ailerons, with enough lift to remove static drop. -37- 5.2 RIGGING DIAGRAM FOR AILERONS, RUDDER AND WING SWEEP: The following diagram illustrates the measurements in mm for the rigging. The sweep can be measured from the fuselage side/wing leading edge to ascertain the sweep. Measurements are made at the factory and the sweep should not change, except from a repair or wing change. -38- Hoffmann Rigging H 36 DIMONA 5.3 WEIGHTS AND MOMENTS OF CONTROL SURFACES: The control surfaces in the DIMONA are mass balanced components. The balancing insures the negation of flutter during high speed maneuvers. Should control surfaces be repaired or repainted, the units must be re-weighed prior to flight. The surfaces must be removed from the aircraft and supported by their hinge assemblies on a flat surface. Such a rigging jig can be easily made from some scrap steel angle and old bolts. The illustrated force “P” can then be applied to deflect the control. To measure the force required, a small spring scale can be used, with values to 1.5 kg (3.3 lb). Remember: 1 kg = 2.2 lb! Don’t forget when measuring the force required for surface deflection, the weight of the spring scale must be included as a part of “P” force. The arm “R” is from the hinge to the trailing edge. Should the repaired surface require an exchange of balance weights, the factory must supply these weights. Approved weights and inertia in surfaces Moment(kg/cm) Surface weight(kg) Elevator +0,608 12,15 -1,458 +0,514 2,57 -0,514 Rudder +1,475 29,5 -3,540 +0,853 3 88 -0,853 Aileron +4,650 12,15 -4,650 +1,100 2,80 -1,100 -39- Hoffmann Weight and Balance H 36 DIMONA 6. WEIGHT AND BALANCE Table of contents Paragraph Page 6.1 Determining C.G -------------- 40 6.2 C.G. Travel, empty aircraft ----- 41