TWIN COMANCHE PA-30 Owner’s Handbook

tube and using airflow to control fuel flow to the engines. Fuel distribution to the cylinders is accomplished by a fuel flow divider. Fuel pressure regulation by means of the servo valve causes a minimal drop in fuel pressure throughout the metering system. Metering pressure is maintained above vapor forming conditions while fuel inlet pressure is low enough to allow the use of a diaphragm pump. Vapor lock and associated problems of difficult starting are thus eliminated. Incorporated in the servo regulator is the airflow sensing system which contains a throttle valve and venturi. The differ- ential pressure between the entrance and the throat of the venturi is the measurement of air entering the engine. These pressures are applied across an air diaphragm in the regulator. A change in power changes the airflow to the engine and across the diaphragm in the regulator. Mounted on top of the engine is the ported fuel flow divider with four nozzle lines routed to the cylinders. The divider con- tains a spring loaded positive shut-off valve. Within each cylinder are continuous flow air bleed nozzles with provisions to eliminate the adverse effects of low manifold pressure when idling. Since fuel metering is provided by the servo regulator rather than the nozzles, more uniform cylinder head temperatures result and a longer engine life is possible. Induction air for the engine enters the opening in the nose cowl and is picked up by a large air duct at the right rear baffle. The air is directed through a filter and on to the servo regulator. An alternate air source for the induction system contains a spring loaded door at the throat of the servo regulator. This door op- erates automatically if primary source is obstructed or manually by the push-pull control on the right side of the power control quadrant. The primary system should always be used for take-off. 7 700505 TWIN COMANCHE SECTION Il STRUCTURES Structures are of sheet aluminum construction and are de- signed to ultimate load factors well in excess of normal require- ments. All components are completely zinc chromate primed and exterior surfaces are coated with acrylic lacquer. The main spars of the wings are joined with high strength butt fittings in the center of the fuselage, making in effect a continuous main spar. The spars are attached to the fuselage at the side of the fuselage and in the center of the structure; wings are also attached at the rear spar and at an auxiliary front spar. The wing airfoil section is a laminar flow type, NACA- 642A215, with maximum thickness about 40% aft of the leading edge. This permits the main spar, located at the point of max- imum thickness, to pass through the cabin under the rear seat, providing unobstructed cabin floor space ahead of the seal. LANDING GEAR The nose gear is steerable with the rudder pedals through a 40 degree arc. During retraction of the gear, the steering mecha- nism is disconnected automatically to reduce rudder pedal loads in flight. The nose gear is equipped with a hydraulic shimmy dampener. Retraction of the landing gear is accomplished through the use of an electric motor and gear train, actuating push-pull cables to each of the main gear and a tube 1o the nose gear. The landing gear motor is beneath the center floor panel and the selector switch on the instrument panel to the left of the power control quadrant. To guard against inadvertent movement of the landing gear selector on the ground, the handle must also be pulled aft before moving it upward. The gear selector has the shape of a wheel to 700505 8 SECTION 1l TWIN COMANCHE distinguish it from the electric flap control which has an air- foil shape. As an added safety feature, the warning horn is connected to the gear selector switch. The horn will then op- erate if the selector is moved to the UP position with the master switch on and the il | weight of the airplane on the landing gear. To prevent geat retraction on the ground, an anti-retraction switch is in- Gear Selector Switch stalled on the left main gear. This prevents the completion of the electric circuit to the landing gear motor until the gear strut is within3/4 inch of full extension. The gear indicating lights are located conveniently by the gear selector switch. The green indicating light below the selec- tor switch shows that all gear are down and locked. The amber light above the gear selector switch is the gear up indication: it will flash if the power of one engine is reduced below 12 inches of manifold pressure while the gear is up and locked. The gear up warning horn will sound when power is reduced (below approx- imately 12 inches of manifold pressure) on both engines and the gear is not down and locked. GEAR INDICATION LIGHTS ARE DIMMED WHILE THE INSTRUMENT LIGHTS ARE ON. The brakes are actuated by toe brake pedals mounted on the left set of the rudder pedals. Hydraulic brake cylinders above the brake pedals are accessible in the cockpit for ser- vicing. Parking brake valves are incorporated in each cylinder and have two cables attached from the parking brake ‘‘T’’ handle. To prevent inadvertent application of the parking brake in flight, a safety lock is incorporated in the valves, thus eliminating the possibility of pulling out the ‘“T’’ handle until pressure is applied by use of the toe brakes. Toe brakes for the right side are available as optional equipment. 9 700505 TWIN COMANCHE SECTION 11 A tow bar is provided with each aircraft. When not in use it is stowed in the baggage compartment, When towing with power equipment, caution should be used not to turn the nose gear beyond its 40 degree arc as this may cause damage to the nose gear and steering mechanism. CONTROL SYSTEM Dual flight controls are provided as standard equipment. Cables connect the movable control surfaces with the rudder pedals and control columns. Directional and longitudi- nal trim is provided by an adjustable trim mechanism for - —— - — | the rudder and stabilator. The | | )= “)|fi] R manual rudder trim control is ' =) - |20 located to the right of the ‘ f_/‘ TS L-A _1" throttle quadrant. N N Max-Lift electrically op- \ erated flaps are used on the ( Twin Comanche. The (laps ate operated by an electric p motor; they can be lowered “Rodder Trim and Flup Controls 700505 10 SECTION Il TWIN COMANCHE and stopped in any desired position. The airfoil shaped flap con- trol is to the right of the power control quadrant. Located on the instrument panel is a flap position indicator marked to show the position of the flap relative to the wing. A range for take-off operation is also shown. Located in the inboard end of the right flap is a lock which holds the flap in the UP position so that it can be used as a step for entry or exit. A second lock is incorporated to prevent the flap from going full down in case a step load is applied and the up lock is not fully engaged. FUEL SYSTEM The fuel is carried in four integral fuel cells located in the leading edge sections of the wings. Capacity of the two main fuel cells is 30 gallons each, of which 27 gallons is usable. The auxiliary fuel system consists of two 15 gallon cells (all usable) installed in the wings just outboard of the main fuel cells. Wing tip tanks are available as optional equipment. Auxil- iary fuel and tip tank fuel is to be used in level flight only. The cells should be kept full of fuel during storage of the airplane to prevent accumulation of moisture and deterioration of the cells. For storage of more than ten days without fuel,the cells should be coated with light engine oil to prevent excessive drying. During normal operation use the engine driven fuel pump to draw fuel from the cell directly adjacent to that engine. How- ever, fuel can be drawn from any cell to both engines through use of the engine driven fuel pump or the electric auxiliary fuel pump. For emergency single engine operation a crossfeed is pro- vided to increase the range. When using fuel from tanks on the same side as the operating engine, the position of the fuel se- lector will remain the same as for normal operation with the 1 700505 SECTION !I TWIN COMANCHE W3LSAS 73nd 12 700505 SECTION Il TWIN COMANCHE auxiliary fuel pump off unless the engine driven pump is inoper- ative. NOTE Do not put both fuel selectors in the crossfeed position at the same time. When using fuel from cells on the opposite side of the oper- ating engine, move the fuel selector for the inoperative engine to the main or auxiliary position; then move the fuel selector for the operating engine to the crossfeed position. For single engine landing, fuel must be pumped from the main cell on the same side as the operating engine. The fuel strainers for the system are located beneath the floor panel in the center section of the fuselage. Daily draining of the strainers may be accomplished in the cockpit by opening the hinged access door located in the floor panel just aft of the fuel selector handles and pulling up on the knob located in the center of the selector valve. The general procedure for draining the fuel system is to open the strainer quick drain for several seconds with the fuel cell selector on the main cell, then to change the selector to the auxiliary cell and repeat the process. Allow enough fuel flow to clear the lines as well as the strainer. Positive fuel flow shut-off can be observed through the clear plastic tube that carries the fuel overboard. Located inside the fuel valves is a by-pass valve which will open at 1/2 psi differ- ential pressure if the strainer screen becomes blocked. Fuel quantity is indicated by two electric gauges located at the top of the instrument cluster. The instruments are connected to a transmitter unit located in each fuel cell. The gauges will indicate the amount of fuel available inthe cells that are selected. 13 700505 TWIN COMANCHE SECTION 1l ELECTRICAL SYSTEM Electrical power for the Twin Comanche is supplied by a 12 volt, direct current system. Incorporated in the system is a 12 volt 50 ampere generator and 35 ampere hour battery, which furnish electrical power during operation. The battery is located behind the baggage compartment bulkhead in a sealed stainless steel battery box. Refer to the Maintenance Section for servicing of the battery. Dual generators are available as optional equip- ment. Electrical switches for the various systems are located on the lower left instrument panel. The circuit breakers, located under the floorboard aft of the nose wheel well, automatically break the electrical circuit if an overload should occur. To teset the circuit breakers simply push in the reset buiton. It may be necessary to allow approximately two minutes before resetting the breakers. Corrective action should be taken in event of continual circuit breaker popping. It is possible to manually trip the breaker by pulling out on the reset button, VACUUM SYSTEM Suction for the vacuum operated gyro instruments is supplied by (wo engine driven (dty type) vacuum pumps, interconnected to form a single system. Either vacuum pump has sufficient capacity to operate the gyro instruments. If suction is lost from one or the other side a check valve automatically closes and suction is supplicd by the remaining system. A vacuum gauge is installed in the instrument panel to pro- vide a constant indication of vacuum source. Incorporated in the instrument are two red indicators (right and left systems). During normal operation the indicators are not visible, but if vacuum is lost, for example on the right side, then the right indicator will 700505 14 SECTION Il TWIN COMANCHE 1. MASTER SWITCH 2. STARTER SWITCH 3. 12 VOLT BATTERY 4. MASTER SOLENOID 5. LEFT GENERATOR SWITCH 1 6. 7. 8. 9. 0. GEAR MOTOR 30 AMP CIRCUIT PROTECTOR FLAP MOTOR 20 AMP CIRCUIT PROTECTOR SHUNT LEFT GENERATOR 50 AMP CIRCUIT PROTECTOR STALL WARNING 5 AMP CIRCUIT PROTECTOR PITOT HEAT 15 AMP CIRCUIT PROTECTOR FUEL PUMP 20 AMP CIRCUIT PROTECTOR FLAP SOLENOID 5 AMP CIRCUIT PROTECTOR GEAR SOLENOID 5 AMP CIRCUIT PROTECTOR INSTRUMENT LIGHTS S AMP CIRCUIT PROTECTOR FUEL GAGE AND GEAR WARNING 5 AMP CIRCUIT PROTECTOR CYL., OIL TEMP. AND GEAR LIGHTS 5 AMP CIRCUIT PROTECTOR HEATER 20 AMP CIRCUIT PROTECTOR TURN AND BANK 5 AMP CIRCUIT PROTECTOR ROTATING BEACON 10 AMP CIRCUIT PROTECTOR POSITION LIGHTS 10 AMP CIRCUIT PROTECTOR LANDING LIGHTS 20 AMP CIRCUIT PROTECTOR RIGHT GENERATOR 50 AMP CIRCUIT PROTECTOR STARTER SOLENOID 15 AMP CIRCUIT PROTECTOR = Elecirical Diagram =sswr RIGHT GENERATOR SWITCH 12, LEFT STARTER SOLENOID 13. RIGHT STARTER SOLENOID 4. LEFT VOLTAGE REGULATOR 1S, RIGHT VOLTAGE REGULATOR 16. . LEFT STARTER RIGHT STARTER LEFT GENERATOR RIGHT GENERATOR PARALLELING RELAY AMMETER 15 700505 TWIN COMANCHE SECTION I be visible. Suction is indicated onthe gauge in inches of mercury; normal opcrating range is 4.8 to 5.1 inches. The system is con- trolled by two adjustable regulators, one located in each engine nacelle. After initial adjustment the regulators require very little attention. VACUUM MANIFOLD CHECK VALVES L -y CENTRAL AIR FILTER A:_JAE%IEAL‘LC e r\\- DlREcVTR‘EAL REGULATOR REGULATOR -&—VACUUM GAGE LEFT ENGINE _quflr EN_GINE VACUUM PUMP VACUUM PUMP INSTRUMENT PANEL The instrument panel is designed to accommodate the cus- tomary advanced flight instruments on the left side in front of the pilot and engine instruments on the right side. The optional in- struments such as the gyro instruments of the flight group are shock mounted. The Artificial Horizon and Directional Gyro in this group are operated by an optional vacuum pump on each engine. The Turn and Bank is an electrically operated instrument and serves as a standby in case of vacuum system failure. 700505 16 TWIN COMANCHE SECTION I WOLYIIONI 03345/3ONVISIO "¥2 WNYE ONV NENL 6} EIlamny vl HOLYIIONI NOILISOd dV14 “ET TOKLNOD ¥V3S ‘@i qIavE SHA “EI HOLYIIONI NOJVIE ¥3NEVA "2T 39NV9 WNN3VYA "L1 JUNSSINL ON0HINYIN 2} E313MLY IT NI TYIILN3A ‘9L WOLVIION] MOT4 NaNnd "L HOAVIIONI SNINEYM 1IVLS ‘02 HOLVIION! INWO “SI ¥0E 3A079 “OI ol I u t nos o wu uos 0w n LiS; (T6 ' ' L 9 5 ' t 4 ¥ILSNTD INIANNLSNI °6 ¥OLYIION dOV °9 O¥AD TWNOILIINIO ‘€ WILINOKIVL ‘8 lovidoiny ‘g Q33dsuly 2 ol0vH 4ov "L NOZIHOM TVIDidILaY *¥ #2073 *1 700505 7 TWIN COMANCHE SECTION |l HEATING AND YENTILATING SYSTEM The flow of airfor heating and defrosting the Twin Comanche is taken through an inlet located in the nose and regulated by controls located in the lower right side of the instrument panel. Heated air for the cabin and windshield defrosting is pro- vided by a Southwind or Janitrol Heater installed in the nose section of the Twin Comanche. Operation for the Southwind Heater is controlled by an Off-Prime-Low-High heat switch which is located on the lower right instrument panel. The ventilating fan motor operates and provides air flow through the heater system whenever the heater switch is in the low or high heat position. In flight, additional air is supplied by ram air pressure through the nose inlet. This arrangement assures an adequate flow of air through the heater at all times. To turn the heater on, first ascertain that the heater fuel valve (located on heater control panel) is full on, then move the heater switch to ‘“High’’ or ‘‘Low’’ heat. If the heater does not starl promptly, return the heater switch to ‘‘Prime’’ position for 15 seconds to prime the heater; then upon moving the switch to ““High’’ heat the heater should start and continue to operate after 1 to 1-1/2 minutes of warm-up. Use of the high heat position on the ground may result in excessive exhaust smoke from the heater; therefore, high heat should only be used in flight and the low heat position be used for heating the cabin during ground operation. To heat the cabin - (1) turn the heater switch to high or low heat as desired, (2) adjust the air flow control as required to heat the rear seat, (3) control the heat to the front seats with the adjustable air outlet located below the right and left corners of the instrument panel. There is a dump valve arrangement in the heater bonnet to exhaust excessive heat; thereby, making it pos- sible to operate the heater withall controlsin the closed position. After the heater switch is turned to the ‘‘Off’’ position com- bustion in the heater stops, both the combustion fan and the 700505 18 SECTION (I TWIN COMANCHE Heating and Ventilating System 19 700505 TWIN COMANCHE SECTION Il circulating air fan continues to operate for about two minutes, while the heater cools slowly and purges itself of hot air and fumes. To obtain best service life from the Southwind heater components, it is recommended that the heater switch be turned off about two minutes befare stopping the engines and shutting off the master switch. This should normally be done during taxiing, after landing. Operation of the Janitrol Heater is controlled by a three position switch, labeled “Fan’’, ‘‘Off’’ and ‘‘Heat’’. The ‘‘Fan”’ position will operate the vent blower only and may be used for cabin ventilation on the ground or windshield defogging when heat is not desired. For heat the manual fuel valve must be on and the three position switch turned towards ‘‘Heat’’. This will commence fuel flow and ignite the burner simultaneously. With instant starting and no need for priming, heal should be felt within a few seconds. Regulation of heat, airflow and defroster operation is con- trolled by levers on the heater control console. The top lever is connected to an adjustable thermostat which makes il possible to select a temperature of heated air through a wide range. Since the air temperature is controllable it is unnecessary to have an overboard dump for excess hot air. Cabin temperature and air circulation can be maintained by using various combinations of lever settings, to suit the indi- viduals desires. To minimize the feeling of drafts a low airflow, high heat combination may be used. Windshield defrasting may be regulated by various settings of the defroster lever and in severe windshield fogging or icing conditions, it may be desirable to restrict the heater air, as this will drive more air through the defrosters. When heat is no longer desired, the Janitrol Heater switch may be turned to the ‘‘Off’’ position and the manual fuel valve closed as there is no purge time required. Either the Southwind or Janitrol Heater can be used to warm the cabin before flight by turning on the master switch, the right auxiliary fuel pump, and starting the heater. They should not 700505 20 SECTION Il TWIN COMANCHE be used in such a way as to run down the battery. The cabin heater uses gasoline from the fuel injector on the right engine. Therefore, anytime the right fuel selector is off, the heater is inoperative. In case of right engine failure the heater can be operated by leaving the fuel selector on and operating the auxiliary pump. The mixture control must be closed. Before the heater is operated under these conditions it must be deter- mined that no fuel leaks are present between the tank and engine. Located in the heater is a heat limit switch which acts as a safety device to render the heater system inoperative if a malfunction should occur which results from excessive high temperatures. This control is located in the downstream end of the vent jacket with the reset button on the heater shroud. It is reached only through the nose section to insure that the mal- function causing the overheat condition is corrected prior to future heater operation. Ventilating air for the cabin interior is obtained from two individual sources. The two ventilators located at each side of the instrument panel obtain air from the inlet in the fuselage nose. Air for the two overhead rear seat vents is obtained from a scoop mounted on the dorsal fin. Each individual vent is ad- justable for the desired airflow. Located in the aft section of the cabin is an exhaust vent to improve the circulation of air in the cabin interior. 21 700505 TWIN COMANCHE SECTION Il INSTRUMENT STATIC PRESSURE SYSTEM Static air for the airspeed indicator, altimeter and vertical speed indicator is supplied from two static ports, one located on each side of the aft fuselage section. An optional, alternate static source is available to provide continuous operation of the pitot static instruments should the static system ports or lines become obstructed. The alternate static source is located in the cabin on the lower left side of the instrument panel. If incorrect instrument readings are suspected the alternate static source valve should be opened, venting the static system to cabin pressure. Cabin pressure will vary, however with cabin ventilators open, cabin heater operating and various airspeeds. Use of the alternate static source may result in the following instrument indications: The altimeter reads higher than normal; indicated airspeed greater than normal; and the vertical velocity indicator monentarily shows a climb. The following table shows airspeed comections for the standard static system and the alternate static system: Standard Alternate Gear and Static System Static System Flaps 1AS CAS CAS MPH MPH MPH 80 82 81 Retracted 88 90 91 120 121 113 160 160 148 200 197 185 220 216 204 80 80 81 91 90 91 100 98 97 Extended 120 117 113 700505 22 SECTION lI TWIN COMANCHE SEATS Front seats are adjustable to provide comfort and facilitate ease of entry and exit from the aircraft for pilot and passengers. They are easily removed by taking out the stops at the end of the mounting tracks and sliding the seats off their tracks. The back of the rear seat is adjusted to various fore and aft positions by use of the latches at the outboard upper corners, The entire rear seat is removed quickly by disengaging the aft seat bottom tube from its attachment clamps, detaching the latches behind the top of the seat back, removing the center safety belt bolt, then lifting both the seat and the back as one unit from the cockpit. FINISH All aluminum sheet components are carefully finished inside and outside to assure maximum service life. Both sides of all pieces are alodine treated. External surfaces are coated with durable acrylic lacquer in attractive high gloss colors. The application of primer to interior surfaces prevents corrosion of structural and non-structural parts on the inside of the airplane, BAGGAGE AREA Maximum weight in the baggage area is 200 pounds, with up to 20 cubic feet of available space. Baggage may be placed in the aircraft through a 20 x 20 inch door or through the passenger entrance. Tie-down straps are available for securing baggage. For additional baggage compartment loading informationrefertopage51. 23 700505 TWIN COMANCHE SECTION I STALL WARNING SYSTEM An approaching stall is indicated by a stall warning light activated by a lift detector installed on the left wing outboard of the engine nacelle. 700505 24 SECTION il OPERATING INSTRUCTIONS Preflight . . . . . . . Starting Engines Flooded Start . Warm-Up and Ground Check . Electrical Power Taxiing and P:e-Take-Off Take-Off and Climb. Wing Flaps Short and Soft Fneld Take-Ofis . Landing Gear Retraction . Deicer Boots Vmc . Stalls . Spins . Spin Recovety Techmque Cruising . Fuel Management Approach and Landing. Post Landing. Emergency Ptocedures Vmc Demonstration. Vmc and Stall Speed Mooring . Loading and Weight and Balance Operating Tips . Flight Conditions Diving Spiral . Radio Operation. 25 27 27 28 29 29 31 31 32 33 33 33 35 36 36 37 39 42 42 49 50 50 50 52 53 55 55 TWIN COMANCHE SECTION 11 SECTION IlI OPERATING INSTRUCTIONS PREFLIGHT The following safety procedure instructions must become an integral part of the pilot’s operational routine and preflight inspection. Begin the preflight inspection in the cockpit. Check that the landing gear selector switch is in the down position. Turn master switch on and check that the green landing gear indicator light is on. If the green light is not on, make sure that the instrument panel light switch is turned to the OFF position. The landing 700505 25 SECTION 1l TWIN COMANCHE gear indicator light is automatically dimmed and is difficult to see in the daytime if the instrument lights are on. Drain about a quarter of a pint of fuel from each tank with the cockpit drains before doing the external preflight check. During the external check, determine that the fuel has stopped draining. During the external preflight check see that the baggage door is properly secured. Prior to flight, passengers should be briefed about seat belts, the use of oxygen when applicable, how to evacuate the airplane, and advised not to smoke during take- off o landing. They should be cautioned against handling or interfering with essential equipment and flight controls, fuel valves, switches, circuit breakers, trim knobs or cranks, radios etc. 1. Ignition and master switches - OFF. 2. Fuel strainer sump - drained and not leaking. 3. Fuel selectors on main cells. 4. Control surfaces, wing, fuselage - no damage or oper- ational interference. S. Control surface - free of obstructions, ice and snow. 6. Fuel supply - adequate, 7. Fuel cell caps - secure. 8. Fuel system vents - open. 9. Lamding gear struts - 2-3/4" piston exposed under static load 10. Tires - inflated and not excessively worn. 11. Cowling, landing gear doors, oil and inspection covers - 12. Propellers - check. 13. 0Oil supply - adequate. 14, Leaks - absent. 15. Windshield - clean and secure. 16. Dorsal fin air scoop - free of obstruction. 17. Control locks - detached. 18. Baggage door - secure. 19. Tow bar - stowed. 20. Cabin controls - operative. 26 700505 TWIN COMANCHE SECTION il 21. Gear selector switch - down. 22. Required papers - in order. 23. Turn master switch on - check stall warning system. 24. Check navigation lights. 25. Fasten safety belts. STARTING ENGINES Master switch - on. . Gear lights - check green, Fuel quantity - check gauge reading. . Cowl flaps - open. Trim tabs - set. Throttles - open 1/2 inch. Propeller controls - forward. Mixtures - rich. 9. Electric fuel pumps-on till indication on fuel flow gauge. 10. Mixtures - idle cut-off. 11. Magneto switches - on. 12. Propellers - clear. 13. Starters - engage. 14. Mixtures - advance. 15. 0Qil, fuel pressure - check. PN A WN - FLOODED START Magneto switches - on. Throttles - open. Mixtures - idle cut-off. Electric fuel pumps - off. Starters - engage. (When engine fires, retard throttle and advance mixture.) g.n_&-wm.- Cranking periods should be limited to 30 seconds with a two minute interval. Longer cranking periods shorten the life of the starter. Do not engage the starter immediately after releasing it as the starter mechanism may be damaged. 753 664 27 731112 SECTION I11 TWIN COMANCHE WARM-UP AND GROUND CHECK Check the oil pressure as soon as the engines start. If no pressure is indicated within thirty seconds, stop the engine and determine the trouble. If cold temperatures exist (10°F or be- low), a longer period of time will be necessary before an indi- cation is received. Warm-up the engines at 1000 to 1400 RPM for not more than two minutes in warm weather and four minutes in cold. The en- gines are warm enough for take-off when no faltering occurs with the throttle opened. Avoid prolonged idling at low RPM to prevent fouled spark plugs. Check the magnetos with the propeller in low pitch and the engine running at 2200 RPM. The maximum drop on each magneto should not exceed 175 RPM while the differential drop between them should not exceed 50 RPM. Operation on one magneto should not exceed 10 seconds. Move the propeller controls through their complete range to check feathering action, then leave them in the full forward low pitch position. Feathering action can be checked by running the engine between 1000 and 1500 RPM and pulling the prop control into feather position momentarily. Do not allow a drop of more than 500 RPM and do not feather the propeller when operating at a high manifold pressure with the aircraft on the ground. Pro- pellers should be cycled three times in cold weather. Cowl flaps permit cooling of the engines by manual control during ground operations or special conditions of flight. It is recommended that cylinder head temperature not exceed 400° F and the oil temperature should not exceed 245°F. Turn off the electric fuel pumps after starting to make sure that the engine driven pumps are operating. The electric fuel pumps should be on during take-off, landing and when changing fuel selector positions to prevent loss of power at critical times. 28 700505 TWIN COMANCHE SECTION Il ELECTRICAL POWER Do not attempt flight with a very low charged battery. CAUTION Be sure to have the gencratars turned on. If the battery charge is low and generators are not operating, an inadvertent gear-up landing is possible because the warning horn and flashing light will not operate and the landing gear can- not be extended electrically. Manual extension of the landing gear is required under these circumstances. TAXIING AND PRE-TAKE-OFF Start to move the airplane forward. During initial taxiing, throttle back and apply brakes to check their operation. Use differential power and nose wheel steering rather than brakes when taxiing. Retard the throttle to the engine on the inside of turn and advance the throttle to the engine on the outside of the turn. The autopilot should be off before take-off. On a cold day test defroster and cabin heaterbefore take-off. Do not fly in cold weather when the heater is inoperative, as the windshield may become frosted. 700505 29 SECTION Il TWIN COMANCHE Lock the door before take-off. If this item is neglected and the door comes open after take-off, maintain normal climb and airspeed until sufficient terrain clearance is obtained. (Do not risk loss of control of the airplane to close the door. It is pos- sible to continue safely for extended periods with the door un- latched.) When it is impossible to land straight ahead, the door may sometimes be closed by the following procedure: slow the airplane to 100 miles per hour; lower landing gear and wing flaps; open the small window to the left of the pilot; pull the door shut and lock it. Check list: 1. Parking brake - on. 2. Engine run-up (a) Mixture controls - forward. (b) Propeller controls - forward. (c) Throttle controls - forward (1500 rpm). (d) Propeller controls - exercise. Check feather, 500 rpm maximum decrease. (e) Throttle controls - forward (2200 rpm). (f) Magnetos - check. Normal drop - 100 tpm Maximum drop - 175 rpm Differential drop left to right - 50 rpm Engine gauges - check green. Lights (as required) - on. Pitot heat (as required) - on. Transponder - stand-by. Flaps - set. Gyro pressure - 4.8 to 5.1 in. Hg. Directional Gyro - set. Turn & Bank - operating. 11. Altimeter - set. 12. Clock - wind & set. 13. Generators - on. 14. Electric fuel pumps - on. 15. Door - locked. 16. Safety belts - fastened. 753 664 30 731112 — SPPNP ;AW TWIN COMANCHE SECTION Il The normally recommended setting for sea level take-off is full throttle at 2700 RPM. The slightly rich mixture for this setting aids in cooling the engine. TAKE-OFF AND CLIMB 1. Parking brake - off 8. Flaps - retracted 2. Mixtures - forward 9. Climb power - set 3. Propellers - forward (At approx. 400 AGL) 4. Throttles - forward 10. Cowl flaps - set S. Accelerate to - 90 MPH (Maintain cyl. hd. temp. (Prior to climb) at or below max) 6. Landing gear - retract 11. Oxygen - no smoking - on 7. Accelerate to - 112 MPH (10,000 ft & above) (Best R/C speed) During take-off roll apply light back pressure to the control wheel to avoid porpoising during the take-off run. Accelerate to single engine minimum control speed (Vpc) before applying stronger back pressure for rotation. During normal conditions, retraction of the landing gear should occur when a gear down landing is no longer possible on the runway. Attain the best rate of climb speed and at least 400 feet above ground level before reducing power. WING FLAPS Wing flaps are not necessaryfor take-off except when operating from a short or soft field. The use of wing flaps during take-off in a lightly loaded airplane may cause the airplane to lift-off the runway befare V¢ is attained. An effort tohold the airplane on the runway too 700505 N SECTION Il TWIN COMANCHE long may result in a ‘‘wheelbarrowing tendency’’ with most of the weight on the nose wheel. Wing flaps are not normally used during a crosswind take-off. After lift-off set up the required crab angle, retract the gear at a safe altitude and continue climb out. An en route climbing speed of 130 miles per haur is recommended for increased forward visibility during continuous climb. SHORT AND SOFT FIELD TAKE-OFFS If it is necessary to get the airplane off the runway in the shortest possible distance, set take-off wing flaps (with the flap position needle at the bottom of the white arc on the flap indicator). With brakes set, run upengines to maximum power and check instruments. If the aitplane is off the runway at less than 90 miles per hour, it is essential to fly level a few feet off the runway immedi- ately after lift-off until reaching 90 mph. After airspeed has increased, initiate a climb at the best angle of climb speed (90 mph at sea level) if an obstacle is to be cleared, or at the best rate of climb speed (112 mph at sea level) if a normal climb out is desired. Since the airplane cannot be controlled in flight below V¢ in the event of the sudden power loss in one engine, be ready to reduce power promptly. NOTE Take-off at high altitude (density altitude), from a soft, wet, rough or grassy field, or with an uphill gradient or tail wind component results in greatly reduced take-off performance. During take-off roll, check to be sure the airspeed indicator is operating properly. The needle should indicate zero when the airplane is at rest. 32 700505 TWIN COMANCHE SECTION 1l LANDING GEAR RETRACTION Make sure the aircraft has sufficient altitude and airspeed with no chance of settling back on the runway before retracting the gear. When taking off from a long runway, retract the landing gear when it would no longer be possible to land straight ahead. DEIJCER BOOTS If your Twin Comanche is equipped with deicer boots, they should not be operating during take-off since inflated boots can change the stall characteristics of the airplane. YMC Vme (Velocity minimum control) is the calibrated airspeed, determined by FAA test pilots, below which a twin engine aircraft cannot be controlled in flight with one engine opetating at take-off power and the other engine windmilling. The Vqc which the FAA has determined for the Twin Comanche is 90 mph CAS. Calibrated airspeedis equal tothe airspeed indicator reading corrected for position and instrument error. Since calibrated ait- speed and density altitude and pilot flight techniques vary, it is best, especially when heavily loaded or on a cold day, to fly the aircraft as though Ve were slightly higher. Under no circumstances should the aircraft be flown below the Ve of the aircraft with one engine operating at maximum power and the other engine windmilling. When operating under single engine flight conditions, either in training or in emergency situations, maintain indicated airspeed above 97 mph. APPROACH YpMC WITH CAUTION On take-off the aircraft should be kept either on, or neat the runway, until reaching Vpe. After Ve has been reached the air- 700505 3 SECTION 11l TWIN COMANCHE craft should be accelerated as rapidly as passible to the best rate of climb speed (112 mph) if there are no obstacles ahead. If there are obstacles ahead maintain the best angle of climb speed (90 mph). The applicable speed should be maintained until all obsta- cles are cleared and the airplane gains sufficient altitude. STALLS 34 WARNING When practicing stalls maintain minimum terrain clearance of 5000 feet. Single engine or asymmetric power stalls prohibited. Power on stalls above 2100 RPM prohibited. Do not practice stalls when carrying passengers, when the airplane is heavily loaded or with the center of gravity near the aft limit. The left wing on the Twin Comanche with clock- wise rotating propellers will, generally speaking, under conditions of moderate symmetrical power, stall mocre rapidly than the right wing, and if re- covery is not promptly initiated, the airplane will have a tendency to roll to the left. As in any multi-engine aircraft, stall recovery in the Twin Comanche should be initiated at the first indication of a pre-stall buffet or warning light. The aircraft should not be permitted to develop into a full stall. 700505 TWIN COMANCHE SECTION 1lI CAUTION Use controls promptly to counteract any rolling or yawing action of the aitplane during the approach to and recovery from the stall. The stall warning system is inoperative if the master switch is off. NOTE An increase in bank angle increases the stalling speed. STALL SPEED TABLE (CAS) Angle of Bank Gear & Flaps Up Gear & Flaps Down 0° 76 69 20° 79 71 40° 87 79 60° 108 98 These figures are at gross weight of 3600 pounds with power off, SPINS The Twin Comanche is FAA approved in the normal category, and in this category all intentional acrobatic maneuvers, in- cluding spins, are prohibited. Spins and other intentional acrobatic maneuvers, may subject the airplane to stresses beyond which it was designed. 700505 35 SECTION 1Nl TWIN COMANCHE SPIN RECOVERY TECHNIQUE In the event of an inadvertent spin, recovery can be accomplished in the following manner: 1. Retard both throttles to idle position. 2. Applyfull rudder in the opposite direction to the spin. 3. Push control wheel full forward. While it is not necessary for recovery, the use of ailerons against the turn (ie. right aileron if spin is to left) will expedite re- covery. Maintain controls in these positions until the spin stops. Then, neutralize rudder and ailerons. 4. Recover from dive with smooth back pressure on control wheel. No abrupt control movement should be used during recovery from the dive. NOTE Altitude loss in a spin may be in excess of 2000 feet. Avoid any maneuver which might result in a spin at low altitude. The more rapidly spin recov- ery is begun the more prompt the recovery will be. CRUISING The cruising speed of the Twin Comanche is determined by many factors including power setting, altitude, temperature, weight, and equipment installed. The normal recommended economy cruising power setting of the Twin Comanche is at 65% power. At 12,000 feet this gives a True Airspeed of 186 MPH. This power setting is obtained under standard conditions at 2400 RPM and full throttle. Fuel consumption is approximately 15.2 gallons per hour total. The optimum cruising speed of the Twin Comanche at 8000’ is 15 MPH. (See Power and Performance charts for power settings and performanée under various conditions.) 36 700505 TWIN COMANCHE SECTION LI The Lycoming engines on the Twin Comanche can be cruised at any percent of power from75% down. 2400 RPM is recommended for maximum cruise performance and lower RPM's, down to 1800, for more economical cruising conditions. Ordinarily an RPM setting should be selected which will give maximum smoothness. To avoid undesirable stresses on the propellers and the possi- bility of detonation in the engine, no manifold pressure settings over 25" should be used with an RPM of less than 2000. To obtain the desired power, set the manifold pressure and RPM according to the power setting table in this manual. After the desired power settings have been set up, adjust the mixture control for cortesponding best power setting as indicated by the fuel flow meter. The low side of the power setting, as shown on the fuel flow meter, indicates best economy for that percent of power while the high side indicates best power, During climbing operation the servo regulator will sense the change in altitude and will automatically lean the mixture. For better economy, manual leaning with the mixture control can also be accomplished if desired. FUEL MANAGEMENT Fuel should be used from the main fuel cells during take-off, landing, climb and descent. Auxiliary fuel and tip tank fuel is to be used in level flight only. The electric fuel pumps should be on during take-off, landing and while switching tanks in order to prevent loss of power at critical times. In turning off the electric fuel pumps allow a time delay of approximately 20 seconds between switching each of the fuel pumps off in order to insure that the engine driven pumps are operating properly. Since a fuel injected engine such as is used on the Twin Comanche takes an appreciable length of time to start after fuel starvation, it is recommended that you avoid emptying a fuel cell to depletion. If the engine should stop because a fuel cell is 700505 37 SECTION I TWIN COMANCHE depleted of fuel be prepared to wait a while for the engine to start after changing to a fuel cell with fuelin it. If it is necessary to use all the fuel in a fuel cell, carefully monitor the fuel flow meter and quickly change the fuel valve position at the first indication of a decrease in fuel flow. This will enable you to keep the engine operating while using all of the fuel in the fuel cell. CAUTION If tiptanks are installed on the airplane and if the tip tanks have been run completely dry in flight, air may be trapped in the line from tip tank to solenoid valve when tip tanks are subsequently filled. The air pocket in the line may prevent im- mediate feeding of fuel from tip tanks. To avoid this condition, purge air from lines prior to starting of aircraft. 1. Turn fuel selector valve to ‘‘AUX’’ po- sition. 2. Tuwrn on aircraft master switch and place tip tank fuel selector switch to tip tank position, Ascertain that tip tank solenoid switch, under fuel console, is operating by listening for a slight click when switch is operated. 3. Lift up appropriate fuel drain valve and allow fuel to drain. Observe for flow in clear plastic tube, followed by interrupted flow of no fuel for a few seconds, further followed by a bubbling flow then full flow. Total drain time should not be less than 30 seconds. 4. Procedure shall be accomplished for each ttp tank separately. 5. In addition to above procedure operate the the power plant from each wingtip separately until steady fuel flow is assured during ground runup prior to flight. 38 700505 TWIN COMANCHE SECTION 1l If not properly inspected and maintained, the bladder-like fuel cells of the airplane could partially collapse, causing the fuel gauging system to be inaccurate. The tanks and gauging system, therefore, should be inspected in accordance with Piper service instructions and kept in good condition. During flight, keep account of time and fuel used in connec- tion with power settings to determine how the fuel flow and fuel quantity gauging systems are operating. If the fuel flow indication is considerably higher than the fuel actually being consumed or an asymmetric flow gauge indication is observed, you may have a clogged fuel nozzle which should be cleaned. APPROACH AND LANDING Prior to extending the landing gear for landing, retard both throttle controls to check that the landing gear warning horn is operating. Flying the airplane with the horn inoperative is not permitted. It can lead to a gear up landing as it is easy to forget the landing gear when approaching for a single engine landing when other equipment is inoperative or when attention is drawn to events outside of the cockpit. Therefore it is especially im- portant to check that the landing gear is down when there is any distraction in the landing situation. Lower the gear at speeds below 150 miles per hour and the flaps at speeds below 125 an hour. CAUTION Maintain sufficient speed during turns in the traffic pattern. It is a good practice to trim the aircraft to establish a speed of at least 115 miles per hour on the downwind leg and 110 miles an hour on the base leg. Hold 110 miles per hour until the turn 700505 39 SECTION 11l TWIN COMANCHE onto final approach has been completed. Then reduce to a final approach speed at 100 miles per hour. Set the propeller ata high cruising RPM of at least 2400 RPM for ample power ifa go-around is neces- sary. Mixture control should be in the full rich position unless density altitude or conditions of high temperature and humidity dictate otherwise. Avoid steep turns at low airspeeds or at low alti- tudes, particularly during the turn from base leg to final approach. Ascertain the landing gear is down and locked on base leg or [inal approach, by checking the green indicator light on the instrument panel, The degree of wing flap extension and touch down speed vary with conditions, but under normal conditions full wing flaps (27 degrees)should be used during the final approach and landing to reduce stall speed and to permit contact with the runway at a slower speed. Contact the ground at the minimum speed consistent with landing conditions. For short, slow landings under normal conditions use full wing flaps, partial power, and hold the nose up as long as possible before and after contacting the ground with the main wheels. In high winds and crosswinds, it is desirable to approach a landing at higher than normal speeds with half or no wing flaps. If a go-around is necessary apply full throttle, retract the landing gear, and slowly retract the wing flaps. During a crosswind approach hold a crabbed angle into the wind until ready to flare out for the landing. Then lower the wing that is into the wind, reduce crabbed angle, and keep the wheels aligned to the runway using rudder. 40 700505 TWIN COMANCHE SECTION Ilf NOTE Landings with a crosswind component greater than 20 miles per hour should be avoided, When extending or retracting wing flaps, do so a few degrees at a time to avoid an asymmetrical flight condition which would result if one wing flap should stick. Do not side slip with wing flaps extended. Avoid prolonged side slip with a fuel selector set to a fuel cell with low fuel indication. Prior to landing and early in the roll out the brakes should be checked for operation. After landing, maximum braking is achieved by retracting wing flaps and pulling back on the con- trol wheel as wheel brakes are applied. CAUTION It is possible for a pilot to inadvertently reach for the landing gear selector switch instead of the wing flap switch while there is still enough lift on the wings to keep full weight of the airplane off the wheels and thus prevent the actuation of the landing gear safety mechanism, causing retraction during the landing roll. If additional braking is not needed, the wing flaps should be retracted after the airplane has been maneuvered to a stop off the runway. If a landing must be made without wheel brakes the air- plane should be flown to contact the ground at a slower speed and landed short on the longest available runway. The procedure for manually lowering the landing gear should be memorized and understood completely so that it can be ac- complished quickly in an emergency situation, such as a single engine landing. (Refer to Emergency Procedures, in this section for manually lowering the landing gear.) 700505 41 SECTION i TWIN COMANCHE Landing check list: Mixtures - rich, Electric fuel pumps - on. Fuel selectors on proper tanks. Propellers at high cruising rpm. Landing gear - down (under 150 mph) - check green. Flaps (under 125 mph) - set. Safety belts - fastened. NO U R WN POST LANDING Check list: 1. Flaps - retract 3. Electric fuel pump - off 2. Cowl flaps - open 4. Prop controls - forward When completely stopped in a parking spot,check the follow- ing items for shut down: 1. Radio & elec. equip. - off S. Master switch - off 2. Heater (if used) fan - off 6. Parking brake - on 3. Mixtures - idle cut-off 7. Generatars - on 4. Magneto switches - off If control locks are not available and the airplane is to be left for more than a few minutes, secure the control wheel with the safety belt strap. Chock the wheels and secure tie downs at appropriate places. EMERGENCY PROCEDURES 1. Engine Failure: (a) During Take-off Or After Lift-off: If an engine failure occurs during take-off run prior to lift- off with adequate stopping distance remaining, reduce the power on both engines and stop the airplane straight ahead. 763 664 42 731112 TWIN COMANCHE SECTION Il If an engine failure occurs after lift-off with adequate landing distance ahead, immediately reduce the power on both engines and effect a landing. If engine failure occurs during climb out after take-off, maintain directional control with rudder and ailerons, and estab- lish the best single engine rate of climb airspeed (105 mph at sea level). Speeds below or above the best rate of climb speed will result in lower than optimum rate of climb. Check that mix- ture, propeller and throttle controls are [ull forward and landing gear and wing flaps are up. If enough altitude has been reacked before the failure occurred, or if performance is satisfactory for teaching the airport with landing gear extended, leave the landing gear in the down position. Make positive identification of inoperative engine by gently throttling back on suspected engine. If no effective power is being delivered by that engine, feather the propeller, and trim directionally with rudder trim. Climb straight ahead to traffic pattern altitude and return to airport for landing. Do not try to turn or climb too sharply. Turns, however, can be made toward the inoperative engine if necessary. NOTE A climbing turn toward an inoperative engine is more critical than a gliding turn toward an in- operative engine because there is more asymmetric thrust with the power setting used for climb. Trim directionally with rudder trim. (b) During Cruise Flight: If engine failure occurs during cruise flight, maintain air- speed and directional control of airplane; immediately advance mixture, propeller and throttle controls. The airplane will yaw in the direction of the inoperative engine. [t will rarely be possible to immediately locate the inoperative engine by viewing the manifold pressure gauge. This yaw in the direction of the in- operative engine can be corrected with rudder and rudder trim. 700505 43 SECTION Il TWIN COMANCHE Carefully retard the throttle control of the suspected in- operative engine in order to identify the malfunctioning engine and verify that it is not producing power. Turn on fuel pumps, check ignition switches, fuel gauges and fuel cell selectors and try to determine cause of the engine failure. If power cannot be regained, the propeller on the inoperative engine should be feathered by retarding the throttle to the idle position and moving the propeller pitch control into the feather position. The mixture should then be moved to idle cut-off and ignition turned off. Reduce power on the operating engine if altitude and loading are such that adequate performance can be maintained on one engine and then reduce the electrical load. Best single engine performance will be obtained with the wing on the side having the inoperative engine held about three to five degrees higher than level to help counteract the tendency to turn in that direction. Rudder trim may be used to correct for additional control pressure needed in single engine flight. (c) Single Engine Approach: As the airport is approached for landing, reduce power on the operative engine and gradually retrim the rudder. When it is obvious that the airport can be reached, lower the landing gear and check the indicators to make sure landing gear is down and locked. During a single engine approach the landing gear should not be lowered until landing is assured. It is important, however, to extend the landing gear soon enough that there will be time to lower it manually in the event of a landing gear malfunction, and also so there will be no great change in airplane configuration just prior to landing. Maintain additional altitude and speed during approach, keeping in mind that landing should be made right the first time and that a go-around may require the use of full power on the operating engine, making control more difficult. A final approach speed of 105 miles per hour and the use of half rather than full wing flaps will place the airplane in the best configuration for a go-around should this be necessary, but it should be avoided if at all possible. It is essential to land 44 700505 TWIN COMANCHE SECTION Il the airplane the first time on a single engine approach in order to avoid the need for a go-around. Under some conditions of loading or density altitude a go-around may be impossible, and in any event the sudden application of power during single engine operation may cause control difficulties. If single engine go-around cannot be avoided, the landing gear and wing flaps should be retracted as soon as possible after application of full power, since under most conditions, climb, or even level flight, is impossible during single engine operation with landing gear and wing flaps extended. CAUTION If rudder trim has been used to ease single engine control pressures, the trim should be adjusted as the throttle control is retarded for final approach and landing. RECOMMENDED PRACTICE When operating single engine maintain speed above 97 mph. This speed, 97 mph, will not provide optimum single engine climb performance. Optimum single engine climb is obtained at the best single engine rate of climb speed, 105 mph, with the operating engine at full throttle, 2700 rpm and the inoperative engine propeller feathered and cowl flap closed. The gear and flaps must be retracted. 700505 45 SECTION lli TWIN COMANCHE 2. Feathering: The Hartzell HC-E2YL-2 feathering propellers can be feath- ered only while the engine is rotating above 1000 RPM. Loss of centrifugal force due to slowing RPM will actuate a stop pin that keeps the propeller from feathering each time the engine is stopped on the ground. If an engine freezes up, it will be im- possible to feather its propeller. Single engine flight with the propeller of the inoperative engine unfeathered will decrease single engine performance. 3. Unfeathering: It is not recommended that propeller feathering and un- feathering be practiced on the ground because of the excessive vibration that occurs in the engine installation. In flight, feath- ering should be practiced only to familiarize the pilot with the proper procedures.To unfeather a propellerin flight,the following technique is recommended: Ignition switches ON. Mixture RICH. Throttle open about 1/2 inch. Prop control at cruise setting. Engage starter until engine starts, f. Allow engine to idle at 1000 to 1500 RPM until oil temper- ature begins to rise. Adjust to cruising powerwhen engine warms. The Twin Comanche, operating under optimum conditions of turbulence and pilot technique, and under standard conditions of temperature and pressure, has a single engine service ceiling of 5800 feet at 3600 pounds gross weight and maximum con- tinuous power. During initial multi-engine training and in order to maintain subsequent proficiency, it is desirable to practice single-engine flight. Such practice is not advisable with passengers aboard the airplane, with a heavy load, or with extreme rearward center of gravity. In no case should single-engine operation be practiced without having in one of the pilot’s seats a well-qualified twin- °oangoP 46 700505 TWIN COMANCHE SECTION Il engine rated pilot who is familiar with the Twin Comanche char- acteristics and procedures. _ For most single-engine practice it is recommended that the reduction of drag accomplished by feathering a propeller be simulated by a power setting of 10 inches of manifold pressure and 2200 RPM. This will accomplish a zero thrust on the selected engine. Under the proper conditions, actual propeller feathering may be practiced. The following precautions should be exercised when an engine is featheted for practice. a. Do not feather a propeller for practice if you think the engine may be difficult to restart. b. Do not feather a propeller for practice at a low altitude above the ground. c. Do not feather a propeller for practice with a low charged battery, as it takes electrical power to get the engine started. d. Do not feather a propeller for practice unless you are within reasonable distance of an airport. e. Do not feather a propeller for practice in conditions of temperature, altitude, weight or turbulence which may prevent single-engine flight at altitudes well above the ground elevations. 4. Manual Gear Extension: Manual landing gear extension is accomplished with the mechanism located under the floorboard directly aft of the nose wheel housing. This system is used only to extend the gear if the electrical actuating system has failed and not to retract the gear manually without the use of the electric motor. With the electric motor disengaged from the gear torque tube, as required in extending the gear manually, there is no mechanism for holding the gear in the ‘“‘UP'’ position so that the gear will not stay up if retracted manually. Before proceeding with emergency gear extension, check the following: a. Master and gear circuit breakers are in. b. Master switch is on. c. Navigation lights are off (daytime). To extend the gear, remove the cover over the emergency 700505 47 SECTION 1l TWIN COMANCHE disengage control located between the two front seats, and follow the instructions on the back of the cover as follows: a. Airspeed not over 100 MPH. b. Landing gear switch in center *‘OFF'’ position if landing gear switch is a three position switch or in the “GEAR DOWN LOCKED"’ position if switch is a two pasition switch, c. Disengage Motor - Raise motor release arm and push forward thru full travel. d. Remove gear extension handle from stowage. If left socket is not in clear position, place handle in right socket. Engage slot and twist clockwise to lock handle. Extend handle and rotate forward until left socket is in clear position. Remove handle and place in left socket. Lock and extend handle. Rotate handle forward full travel to extend landing gear. Green light on panel indicates landing gear down and locked. After the gear has been extended manually, do not perform any unnecessaty operation to the gear until the aircraft is placed on jacks. NOTE Reducing power and rocking gear extension handle will aid in manually extending the landing gear. DO NOT RETRACT WITH HANDLE IN SOCKET. DO NOT RE-ENGAGE MOTOR IN FLIGHT. Procedure for returning the gear to electric operation: a. Place the airplane on jacks. b. Landing gear circuit breaker should be disengaged. c. Pull landing gear emergency extension handle about half- way back, allowing gear to hang partially retracted. d. Re-engage circuit breaker and with landing gear control switch move end of the electric motor drive shaft into position about halfway back so that the slot in the drive shaft is near the mating pin on the torque tube. e. Using the extension handle move the torque tube pin slightly back and forth until it can be engaged with the drive shaft slot, then push the parts together. 48 700505 TWIN COMANCHE SECTION Il f. Lock the drive shaft to the torque tube by pulling the motor release arm full back to the normal locked position. g. Disengage the extemsion handle and return to stowage. h. Check gear for proper operation. 5. Gear-Up Landing: An emergency gear-up landing may be necessary under the following conditions: a. If surface is too soft or rough for gear down landing. b. When the field is too short for a gear down landing. c. When a water landing is necessary. During a gear-up landing use a normal flaps up approach. During flare out close the throttles, shut off the master and ignition switches, turn fuel selectors off and contact the ground at minimum speed. YmMC DEMONSTRATION WARNING The engine-out minimum control speed demon- stration required for the FAA flight test for the multi-engine rating approaches an uncontrolled flight condition with power reduced on one engine, The demonstration should not be performed at an altitude of less than 3500 feet above the ground. APPROACH Vyc WITH CAUTION. Initiate re- covery during the demonstration by immediately reducing power on the operating engine and promptly lowering the nose of the airplane, 700505 49 SECTION 1l TWIN COMANCHE VMmc AND STALL SPEED More power is available on the operating engine at lower altitudes (if the engine is normally aspirated)and hence there can be more asymmetric thrust. The Vg is highest at low altitudes. The Vpye decreases with altitude and at higher altitudes the air- plane will approach a stall speed before reaching Vyc. The most critical situation occurs at the altitude where the stall speed and Vmc speed coincide. Care should be taken to avoid this flight condition because at this point loss of directional control could lead to a spin. MOORING The airplane should be moved on the ground with the aid of the nose wheel towing bar provided with each plane. The tow bar is stowed in the baggage compartment. Tie down ropes for mooring the airplane can be fastened to the wing tie down rings and tail skid. The aileron and stabilator controls should be secured by means of a safety belt or control locks to prevent control surface damage. The rudder is held in position by its connections with the steerable nose wheel and does not need to be secured except under unusually high wind conditions. LOADING AND WEIGHT AND BALANCE CAUTION It is the responsibility of the owner and pilot to determine that the gross weight of the airplane is not exceeded and to determine that the airplane 50 700505 TWIN COMANCHE SECTION Il remains within the allowable weight vs center of gravity envelope while in flight. The owner or pilot must determine before each flight that the gross weight is not exceeded and that the center of gravity is within allowable limits. For weight and balance see the Airplane Flight Manual and Weight and Balance form supplied with each air- plane. The airplane can carry four passengers with full fuel capacity of 90 gallons (without wing tip tanks) and less than the allowable baggage. As with any airplane, improper loading will cause undesirable flight characteristics if the airplane approaches a critical or marginal flight condition. Make sure that baggage and/or cargo are secured properly with tie down straps to avoid an acciden- tal in-flight shift of the center of gravity or injury to passengers. With tip tanks installed, the airplane has an allowable gross weight of 3725 pounds. It is important to remember that any weight in excess of 3600 pounds however, must be in the form of fuel in the tip tanks. 700505 5 SECTION Il TWIN COMANCHE OPERATING TIPS 1. Trim for takeoff so that a light back pressure on the control wheel allows the airplane to lift from the runway. 2. When checking the propeller feathering action, it is necessary to move the propeller control rapidly in and out of feathered position to prevent a drop of more than 500 RPM. Excessive manifold pressure will occur if the RPM count falls below 1000 during this check. 3. Do not retract the landing gear prematurely on takeoff. 4. To reduce wing flap operating loads, lower the wing flaps at airspeeds well below 125 miles per hour. 5. Determine the position of the landing gear by checking the gear position lights. 6. During landing, allow the main wheels to contact the ground while centering the rudder pedals. Apply additional back pressure to the control wheel and retract the wing flaps for good directional control and maximum cffectiveness of brakes during landing roll. 7. When the instrument lights are on, the gear position lights are dimmed for night flight. 8. Be sure that all radio switches, light switches and pitot heat switch are in the off position before startung engines. 9. Duc to the responsive trim tab controls, 2 small adjustment in trim gives a rapid change in attitude. 10. Enginc shut down by usc of the mixture controls may causc a rough stop during high ambicnt temperature conditions. A spring loaded device on the throttle will shut down the engines by closing the throttle valves and shutting off air to the engines. As this mechanism is connected to and operated by the last 1/8 inch travel of the throttles, a stop on the quadrant prevents the throtdes from being pulled fully aft and closing the throttle valves. This throttle cut-off is not intended to be used in lieu of the mixture control for engine shut down: it is to be used only when the mixture control is placed in idle cut-off and there is indication of a rough stop. 11. During single engine flights be sure that the gear and flaps are fully retracted when climbing at the best single engine climb speed. Speeds above or below the best single engine climb speed will decrease climb performance. Close the cowl flap on the inoperative cngine and trim the airplane to reduce drag. 52 753 664 731112 TWIN COMANCHE SECTION 11l 12. Fuel from auxiliary cells and from optional wing tip tanks is to be used in level flight only. Takeoffs should not be made using fuel from the auxiliary cells or tip tanks or with the main cells less than one-quarter full. Certain maneuvers should be avoided. These mancuvers could cause fuel to move away from fuel cell outlets. If the outet is uncovered, the flow of fucl will be interrupted and a temporary loss of power may result. Running turning takeoffs, prolonged slips or skids in any pitch attitude, or any unusual or abrupt mancuvers which could cause uncovering of the fuel outlet should be avoided. 13. The rudder pedals are suspended from a torque tube which extends across the fuselage. The pilot should become familiar with the proper positioning of his feet on the rudder pedals so as to avoid interference with the torque tube when moving the rudder pedals or operating the toe brakes. 14. Anti<collision lights should not be operated in heavy haze or clouds, since reflected light can produce spacial disorientation. Show courtesy for other pilots by not operating strobe lights while taxiing in the vicinity of other aircraft. FLIGHT CONDITIONS Do not fly into marginal or deteriorating weather unless you are equipped and qualified to fly as an instrument rated pilot under instrument conditions. Before taking off on an instrument flight, or a flight at night or in marginal conditions, make sure all instruments and equipment are operating properly. In mountainous terrain, maintain proper distance from the mountains, especially in strong winds, which may cause extreme downdrafts and turbulence. Flight should be planned to avoid thunderstorm areas. In conditions of extreme turbulence, reduce power to slow the air- plane below the design maneuvering speed of 162 miles per hour. A further reduction of power will ease the stress to which the airplane is subjected by virtue of turbulence. When flying in extreme turbulence or strong vertical currents, using the auto- pilot, the altitude-hold mode should not be used. 753 664 53 731112 SECTION Il TWIN COMANCHE Sccure safety belts in severe turbulence. Flying over 10,000 feet without using supplemental oxygen should be avoided. Do not take-off with ice or frost on the wings, as ice or frost will radically change the flight conditions of the airplane. The deicing equipment on light twins, if installed, is de- signed to allow the pilot to fly out of inadvertent icing situations, not to handle heavy icing. Even if the airplane is equipped with deicing equipment, do not plan to fly it in any icing condition. Deicing equipment should be checked in accordance with the Airplane Flight Manual instructions prior to entering known icing conditions. When flying in wet, heavy snow or other conditions where the induction air filters may become clogged, monitor the manifold pressure gauge. A decrease in manifold pressure may indicate a clogged filter. If the decrease is followed by a slight increase in manifold pressure, this will then indicate that the automatic alternate induction air system is in operation, and the manifold pressure may then be brought back to the desired level with the throttle control. A continued drop in manifold pressure would indicate that the automatic induction air system was not working. In this case, actuate the manual alternate air control, which serves as a back- up for the automatic system. A partial regain of manifold pressure will indicate that the manual alternate air induction system is operating. Throttle controls may be advanced to gain additional manifold presswe. The manual alternate air control should not be actuated on the ground with the engines operating, because the engines would then be supplied with unfiltered air. 54 753 664 731112 TWIN COMANCHE SECTION 1l DIVING SPIRAL At night or during instrument flying conditions, it is possible for a pilot not proficient at instrument flying to get into an in- advertent steep diving spiral. If a spiral should develop, recover in the following manner: a. Reduce power. b. Level the wings. c. Bring the nose of th& airplane to the horizon. RADIO OPERATION Communication and navigational equipment controls are located in the center of the instrument panel. Associated auxiliary switches are located on a separate panel below the control column on the lower right side of the instrument panel. Citcuit breakers for the radios are located on the main circuit breaker panel. All sets are turned ‘‘ON’’ by the switch located on the control head of each particular unit, with the exception of the marker beacon and glide slope power switches which are located on the Audio Selectoar Switch Panel. After power is supplied, the pilot may wish to operate one of the two transmitters by moving the transmitter selector switch to the proper position. The switch is located on the selector switch panel. A separate three position audio selector switch is provided for each receiver. Each receiver audio output may be connected to either the speaker or the headset. In addition they may be placed in the ‘‘OFF'’ ot standby position. To receive audio through the speaker from the Marker Beacon and DME the top Mark 12 must be in operation. Power from this radio is not re- quired when the headphones are connected to the Marker Beacon or DME. Two or more sets may be simultaneously connected to either the headset or speaker position by placing the selector switches in the desired combination. For example, the A.D.F. and the top Mark 12 may be selected to operate on the speaker and the lower Mark 12 may be selected for headset operation. If desired the pilot may listen to the speaker and the co-pilot the headset. 763 664 731112 55 SECTION IV PERFORMANCE CHARTS Take-off Ground Run Distance Take-off Distance Over 50-Foot Obstacle . Multi-Engine Climb Rate and Airspeed . Single-Engine Climb Rate and Airspeed Altitude Conversion Chert . Range vs Density Altitude . True Airspeed vs Density Altitude Landing Ground Run Distance Landing Distance Over 50-Foot Obstacle Fuel Flow Indicator ., . Power Setting Table . . 56 . 57 . 58 . 59 . 60 61 - 62 - 63 - 65 66 TWIN COMANCHE SECTION IV TWIN COMANCHE i e T I W ST Ny — TAKE-0FF GROUND RUN DISTANCE — AT YARIOUS ALTITUDES, UENJP&[M&‘M@[ES WEIGHTS, AND uJflN@S FLAP SETTING- 15° s LIFT - OFF SPEED - 80 MPH. IAS PAVED LEVEL RUNWAY 4 i 1l l i 1 I 1 F T YO OBTAN TWF T Tl ‘LTlm AT A —1 §ug:'g;iAnu.zl. YREFERENCE LINE TO C AT —__{ 5}zll R;AaLL&TOR FEIENCE LINE TOE AT 6 READ TAKEOFF DISTANCE AT F ‘\IZ NG \ 2400 &1 Y \ \G‘\\ - \ \ \\"ss e \ \ 2000 8000, A 9 \ = TN TN \ : Loono | — B, NS ™ g il LT L LI\ s / ~ : = d % ‘\ N a o TR NN ™ &st . b ISL IS RN N g TN &~~ : Q\‘\\ 1 e 400 0 20 40 60 80 3500 3400 3200 3000 2800 0 10 20 30 TEMPERATURE - °F WEIGHT - LBS. HEADWIND - MPH. 700505 56 SECTION IV TWIN COMANCHE TWIN COMANCHE 1 I 1 I | 1 4 - | [ gLr - TAKE-OFF DISTANCE = | OVER 50 FOOT _ OBSTACLE AT YARIOUS ALTITUDES, ~ TEMPERATURES, WEIGHTS, AND WINDS = FLAP SETTING - 15° ATTAIN 81 MPH_IAS AT 50 FT. - PAVED LEVEL RUNWAY . . NOTE: THE TAKE - OFF DATA SHOWN BELOW WAS PREPARED IN ACCDRDANCE WITH CIVIL AIR REGULATION 3.84 p— s j‘— 6000 T LSCAN T T NR] e L\é VZ&\\ \x\ &:\\L g SEXAADND TN e = J/‘/é\\ = \\\\\ N " r 5 A7 RS fi\\-\ - MZZZ ZiSSINNS NNSE | st b| B T gTewp. N : ! 1000 I il L 0 20 40 60 80 23600 3400 3200 3000 2800 O w 20 TEMPERATURE - °F WEIGHT - LBS. HEADWIND - MPH. 57 700505 TWIN COMANCHE SECTION IV TWIN COMANCHE T T T T T I T T T 1T T 7T — MULTI-ENGINE CLIMB RATE AND SPEED — ks Vs o DENSITY ALTITUDE AND WEIGHT GEAR AND FLAPS RETRACTED COWL FLAPS OPEN EXCEPT AS NOTED j?%f‘jlr ) 4 ‘4 N [ 20000 Yi l_ . _l__ F__E#A_X‘T_____ N\ ARSEE SIS S 16000 ;RE - 4‘ flb_‘_%_ \ NS % 12000 % ’\ \ | L4 4] RN ISR HRATE OF CLIME FT. /MIN. BEST RATE OF CLIMB SPEED MPH DENSITY ALTITUDE - FEET 700505 58 SECTION IV TWIN COMANCHE TWIN COMANCHE Fslad-d Lad L &—1-3 SINGLE ENGINE RATE OF CLINS L ALTITUDE AND WEIGHT kool LEFT ENGINE INOPERATIVE = LD coming AR e | | ,A! L - 12000 | i_‘ R e e S 1 T E e e i : NS N \\_ S00 %0 100 WO BEST RATE OF CLIMB SPEED MPH 59 700505 TWIN COMANCHE SECTION IV TWIN COMANCHE V% &% L ey K] ALTITUDE CONYERSION CHARY THIS CHART SHOULD BE USED TO DETERMINE DENSITY ALTITUDE 4 FROM EXISTING TEMPERATURE - AND PRESSURE ALTITUDE CONDITIONS FOR USE WITH PERFORMANCE CHARTS. ez “ = + | '(—4._ i /l 24000 ~ ] 1 [ /— 20000 . DT | ] | T 1 et 7 i - 16000 DENSITY ALTITUDE - FT \ @ \| 8000 < 4000 —a St TEMPERATURE - °F 700505 60 SECTION IV TWIN COMANCHE TWIN COMANCHE T T T T T T 1T T[] RANGE VS DENSITY ALTITUDE || MLM ”HLA‘HAIENF l "__‘_LT,:LT T | L% ilCRUISE FUEL CONSUMPTION [_ mnustum —_— YRATED RPM ' l— PoOwER mu B e " 15 400 172 | F B AT L E 85 2 12 _| LE | ‘ralllm& , l | | | | — 4 f—t— - = s E | | | | = | Jr_>I 1T —¥‘ uil;;fikk 5% AS% | 55% m. g 15000} T T T T T ;—*;fi T T ' LT T g 900 1000 1100 1200 IMGE STATUTE MILES 61 700505 TWIN COMANCHE SECTION IV 700505 TWIN COMANCHE T T T T T T T T T T TAUE AlRSPEED =1 Vs -t || emsITY AtTiTupE || Lo z) WEIGHT - 3600 LBS. COWL FLAPS CLOSED T g INN . e 62 SECTION 1V TWIN COMANCHE TWIN COMANCHE '_ LT B A =wd ITY LANDING GROUND RUN DISTANCE -AT VARIOUS ALTITUDES, TEMPERATURES, WEIGHTS, AND WINDS = FLAP SETTING - 27° TOUCH-DOWN 70 MPH IAS PAVED LEVEL RUNWAY 1200 .t 1000 S&\\t \\.\\‘fl‘ K S . & ~ = R A~7/"‘\\\\ e | K - i ) N © e DRI L\ B2000 I~ N = s T-T’“"' r\b\gv‘\\ 00 = | N 2 | N W § : Oy e 2 ; N 200 TEMPERATURE - °F 63 1 20 40 G0 80 3600 34003200 3000 2800 0 0 20 30 WEIGHT - LBS. HEADWIND - MPH. 700505 TWIN COMANCHE SECTION IV TWIN COMAN CHE T T T T T T T LANDING DISTANCE OVER 50 FOOT — OBSTACLE AT YVARIOUS ALTITUDES, — | TEMPERATURES, WEIGHTS, AND WJN@S FLAP SETTING- 27° | = POWER OFF - APPROACH SPEED - 90 MPH IAS PAVED LEVEL RUNWAY o | NOTE: THE LANDING DATA SHOWN BELOW WAS PREPARED IN ACCORDANCE WITH CIVIL AIR REGULATION 3.86. fil‘y‘ — 2800 S \“,‘/‘/ \J\ \ L s000 e j = N ~ \\ 2400 _-|ul /g,l” 8 i@i: \}\ \ SRRSO - $10. h'\\QX \ o | TEwp AN \_ 1 S\ 1600 LANDING DISTANCE - FT \\\ 800 b o anpe - o - - - --—-.1'_-._ 400 0 20 40 60 80 3600 3400 3200 30002800 O 10 20 30 TEMPERATURE - °F WEIGHT - LBS. HEADWIND - MPH. 700505 64 TWIN COMANCHE SECTION IV YOLVIIONI IHL INIOVIY guiyie}s 10) aduey Mo|4 [3n4§ .wm»\n Awouoay )sag Ty & 1am04 %G9 g 2 jamoq 1599 oL o w Crui aduey }0-3%e] 1am0g 183§ aduey jy0-axel auly pay JOLVIIANI MOT4 13Nnd \ 43idid 4 H¥H/IYO SN MOT4 13Nd / Ty g oS ovfl %SL O—.u nO—. zl 0009 7 Tl vl vl 9l 000t \K O-.‘ ~ 0002 1S 1y 430 VL 0€-Vd 700505 65 SECTION IV TWIN COMANCHE ‘piepums mo[aq saimeladuway 10] 10vIqNS PIBPUEIS IAOQT gaimeiadwsal Ite 10) aInssaxd plojjuell ppy 3IImeladwa) aplnje p1epuerls Woy armeaadula) 1je uononpul Uy uopiElIEA f 0T yoed 10§ “8YH L1°0 Ad1ewrtxoadde ainssaid piojTuew 1331100 ‘lamod JUMSUOD UIBIUTRW O], 14 S sl 691 14 6 ! Tl st a4 --- u €l y L 8°L1 ¢'81 14 91 A 1d L Tl L'81 ¥6l 61 11 00z la --- 6Ll £'s1 06l L6T €T ot €0z Loz 13 --- A1 981 T'61 661 L 6 S 0T o'tz g1z --- #°8l 691 S'6l T'0T 1€ 8 14 --- e-- 8° 02 £l 1'zz 14 L°81 161 861 60 ¥e L 'gc 14 --- 1"12 9°1Z #°TT T'€T 681 ¥'6l T1°0T RO He 9 p'€z 0% 1d £ 1z 6'1Z L'TT S'¢€T z6l L6l ¥'0T 01T " S L€ €% €£°ST 9°1Z T 0°€T BR'€T #6l 661 902 €12 4 v 0'¥T L'¥T 9°ST 61z €'zt €€ 1'¥ L 61 oz 60 91T 8¢ € £'¥Z 0°'ST 6°'ST e 8'7C 9°€C ¥'#C 661 $0z Tz 812 s z 9'¥Z €'ST T°9C ¥ zz 0°'€C 6€T L'¥C 07 Loz s’ ree SS 1 6'¥C 9°ST S9T LTt €'€C T'¥C 0'ST ¥ 07 01z L'1T ¥l 6S s 00¥Z O00EZ 00TZ 00¥Z 00£Z 00ZZ 001C 00¥Z 00EC 00ZZ 0012 do | 1994 *SST ¥ "NYW ANV WdY "SSTHd "NVIN ANV W4 "SSHUd "NV ANV WdY dway, | 0001 paiey ¥SL — dH OC1 parey %59 — dH ¥01 paiey ¥¢6S — dH 88 ‘ny | uv 'pIs [ssaxgd suiBu3z dH 091-9-0ZE€-O1 [°POW Bulwol4q -9|qD) Bullias Jemoyg 700505 SECTION V GENERAL MAINTENANCE Tire Inflation. Battery Service . Brake Service Landing Gear Service . Fuel and Oil Requirements Cate of Air Filter Care of Windshield and Windows Serial Number Plate Propeller Service Fuel System . . 67 . 67 . 69 . 69 .70 .70 73 73 .74 TWIN COMANCHE SECTION V SECTION V GENERAL MAINTENANCE This section contains information on preventive maintenance. Refer to the Twin Comanche Service Manual for further main- tenance. Any complex repair or modification should be accom- plished by a Piper Certified Service Center. TIRE INFLATION For maximum service from the tires, keep them inflated to the proper pressure of 42 psi. Interchange the tires periodically for even wear. All wheels and tires are balanced before original installation, and the relationship of tire, tube and wheel should be maintained upon reinstallation. In the installation of new components, it may be necessary to rebalance the wheels with the tires mounted. Out of balance wheels can cause extreme vibration in the landing gear. BATTERY SERVICE Access to the 12 volt 35 ampere hour battery is through the right rear baggage compartment panel. The stainless steel box has a plastic drain tube which is normally closed off with a clamp and which should be opened occasionally to drain off any accumulation of liquid. 700505 67 SECTION lV TWIN COMANCHE The battery should be checked frequently for proper fluid level, but must not be filled above the baffle plates. All con- nections must be clean and tight. 1f the battery is not up to proper charge, recharge starting with a charging rate of 4 amps and finishing with 2 amps. Quick charges ate not recommended. BRAKE SERVICE The brake system is filled with MIL-11-5606 (petroleum base) hydraulic brake fluid. This should be checked at every 100 hour inspection and replenished when necessary. Refill the brake reservoir on the aft bulkhead of the nose section to the indicated level. No adjustment of brake clearance is necessary. If the brake blocks become worn to 1/64 inch minimum lining, replace them with new brake segments. Remove the four cap bolts that join the brake cylinder housing and lining back plate assemblies, then remove the back plates from between the brake disc and wheel. Slide the brake cylinder housing from the torque plate and slide the pressure plate and lining from the anchor bolts of the cylinder housing. Remove the lining by prying it from the pressure plate and back plates. With the four cap bolts 68 700505 TWIN COMANCHE SECTION V removed, it is possible to remove the main wheels by taking off the dust cover and axle nut. LANDING GEAR SERVICE To raise the aircraft for servicing, use two hydraulic jacks and a tail support. Place about 300 pounds of ballast on the base of the tail support before jacking the aircraft. Landing gear oleos should be serviced according to instruc- tion on the units. All three oleos should be extended until about two and three-quarter inches of oleo strut extension is exposed in static position. To add air to the oleo struts, attach a strut pump to the air valve and pump the oleo up to the proper position. To add oil, release the air through the strut valve, and allow the strut to extend fully. Remove the air valve and fill the unit through its opening. Compress the oleo to within one-quarter inch of full compression, allowing air and excess oil to escape. Reinsert the valve core and pump up the strut. FUEL AND OIL REQUIREMENTS A minimum octane of 91/96 Aviation Grade fuel must be used in the Twin Comanche. Since the use of lower grades of fuel can cause serious engine damage in a short period of time, the engine warranty is invalidated by use of lower octanes. The oil capacity of the Lycoming 10-320-B is 8 quarts with a minimum safe quantity of 2 quarts. It is recommended that engine oil be changed every 50 hours or sooner under unfavorable conditions. Intervals between oil changes can be increased as 700505 69 SECTION V TWIN COMANCHE much as 100% on engines equipped with full flow cartridge type oil filters provided the element is replaced each 50 hours of operation. The following grades are required for the specified temperatures: Temperatures above 60° F S.A.E. 50 Temperatures between 30°F and 90° F S.A.E. 40 Temperatures between 0°F and 70°F S.A.E. 30 Temperatures below 10° F S.A.E. 20 CARE OF FILTER The induction air filters must be clcaned at least once every fifty hours. Depending on the type of condition existing, it may be necessary to clean the filters more often. The following cleaning procedure is recommended by the manufacturer of the filter: 1. Remove the filter from the engine compartment. 2. Tap filter gently to remove dirt particles. Do not use compressed air or cleaning solvents. 3. Reiastall air filter. CARE OF WINDSHIELD AND WINDOWS The following procedure is recommended for care of the plexiglas windows: 1. Flush with clean water and dislodge excess dirt and mud by hand. 2. Wash with mild soap and warm water, using a soft cloth or sponge. Do not rub. 70 700505 TWIN COMANCHE SECTION V 3. Remove oil, grease or sealing compounds with a cloth soaked in kerosene. 4. After cleaning, apply a thin coat of hard polishing wax. Rub lightly with a soft dry cloth. 5. A severe scratch or mar can be removed by using jew- eler’s rouge. After the flaw has been removed apply wax to the area. SERIAL NUMBER PLATE The serial number plate is located inside the fuselage, on the left skin, opposite the rear fuselage access plate or on the fuselage adjacent to the left side of the tail skid. The serial number of the airplane should always be used when referring to service or warranty matters. PROPELLER SERVICE The air charge in the propeller cylinder should be kept at the pressure specified on the placard located in the spinner cap. (A copy of the placard is shown on page 74.) The pressure in the cylinder will increase about one-third psi for every Fahrenheit degree increase in temperature. This effect should be considered when checking pressure. The charge maintained must be accurate and free of excessive moisture since moisture may freeze the piston during cold weather. Dry nitrogen gas is recommended. 700505 73 SECTION V TWIN COMANCHE CHAMBER PRESSURE REQUIREMENTS WITH TEMPERATURE Temp. °F Press. (psi) Temp.°F Press. (psi) 100 188 30 165 90 185 20 162 80 182 10 159 70 178 0 154 60 175 -10 152 50 172 -20 149 40 168 -30 146 NOTE: Do not check pressure or charge with propeller in feather position. FUEL SYSTEM The fuel screens in the strainers require cleaning at fifty hour or ninety day intervals whichever first occurs. The fuel strainers beneath the floor panel are accessible through a plate in the underside center of the fuselage. The fuel injector screen is located in the housing where the fuel inlet line connects the injector. This screen should be cleaned every fifty hours of operation. 74 700505 TWIN COMANCHE SECTION V NOTES 700505 75 INDEX SECTION | Page Specifications: Performance . 1 Weights 2 Power Plant . 2 Fuel and OQil . 3 Baggage Area 3 Dimensions 3 Landing Gear 4 SECTION It Design Information: Engine and Propeller . e e e e e e 6 Fuel Injection . . . . . . . . . . . . 7 Structures . e e e e e e e e e 8 LandingGear . . . . . . . . . . . . 8 Control System . . . . . . . . . . . . 10 Fuel System . . . . . . . . . . . . . 11 Electrical System . . . . . . . . . . . 14 Vacuum System . . . . . . . . . . . . 14 Instrument Panel . . . . . . . . . . . 16 Heating and Ventilating System. . . . . . . 18 Instrument Static Pressure System . . . ., . . 22 Seats . . . . . . . ... e e 23 Finish. . . . . . . . . . . . . . . 23 Baggage Area . . . . . . . . . . . . 23 Stall Warning System . . . . . . . . . . 24 SECTION I Operating Instructions: Preflight. . . . . . . . . . . . . . 25 Starting Engines. . . . . . . . . . . . 27 INDEX (cont) SECTION Il (cont) Page Flooded Start . . . e e e e e e e e Warm-Up and Ground Check e e e« « o« . . 28 Electrical Power . . e e e e e e .29 Taxiing and Pre-Take-Off e e e e e e e 29 Take-Offand Climb . . . . . . . . . . . 31 Wing Flaps . . . e e e e . e 3 Short and Soft Field Take—Offs e e e e e .32 Landing Gear Retraction . . . . . . . . 33 DeicerBoots . . . . . . . . . . . . 33 2 X Stalls . . . . . . . . . . . . . . . 3 Spins . . e e e e e e .. 35 Spin Recovery Techmque v e e« 4 . . . 36 Cruising. . . . . . . . . . +« « +« « » 36 Fuel Management . e e e e . Approachand Landing . . . . . . . . . . 39 Post Landing . . . . . . . . . . . . . 42 Emergency Procedures . . . . . . . . . . 42 Vme Demonstration . . . . . . . . . . . 49 Vmcand Stall Speed . . . . . . . . . . . 50 Mooring. . . . o+ o« . . . 50 Loading and Welght and Balance .« « « . . 50 OperatingTips . . . . . . . . . . . . 52 Flight Conditions. . . . . . . . . . . . S3 DivingSpiral . . . . . . . . . . . . . 55 Radio Operation . . . . . . . . . . . . 55 SECTION IV Performance Charts: Take-Off Ground Run Distance . . .« . . 56 Take-Off Distance Over 50-F oot Obstacle . . . . 587 Multi-Engine Climb Rate and Airspeed . . . . . 58 763 664 731112 INDEX (cont) SECTION 1V (cont) Page Single-Engine Climb Rate and Airspeed . . . . 59 Altitude Conversion Chart . . . . . . . . 60 Range vs Density Altitude . . e e e e 61 True Airspeed vs Density Alulude e e 62 Landing Ground Run Distance . - e 63 Landing Distance Over 50-Foot Obstacle . o 64 Fuel Flow Indicator . . . .+ .« . « « + = 65 Power Setting Table . . . . . . . . . . 66 SECTION V General Maintenance: Tite Inflation. . . . . . . . . . . . . 67 Battery Service . . . . . . . . . . . . 67 Brake Service . . . . . . . . . . . . 68 Landing Gear Service . . . . . . . . . . 69 Fuel and Oil Requirements . . . . . . . . 69 Care of Air Filter . . . v e e e e 70 Care of Windshield and Wmdows C e e e e 70 Serial Number Plate . . . . . . . . . . 73 Proper Service . . . . . . . . . . . . 73 FuelSystem . . . . . . . . . . . . . 74