Owner’s Handbook

when applied across a fuel control (jetting system), makes fuel flow proportional to airflow. Fuel pressure regulation, by means of the servo valve, necessitates only a minimum fuel pressure drop through the en- tire metering system. This makes it possibleto maintain metering pressure above vapor forming conditions, and at the same time requires a fuel inlet pressure sufficiently low so that a diaphragm pump can be used. An inherent feature of the servo system is self-purging which eliminates any possibility of vapor lock and associated problems of difficult starting. The injection system consists of a Servo Regulator, which meters fuel flow in proportion to airflow to the engine, giving proper fuel air mixture at all engine speeds, and 3 Flow Divider, which receives the metered fuel and accurately divides fuel flow to each cylinder fuel nozzle. Installed in the instrument panel is a fuel flow indicator. This instrument is connected to the flow divider and monitors fuel pressure. The instrument converts fuel pressure to an accu- rate indication of fuel flow in gallons per hour. NOTE An increasing or abnormally high fuel flow in- dication is a possible symptom of restricted injector lines or nozzles. Induction air for the engine enters a large air duct at the front of the top cowl. The air is directed through a filter, and on 6 690401 COMANCHE “C" SECTION II to the injector. A heated alternate air source is incorporated to provide airflow to the engine in case the normal flow of air through the filter is restricted. The alternate air door is spring loaded, and will remain closed during normal operation. The alternate air door will operate automatically, as the normal in- duction airflow through the filter is restricted, or when the in- jector heat (INJR.) push-pull control, located on the instrument panel, is placed in the FULL ON position. The control should be placed in the FULL ON position if icing conditions aresuspected. 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 con- tinuous main spar. The spars are attached to the fuselage at the side of the fuselage. The wings are also attached to the fuselage at the rear spar and at an auxiliary front spar. Wing airfoil section is a laminar flow type, NACA-642A215, modified with maximum thickness about 4071; aft of the leading edge. This permits the main spar, located at the point of maxi- mum thickness, to pass through the cabin under the center seat, providingunobstructed cabinfloor space ahead of the center seat. LANDING GEAR The nose gear is steerable with the rudder pedals through a 40 degree arc. During retraction of the gear the steering mech- 690401 7 SECTION II COMANCHE “C” anism is disconnected auto- matically 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 transmission located under the floorboards, actuating push—pull cables to each main gear and a push-pull tube to the nose gear. The landing gear motor is activated by a selector switch located on the instrument panel. To guard against inadvertent movement of the landing gear selector on the ground, the handle must be pulled aft before moving it upward. The gear selector is in the shape of a wheel, to differentiate from the electric flap control knob, which has an airfoil shape. As an added safety feature, the warning horn is connected to the gear selector switch. The horn will operate if the selector is moved to the UP position with the master switch on and the weight of the airplane on the landing gear. As a final safety factor to prevent gear retraction on the ground, an anti- retraction switch is installed on the left main gear. This prevents the electric circuit to the landing gear motorfrorn being completed until the gear strut is within three quarter inch of full extension. The gear indicating lights are located conveniently by the gear selector switch. The green (DOWN) indicating light below the selector switch shows that all gear are down and locked. The amber (UP) light above the gear selector switch is the gear up indication. The white light indicates that the landing gear is in transit. The gear up warning horn will sound when power is reduced (below approximately 12 inches of manifold pressure) on the engine and the gear is not down and locked. GEAR INDI- CATION LIGHTS ARE DIMMED WHILE THE INSTRUMENT LIGHTS ARE ON. r——LAnnme—\ I "F-ll Our 05m ”_J] , ‘1 m i ,. Landing Gear Selector Switch 8 690401 COMANCHE “C" SECTION II The brakes are actuated by toe brake pedals mounted on the left set of rudder ped- als. Hydraulic brake cylinders are located above the left rudder pedals and are acces- sible in the cockpit for ser- vicing. Parking brake valves are incorporated in each cylinder. Two cables ex- tending from the parking brake “T” handle are attached to the parking brake valves. To prevent inadvertent appli- Tow Bar Stowoge cation 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. A tow bar is provided with each aircraft. When not in use it is stowed next to the main spar. It may be removed by lifting the flap covering the forward side of the spar and removing the bar from its fasteners. When towing with power equipment, caution should be used not to turn the nose gear beyond its 20 degree radius from center as this may damage the nose gear and steering mechanism. CONTROL SYSTEM The flight controls are the conventional three control type operated by a control column and rudder pedals. For coordinated action of the rudder and ailerons, their control cables are inter- connected by a cable-spring system. Provision for directional and longitudinal trim is provided 69040I 9 SECTION II COMANCHE “C” by an adjustable trim mecha- nism for the rudder and sta- bilator. ElectricallyoperatedMax— Lift flaps can be lowered and stopped in any desired posi- tion. The flap control switch is located on the instrument panel along with a flap posi- . tion indicator which is marked ., \ '/C to show the flap travel. The fit" ., < white arc is a range for take- off operation. Flflp and Tnm Control 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 two rubber-like fuel cells located in the inboard leading edge sections of the wings. Capacityof these cells, which are classified as the main fuel cells is 30 gallons each (28 gallons usable). ' As optional equipment, a 30 gallon auxiliary fuel system is available. The system consists of two 15 gallon fuel cells in- stalled in the wings just outboard of the main fuel cells. Use auxiliary fuel 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 overten days without fuel,the cells should be coated with lightengine oil to keep the rubber from drying out. 10 690401 SECTION II COMANCHE “C” 5.3. 1... U_._.<zm_._Uw «gm—Hm; Juan. a 690401 SECTION II COMANCHE “C” During normal operation the fuel is drawnto the engine from the cells by a mechani- cally operated fuel pump lo- cated on the engine accessory section. In the event the engine drivenfuel pump fails, an electric auxiliary fuel pump is provided. This pump should be operated during starting, take-offs, and land- ings. The fuel selector and strainer units for the system are located between the front seats. Daily draining of the strainer is accomplished in the cockpit by opening the hinged access door located in FueI Selector And Drain the floor panel just aft of the fuel selector valve and moving the quick drain valve handle to full aft position. The general procedure for draining the fuel system is to open the strainer quick drain for a few seconds with the fuel cell selector on one cell, then change fuel selector to the opposite cell and repeat the process. The same process ap- plies to the auxiliary fuel system. Allow enough fuel to flow to clear lines as well as the strainer. Positive fuel, flow shut-off can be observed through the clear plastic tube which carries fuel overboard. Fuel quantity is indicated by an electric gauge located in the instrument cluster. This gauge will indicate the amount of fuel in the cell that is selected. An override system is incorpo- rated so that it is possible to check the amount of fuel available in the remaining cells without moving the selector handle to that cell position. This is accomplished by depressing the red button (located on the fuel selector plate) under the desired fuel cell position. The fuel gauge will indicate the amount of fuel avail- I2 69040] COMANCHE “C” SECTION II able in that cell. When the red button is released the indicating system will return to its normal operation. When the fuel selector handle is not in a positive selector detent position, more than one fuel port may be open at the same time. It should be determined that the fuel selector is positioned in a detent, which can be easily felt when moving the handle through its various positions. \ ELECTRICAL SYSTEM The electrical system includes a 12 volt 70 ampere alter- nator, providing power at all engine speeds, a transistorized voltage regulator, an overvoltage relay and a 35 ampere hour battery. This results in improved performance for radio and electrical equipment and long battery life. The voltage regulator is mounted on the top right of the fire- wall. The battery mounted aft of the baggage compartment is easily accessible for service or inspection through a panel in the rear of the cockpit. Electrical switches are located in the lower left sub-panel, while the circuit breakers are in the lower right sub-panel. The circuit breakers automatically break the circuit if an overload occurs. To reset circuit breakers, push in the reset button.ltmay be necessaryto allow approximately two minutes for the breakers to cool before resetting them. Corrective action should be taken in event of continual circuit breaker popping. It is possible to manually trip the breakers by pulling out on the reset button. The alternator circuit breaker, mounted on the same panel, is of the switch type andshould not be opened without consulting the , ’ f Service Manual for detailed procedure. ‘ Standard electricalaccessories, in addition to those already listed, include a geared starter, stall warning indicator, cigar lighter, ammeter and position lights. Glare ban instrument light- ing, pitot heat, auxiliary power unit, and anti-collision light are 69040 I I3 SECTION II . . .fit as f e" of»? of? s" sf“ . v at we? a“; as... e He xx . «x,» . m CIGAR I LIGHTER I PWER mmr mo murmur “METER 5 ”‘P ALTERNATa on n vnnme neauurnn COMANCHE “C” o ewe a e x» i‘ r s" a“ , 55 set ,« r e z. 5 “we? \ e ' e‘ a“ y we r? a" “t 0 e or r o t 4 49 «$2 -. a a or Q « 4 r Q v e v 4k e or o t ‘Y. Q" ‘n‘ ”s‘ w“ SS Auzkmrm FIELD cmcun smrcu mama vmnon mom MAGNETO LEFT mensru e“ a e) ,\ s‘ Q 30 at ao g x)’ q «6 e gs ate maven 3mm“ (snow in sun PusmuN) L FIREWALL cwnscrun ELECTRICAL SYSTEM SCHEMATIC .ge‘ a“? 95 of S“ e xfis‘? A ”v to mm SWITCH 69040I COMANCHE “C” SECTION II offered as optional accessories. Circuit provisions are made to handle optional communications and navigational equipment. Operation of the alternator system, as far as visual indi- cation to the pilot, is the same as a standard generator system. The ammeter, located in the lower right corner of the instrument panel, will give a constant indication of battery charge, or dis- charge in case of a malfunction of the system. Should a mal- function of the voltage regulator occur that would cause a high voltage condition, the overvoltage relay will cut the alternator out of the system. Battery power will still be available to the bus bar. HEATING AND VENTILATING SYSTEM There are four individual controls provided for regulating the heating, defrosting and ventilating air. The controls are located on the lower right side of the instrument panel in a console panel. Heated air for the cabin interior is provided by a heater shroud attached to the exhaust muffler. Fresh air is picked up at the front of the engine and passes through the heater shroud to control valves for distribution to the cabin. Warm air for the defroster system is also obtained from the heater shroud. The amount of air applied to the wind- shield is regulated with the defroster (DEF.) control in the console. Caution should be used if it is necessary to operate the defroster on the ground as prolonged appli- Heat and Ventilation Controls 690401 ' I5 COMANCHE “C" SECTION II 2mhm>m Oz_._.<|__._.2m> d oz_._.<m_._ 69040I 16 COMANCHE “C” SECTION II cation of heat to the windshield may cause distortion. Fresh air for the cabin interior is picked up from air inlets in the leading edge of each wing. The air passes through the wings to the wing root area and is discharged into the cabin near the floor just forward of the front seats. In addition, two fresh air scoops are located on the dorsal fin. These provide air for two overhead ventilators in the rear seat area and two front seat ventilators located adjacent to the windshield posts. Cabin air is exhausted through an outlet located above the hat shelf. VACUUM SYST EM Suction for the vacuum operated Gyro instruments with central air filter system is supplied by an engine driven (dry type) vacuum pump. A vacuum gauge is installed in the instrument panel to pro- vide a constant indication of vacuum source. Suction is indicated on the gauge in inches of mercury; normal operating range is 4.8 to 5.1 inches. The system is controlled by one adjustable regu- lator, located under the instrument panel. After initial adjustment the regulator will require very little attention. 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 the engine instruments on the right side. Provision for extra instruments is made in both sections. All instruments in the left side are shock mounted and all are accessible for main- tenance by removing the access panel over the instruments. 690401 I7 COMANCHE “C ’ SECTION II dz: ¢m=<mzm tnosu cup—a: zuxflzm tsuEu..5< 5m: 52:zokumz: zop<=hu<min Jock—Eu meats: «3,53xu<omnm<x><z nozbzouxmjmmomu £9522: 32.32min .mQ .vv .m¢ .Nv iv 5? .mn in fin 3363.5.56m mate?» 6m fomhzou m4: Jsou 6m mohomnmm 5:3 .mm zursiw 55..— pmom mx<zmoz§m<m 234mm 05.55: mhxu: zo_h¢u_><z m._._._..._o._.:< .Nn zmhxfpm a 95:32 uua<w chum Jm him: potm én zu._._>>m eta... m4!6“ PEG..—u=_nz<._6m mop—3m «mpg: min maomhzou mu._.<mm «GEE—s: .hN .wN .r.N 5M .mN .NN JN .oN $— mmungquzu 323 so: one... mesmmmzm39:52 552055. m :_ u:<2_._.._< mmuzmumzfit 552223 SEEae- dzfi xohumnmm 2:5 9:5... zoo<mm5:5: 6— uh— .m_ 6— .v_ .n_ .N— .: 6— mmoptuEz- EEO mupmz_._.._< mzju he mh<¢ °¢>u ._<=o_hum5n 2055: 059 9.25.3 4.5.5 numumzz ¢0h<z_nxoau zma zuoqu .m 6 .h .w .n .v .n .N ._ 69040I 18 COMANCHE “C” , SECTION II The flight instruments are arranged in the preferred basic T configuration. Gyro Horizon and Directional Gyro are vacuum operated through the use of an engine driven vacuum pump. The Turn Coordinator is an electrically operated instrument, con- trolled by the master switch, and serves as a standby for the Gyros in case of vacuum system failure. Instrument illumination is produced by an overhead white light controlled by an intensity adjustable switch in the stabilator trim panel. Optional equip- ment glare ban white lighting is controlled by an intensity ad- justable switch in the lower left sub-panel. The power controls are grouped in the centrally located power control quadrant. A separation of the flight and engine instruments is provided by the radio stack. SEATS The front and center reclining seats are adjustable fore and aft to provide comfort for pilot and passengers. Seat backs may be tipped forward to facilitate ease of entry and exit from the aircraft. They are easily removed by taking out the stops at the end of the mounting tracks and sliding the seats off their tracks. The optionalfamily seat(s) may be removed, allowing for more baggage area and access to the rear fuselage panel by releasing the snap fasteners that attach the seat backs to the hat shelf and turning the wing fasteners at the back of the seat cushions. Seat Miusflnent Handles . 690401 ' k 19 SECTION II COMANCHE “C” BAGGAGE AREA 45 XX Maximum weight in the " \ ( baggage area, including bag- gage and/or passenger(s) and family seat(s) is 250 pounds, with up to 20 cubic feet of available space.Baggage may be placed in the aircraft through a 19 x 21 inch door or the passenger entrance. Tie- down straps are available for Baggage- Emergency Door securing baggage when the family seat(s) are not installed. The baggage door may also be used as an emergency exit and is opened by holding the inside door knob up and, at the same time, turning the latch clockwise. The baggage door should not be opened in flight as it is difficult to close. FINISH All aluminum sheet components are carefully finished inside and outside to assure maximum service life. Both sides of all pieces are alodine treated, and are sprayed with zinc chromate primer. External surfaces are coated with durable acrylic lacquer in attractive high gloss colors. The application of primer to interior surfaces will prevent corrosion of structural and non- structural parts onthe inside where there is no access for normal maintenance . . ' 20 690401 COMANCHE “C” SECTION II NOTES 69040] 21 SECTION III OPERATING INSTRUCTIONS Preflight . Starting Engine . Warm-Up and Ground Check . Take-Off . Climb . Cruising Stalls . Spins Approach and Landing Stopping Engine Emergency Procedures Mooring Operating Tips . Radio Operation 690401 22 23 24 25 26 27 28 28 28 29 30 32 32 34 COMANCHE “C" SECTION III SECTION III OPERATING INSTRUCTIONS PREFLIGHT The following safety procedure instructions must become an integral part of the pilot’s operational routine and preflight inspection. Below is an outline for preflighting the Comanche: 1. a. Ignition and master switches are OFF. b. Drain fuel strainer. L.....—.-.......-.J 69040] 22 SECTION III COMANCHE “C” 2. a. Check for external damage or operational interference to the control surfaces, wings or fuselage. b. Check for snow, ice, or frost on the wings or control surfaces. 3. a. Check fuel supply. b. Check fuel cell caps and covers for security (adjust caps to maintain a tight seal). c. Fuel system vents open. 4. a. Landing gear shock struts properly inflated (approxi- mately 2-3/4“ extension). b. Tires satisfactorily inflated and not excessivelyworn. c. Cowling, landing gear doors and inspection covers properly attached and secured. d. Propeller free of detrimental nicks. e. No obvious fuel or oil leaks. f. Engine oil at the proper level. (Insure dipstick is properly seated.) 5. a. Windshield clean and free of defects. 6. a. Tow-bar and control locks detached and properly stowed. Check that baggage-emergency door is secured. 7. a. Upon entering the airplane check that all controls operate normally. b. Check that the landing gear selector and the other controls are in their proper position. c. Close and secure the cabin door. d. Check that required papers are in order and in the airplane. STARTING ENGINE Starting Engine When Cold: 1. Open throttle approximately 1/2 inch. 2. Turn on master switch and electric auxiliary fuel pump. 3. Move mixture control to full rich until an indication on the fuel flow meter is noted. (Engine is primed.) 23 69040I COMANCHE “C” SECTION III 4. Move mixture control to idle cut-off. 5. Engage starter. 6. When engine fires, advance mixture control to full rich. If engine does not fire within 510 seconds, disengage starter and reprime. Starting Engine When Hot: 1. Throttle open approximately 1/2 inch. 2. Mixture in idle cut-off. 3. Electric auxiliary fuel pump off. 4. Engage starter. When engine fires, advance mixture. Starting Engine When Flooded: 1. Throttle full open. 2. Mixture in idle cut-off. 3. Electric auxiliary fuel pump off. 4. Engage starter. When engine begins to fire, advance mix- ture and retard throttle. Turn electric fuel pump on for take-off. Do not take off with a dead batteryas some voltage is needed to excite the alternator. Starter manufacturers recommend that cranking periods be limited to thirty seconds with a two minute rest between cranking periods. Longer cranking periods will shorten the life of the starter. WARM-UP AND GROUND CHECK As soon as the engine starts, the oil pressure should be checked. If no pressure is indicated within thirty seconds, stop the engine and determine the trouble. In cold weather it will take a few seconds longer to get an oil pressure indication. Warm-up the engine at 800 to 1200 RPM for not more than two minutes in warm weather, four minutes in cold weather. Avoid prolonged idling at low RPM as this practice may result in fouled spark plugs. The magnetos should be checked at 2000 690401 24 SECTION III I, f , COMANCHE “C" RPM with the propeller in high RPM, the drop should not exceed 175 RPM with a differential of not more than 50 RPM. The engine is warm enough for take-off when the throttle can be opened with- out the engine faltering. The electric fuel pump should be turned off after starting or during warm-up to make sure that the engine driven pump is operating by noting if fuel flow is maintained. Prior to take-off the electric pump should be turned on again to prevent loss of power during take-off should the engine driven pump fail. The propeller control should be moved through its complete range during the warm-up to check for proper operation, then left in the full high RPM position. During cold weather operation the propeller should be cycled a minimum of three times to insure that warm engine oil has circulated throughout the entire system. During the propeller check, as during other ground oper- ations, care must be taken not to run-up the engine with the propeller over loose stones, Cinders or other objects which can be picked up by the propeller, and which frequently cause ex— tensive damage to the propeller blades. TAKE-OFF Just before take—off the following should be checked: 1. Controls free 6. Cowl flaps set 2. Flaps set 7. Injector (INJR.) heat OFF 3. Tabs set 8. Fuel on proper tank 4. Propeller set 9. Electric fuel pump ON 5. Mixture set (rich) 10. Engine gauges normal 11. Doors locked In a smooth, steady motion of the throttle apply full power allowing the aircraft to accelerate in the three point attitude until the control surfaces become effective. Then apply slight back pressure on the control column to lift the nose wheel. Under 25 690401 COMANCHE “C” SECTION III normal take-off conditions the aircraft will rotate at/about 65“) MPH. Trying to pull the aircraft off before the proper speed'is obtained will only prolong the take-off run. After the take-off has proceeded to the point at which a landing could no longer be made with the wheels down in the event of power failure, the gear should be retracted. As soon as the gear is up and sufficient altitude has been gained, reduce power to climb setting of 25 inches of manifold pressure and 2500 RPM. For a minimum take-off run the flaps should be lowered to the recommended 15 degrees. With the flaps in this position, the take-off run will be reduced approximately 20 percent. Normally flaps are not used during crosswind take-offs. It is desirable to hold the nose wheel on the runway until a higher than normal take-off speed is obtained, then apply a definite but not abrupt back pressure to the control column to lift the aircraft from the runway. Once airborne, set up the required crab angle, retract the gear at a safe altitude, and continue the climb-out. During cold weather operation, when taking off from slush or water covered runways, allow the gear to remain down longer than usual so that any slush remaining on the gears will freeze and be broken away when the gear is retracted. When taking off from a high altitude field the mixture should be leaned to obtain maximum power. This is done during the pre- take-off check. CLIMB The best rate of climb speed at gross weight will be ob- tained at 112 MPH. The best angle of climb may be obtained at 88 MPH. At lighter than gross weight these speeds are reduced somewhat. For climbing en route a speed of approximately 130 MPH is recommended. This will produce better forward speed and increase visibility over the nose during the climb. 690401 26 SECTION III COMANCHE “C" CRUISING The cruising speed is determined by many factors including power setting, altitude, temperature, weight, and equipment installed. The normal recommended economy cruising power setting is 65% power. At 10,500 feet this gives a true airspeed of 181 MPH. This power setting is obtained under standard conditions at 2400 RPM and full throttle. Fuel consumption is approximately 12.7 gallons per hour. The optimum cruising speed at 6300 feet is 185 MPH. (See Power and Performance charts for power settings and performance under varifrus conditions.) Manual leaning can be accomplished at cruise power settings below 75% of power. Recommended cruise of 2400 RPM gives maximum performance with lower RPM’s through 1800 RPM for an economical cruise. Ordinarily an RPM setting should be selected which will give maximum smoothness. 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 setup, adjust the mixture control according toKAvco Lycoming Operator”sManualj and current service instructions. ‘ During climbing operation the ervoregulator will sense the change in altitude and willautomatically lean the mixture, The continuous use of injector (INJR.)heatduring cruising flight reduces power and performance. Unless icing conditions) ,‘ care severe, do not cruise with the heat on. Apply heat slow1y and only for a few seconds at intervals determined by icing severity. In order to keep the airplane in best lateral trim during cruising, the fuel should be used alternately from each tank. If auxiliary tanks are installed, it is suggested that the fuel in the two auxiliary tanks be used first. 27 690401 COMANCHE “C" SECTION III STALLS STALL SPEED TABLE 77 MPH 6 MPH SPINS Intentional spins are not permitted in this aircraft. However, should one occur, the following recovery technique is recommended . 1. Reduce engine power to idle. 2. Apply full rudder opposite to the direction of rotation. 3. Apply full nose down elevator until the spin stops. (When nose bobs down rapidly, the stall is broken.) 4. During the recoveryfrom the dive that results, use steady back pressure until the aircraft is flying level. (Do not use abrupt elevator movements during this phase and if a buffet is felt during the recovery, release the back pressure slightly.) The spin recovery may be expedited by using aileron oppo- site to the direction of rotation. APPROACH AND LANDING Before landing check list: . Fuel selector on proper tank. . Mixture RICH. Propeller set. . Cowl flaps SET. . Electric fuel pump ON. 6. Landing gear DOWN. (Under 150 MPH check green light ON, warning horn OFF.) 7. Flaps as desired (under 125 MPH). 69040 I 28 MASHNH SECTION III COMANCHE “C” During the approach, the landing gear can be lowered at speeds under 150 MPH, preferably on the downwind leg. The air- plane should be trimmed to approach speed of about 90 MPH and flaps extended. The flaps can be lowered at speeds up to 125 MPH, if desired. The propeller should be set at full RPM or at a high cruising RPM to facilitate an emergency go-around if needed. The amount of flap used during landings and the speed of the aircraft at contact should be varied according to the wind, the landing surface, and other factors. It is always best to con- tact ground at the minimum practicable speed consistent with landing conditions. Normally, the best technique for short and slow landings is to use full flap and a small amount of power, holding the nose up as long as possible before and after ground contact. In high wind conditions, particularly in strong crosswinds, it may be desirable to approach the ground at higher than normal speeds with partial or no flap. Maximum braking effect during short field landings can be obtained by holding full back on the control wheel with flaps up while applying brakes. This forces the tail down and puts more load on the main wheels, resulting in better traction. Injector heat should not be applied unless there is indication of icing, since the use of injector heat causes a loss in engine power which may be crucial in the event of a go-around, and can induce detonation in this situation. STOPPING ENGINE The flaps should be raised and the electric fuel pump turned off at the pilot’s discretion. After parking, the radios should be turned off, the propeller set at minimum blade angle, and the engine stopped by placing the mixture control in idle cut-off. The throttle should be left full aft to avoid engine vibration while stopping. Then the ignition and master switches must be turned off and the parking brake set. 29 690401 -_.,f=. as ”7 ———T COMANCHE “C" SECTION III EMERGENCY PROCEDURES Manual Gear Extension: Manual extension of the landing gear is accomplished with the emergency disengage control located under the floor panel cover between the pilots’ seats. The gear cannot be retracted manually once it is in the down and locked position. Check the following before extending the gear manually. a. Master and gear circuit breakers - IN. b. Master switch - ON. c. Instrument lights - OFF (daytime). To extend the gear, remove the plate covering the emergency disengage control and proceed in these steps as listed on the underside of the cover plate: a. Reduce power - airspeed not to exceed 100 MPH. b. Place landing gear selector switch in“gear down locked” position. c. Disengage motor - raise motor release arm and push for- ward through 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 secure handle. Extend handle and rotate forward until left socket is in clear position. Remove handle and place in left socket and secure. Extend handle. Ro- tate handle FULL FORWARD to extend landing gear and to engage emergency safety lock. Pull aft on the handle to check that the safety lock has engaged. e. HANDLE LOCKED in full forward position indicates landing gear is down and emergency safety lock engaged. Gear “down locked” indicator light should be ON. If the gear selector switch is moved to the up position with the emergency safety lock engaged, the white light will indicate that the gear is in transit although the gear will remain down and locked as indi- cated by the green light. 690401 30 SECTION III COMANCHE “C" NOTE Reducing power and rocking gear extensionhandle 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 aircraft on jacks. b. Be sure the landing gear circuit breaker is disengaged and release the landing gear safety lock assembly. c. Partially retract the gear by pulling the extension handle halfway back. (1. Re-engage the circuit breaker and align the slot in the electric motor drive shaft with the mating pin on the torque tube by using the landing gear control lever. e. Engage the torque tube pin with the slot in the drive shaft by moving the extension handle. f. Push torque tube and drive shaft together, then lock by pulling the motor release arm back to normally locked position. g. Disengage the extension handle and return it to stowage. Check the landing gear operation. Gear-Up Landing: A gear-up landing should only be made during an emergency (1) when the surface is too soft or rough to permit a gear-down landing, (2) when a field is too short for a gear-down landing, which might cause more damage through hitting obstructions than the gear-up landing would cause, (3) when a water landing is necessary. In the event of a gear-up landing, make a normal approach as with gear-down, leave flaps up (to reduce flap and wing dam- age); close the throttle and cut the master and ignition switches during the flare out, turn the fuel selector off, and contact the ground at minimum speed. 31 690401 COMANCHE “C” SECTION III Engine Failure: The most common cause of engine failure is mismanagement or malfunction of the fuel system. Therefore, the first step to take after engine failure is to move the fuel selector valve to the tank not being used. This will often keep the engine running even if there is no apparent reason for the engine to stop on the tank‘being used. If changing to another tank does not restore the engine: 1. Check fuel flow and turn on electric fuel pump, if off. 2. Push mixture control to full RICH. 3. Apply injector (INJR.) heat. 4. Check ignition switch. MOORING The aircraft should be moved on the ground with the aid of the nose wheel tow-bar provided with each plane and stowed on the front spar. Tie-down ropes for mooring the airplane can be fastened to the wing tie-down rings and the tail skid. The aileron and elevator controls should be secured by means of the safety belt 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 un- usually high wind conditions. OPERATING TIPS In the operation of the Comanche ”C”, as in that of any other type of aircraft, there are a few points of technique and information that apply particularly to this model. The following 690401 32 SECTION III COMANCHE “C” Operating Tips may be helpful: 1. Remember that when the instrument lights are on, the gear position lights are dim. 2. Learn to trim the airplane for take-off so that only a very light back pressure on the wheel is required to rotate the ship from the ground. 3. On take-off, do not retract the gear prematurely. The air- craft may settle and make contact with the ground because of lack of flying speed, atmospheric conditions or rolling terrain. 4. The best speed for take-off is at about 65 MPH under normal conditions. Trying to pull the airplane off the ground at too low an airspeed will increase the take-off roll rather than decrease it. 5. Although it is permissible to extend the landing gear at speeds up to 150 MPH, the loads on the landing gear extension motor and on the gear doors are much lower if slower speeds are used. For this reason, it is recommended that unless there is a good reason to lower the gear at a higher speed, it should nor- mally be extended at speeds below 125 MPH. 6. The flaps can be lowered at airspeeds up to 125 MPH. To reduce flap operating loads, however, it is desirable to slow the airplane to 100 MPH or less before extending the flaps. At these reduced speeds, the load applied to the flaps is greatly reduced. 7. If, under unusual circumstances, the landing gear motor is apparently overloaded and the circuitbreaker opens repeatedly, the electric motor can be assisted by applying light hand pres- sure to the emergency gear lever. 8. Before attempting to reset any circuit breaker, allow a two to five minute cooling off period. 9. When landing and upon making contactwith the ground on the main wheels, neutralize the rudder pedals, apply additional back pressure to the control wheel and retract the flaps. This gives best directional control on the ground and provides for full effectiveness of the brakes during the landing roll. 10. In some instances when operating with fuel injection at altitudes over 10,000 feet, surging of the engine may be expe- 33 69040] COMANCHE “C" SECTION III rienced. This condition may be eliminated by proper leaning of the mixture or by use of the electric fuel pump. ll. An increasing or abnormally high fuel flow indication is a possible symptom of restricted injector lines or nozzles. 12. The shape of the wing fuel tanks is such that in certain maneuvers the fuel may move away from the tank outlet. If the outlet is uncovered, the fuel flow will be interrupted and a temporary loss of power may result. Pilots can prevent inadvertent uncovering of the outlet by having adequate fuel in the tank selected and avoiding maneuvers which could result in uncovering the outlet. Running turning takeoffs should be avoided as fuel flow interruption may occur. Prolonged slips or skids in any pitch attitude or other unusual or’ abrupt maneuvers which could cause uncovering of the fuel outlet must be avoided. RADIO OPERATION Communications and navigation equipment controls are located in the center of the instrument panel with associated radio selector panel above the radios. Circuit breakers for the equipment are located in the lower right sub—panel. All sets are turned ON by the switch on the control head of each unit, with the exception of the marker beacon which is energized by the rocker switch in the radio selector panel. Transmitter selection is made available with rocker type switches also in the radio selector panel. Each receiver is connected to a three position audio switch in the selector panel allowing connection of the audio output to the speaker, headset, or an OFF, stand-by position. Two or more sets may be simultaneously connected to either the headset or speaker by placing the selector switches in the desired combination. For example, the ADP and top transceiver may be selected to operate on the speaker, while the lower transceiver is selected for headset operation. Thus, the pilot may listen to the speaker while the copilot monitors the headset. 721218 34 SECTION IV PERFORMANCE CHARTS Take-off Distance Over 50 Foot Barrier . Take-off Ground Run Distance Speed for Best Rate and Angle of Climb . Climb Rate vs Standard Altitude and Weight . True Airspeed vs Altitude . . Range vs Standard Altitude Landing Distance Over 50 Foot Barrier Landing Ground Roll Stalling Speed vs Gross Weight . Airspeed Calibration Chart Altitude Conversion Chart Power Setting Table, Lycoming IO-540-N 690401 35 36 37 38 39 40 41 42 43 44 45 46 COMANCHE “C” SECTION IV PA-24-260 COMANCHE C ‘ masons pastimes , even so lF©©i . - ©ISMCEE Mvaauous mutants, _ _ TQMPERAWTBES, WEUQHITI'S, ANNE WHNEDS . mp smmc. - 15° mm itvn mmw ATTAIN 1,3 x STALL SPEED in st rm IilIIII] Q‘ 5/ \ 5000 e $4? E __¢s/ \ u... 4 figs“ / / \ E s// 5gm“ nun E K K \ e //3:4 +§ \ \ s/ z? - \ \ \ '- //‘ \Isrn \ \\ \‘\ X, [TEMP \ \\ \L\ \llllD \ ‘\ n a zu in an an ion aznusluuzunnznnnmnu m 20 an TEMPERATURE - °E WEIGHT ~ 158 IIEIBWIIII - MPII 69040_'| 35 SECTION V COMANCHE “C" PA-24-260 COMANCHE C , intents enema nun outlines I , . m vanities mutants, , -TEMPERATMRES, WEHGMTS, ANNE WIRES . rm stnme - 15° ACCELERATE in sun SPEED PAVED szn nunwnv it 1300 \ , \ “I0 0 <4; 4I0 ae‘ / 4,0“ // \\ “W“ // p \\ \\ mu :‘ \ l: / “x“ y k.\ i\ won g first A / K ”I \ Vi\ \ % ///\l.§,£ \\ \ Tim 5 map \\ = l \\ \\ \ I m a l \ g \ l l | i 0 10 40 00 80 100 310030002000160024000 10 20 30 TEMPERATURE - °F WEIGHT - LBS HEADWINB - MPH 36 . 690401 COMANCHE “C” SECTION IV PA-24-260 COMANCHE C ’_. SYIPEE®STF©KR test this or cunt __' awn BEST more or ClLlllMl ,_ GEAR AND FLAPS RETRAOTED com FLAI‘S OPEN 2700 RPM FIJLL THROTTLE 5&12m €\ .. a > 20000 BEST RATE l0000 “Muss“ “m s S 5001, ”MmiT2000 —.__ 2 -___ Bum: BEST ANGLE DENSITY ALTITUDE - FT ‘- Talm\ 5 \2400 lbs 0000 \ \ \ 5 a \ \ \ f / 10 I0 00 100 110 CLIMB INDICATED AIRSPEEDS - MFR 69040] 37 SECTION IV COMANCHE “C" PA-24-260 COMANCHE C E. A trim. we m 7 vs 7 _. 001010000 AHEW®E 401010) WEIGHT? ; em AND FLAPS RETRABTED EXCEPT AS norm BEST an: or cum SPEED run mum: 2700 mm com FLAPS um 10000 10000 10000 EFT / ' isruu 15; 12000 . $3“ is / / / DENSITY ALTITIID 0000 / / X? T 5000 0 400 000 1200 1000 1000 1000 RATE OF CLIMB - FT/MIN 38 _ 690401 COMANCHE "C” SECTION IV PA-24-260 COMANCHE C 00’in AURSREEO VS EDENSWY AHU‘WOE cross WEIGHT 3200 ms cum FLAPS anstn 10000 18000 12000 DENSITY ALTITUDE - ET 0000 4000 110 no 160 ‘m in nu TRUE AIRSI’EEI] - MPII 690401 39" COMANCHE “C” SECTION IV gaw— san— mfii “SE.“ . was: 8: == 52 2.2. SE 8: ask—mm 25.5: 5953 pawn 53.3 23; “is an.— ==Nn 52m! awe—u m©§§5< >§m2m© w» mgzflm UmIUZ<EOUOON|¢N|<L cap aca- UHL'IY 0118010 u so:1 u nee-— ages“ 69040 1 40 COMANCHE “C” ' SECTION IV PA-24-260 COMANCHE C mum o'ustauee'orenso'toor' oust/me Air venous Militants, _ temmm‘unes, weuents, ans wunos _ FLAP SETTING 02° | APPIIDACN AT 1.3 K STALL SPEED AYEIT LEYEL RUNYIAY w “fl“;fi $0“! ‘\ mm _\W“‘ ///A0“! \\\\\ \ /9/// 1‘“ \\ R\\ \\ 1m //& ‘ \}\N \\ é/sL \ \:\\ \\: \\ mm .."_. / a". ‘~ \§ \\ l \ \ \\\ rm f , \\\\ 5 : \\\ 000 1 \\ 0 20 40 00 00 100 1000 2000 ”III! 2000 II 10 20 SI TENI’ERATURE"- “F WEIGHT - LBS IIEAWIIW - IPII fé// /4/ 690401 4 '| SECTION IV COMANCHE “C” 42 PA-24-260 _ COMANCHE C Immune mmmoutlines , Mvanuous Attituuss, _ tsunenmunts, WEHGWS, ans Wines , ELAI’ SETTING 32° PAVEU LEVEL RUNWAY APPRUACI‘I AT 1. x STALL SEE I! t 00)» non w‘“ \AI“ 5 mm 9“ _' i . wfif «I 7 \ mun 2 51K%; n \ N \ gn “ lrm ‘:il\\\ \ \ sun 3 I l\ \ \ \ g I \ \ \ 2; | \ a i 5 I I um I 1 I I m I 1 | . | . I, u n in w an to ion stun zanuzsnumn n 10 n so TEMPERATURE - °E l WEIIENT - LBS NEAUWINUI- "EN 69040] SECTION IV COMANCHE “C” m3 . 52; $23 oaNn ===n ==°N ==¢N ==.N 5 5:2 £5ng $93 m» 35m ©2335 U mIUZ<EOU OON|¢N|<m gen“ ==eu IIdYI ' Ullds DNI'ITYLS 43 69040I SECTION IV COMANCHE “C" PA-24-260 COMANCHE C AERSPEW CAMIIRM'TOIN smut"! sum: $0000! anuss wneur ml LBS. LEVEL mam INDICATEDAIIISPEED - IAPII 00 100 120 140 100 100 200 220 CALIBRATED AIRSPEED - NPR 44 690401 COMANCHE “C” SECTION IV PA-24-260 COMANCHE C l | I I | I | I I I I — 10001100100 CONVERSUON CED/011111 i, nus cum SIIIIULD BE ustn m DETERMINE DENSITY muunt ___ mu EXISTING murmur: 7; AND PRESSURE ammo: murmurs 74 FOII us: 0110 ptnronmuct cunts. 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Eu ._< 5meii. nz< 2am .mmmE .z<znz< Ex .mmmE .zsz nz< 2.2 9.5... ._< 021 123. um“ Iazmz 123.ohmic: $_ 1.3: “an Imznz 5. 1.“ is... use.“ .=_ SN i533: 3.5: “5583 .. use... 2.5332:— 690401 46 COMANCHE “C" SECTION IV 690401 NOTES 47 SECTION V MAINTENANCE Tire Inflation . Battery Service Brake Service. . . Landing Gear Service . Fuel and Oil Requirements Leveling and Rigging . . . . . . Care of Air Filter Care of Windshield and Windows . Serial Number Plate Fuel System 690401 48 48 49 49 52 53 54 55 55 55 COMANCHE “C” SECTION V SECTION V MAINTENANCE This section of the Comanche “C” Handbook contains infor- mation which pertains to minor maintenance of the airplane. Any complex repair or modification should be accomplished by a Piper Service Center or equivalent. TIRE INFLATION For maximum service keep the tires inflated to the proper pressure of 42 lbs. on the main wheels and 27 lbs. on the nose wheel. Interchange the tires on the main wheels if necessary to produce even wear. All wheels and tires are balanced before original installation, and the relationship of tire, tube and wheel should be maintained whenever possible upon reinstallation. Out of balance wheels can cause extreme vibration in the landing gear during take-off. In the installation of new components, it may be necessary to rebalance the wheels with the tires mounted. BATTERY SERVICE Access to the 12 volt 35 ampere hour battery is through the access panel in the baggage compartment. The battery should be checked frequently for proper fluid level, but must not be filled above the baffle plates. All con- 690401 43 SECTION V COMANCHE “C" nections must be clean and tight. The battery and battery box should be removed periodically and checked for corrosion. Corrosion effects may be neutralized by applying a solution of baking soda and water, allowing no soda solution to enter the battery. Wash battery and box with clean water and dry. If the battery is not up to proper charge, recharge starting with a charging rate of 4 amps and finishing with 2 amps. Quick charges are not recommended. BRAKE SERVICE The brake system is filled with MIL-H-5606 (petroleum base) hydraulic brake fluid. This should be checked at every 50 hour inspection and replenished when necessary, refilling the brake reservoir on the firewall to the indicated level. No adjustment of brake clearances is necessary. If after extended service the brake blocks become worn excessively, they are easily replaced with new brake segments. To remove the brake disc, lining and backing plate, remove the four bolts through the brake housing, then the main wheels are easily removed by taking off the axle nut and withdrawing the wheel from the axle. Tires are dismounted from the wheels by deflating the tube, then removing the wheel through-bolts, allowingthe wheel halves to be separated. LANDING GEAR SERVICE In jacking the aircraftfor landing gear and other service,two hydraulic jacks and a tail support should be used. Approximately 49 69040] COMANCHE “C" IIIIIJIS lIIlfllIiAIII nunnER mNEEsAND «mu m v manner mm TA! mo manner mu nscmmsu KM mmuvoa cmucr MILLEVS aAWAGE noou AND m mu noon umurs Amwmms mmsmnammux m FLAPIELLCRNKA mcnuunLEn muss. um am now, me |EACN rum wows cm musFumes m bug“nun LE", mm mm mums mm Am err W“ unnms rrAn ARI! vLAP YIMSHLBIWS m (is:"are n uNan GEAR AND FLAP mmsmssxw screw m (see More 7) ensure mL in», A w m “ sn GEE “ME 11 III)!“ I. mmmum Am vLAruAmnrsvm. AND mm mums:DlunEMlu Am crmmnrn "Assn-um“mum-m, nLL mm |.IJI ruralinfi E‘Aumx! vvrrmr num- mumm:mum nun-mm mu m mm rectumm! {trim"siv'v’m"?mmLFauna5mmArm-xx Av run or mm m g? mo. ,. mun nmmnn. m mum:- AND mu: n uv, no Au mumin 69040] mums mum nIL mm:m -r lac-min As Am A; um on mum more“? or in ma mum Ann nun: mum.mu m Putnam muncnm on Arm vnrrnvlu mmu; mum nu ma- nun. Arm Gun!muuw mum Ann nus-um.mm mm"mm mm mmmm mun-mum (mm Am mm- Yo CHAN mmam out mu cwnsrssn All rmmm m! n! mu on!!! ,AN n r m Awn Fuv uAAsuusm’us, Ann mm mmuu-E chAn Am Amv A comm [LUQIUCATIKQN CHANT C©MIANCIHIE “C" lfilll “Mr. Lumen m w .. Am vmr 8A! in ummAll r m chnulmi mum luxrnucnmfl no. mu m In: all nlmwm 0er GIEAIEJIICIAFV. lair-want mu M Amman rem mum mL-alNllAI. mm:m Mums“ num-Lumurlm mm mar-Arm urn-Ann: mun mm W mm» mm, up SECTION V [LUEEIEDCATDGDN CHAN C©MANCWE“C" mm mm, AvAcAAn, nun-rum, on!An AzmAm mu- LmchNT nnurs V STABILATUII mu mo PULLEYS V m cnnrorroLuun MAKE rsssnvmn, so uAmAm FLIIID LEVEL mmmzn an m:smE or nzsslvuln no annual PEDAL mu mu “5va m SEAT Aniumsurs um um: wnEzL 515mm: mwcrlofi An nusn or:«are A) muPELLEn «was: mo rumor, 1NHL or! NOTE A) me me GEAR rum mefi. 5 HTML Wm AND Lam m 132” um cmmr M mm mm cums FIYTINES, s YIflAL m not: wear sums m muses—nus! IHHL noon, 2 Wm O 0 v 0 I: P V nmAmnu ruxmuLL ‘W non sun Flmm‘. ) new mAmrn-munw mun vlwnmlu r/ ”bum mummrmmrm tmflrullllcflm D 0 anyone rulln run) m “(Weinvite mmucvnm no. mu m us: av unnam an. |. no nor m Ann-Aw: mun Inn Arum m w um .An. 2. no new WEI-I- mwz vrnmALcm-«m. r. on NB! Amy ancm w mm um. 1. mm ALL Excrrsflrue mucum: "mm. 50/51 COMANCHE “C" SECTION V 300 lbs. of ballast should be placed on the base of the tail support before jacking up the airplane. Landing gear oleos should be serviced according to instruc- tions on the units. Under static load the main oleos should show about 2-1/2 inches extension while the nose should be extended 2-3/4 inches. To add air to the oleo struts, a strut pump is attached at the air valve and the oleo pumped up to the proper position. To add oil, jack the aircraft, release the air through the strut valve and allow the strut to extend fully. Next remove the air valve and fill the unit through this opening. Then compress the oleo to full compression allowing air and excess oil to escape. Then reinsert the valve core and pump up the strut. FUEL AND OIL REQUIREMENTS Aviation Grade 91/96 Octane (minimum) fuel must be used, for the use of lower grades of fuel can cause serious engine damage in a very shortperiod of time. This is considered of such importance that the engine warranty is invalidated by such use. The oil capacity of the Lycoming IO—540-N is 12 quarts and the minimum safe quantity 2-3/4 quarts. The operating oil level is normally kept a quart or more below the maximum to reduce oil consumption. It is recommended that engine oil be changed every 50 hours or sooner under unfavorable conditions. 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 69040I 52 SECTION V COMANCHE “C" LEVELING AND RIGGING Leveling for purposes of reweighing or rigging is accom- plished as follows: 1. Partially withdraw the two machine screws on the side of the fuselage located one fore and one aft of the right rear window. These screws are leveling points and the airplane is longitudinally level when a level placed on the head of these screws indicates level. 2. To put the airplane in a longitudinally level position on scales, first block the main gear oleos to full extension, then deflate the nose wheel tire until the proper position is reached. For rigging purposes place airplane on jacks. 3. To level the airplane laterally, place a level on or par- allel to the hat section channel of the firewall. (Even length spacers may be used to bring the level above any obstacles in the area of the channel.) Rigging: Although the fixed flight surfaces cannot be ad- justed in position for rigging purposes, it may be necessary on occasions to check the position of these surfaces. The movable surfaces all have adjustable stops as well as adjustments on LongitudinnIIy Leveling LuteraIIy LeveIing 53 690401 COMANCHE “C" SECTION V their cables or push-pull connections so that their range of move- ment can be altered. The positions and travels of the various surfaces are as follows: 1. Wings: 5° dihedral, no twist. 2. Stabilator: No dihedral, trailingedge travel 14° tl° up, 4° fl“ down. . Fin: Vertical and in line with center of fuselage. . Ailerons: Travel 19° i2° up, 15° i2° doWn. Flaps: Travel 32° i1° full down. . Rudder: Travel 25° left or right, t2°. . Horizontal Tail Tab Travel: 7° tl“ up, 15“l il" down. Stabilator Tab Ratio. 1‘/z:l For purposes of changing the lateral trim, fixed tabs are provided on the ailerons which can be adjusted as necessary. ooqmgndaw CARE OF AIR FILTER The induction air filter must be cleaned at least once every fifty hours and depending on the type of condition existing, it may be necessary to clean the filters daily or every (5) five hours. The following cleaning procedure is recommended by the manufacturer of the filter: a. Blow compressed air through the filter, in the opposite direction of normal airflow. b. To prevent damage to the filter, use less than 100 psi, and keep the nozzle at least one inch away from the filter. c. Blow air through the filter until no more dust is being removed. The filter is now ready to be inspected. For further instructions on cleaning see current PA—24 Service Manual. 690401 54 SECTION V COMANCHE “C” I CARE OF WINDSHIELD AND WINDOWS A certain amount of care is required to keep the plexiglas windows clean and clear. The following procedure is recom- mended: 1. Flush with clean water and dislodge excess dirt, mud, etc., with your hand. 2. Wash with mild soap and warm water. Use a soft cloth or sponge. Do not rub. 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 scratchor mar canbe removed byusingjeweler’s rouge to rub out scratch, smooth on both sides and apply wax. SERIAL NUMBER PLATE The serial number plate is located on the firewall. The serial number of the plane should always be used in referring to the airplane in service or warranty matters. FUEL SYSTEM The fuel screens in the strainer, the injector screen and fuel nozzles will require cleaning at the first 25 hour inspection and every 50 hour inspection thereafter. The screen in the injector is located in the housing where the fuel inlet line connects to the injector. The fuel strainer located under the floorboards is ac- cessible for cleaning through an access plate on the bottom of 55 69040] COMANCHE “C” SECTION V the fuselage. When reassembling the strainer after cleaning, a Small amount of grease applied to the gasket will facilitate assembly. Acetone is recommended for cleaning these screens. 690401 56 SECTION I Specifications: . Performance . Weights Power Plant . Fuel Baggage Dimensions Landing Gear SECTION II Design Information: INDEX Engine and Propeller . Induction System Structures . Landing Gear Control System . Fuel System . Electrical System . Heating and Ventilating System. Vacuum System . Instrument Panel Seats Baggage Area Finish . SECTION III Operating Instructions: Pref light . Starting Engine . . Warm—Up and Ground Check . Take-Off. 69040I Page WwNNMNr—‘H NNHHHHHHoooflqmwowflqmmm INDEX (cont) SECTIONIH konfl. Page Climb . . . . . . . . . . . . . . 26 Cruising . . . . . . . . . . . . . . 27 Stalls . . . . . . . . . . . . . . . 28 Spins . . . . . . . . . . . 28 Approach andLanding . . . . . . . . . 28 Stopping Engine. . . . . . . . . . . . 29 Emergecny Procedures. . . . . . . . . . 30 Mooring . . . . . . . . . . . . . . 32 Operating Tips . . . . . . . . . . . . 32 Radio Operation . . . . . . . . . . . . 34 SECTIONIV Performance Charts: . . . . . 35 Take-off Distance Over 50 FootBarrier . . . . 3S Take-off Ground Run Distance . . . . . 36 Speed for Best Rate and Angle of Climb. . . . 37 Climb Rate vs Standard Altitude and Weight. . . 38 True Airspeed vs Altitude . . . . . . . 39 Range vs Standard Altitude . . . . . . . . 40 Landing Distance Over 50 Foot Barrier . . . . . 41 Landing Ground Roll . . . . . . . . . . 42 Stalling Speed vs Gross Weight . . . . . . . 43 Airspeed Calibration Chart . . . . . . . . 44 Altitude Conversion Chart . . . . . 45 Power Setting Table, Lycoming IO-540-N . . . 46 SECTION V Maintenance: . . . . . . . . . . . . . 48 Tire Inflation. . . . . . . . . . . . . 48 Battery Service . . . . . . . . . . . . 48 Brake Service . . . . . . . . . . . . 49 679040I INDEX (cont) SECTION V (cont) Page Landing Gear Service . . . . . . . . . 49 Fuel and Oil Requirements . . . . . . . . 52 Leveling and Rigging . . . . . . . . . . 53 Care of Air Filter . . . . . . . . . . . 54 Care of Windshield and Windows . . . . . . 55 Serial Number Plate . . . . . . . . . . 55 FuelSystem . . . . . . . . . . . . . 55 69040I