C172F POH.pdf - Monticello Flying Club

Check baggage door for security. f. Make visual check to insure that to strainer drain valve is closed after draining, operation. Check carburetor an alter or restrictions. by dust or other foreign matter. (2) Remove rudder gust lock, if installed. 2. b. Disconnect tail tie-down. 3 1. Check main wheel tire for proper inflation. Inspect airspeed static source hole on side of 1. fuselage for stoppage (left side only). Disconnect wing tie-down. 5 .t. D. Remove pitit tribe cover it installed, and check pitol tabe operum for stoppage. Check fuel tank vent opemme for stoppage. BEFORE ENTERING THE AIRPLANE. (1) Make an exterior inspection in accordance with figure 1-1. 0 Same as 3 Figure 1-1. BEFORE STARTING THE ENGINE. (1) Seats and Seat Belts Adjust and lock. (2) Brakes -- Test and set. (3) Master Switch (4) Fuel Selector "ON. 11 "BOTH ON. " 1-1 STARTING THE ENGINE. (1) Carburetor Heat -- Cold. (2) Mixture -- Rich. Primer -- As required. (4) Ignition Switch -- "BOTH." " (5) Throttle Open 1/8". (6) Propeller Area -- Clear. (7) Starter -- Engage. -- (3) Brakes (4) Power -- (5) Brakes (6) Apply. Full throttle. Release. Elevator Control (7) Climb Speed -- Slightly tail low. 65 MPH (with obstacles ahead). BEFORE TAKE-OFF. Within green arc and generator light out. (3) Magnetos Check (75 RPM maximum differential between mag- (1) Throttle Setting -- 1600 RPM. (2) Engine Instruments -- netos). (4) Carburetor Heat -- Check. (5) Flight Controls (6) Trim Tab -- -- Check. "TAKE-OFF" setting. -- Cabin Doors Closed and locked. (8) Flight Instruments and Radios Set. CLIMB. NORMAL CLIMB. (1) Airspeed (2) Power - (3) Mixture 80 to 90 MPH. Full throttle. Full rich (unless engine is rough). MAXIMUM PERFORMANCE CLIMB. (1) Airspeed -- 80 MPH at sea level to 77 MPH at 10,000 feet. (2) Power - Full throttle. (3) Mixture Full rich (unless engine is rough). -- TAKE-OFF. NORMAL TAKE-OFF. Carburetor Heat Cold. Full throttle (applied smoothly). (1) Wing Flaps 0° (2) (3) Power -- (4) Elevator Control (5) Climb Speed -- -- Lift nosewheel at 60 MPH. 85 MPH. MAXIMUM PERFORMANCE TAKE-OFF. -- 0° (1) Wing Flaps Carburetor Heat (2) -- Cold. CRUISING. (1) Power -- (3) Trim Tab Mixture -- 2200 to 2700 RPM. Adjust. Lean. LET-DOWN. (1) Mixture -- Rich. (2) Power -- As desired. (3) Carburetor Heat As required to prevent carburetor icing. 1-3 BEFORE LANDING. (1) Fuel Selector -- "BOTH ON." 2) Mixture -- Rich. (3) (4) -- (5) (6) Airspeed -- Airspeed -- 70-80 MPH (flaps up). Carburetor Heat · Apply before closing throttle. Wing Flaps -- As desired (below 100 MPH). 65 to 75 MPH (flaps down). Section 172 II DESCRIPTION AND OPERATING DETAILS NORMAL LANDING. (1) (2) Touchdown Landing Roll (3) Braking -- Main wheels first. -- Lower nosewheel gently. Minimum required. The following paragraphs describe the systems and equipment whose function and operation is not obvious when sitting in the airplane. This section also covers in somewhat greater detail some of the items listed in Check List form in Section I that require further explanation. AFTER LANDING. (1) Wing Flaps - Up (2) Carburetor Heat Cold. SECURE AIRCRAFT. | 1 (1) (2) (3) Mixture -- Full lean. All Switches Off. Brakes Set. -- (4) Control Lock Installed. FUEL SYSTEM. Fuel is supplied to the engine from two aluminum tanks, one in each wing. From these tanks, fuel flows by gravity through a selector valve and a strainer to the carburetor. Refer to figure 2-1 for fuel quantity data. For fuel system servicing information, refer to Lubrication and Servicing Procedures in Section IV. FUEL QUANTITY DATA (U.S. GALLONS) TOTAL TANKS USABLE FUEL NO. ALL FLIGHT CONDITIONS ADDITIONAL USABLE FUEL (LEVEL FLIGHT) UNUSABLE FUEL (LEVEL FLIGHT) FUEL VOLUME EACH LEFT WING 1 18.0 gal. 1.0 gal. 0.5 gal. RIGHT WING 1 18.0 gal. 1.0 gal. 0.5 gal. 19.5 gal. 19.5 gal. Figure 2-1 2-1 LEFT FUEL TANK RIGHT FUEL TANK TO ENGINE ENGINE PRIMER SELECTOR VALVE FUEL STRAINER DRAIN KNOB. Refer to fuel strainer servicing procedures, Section IV. FUEL STRAINER THROTTLE MIXTURE CONTROL KNOB ELECTRICAL SYSTEM. Electrical energy is supplied by a 14-volt, direct-current system the left-hand forward portion of the firewall. powered by an engine-driven generator. A 12-volt battery is located on CIRCUIT BREAKERS. All electrical circuits in the airplane, except the clock circuit, are protected by circuit breakers. The clock has a separate fuse mounted adjacent to the battery. The stall warning transmitter and horn circuit and turn-and-bank indicator circuit are protected by a single automati- cally resetting circuit breaker mounted behind the instrument panel. the instrument panel. The remaining circuits are protected by "push-to-reset" breakers on GENERATOR WARNING LIGHT. The red generator warning light indicates generator output. The light remains off as long as the generator functions properly. If a mal- function interrupts generator output, the light will illuminate. It also will illuminate when the battery or external power is on, before starting the engine, and whenever engine speed is insufficient to produce gen- erator output. The light does not show battery drain. LANDING LIGHTS (OPT). A three-position, push-pull switch controls the optional landing lights. To turn one lamp on for taxiing, pull the switch out to the first ond stop. stop. To turn both lamps on for landing, pull the switch out to the sec- ROTATING BEACON (OPT). The rotating beacon should not be used when flying through clouds or overcast: the moving beams reflected from water droplets or particles in the atmosphere, particularly at night, can produce vertigo and loss of orientation. FUEL SYSTEM CARBURETOR .. SCHEMATIC ΤΟ ENGINE Figure 2-2. 2-3 CABIN HEATING AND VENTILATION SYSTEM. For cabin ventilation, pull the "CABIN AIR" knob out. To raise the air temperature, pull the "CABIN HT" knob out approximately 1/4" to 1/2" for a small amount of cabin heat. Additional heat is available by pulling the knob out farther; maximum heat is available with the "CABIN HT" knob pulled full out and the "CABIN AIR" knob pushed full in. When no heat is desired in the cabin, the "CABIN HT" knob is pushed full in. Front cabin heat and ventilating air is supplied by outlet holes spaced across a cabin manifold just forward of the pilot's and copilot's feet. Rear cabin heat and air is supplied by two ducts from the manifold, one extend- ing down each side of the cabin. Windshield defrost air is also supplied by a duct leading from the cabin manifold. Separate adjustable ventilators supply additional air; one near each upper corner of the windshield supplies air for the pilot and copilot, and two optional ventilators in the rear cabin ceiling supply air to the rear seat passengers. TAXIING DIAGRAM USE UP AILERON ON LH WING AND NEUTRAL ELEVATOR USE UP AILERON ON RH WING AND NEUTRAL ELEVATOR STARTING ENGINE. Ordinarily the engine starts easily with one or two strokes of the primer in warm temperatures to six strokes in cold weather, with the throttle open approximately 1/8 inch. In extremely cold temperatures, it may be necessary to continue priming while cranking. Weak intermittent explosions followed by puffs of black smoke from the exhaust stack indicates overpriming or flooding. Excess fuel can be cleared from the combustion chambers by the following procedure: Set the mixture control full lean and the throttle full open: then crank the engine through several revolutions with the starter. Repeat the start- ing procedure without any additional priming. If the engine is underprimed (most likely in cold weather with a cold engine) it will not fire at all, and additional priming will be necessary. As soon as the cylinders begin to fire, open the throttle slightly to keep it running. After starting, if the oil gage does not begin to show pressure within 30 seconds in the summertime and about twice that long in very cold weather, stop engine and investigate. Lack of oil pressure can cause CODE USE DOWN AILERON ON LH WING AND DOWN ELEVATOR WIND DIRECTION USE DOWN AILERON ON RH WING AND DOWN ELEVATOR NOTE Strong quartering tail winds require caution. Avoid sudden bursts of the throttle and sharp braking when the airplane is in this attitude. Use the steerable nose wheel and rudder to maintain direction. Figure 2-3. 2 4 2-5 serious engine damage. After starting, avoid the use of carburetor heat unless icing conditions prevail. TAXIING. When taxiing, it is important that speed and use of brakes be held to a minimum and that all controls be utilized (see taxiing diagram, figure 2-3) to maintain directional control and balance. Taxiing over loose gravel or cinders should be done at low engine speed to avoid abrasion and stone damage to the propeller tips. BEFORE TAKE-OFF. WARM-UP. Since the engine is closely cowled for efficient in-flight engine cool- ing, precautions should be taken to avoid overheating during prolonged engine operation on the ground. MAGNETO CHECK. The magneto check should be made at 1600 RPM as follows: Move the ignition switch first to "R" position, and note RPM. Next move the switch back to "BOTH" position to clear the other set of plugs. Then move the switch to the "L" position and note RPM. The difference be- tween the two magnetos operated individually should not be more than 75 RPM. HIGH RPM MAGNETO CHECKS. If there is a doubt concerning the operation of the ignition system, RPM checks at higher engine speeds will usually confirm whether a de- ficiency exists. If a full throttle runup is necessary, the engine should run smoothly and turn approximately 2230 to 2330 RPM with the carbu- refor heat off. An absence of RPM drop may be an indication of faulty grounding of one side of the ignition system or should be cause for suspicion that the peto timing has been "bumped-up" and is set in advance of the set- fine specified. ין,יו! TAKE-OFF. POWER CHECK. It is important to check full-throttle engine operation early in the take-off run. Any signs of rough engine operation or sluggish engine acceleration is good cause for discontinuing the take-off. If this occurs, you are justified in making a thorough full-throttle, static runup before another take-off is attempted. Full-throttle runups over loose gravel are especially harmful to pro- peller tips. When take-offs must be made over a gravel surface, it is very important that the throttle be advanced slowly. This allows the air- plane to start rolling before high RPM is developed, and the gravel will be blown back of the propeller rather than pulled into it. When unavoid- able small dents appear in the propeller blades, they should be inımedi- ately corrected as described in Section IV under propeller care. Prior to take-off from fields above 5000 feet elevation, the mixture should be leaned to give maximum RPM in a full-throttle, static runup. WING FLAP SETTINGS. Normal and obstacle clearance take-offs are performed with wing flaps up. The use of 10° flaps will shorten the ground run approximately 10%, but this advantage is lost in the climb to a 50-foot obstacle. There- fore, the use of 10° flap is reserved for minimum ground runs or for take- off from soft or rough fields with no obstacles ahead. If 10 of flaps are used in ground runs, it is preferable to leave them extended rather than retract them in the climb to the obstacle. The ex- ception to this rule would be in a high altitude take-off in hot weather where climb would be marginal with flaps 10°. Flap deflections of 30° to 40° are not recommended at any time for take-off. PERFORMANCE CHARTS. Consult the take-off chart in Section V for take-off distances under various gross weight, altitude, and headwind conditions. 2-7 CROSSWIND TAKE-OFFS. Take-offs into strong crosswinds normally are performed with the minimum flap setting necessary for the field length, to minimize the drift angle immediately after take-off. The airplane is accelerated to a speed slightly higher than normal, then pulled off abruptly to prevent possible settling back to the runway while drifting. When clear of the ground, make a coordinated turn into the wind to correct for drift. settings required to obtain these powers at various altitudes and outside air temperatures can be determined by using your Cessna Power Computer. Cruising can be done most efficiently at high altitudes because of lower air density and therefore lower airplane drag. This is illustrated in the following table which shows performance at 75% power at various altitudes. CLIMB. CLIMB DATA. For detailed data, refer to the Maximum Rate-of-Climb Data chart in Section V. CLIMB SPEEDS. Normal climbs are performed at 80 to 90 MPH with flaps up and full throttle for best engine cooling. The mixture should be full rich unless the engine is rough due to too rich a mixture. The best rate-of-climb speeds range from 80 MPH at sea level to 77 MPH at 10,000 feet. If an obstacle dictates the use of a steep climb angle, the best angle-of- climb speed should be used with flaps up and full throttle. These speeds vary from 65 MPH at sea level to 71 MPH at 10,000 feet. NOTE Steep climbs at these low speeds should be of short duration to improve engine cooling. GO-AROUND CLIMB. In a balked landing (go-around) climb, the wing flap setting should be reduced to 20° immediately after full power is applied. Upon reach- ing a safe airspeed, the flaps should be slowly retracted to the full up position. OPTIMUM CRUISE PERFORMANCE ALTITUDE RPM TRUE AIRSPEED RANGE Sea Level 5000 ft. 7000 ft. 2450 123 520 2560 128 540 Full Throttle 130 550 All figures are based on lean mixture, 36 gallons of fuel (no re- serve), zero wind, standard atmospheric conditions, and 2300 pounds gross weight. STALLS. The stall characteristics are conventional and aural warning is pro- vided by a stall warning horn which sounds between 5 and 10 MPH above the stall in all configurations. Power-off stall speeds at maximum gross weight and aft c.g. con- dition are presented on page 5-2 as calibrated airspeeds since indicated airspeeds are unreliable near the stall. CRUISE. Normal cruising is done between 65% and 75% power. The power 2-8 LANDING. Normal landings are made power-off with any flap setting. Slips are prohibited in full flap approaches because of a downward pitch en- countered under certain combinations of airspeed and sideslip angle. 2-9 SHORT FIELD LANDINGS. For a short field landing, make a power-off approach at approxi- mately 67 MPH with flaps 40°, and land on the main wheels first. Im- mediately after touchdown, lower the nose gear to the ground and apply heavy braking as required. Raising the flaps after landing will provide more efficient braking. CROSSWIND LANDINGS. When landing in a strong crosswind, use the minimum flap setting required for the field length. Use a wing-low. crab, or a combination method of drift correction and land in a nearly level attitude. Hold a straight course with the steerable nosewheel and occasional braking if necessary. COLD WEATHER OPERATION. Prior to starting on cold morning, it is advisable to pull the pro- peller through several times by hand to "break loose" or "limber" the oil, thus conserving battery energy. In extremely cold (0°F and lower) weather, the use of an external preheater for both the engine and battery is recommended whenever possible to reduce wear and abuse to the engine and the electrical system. When using an external power source, the position of the master switch is important. Refer to Section VI, GROUND SERVICE PLUG RECEPTACLE, for operating details. Cold weather starting procedures are as follows: With Preheat: (1) Clear propeller. Without Preheat: (1) Prime the engine 8 to 10 strokes while the propeller is being turned by hand. (2) Clear propeller. (3) Pull master switch "ON. (4) ་་ Turn magneto switch to "BOTH." (5) Open throttle 1/4". (6) (7) Pull carburetor air heat knob full on. Engage starter and continue to prime engine until it is run- ning smoothly. (8) Keep carburetor heat on until engine has warmed up. NOTE If the engine does not start the first time, it is probable that the spark plugs have been frosted over. Preheat must be used before another start is attempted. During cold weather operations, no indication will be apparent on the oil temperature gage prior to take-off if outside air temperatures are very cold. After a suitable warm-up period (2 to 5 minutes at 1000 RPM), accelerate the engine several times to higher engine RPM. If the engine accelerates smoothly and the oil pressure remains normal and steady, the airplane is ready for take-off. When operating in sub-zero temperature, avoid using partial car- buretor heat. Partial heat may increase the carburetor air tempera- ture to the 32° to 80°F range, where icing is critical under certain atmos- pheric conditions. Refer to Section VI for cold weather equipment. 2 10 (2) Pull master switch "ON. 11 (3) With magneto switch "OFF" and throttle closed, prime the engine four to ten strokes as the engine is being turned over. NOTE Use heavy strokes of primer for best atomization of fuel. After priming, push primer all the way in and turn to locked position to avoid possibility of engine drawing fuel through the primer. " (4) Turn magneto switch to "BOTH. (5) Open throttle 1/4" and engage starter. 2-11 172 MODIFIED FUEL MANAGEMENT PROCEDURES With a combination of highly volatile fuel, high fuel temperature, high operating altitude, and low fuel flow rate in the tank outlet lines, there is a remote possibility of accumulating fuel vapor and encountering power ir- regularities on some airplanes. To minimize this possibility, the follow- ing operating procedures are recommended: (1) Take-off and climb to cruise altitude on "both" tanks. (This is consistent with current recommendations.) (2) When reaching cruise altitude above 5000 feet MSL, promptly switch the fuel selector valve from "both" tanks to either the "right" or "left" tank. (3) During cruise, use "left" and "right" tank as required. (4) Select "both" tanks for landing as currently recommended. POWER RECOVERY TECHNIQUES In the remote event that vapor is present in sufficient amounts to cause a power irregularity, the following power recovery techniques should be followed: OPERATION ON A SINGLE TANK Should power irregularities occur when operating on a single tank, power can be restored immediately by switching to the opposite tank. In addition, the vapor accumulation in the tank on which the power irregu- larity occurred will rapidly dissipate itself such that that tank will also be available for normal operation after it has been unused for approximately one (1) minute. OPERATION ON BOTH TANKS Should power irregularities occur with the fuel selector on both tanks, the following steps are to be taken to restore power: (1) Switch to a single tank for a period of 60 seconds. (2) Then switch to the opposite tank and power will be restored. Section OPERATING LIMITATIONS OPERATIONS AUTHORIZED. Your Cessna exceeds the requirements of airworthiness as set forth by the United States Government, and is certificated under FAA Type Cer- tificate No. 3A12 as Cessna Model No. 172F. With standard equipment, the airplane is approved for day and night operations under VFR. Additional optional equipment is available to in- crease its utility and to make it authorized for use under IFR day and night. An owner of a properly equipped Cessna is eligible to obtain ap- proval for its operation on single-engine scheduled airline service under VFR. Your Cessna Dealer will be happy to assist you in selecting equip- ment best suited to your needs. MANEUVERS - NORMAL CATEGORY. The airplane exceeds the requirements for airworthiness of the Fed- eral Air Regulations, Part 3, set forth by the United States Government. Spins and aerobatic maneuvers are not permitted in normal category air- planes in compliance with these regulations. In connection with the fore- going, the following gross weights and flight load factors apply: Gross Weight Flight Load Factor *Flaps Up Flight Load Factor *Flaps Down 2300 lbs. +3.8 -1.52 +3.5 *The design load factors are 150% of the above, and in all cases, the structure meets or exceeds design loads. Your airplane must be operated in accordance with all FAA approved markings, placards and check lists in the airplane. If there is any infor- mation in this section which contradicts the FAA approved markings, pla- cards and check lists, it is to be disregarded. 2-12 3-1 3-4 WEIGHT AND BALANCE. The following information will enable you to operate your Cessna within the prescribed weight and center of gravity limitations. To figure the weight and balance for your particular airplane, use the Sample Problem, Loading Graph, and Center of Gravity Moment Envelope as follows: Take the licensed Empty Weight and Moment/1000 from the Weight and Balance Data sheet, plus any changes noted on forms FAA-337, carried in your airplane, and write them down in the proper columns. Using the Loading Graph, determine the moment/1000 of each item to be carried. Total the weights and moments/1000 and use the Center of Gravity Moment Envelope to determine whether the point falls within the envelope, and if the loading is acceptable. 172 Sample Airplane SAMPLE LOADING PROBLEM Weight Moment (lbs) (lb-ins. Your Airplane Weight Moment /1000) 1. Licensed Empty Weight (Sample Airplane) ... 1324 48.2 2. Oil- 8 Qts.* 3. Pilot & Frant Passenger 4. Fuel (36 Gal at 6 #3 /Gal) 15 -0.3 15 -0.3 340 12.2 216 10.4 5. Rear Passengers...…………… 340 23.8 6. Baggage (or Passenger an Auxiliary Seat) 65 6.2 7. Tatal Aircraft Weight (Loaded) 2300 100.5 8. Locate this point (2300 at 100.5) an the center of gravity envelope, and since this point falls within the envelope the loading is acceptable. *Note: Normally full oil may be assumed for all flights. LOADING GRAPH 320 280 240 36 GAL. (MAX.) 200 30 GAL. 160 120 120 0 20 GAL. 10 GAL. 13 CODE PILOT (36 GAL. MAX. @ 6#/GAL. ) REAR PASSENGERS AND FRONT PASSENGER FUEL BAGGAGE or Passenger on Auxiliary Seat (120% MAX. ) 19 15 -2 0 2 4 6 8 10 12 14 16 18 20 22 7 5 I- 6 11 13 17 MOMENT/1000 ( POUND - INCHES) 21 24 23 25 29 26 28 30 27 (SⱭNnod) PHOTO 3-5 3-6 2300 CENTER OF GRAVITY MOMENT ENVELOPE 2200 2100 2000 1900 (SⱭNNO) LED LED A 1800 1700 1600 АНОНІ 1500 45 50 55 NORMAL CATEGORY 08 85 90 95 100 105 110 LOADED AIRCRAFT MOMENT/1000 (POUND-INCHES) 09 65 70 75 ection CARE OF THE AIRPLANE 172 If your airplane is to retain that new plane performance and depend- ability, certain inspection and maintenance requirements must be followed. It is wise to follow a planned schedule of lubrication and preventative main- tenance based on climatic and flying conditions encountered in your locality. Keep in touch with your Cessna Dealer and take advantage of his know- ledge and experience. He knows your airplane and how to maintain it. He will remind you when lubrications and oil changes are necessary, and about other seasonal and periodic services. GROUND HANDLING. The airplane is most easily and safely maneuvered by hand with the tow-bar attached to the nosewheel. NOTE When using the tow-bar, never exceed the turning angle of 30. either side of center, or damage to the gear will result. MOORING YOUR AIRPLANE. Proper tie-down procedure is your best precaution against damage to your parked airplane by gusty or strong winds. To tie-down your air- plane securely, proceed as follows: (1) Set the parking brake and install the control wheel lock. (2) Tie sufficiently strong ropes or chains (700 pounds tensile strength) to wing, tail, and nose tie-down fittings and secure each rope to a ramp tie-down. 4-1 (3) Install a surface control lock over the fin and rudder. (4) Install a pitot tube cover. WINDSHIELD-WINDOWS. The plastic windshield and windows should be kept clean and waxed at all times. To prevent scratches and crazing, wash them carefully with plenty of soap and water, using the palm of the hand to feel and dislodge dirt and mud. A soft cloth, chamois or sponge may be used, but only to carry water to the surface. Rinse thoroughly, then dry with a clean, moist chamois. Rubbing the surface of the plastic with a dry cloth builds up an electrostatic charge so that it attracts dust particles in the air. Wiping with a moist chamois will remove both the dust and this charge. Remove oil and grease with a cloth moistened with kerosene. Never use gasoline, benzine, alcohol, acetone, carbon tetrachloride, fire ex- tinguisher or anti-ice fluid, lacquer thinner or glass cleaner. These materials will soften the plastic and may cause it to craze. After removing dirt and grease, if the surface is not badly scratched, it should be waxed with a good grade of commercial wax. The wax will fill in minor scratches and help prevent further scratching. Apply a thin, even coat of wax, and bring it to a high polish by rubbing lightly with a clean, dry, soft flannel cloth. Do not use a power buffer; the heat gen- erated by the buffing pad may soften the plastic. Do not use a canvas cover on the windshield unless freezing rain or sleet is anticipated. Canvas covers may scratch the plastic surface. PAINTED SURFACES. The painted exterior surfaces of your new Cessna require an initial curing period which may be as long as 90 days after the finish is applied. During this curing period some precautions should be taken to avoid dam- aging the finish or interfering with the curing process. The finish should be cleaned only by washing with clean water and mild soap, followed by a rinse with water and drying with cloths or a chamois. Do not use polish or wax, which would exclude air from the surface, during this 90-day curing period. Do not rub or buff the finish, and avoid flying through rain. hail or sleet. 4-2 Once the finish has cured completely, it may be waxed with a good automotive wax. A heavier coating of wax on the leading edges of the wings and tail and on the engine nose cap and propeller spinner will help reduce the abrasion encountered in these areas. ALUMINUM SURFACES. The clad aluminum surfaces of your Cessna may be washed with clear water to remove dirt; oil and grease may be removed with gasoline, naptha, carbon tetrachloride or other non-alkaline solvents. Dulled alu- minum surfaces may be cleaned effectively with an aircraft aluminum polish. After cleaning, and periodically thereafter, waxing with a good auto- motive wax will preserve the bright appearance and retard corrosion. Regular waxing is especially recommended for airplanes operated in salt water areas as a protection against corrosion. PROPELLER CARE. Preflight inspection of propeller blades for nicks, and wiping them occasionally with an oily cloth to clean off grass and bug stains will as- sure long, trouble-free service. It is vital that small nicks on the pro- pellers, particularly near the tips and on the leading edges, are dressed out as soon as possible since these nicks produce stress concentrations, and if ignored, may result in cracks. Never use an alkaline cleaner on the blades; remove grease and dirt with carbon tetrachloride or Stoddard solvent. INTERIOR CARE. To remove dust and loose dirt from the upholstery and carpet, clean the interior regularly with a vacuum cleaner. Blot up any spilled liquid promptly, with cleansing tissue or rags. Don't pat the spot; press the blotting material firmly and hold it for sev- eral seconds. Continue blotting until no more liquid is taken up. Scrape off sticky materials with a dull knife, then spot-clean the area. Oily spots may be cleaned with household spot removers, used spar- ingly. Before using any solvent, read the instructions on the container 4-3