AC 43.13-1A CHG 1 1975 *ratio of eight parts detergent to 20 parts of alcohol. Add the detergent/alcohol mixture to 72 parts of tap water and mix thoroughly. For use, add one part of the foregoing concentrate to nine parts of tap water (warm water if available) and mix thoroughly.
(2) If the above specified detergent/alcohol materials are not available, use water emulsion cleaning compound (MIL-C-43613). Add one part compound to nine parts water. If the MIL cleaning compound is not available, use any available mild household detergent solution with fresh tap water.
b. Safety Precautions. The following safety precautions should be observed:
(1) Electrically ground the aircraft. Attach the ground lead to the aircraft at a point which is outside the area that could contain explosive vapors.
(2) If the landing gear of land planes is used as a supporting mechanism, install a spreader bar, jury strut, landing gear downlocks or other suitable devices to insure that the gear will not collapse. If the landing gear is not serviceable, insure that the aircraft is solidly supported to prevent hazardous movement.
(3) Disconnect and remove wet- and/or drycell batteries and isolate aircraft from all sources of electricity or other spark-producing devices.
Spark-producing static electricity is genernted at compressed air hose outlets, so this method should not be used for ventilating or purging fuel vapors.
(4) Remove all fuel, oil, and hydraulic fluid.
15) Flush all fuel and oil cells with clean fresh water.
(6) Deflate tires, especially on magnesium wheels. Depressurize landing genr struts, pneumatic systems, and hydraulic accumulators.
c. Reciprocating Engines and Propellers. The propeller should be removed from the engine and the engine from the aircraft. The exterior of the engine and propeller should be washed with stenm, or hot or cold fresh water.
The major accessories, engine parts, etc., should be removed and all surfaces flushed with fresh water, preferably hot. If facilities are available, the removed parts, size permitting, should be Chap 6 Page 128-1 immersed in hot water or hot oil, 180° F., for a short period of time. Soft water is preferred and should be changed frequently. All parts must be completely dried by air blast or other means. If no heat drying facility is available, wipe the cleaned parts with suitable drying cloths.
Constant speed propeller mechanism should be disassembled, as required, to permit complete decontamination. Clean parts with steam or hot or cold fresh water. Dry the cleaned parts in an oven, but if a heat drying facility is not available, wipe the cleaned parts with suitable drying cloths.
d. Gas Turbine, Turboprop and Turboshaft Engines. The engine exhaust shield, insulation blankets, separate exhaust collectors, compressor housing, pinion cowl and/or upper pinion housing should be removed. The engine accessories, outer housing exhaust shields, and other exposed parts should be steam cleaned. The steamcleaned parts should be dried in an oven at approximately 200° F., or with hot air from a portable engine heater, or with clean wiping cloths.
Immerse remainder of engine in 10-20 percent water solution of sodium dichromate, or hot, fresh water and apply sufficient agitation to provide complete flushing.
If immersion cannot be accomplished, flood the lower section of the compressor housing and thoroughly flush rotor blades with sodium dichromate solution or warm fresh water. Seal off combustion chamber openings and alternately fill and drain the combustion chamber with fresh water. Dry clean parts in an oven, or use dry air from a portable engine heater or wipe with suitable drying cloths.
e. Airframe. 'The salvageable components of the fuselage, wings, empennage, seaplane and amphibian hulls and floats, and movable surfaces should be processed as follows:
(1) The fabric from fabric-covered surfaces should be removed and replaced.
(2) The aircraft interior and exterior should be cleaned using steam under pressure with steam-cleaning compound. The steam should be directed into all seams and crevices where corrosive water may have penetrated. Avoid steam * Par 254
*cleaning electrical equipment, such as terminal boards and relays.
(3) Areas that have been steam cleaned should be rinsed immediately with either hot or cold fresh water.
(4) Touch up all scratches und scars on painted surfaces using zinc chromate primer or preservative.
(5) Undrained hollow spaces or fluid entrapment areas should be provided temporary draining facilities by drilling out rivets at lowest point. Install new rivets after drainnge.
(6) All leather, fabric upholstery, and insulation should be removed and replaced. Plastic or rubber foam which cannot be clenned of all corrosive water should be replaced.
(7) All drain plugs or drive screws in tubular struotures should be removed and the structure blown out with compressed air. If corrosive water has reached the tubular interiors, carefully flush with hot, fresh water and blow out water with compressed air. Roll the structure as necessary to remove water from pockets. Fill the tubes with hot linseed oil at upproximately 180° F. Drain oil and replace drain plugs or drive screws.
(8) Clean sealed wood, metalite, and other nonmetallic areas, excluding acrylic plastics, with warm water. Wood, metalite, and other porous materials exposed to water immersion should be replaced, unless surfaces are adequately sealed to prevent penetration by corrosive water. Virtually all solvents and phenolic type cleaning agents are detrimental to acrylics and will either soften the plastic or cause crazing.
f. Helicopter Rotor Dynamic Components.
(1) All evidence of corrosive water should be removed from the exterior of transmissions and gear boxes by flushing with clean hot or cold fresh water.
(2) Where it is possible that corrosive water has reached the interior of the transmission or gear boxes, remove plugs and/or covers and drain completely. Flush interior of part with hot or cold fresh water. Drain residual water, replace plugs and/or covers, and reapply proper lubricant.
g. Helicopter Blades. Except for blades with wooden or other nonmetallic constructions, treat Par 254 AC 43.13-1A CHG 1 1975 helicopter blades the same as propellers for reciprocating engines. Clean nonmetallie blades by hand, using warm water. Dry with wiping cloths or a warm air blast. When cleaning helicopter rotor blades, insure that nonsealed hollow members, such as the spars and blade pockets, are cleaned and dried.
h. Fuel and Oil Systems. Contaminated fuel and oil systems should be processed as follows:
(1) Flush oil system, inchiding lines, using water-displacing preservative.
(2) Open fuel systems. Purge cells and fuel lines. Check effectiveness of the purging with combustible gas indicator. Remove bladder and self-sealing type fuel cells and all cavity liners or pads.
(3) Use clean, fresh water to wash fuel cells.
After drying, spray interior walls with oil.
(4) Chemically treat bare metal surfaces of cleaned aluminum tanks with 10-20 percent water solution of sodium dichromate.
(5) Flush fuel lines with hot water (150° F.
maximum). Dry, using clean, dry, compressed air.
i. Landing Gear. Process salvageable components of the landing gear, wheels, and brakes as follows:
(1) Remove tires and wheels.
(2) Steam clean wheels, rinse in fresh water, and dry.
(3) Remove wheel bearings and clean, using dry cleaning solvent.
(4) Immerse bearings in methyl alcohol and dry the cleaned brarings in air blast. Do not permit bearings to rotate during air blast drying.
Reapply proper lubricant.
(5) Remove brakes, steam clean, and rinse with fresh water and dry.
j. Electrical Equipment.
(1) Wet cell batteries. The risk involved in using wet cell batteries that have been immersed in sea water may outweigh any economic advantage and should be replaced.
(2) Because of posable flight hazards and later defects caused by progressive corrosive attack, all electrical wiring immersed in corrosive water should be replaced. If wiring is* Chap 6
AC 43.13-1A CHG 1 Poge 128-3 1975 * merely splashed or sprayed with corrosive water, flush thoroughly with clean, fresh water and dry, using compressed air. Following compressed air drying, coat with water dispensing preservative (MIL-C-81309, Grade A).
k. Miscellaneous Equipment. The following equipment should be thoroughly washed to remove dirt, salt, and other contaminants. Dry with air blast or other means, and, if required, reapply proper lubricant:
(1) Wiring and fuselage hydraulic units.
(2) Electric landing gears.
(3) Actuators.
(4) Cables.
(5) Accumulators.
(6) Hydraulic reservoirs.
(7) Flight control.
(8) Torque tubes and bell cranks.
(9) Heating units, ducts, etc. *
255.-264. RESERVED.
Chap 6 Par 254
AC 43.13-1A 1972 essary to remove anodic films from parts to be inspected, since the dye readily penetrates such films. Special procedures for removing the excess dye should be followed.
b. Application of Penetrant. The penetrant is applied by brushing, spraying, or by dipping and allowed to stand for a minimum of 2 minutes. Dwell time may be extended up to 15 minutes, depending upon the temperature of part and fineness of the defect or when the surface being inspected is ground. Parts being inspected should be dry and heated to at least 70° F., but not over 130° F. Very small indications require increased penetration periods.
c. Removal of Dye Penetrant, Surplus penetrant is usually removed by application of a special cleaner or remover, or by washing with plain water and the part allowed to dry. Water rinse may also be used in conjunction with the remover, subject to the manufacturer's recommendations.
d. Application of Developer. A light and even coat of developer is applied by spraying, brushing, or dipping. When dipping, avoid excess accumulation. Penetrant which has penetrated into cracks or other openings in the surface of the material will be drawn out by the developer resulting in a bright red indication. Some Chap 7 Page 139 idea of the size of the defect may be obtained after experience by watching the size and rate of growth of the indication.
301. ULTRASONIC FLAW DETECTION. Ultrasonic flaw detection equipment has made it possible to locate defects in all types of materials without damaging the material being inspected.
Very small cracks, checks, and voids, too small to be seen by X-ray, are located by means of ultrasonic inspection. An ultrasonic test instrument requires access to only one surface of the material to be inspected, and can be used with either straight line or angle beam testing techniques. The instrument electronically generates ultrasonic vibrations and sends them in a pulsed beam through the part to be tested. Any discontinuity within the part, or the opposite end, will reflect the vibration back to the instrument, which measures the elapsed time between the initial pulse and the return of all reflections and indicates such time lapse on a cathode ray indicator or paper recorder. Ultrasonic inspection requires a skilled operator who is familiar with the equipment being used as well as the inspection method to be used for the many different parts being tested.
302.-312. RESERVED.
Par 300
Page 140 AC 43.13-1A CHG 1 1975 Section 4. IDENTIFICATION OF FABRICS AND PLASTICS
313. IDENTIFICATION OF FABRIC. Cotton fabric is often used as covering for wing, fuselage, and control surfaces of aircraft. Acceptable grades of fabric for use on civil aircraft are listed in Chapter 3. In general, the fabric can be readily identified by a continuous marking to show the manufacturer's name or trademark and specification number. This marking may be found stamped along the selvage edge. The specification number for grade "A" fabric is AMS-3806, and for the intermediate grade AMS-3804. The corresponding FAA Technical Standard Order * Numbers for these materials are TSO-C15 and 1SO-C14, respectively. Increasing interest in* the use of linen and certain synthetic fabrics in lieu of cotton has been noted. Identity of such materials should always be verified by the user.
314. IDENTIFICATION OF PLASTICS, Plastics cover a broad field of organic synthetic resins and may be divided into two main classifications -thermoplastic and thermosetting plustics.
a. Thermoplastics. Thermoplastics may be softened by heat and can be dissolved in various organic solvents. Two kinds of transparent thermoplastic materials are commonly employed in windows, canopies, etc. These materials are known as acrylic plastics and cellulose acetate plastics. These two plastics may be distinguished by the absence of color, the greater transparency, and the greater stiffness of the acrylic as compared to the slight yellow tint, lower transparency, and greater flexibility of cellulose acetate.
b. Thermosetting Plastics. Thermosetting plastics do not soften appreciably under heat but may char and blister at temperatures of 204° to 260° C. (400° to 500° F.). Most of the molded products of synthetic resin composition, such as phenolic, urea-formaldehyde, and melamineformaldehyde resins, belong to the thermosetting group.
315.-320. RESERVED.
Par 313 Chap 7
AC 43.13-1A CHG 1 Page 140-1 1975 * Section 5. CABIN INTERIOR MATERIALS, FIRE PROTECTION QUALITIES
321. REQUIREMENTS FOR FIRE PROTECTION. The cleaning, repairing. and/or replacement of cabin interior materials necessitates continuing compliance with the fire protection requirements of the FARs. A recent field survey on this matter revealed a wide variance in the procedures used for maintaining cabin interior materials with respeot to the fire protection qualities of these materials.
a. Interior Materials. The methods, techniques, practices, and materials used in the cleaning, repair, and replacement of cabin materials must meet the requirements of Section 43.13 of the FARS.
b. Fire Protection. The requirements relative to fire protection qualities of cabin interior materials are specified in:
(1) Section 121.312, for aircraft operated under Parts 121, 123, and 135.
(2) Section 127.91, for helicopters used in passenger service under Part 127.
c. Source of Information. If information regarding the original or properly altered fire protection qualities of certain cabin interior materials is not available, requests for this information should be made to the aircraft manufacturers or the local FAA regional office, specifying the model aircraft, the aircraft manufacturer, the date the aircraft was manufactured or the serial number, and the FAR Part under which the aircraft is operated (i.e., Part 91, Part 121, etc.).
322.-325. RESERVED.
Chap 7 Par 321
AC 43.13-1A CHG 1 1975 cycles. The dynamometer landings will consist of 50 Test A, load-speed-time cycles and 50 Test B, energy cycles.
(a) Test A, Load-speed-time.
1. Speed cycle. Land the tire against a dynamometer flywheel rotating at a peripheral speed of S, m.p.h. Immediately thereafter, de.
crease the flywheel speed at an uverage deceleration rate of D ft./sec./sec. until a value of Sz is attained. No specific rate of deceleration is required after the flywheel's peripheral speed reaches a value of S2. Decrease the speed of the flywheel in the ubove manner until a roll distance of RD feet has been covered, at which time the tire is unlanded.
2. Load cycle. After landing, increase the load from zero to L, pounds within 1, seconds. Linearly increase the load with time to a value of Is pounds within I; seconds after landing, or at the moment of unlanding, whichever occurs first. If it is necessary to continue the roll after T, seconds to complete the required roll distance (RD), maintain the load at La pounds.
3. Symbol deflnitions. Determine the numerical values, which are used for the following symbols, from the applicable airplane load-speed-time data:
S, = Initial dynamometer test speed.
Sz=Speed at which the average deceleration between S, and S, does not exceed the specified values.
D=Constant rate of deceleration between Si and S2 speeds.
RD= Roll distance in feet.
L, = Initial tire load.
L½=Maximum rated static load of the tire.
T, =Time for applying I, load. A T, tolerance of +1 second is acceptable.
S1- VS, -2D (RD) D T, is the elapsed time for applying the I load.
A T½ tolerance of +10% is acceptable.
When T, is calculated by the aforementioned formula, S, may be ignored and D is assumed constant throughout roll distance (RD).
Chap 8 Page 149
4. Test load adjustment. If the test load curve results in loads at a given speed being less than those dictated by the applicable aircraft data, eliminate the condition by making adjustments in T., L1, and/or T,
(b) Test B, Energy.
1. Kinetic energy. Calculate and adjust the kinetic energy of the flywheel for the rated maximum static load of the tire. In the event that the correct number of flywheel plates cannot be used to obtain the calculated kinetic energy value or proper flywheel width, select a greater number of plates and adjust the dynamometer speed to achieve the required kinetic energy.
2. Kinetic energy computation. Compute kinetic energy as follows:
KE=OWV:
Where KE = Kinetic energy, ft.-1b.
C=0.011 W=tire load, pounds V = 120 m.p.h.
3. Speed cycle. Land the test tire at 90 m.p.h. and unland at 0 m.p.h. Decrease the landing speed as necessary to assure that 56% of the calculated kinetic energy is absorbed by the tire.
4. Load cycle. Upon landing, and during the entire roll test, force the tire against the flywheel at its rated static load.
(c) Taxi Test.
1. Test parameters. Conduct a minimum of three dynamometer taxi tests under the following conditions:
Speed =35 m.p.h.
Tire Load = Maximum static rating Roll Distance =35,000 feet.
2. Tire temperature. Heat the test tire to a temperature of not less than 120° F. at the start of each of the three taxi test cycles. Rolling the tire on the dynamometer is acceptable in obtaining this minimum tire temperature.
Make no adjustments in the tire inflation pressure to compensate for increases due to temperature rise.
(9) Alternate Dynamometer Tests.
(a) Variable Loading. An alternate dynamometer test which more realistically simulates Par 332
actual airplane performance on the runway may be used in lien of the deceleration load-speedtime schedule. An acceleration load-speed-time schedule, wherein the dynamometer flywheel is accelerated to the applicable conditions, is accept-
(b) Alternate Procedure for Reinforced-tread Tires. Qualification of a high-speed tire with a given ply rating and reinforced tread will automatically qualify a lesser ply rating reinforced tread tire of the same size and skid depth, provided :
1. The test conditions S1, RD, S2, I.
and T, are no less severe than those which are applicable to the lesser ply rating tire.
2. The ratio of the test loads, Ly to I is not less than that applicable to the lesser ply rating tire. Make any necessary adjustment in this ratio by increasing L..
(10) Optional Dynamometer Equipment. Dynamic tests may be conducted on any dynanometer test equipment which will provide the load, speed, time, and roll distance parameters of the tire.
c. Tubes. Punctured tubes may be repaired by the use of cemented or vulcanized patches.
(1) The procedure for making such repairs is substantially identical to that used in connection with repair of automobile tires:
(a) Keep the size of the patch to a minimum and avoid use of an excessive number of patches, particularly in one area, as the weight of the material may contribute to excessive wheel vibration due to the tube being out-of-balance.
(b) The use of vulcanized patches is recommended because they are considered more reliable.
(c) Reinstalled tires should be inflated, deflated, and again inflated to insure that the inner- Par 362 AC 43.13-1A CHG 1 1975 tube is not pinched. A pinched tube will chafe against the walls of the carcass and a thin spot will result in the rubber. In time, the tube wall will leak at this point. The pinching generally is due to the sticking of the tube to the carcass wall during the first inflation and the failure of the carcass to properly seat against the flange.
(d) The tube is then confined to a smaller space and wrinkling (pinching) of the tube results. Complete deflation followed by inflation allows the tube to properly accommodate itself to the carcass which should now seat itself tightly against the flanges.
*333. TIRE SUIPPAGE. To reduce the possibility of tire and tube failure due to slippage, and to provide a means of detecting tire slippage, tires should be marked and indexed with the wheel rim. Marking should be accomplished by painting a mark 1 inch in width and 2 inches in length across the tire sidewall and wheel rim. The paint used should be of a permanent type and contrasting color, such as white, red, or orange.
Preflight inspection should include a check of slippage marks for alignment. If the slippage mark is not in alignment, the aircraft should not be operated until a detailed inspection is made.
the reason determined, and if necessary the condition corrected.
334. TIRE MAINTENANCE. A program of tire maintenance can minimize tire failures and increase tire service life. Overinflation wears the center of the tread excessively, and reduces a tire's resistance to bruising, strains the tires beads, reduces traction and skid resistance. Underinflation increases deflection and may cause breakdown of the tire sidewalls. The manufacturer's recommendations should he followed to obtain maximum tire service life.
345.-349. RESERVED. * Chap 8
AC 43.13-1A CHG 1 .. Page 165 1975 Chapter 10. HYDRAULIC AND PNEUMATIC SYSTEMS Section 1. HYDRAULIC SYSTEMS
392. GENERAL. Maintain, service, and adjust connection fittings: AN-818 nut and AN-819 airplane hydraulic systems in accordance with sleeve.
manufacturers' maintenance manuals and pergeneral principles of maintenance and repair tinent component maintenance manuals. Certain which apply are outlined below. Tube O.D. for tightening tube nuts Wrench torque rauge (inch pounds) Minimum bend radil * Dimension in inches. * measured at inalde of bend.
(Inches)
393. HYDRAULIC LINES AND FITTINGS. Carefully 1100-H14, Alum alloy Alum. alloy 1100-114, inspect all lines and fittings at regular intervals 5052-0 Steel 5052-0 Steel to insure airworthiness. Investigate any evidence of fuid loss or leaks. Check metal lines for 80-70 leaks, loose anchorages, scratches, kinks, or other 40-05 60-30 50-90 70-120 2132 damage, Inspect fittings and connections for 75-125 90-150 leakage, looseness, cracks, burrs, or other damage. 150-250 155-250 1¾G Replace or repair defective elements. 200-350 300-400 1¾ 300-500 430-575 210
a. Replacement of Metal Lines. When inspec 500-700 550-750 28 tion shows a line to be damaged or defective, 600-900 replace the entire line or if the damaged section 600-900 3¾ is localized, a repair section may be inserted. 5 7 In replacing lines, always use tubing of the same 8 7 size and material as the original line. Use the old tubing as a template in bending the new line, FIGURE 10.1.-Tube data.
unless it is too greatly damaged, in which case a template can be made from soft iron wire. In forming fares, cut the tube ends square, file Soft aluminum tubing (1100, 3003, or 5052) smooth, remove all burrs and sharp edges, and under ¼-inch outside dinmeter muy be bent by thoroughly clean. The tubing is then flared hand. For all other tubing usa an acceptable using the correct 37° aviation flare forming tool hand or power tube bending tool. Bend tubing for the size of tubing and type of fitting. A carefully to avoid excessive flattening, kinking, double flare is used on soft aluminum tubing or wrinkling. Minimum bend radii values are ⅛-inch outside diameter and under, and a single shown in figure 10.1. A small amount of flatten- flare on all other tubing. In making the connecing in bends is acceptable but do not exceed an tions, use hydraulic fluid as a lubricant and then amount such that the small diameter of the flat- tighten. Overtightening will damage the tube tened portion is less than 75 percent of the origi- or fitting, which may cause a failure; undernal outside diameter. When installing the tightening may cause leakage which could result replacement tubing. line it up correctly with the in a system failure.
mating part so that it is not forced into line by means of the coupling nuts. CAUTION Mistaken use of 45° automotive fare forming tools will
b. Tube Connections. Many tubing connections result In improper tubing flare shape and angle causing are made using fured tube ends, and standard misfit, stress and strain, and probable system fallure.
Chap 10 Par 392
Page 166 AC 43.13-1A CHG 1 1975 Any excessive If the of connection fittings.
fittings.
e. O-Ring Seals. A thorough understanding of O-ring seal applications is necessary to determine when replacement must be made. The simplest application is where the O-ring merely serves as a gasket when it is compressed within a recessed area by applying pressure with a packing nut or screw cap.
Leakage is not normally acceptable in this type of installation. In other installations the O- ring seals depend primarily upon their resiliency to accomplish their sealing action. When moving parts are involved, minor seepage may be normal and acceptable. A moist surface found on moving parts of hydraulic units is an indication the seal is being properly lubricated.
In pneumatic systems, seal lubrication is provided by the installation of a grease-impreg- Par 393 * U.S.. GOVERNMENT PRINTING OFFICE: 1975-631-513/928 3-1 Chap TO
CHANGE AC NO: 48.18-1A CHG 1 DATE: 5/12/75
NONENT DE TRANSO ADVISORY
TED STATES OF ARE CIRCULAR
DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
ACCEPTABLE METHODS, TECHNIQUES, AND SUBJECT: PRACTICES-AIRCRAFT INSPECTION AND RE- PAIR
1. PURPOSE.
This change transmits new and revised material for Advisory Circular 43.13-1A.
2. PRINCIPAL CHANGES.
a. Correotions have been made to paragraph 818 and Figure 10.1.
b. Chapter 2, Section 3, has been revised to add Selective Plating in aircraft maintenance.
Chapter 4, Section 6 has been revised to add handling and care of aircraft recovered from water immersion.
c. A new Section 5, Cabin Interior Materiale Fire Protection Qualities, has been added to Chapter ?.
d. New information on tire slippage and maintenance has been added to Section 1 of Chapter 8.
3. HOW TO GET THIS PUBLICATION.
Copies of this change to AC 13.13-1A may be obtained by ordering from:
Superintendent of Documents U.S. Government Printing Office Washington, D.C. 20402 For up-to-date information on how to order, and the price of this publication, check with the closest FAA office or obtain the latest copy of Advisory Circular 00-2, Advisory Circular Checklist and Status of the Federal Aviation Regulations. This checklist may be obtained without charge by requesting from:
Department of Transportation Publications Section, TAD 443.1 Washington, D.C. 20590 Initlated by: AFS-B30 PoP Sally R. P. SKULLY, Director Flight Standards Service Initiated by:
PAGE CONTROL CHART Remove Pages Dated Insert Pages Dated i thru iv 1972 1972 ii thru iv 1975 78 and 74 1972 73 thru 73-3 1975 1972 127 and 128 1972 1972 128 thru 128-3 1975 139 and 140 1972 1972 140 thru 140-1 • 1975 149 and 150 1972 1972 1975 165 and 166 1972 1975 166 1972