ac 43.13-1b update - ercoupe parts

©January 2002 ASA Advisory Circular 43.13-1B Change 1 Update 1

Page Paragraph Description of ChangeNumber or FigureUPDATE to Advisory Circular 43.13-1B January 2002The following are the essential revisions in Change 1 by the FAA to AC 43.13-1B, effective September 2001.Use this update with #ASA-AC43.13B to find the text areas to which these revisions apply.

Page Paragraph Description of ChangeNumber or Figure

1-4 1-4.b.(1) Change to read (“CAUTION” note stays the same):

(1) Casein adhesive performance is generally inferior to other products available today,modern adhesives should be considered first.

1-4 1-4.b.(4) Add new sentence to read as follows:

(4) Federal Specification MMM-A-181D and Military Specification MIL-A-22397 bothdescribe a required series of test that verify the chemical and mechanical properties ofresorcinol. Resorcinol is the only known adhesive recommended and approved for use inwooden aircraft structure and fully meets necessary strength and durability requirements. …

1-33 Fig. 1-18 In “Dimensions” table, change the 2-6/8 under column A (small circular plug patch) to 2-5/8.

2-21 Fig. 2-12 Change callout “spacing other than in slipstream” to read:

spacing other than in slipstream (non prop wash area)

Change callout “spacing in slipstream” to read:

spacing in slipstream (prop wash area)

2-21 2-11.b. Change paragraph b. to read as follows:

When the original lace spacing on the empennage surfaces and fuselage, is not known, amaximum spacing of two times the spacing shown in figure 2-12 for the slipstream area (propwash) on the wings may be used.

2-23 2-14.b.(1) Change the word “and” in the second line of this paragraph to read “at.”

2-27 2-21.c. The “NOTE: Dressing out” paragraph has been redesignated as paragraph 2-21.d., andsubsequent paragraphs are renumbered. The “NOTE:” in the right column under old paragraph2-21.e. has been changed in one line to read:

…satisfactory for light aircraft up to 9 lb. per square foot wing loading.

2-28 2-21.f.(1) Change the last sentence in this paragraph to read:

A higher ratio of aluminum-pigment added to the dope may cause a loss of primer-coat andfinish-coat adhesion, and peeling may occur especially when high tack tape is used to mask forthe trim colors and registration numbers.

2-28 2-21.h.(1) Change the first sentence in this paragraph to read:

(1) When exposed to the sun, dark colors absorb more sun energy and convert that energy toheat more easily than light colors.

4-1 4-1.c. Add a new paragraph 4-1.c. to read as follows:

c. Normalizing is heating steel to approximately 150°F to 225°F above the steel’s criticaltemperature range, followed by cooling to below that range in still air at ordinary temperature.Normalizing may be classified as a form of annealing. This process also removes stresses due tomachining, forging, bending, and welding. After the metal has been held at this temperature for asufficient time to be heated uniformly throughout, remove the metal from the furnace and cool in

2 Advisory Circular 43.13-1B Change 1 Update ©January 2002 ASA


4-1 4-1.c. continued…still air. Avoid prolonging the soaking of the metal at high temperatures, as this practice willcause the grain structure to enlarge. The length of time required for the soaking temperaturedepends on the mass of the metal being treated. The soaking time is roughly 1/4-hour per inch ofthe diameter or thickness (Ref: Military Tech Order (T.O.) 1-1A-9).

4-11 4-52 Change introduction to 4-52 to read:

Extensive repairs to damaged stressed skin on monocoque-types of aluminum alloy structuresmust be made in accordance with FAA-approved manufacturer’s instructions or other FAA-approved source.

4-19 4-57.f. Change introductory text and add 2 new subparagraphs to read:

f. Blind rivets are used under certain conditions when there is access to only one side of thestructure. Typically, the locking characteristics of a blind rivet are not as good as a driven rivet.Therefore, blind rivets are usually not used when driven rivets can be installed.

Blind rivets shall not be used:(1) in fluid-tight areas;(2) on aircraft in air intake areas where rivet parts may be ingested by the engine, on aircraft

control surfaces, hinges, hinge brackets, flight control actuating systems, wing attachmentfittings, landing gear fittings, on floats or amphibian hulls below the water level, or otherheavily-stressed locations on the aircraft;

CAUTION: For metal repairs to the airframe, the use of blind rivets must be specificallyauthorized by the airframe manufacturer or approved by a representative of the FAA.

Then, change paragraph numbering from there to the end of 4-57.f.

4-27 4-58.g.(2) Change subparagraphs (b) and (c) to read:

(b) Use the number of rivets required per inch of width “W” from table 4-10. (Number perinch 4.9 x .75 = 3.7 or the total number of rivets required = 10 x 3.7 or 37 rivets.) See notes intable.

(c) Lay out rivet pattern with spacing not less than shown in figure 4-5. Referring to figure4-5(A), it seems that a double row pattern with the minimum spacing will give a total of 40rivets. However, as only 37 rivets are required, two rows of 19 rivets each equally spaced overthe10 inches will result in a satisfactory splice.

4-53 4-74.e.(1) Delete 4-74.e.(1), and add in its place new paragraphs f., g., and h. as follows:

f. Aircraft welding Qualifications. Four groups of metals a person can be certified andqualified to use are:

(1) Group 1, 4130 Steel.(2) Group 2, Stainless steel.(3) Group 3, Aluminum.(4) Group 4, Titanium.g. For other group listing of metal the welder may qualify, refer to Mil-Std-1595A.h. Most large business or agencies conduct their own certification tests, or they have an

outside testing lab validate the certification tests.

4-53 4-75 Add new paragraph 4-75 introduction following 4-74.h., to read:

4.75. EQUIPMENT SELECTION. Use the welding equipment manufacturer’s information todetermine if the equipment will satisfy the requirements for the type of welding operation beingundertaken. Disregarding such detailed operating instructions may cause substandard welds. Forexample, when using GTAW equipment, a weld can be contaminated with tungsten if the propersize electrode is not used when welding with direct current reverse polarity. Another example,



the depletion of the inert gas supply below the critical level causes a reduction in the gas flowand will increase the danger of atmospheric contamination.

4-54 4-74.b.(2) Redesignate this paragraph as 4-76.

4-54 4-74.b.(3),(4) Redesignate these paragraphs as 4-77.a and 4-77.b., under a new paragraph title:

4-77. PREPARATION FOR WELDING.

4-54 4-74.b.(5) Redesignate this paragraph as 4-78, and change subparagraphs (a), (d) and (g) to read asfollows:

4-78. INSPECTION OF A COMPLETED WELD. Visually inspect the completed weld for thefollowing:

a. The weld has a smooth seam and uniform thickness. Visual inspection shall be made ofthe completed weld to check for undercut and/or smooth blending of the weld contour into thebase metal.

* * *d. There are no signs of blowholes, porosity, or projecting globules. Many military

specifications, as well as American Society of Testing Materials (ASTM) codes, specifyacceptable limits of porosity and other types of defects that are acceptable.

* * *g. The welding scale is removed. The welding scale can be removed using a wire brush or by

sandblasting. Remove any roll over, cold lap, or unfused weld metal. Check underside of weldedjoint for defects.

4-55 4-74.b.(6) Delete this paragraph.

4-55 4-74.b.(6)(a) Redesignate this as 4-79:

4-79. MICROFISSURES.

4-55 4-74.b.(6)(b) Redesignate this as 4-80.

4-55 4-74.b.(7) Redesignate this as 4-81:

4-81. PRACTICES TO GUARD AGAINST.


4-82. TORCH SIZE (Oxyacetylene welding).


4-83. WELDING RODS AND ELECTRODES.

4-56 4-74.b.(10) Redesignate this as 4-84.


4-85. HEAT-TREATED MEMBERS.

4-56 4-75 Redesignate this as 4-86.





4-61 through 4-67 Redesignate paragraphs 4-78 through 4-86 as 4-89 through 4-97.


4-73 Fig. 4-42 Change the table within Figure 4-42 to read as follows:


4-74 Fig. 4-43 Change the table within Figure 4-43 to read as follows:


4-75 Fig. 4-44 In the far right column of the table in Figure 4-44, in the top line, change “6A” to read “L”.

4-76 Fig. 4-45 In the “B” column of the table in Figure 4-45, in line across from “1”, change “.82” toread “.382”.


5-22 5-47.a. Change the last sentence in the paragraph to read:

Apply two shots of magnetizing current, each at least 1/2 second long.

5-33 5-63 Change the heading and first sentence to read:

5.63. CLEANERS AND APPLICATIONS. Use a cleaner to remove contaminants fromparts prior to the application of penetrant inspection materials.



6-1 6-2.a. Add new item (11) to read:

(11) Lead/graphite pencil marks on aircraft surface metals.

6-5 Fig. 6-5(b) Replace drawing in Figure 6-5(b) with the following:

6-6 6-14.b. Replace last sentence in this paragraph with the following:

Alloys such as stainless steel are particularly susceptible to this type of crevice corrosion.

7-2 7-2.j. Paragraph j. has been edited to read:

j. Blind rivets in the NASM20600 through NASM20603 series rivets and the mechanically-locked stem NAS 1398, 1399, 1738, and 1739 rivets sometimes may be substituted for solidrivets. They should not be used where the looseness or failure of a few rivets will impair theairworthiness of the aircraft. Design allowable for blind rivets are specified in MIL-HDBK-5.Specific structural applications are outlined in NASM33522. Nonstructural applications for suchblind rivets as NASM20604 and NASM20605 are contained in NASM33557.

CAUTION: For sheet metal repairs to airframe, the use of blind rivets must be authorizedby the airframe manufacturer or approved by a representative of the FAA.

For more information on blind rivets, see page 4-19, f. of this document.

8-7 8-14.b.(1) Replace this paragraph with the following:

(1) For an engine cylinder having less than a 5.00-inch bore; 0.040-inch orifice diameter;.250 inch long; and a 60-degree approach angle.

8-7 8-14.b.(2) Replace this paragraph with the following:

(2) For an engine cylinder with 5.00 inch bore and over: 0.060 inch orifice diameter, .250inch long, 60 degree approach angle.

8-29 8-73.a. In the 14th line up from the bottom, right column, this sentence was edited as follows (removedthe words “longitudinal surface cracks”):

On the thrust and camber face of blades, remove the metal around any dents, cuts, scars, scratches,nicks, and pits to form shallow saucer-shaped depressions as shown in figure 8-24 (view C).

8-30 Fig. 8-24 Two callouts at the bottom of the figure have been edited to read as follows:

“Surface crack before repair” now reads, “Surface scratch before repair”

“After repair–crack worked out” now reads, “After repair–scratch worked out”

8-30 Fig. 8-25 Typographical error in top left callout “cord lenth” has been corrected to read “chord length.”



9-1 9-3 Replace the first paragraph in the right column with the following:

Wear points, such as landing gear up-and-down latches, jack-screws, door hinges, pulleys,cables, bellcranks, and all pressure-type grease fittings, should be lubricated after every cleaningoperation.

To prevent possible failure of a component due to incompatibility or breakdown of the grease,the following should be observed:

1. Use only greases approved for use by the product manufacturer.2. Never mix different kinds of grease without approval from the product manufacturer.3. Follow the manufacturer’s instructions or FAA approved process for cleaning, purging,

and lubricating of the component.

To obtain proper lubrication of the main support bushings, it may be necessary to jackthe aircraft. …

9-5 9-8 Move the “9-8 TIRE AND TUBE MAINTENANCE” section to Page 9-9, to come before “9-14TIRE INSPECTION AND REPAIR” and redesignate it as “9-13.”; renumber the sectionsbetween them starting with “9-8. FLOATS AND SKIS”… through “9-12 RETRACTIONTESTS” (on Page 9-9).

9-6 Fig. 9-1 In the callout list at the bottom of Figure 9-1, replace “9. Ski Pedestal” with “9. Pedestal.”

9-7 9-10.a. Paragraph has been redesignated as “9-9.”; in subparagraph a., insert a new “Note:” beforethe sentence that begins, “…In the case of wooden floats,…” to read:

Note: Blind rivets should not be used on floats or amphibian hulls below the water line.

9-9 9-12 Paragraph has been redesignated as “9-11.”; replace with the following:

9-11. SPECIAL INSPECTIONS. When an aircraft experiences a hard or overweight landing,the mechanic should perform a special structural inspection of the aircraft, including the landinggear. Landing gear support trusses should be inspected for cracked welds, sheared bolts andrivets, and buckled structures. Wheels and tires should be inspected for cracks and cuts, andupper and lower wing surfaces should be inspected for wrinkles, deformation, and loose orsheared rivets. If any damage is found, a detailed inspection is recommended.

9-10 9-15 Replace entire paragraph 9-15 with the following:

9-15. INFLATION OF TIRES. There is serious danger involved with inflating and tireassembly. The tire should not be inflated beyond the recommended pressure (when it is not beinginstalled in a safety cage). Over-inflation can cause damage to the aircraft, as well as personalinjury. Under-inflation will cause excessive tire wear and imbalance. The airframemanufacturer’s load and pressure chart should be consulted before inflating tires. Sufficientlyinflate the tires to seat the tire beads; then deflate them to allow the tube to assume its position.Inflate to the recommended pressure with the tire in a horizontal position.

Tire check of storage aircraft should be done in accordance with the applicable aircraftstorage manual.



9-11 9-16 Move current paragraph 9-16 to the end of the section, and insert a new paragraph with a newheading, new text, and a new illustration:

9-16. PERSONAL SAFETY. When servicing aircraft tires, personnel should stand either in thefront or rear of the wheel and avoid approaching from either side of the tire. See illustrationbelow:

Personnel should wear protective eye gear to reduce the risk of eye injury due to inflation anddeflation of tires.

Note: The use of nitrogen to inflate tires is recommended. Do not use oxygen to inflate tires.Deflate tires prior to removing them from the aircraft or when built-up tire assemblies arebeing shipped.

9-11 9-17 Move current paragraph 9-17 to the end of the section, and insert a new paragraph with a newheading and new text:

9-17. DISASSEMBLE THE WHEEL in accordance with aircraft manufacturer’s instructions.

Do not attempt to disassemble wheel until the tire has been completely deflated: otherwiseserious injury or damage to equipment can result.

Do not attempt to remove valve core until tire has been completely deflated. Valve cores willeject at high velocity if unscrewed before air pressure has been released.

Never attempt to remove wheel bolts or break tire beads loose until tire has been completelydeflated: otherwise, explosive separation of wheel components will result.

Do not pry between wheel flanges and tire beads as this can damage the wheel and tire.

Use caution when removing wheel bolts or nuts.

Remove tire from wheel using a wheel demounting fixture.

Valve stem, fusible plugs, wheel keys, heat shields, balance weights, and associated hardwareshould not be removed if demountable flange only is to be removed for tire change.

Fusible plugs and bearing cups should not be removed unless replacement is necessary, if paintis to be stripped, or if a thorough inspection of the wheel is to be made.

When removal and replacement of fusible plugs is required, remove by pressing out with ablunt instrument such as a wooden rod. Exercise caution to ensure wheel sealing surfaces arenot damaged.

9-12 9-20 Current paragraph “9-16. WHEEL INSPECTION” now redesignated as “9-20”; insert at endof Section 1.



9-12 9-21 Current paragraph “9-17. WHEEL INSTALLATION” now redesignated as “9-21”; insert atend of Section 1.

9-14 9-28.f. Replace the second sentence in the paragraph with the following:

… To work with these fluids, reasonable handling procedures must always be followed. …

9-18 9-30.a. Replace the fourth and fifth sentences in this paragraph with the following:

… Soft aluminum tubing (1100, 3003, or 5052) under 1/4-inch outside diameter may be bent byhand. For all other tubing use an acceptable hand or power tube-bending tool. …

9-18 9-30.a. Replace the eighth sentence in this paragraph with the following:

A small amount of flattening in bends is acceptable, but do not exceed 75 percent of the originaloutside diameter.

9-18 9-30.c. Correct the fourth sentence in this paragraph with “20 percent” to read:

A dent less than 20 percent of the tube diameter is not objectionable unless it is in the heel ofa bend.

9-19 9-30.d.(1) Correct the third sentence in this paragraph to read:

… It has an operating range of -65°F to 450°F. …

9-20 9-30.d.(2) Change the first two sentences in the top left column to read:

…fabricated as described in figure 9-8. Refer to figure 9-10 for minimum bend radii. When ahose assembly is removed, the ends should be tied as shown in figure 9-11, so that the preformedshape will be maintained. Refer to figure 9-12 for minimum bend radii for Teflon hose.

9-20 9-30.e. Insert a new sentence, just before the last in this paragraph, to read:

… In pneumatic systems, seal lubrication is provided by the installation of a grease-impregnatedfelt wiper ring. …

9-20 9-30 Insert new subparagraphs f., h., and j., and redesignate current f. as “g.”, and current g. as “i.”:

f. Storage of replacement seals.

(1) Store O-ring seals where temperature does not exceed 120°F.

(2) Keep seals packaged to avoid exposure to ambient air and light, particularly sunlight.

h. Do’s and Don’ts that apply to O-ring seals.

(1) Correct all leaks from static seal installations.

(2) Don’t retighten packing gland nuts; retightening will, in most cases, increase rather thandecrease the leak.

(3) Never reuse O-ring seals because they tend to swell from exposure to fluids, and becomeset from being under pressure. They may have minor cuts or abrasions that are not readilydiscernible by visual inspection.

(4) Avoid using tools that might damage the seal or the sealing surface.

(5) Do not depend upon color-coding. Coding may vary with manufacturer.

(6) Be sure that part number is correct.

(7) Retain replacement seals in their package until ready for use. This provides properidentification and protects the seal from damage and contamination.



(8) Assure that the sealing surfaces are clean and free of nicks or scratches beforeinstalling seal.

(9) Protect the seal from any sharp surfaces that it may pass over during installation. Use aninstallation bullet or cover the sharp surfaces with tape.

(10) Lubricate the seal so it will slide into place smoothly.

(11) Be sure the seal has not twisted during installation.

j. Hydraulic Components. Hydraulic components such as pumps, actuating cylinders,selector valves, relief valves, etc., should be repaired or adjusted following the airplane andcomponent manufacturer’s instructions. Inspect hydraulic filter elements at frequent intervals andreplace as necessary.

9-26 Fig. 9-12 Insert new figure and caption, as shown below:

9-28 9-39.a. Replace item in the “Survival Kit Contents” list, “Space Blankets (if required)” with thefollowing:

Thermal Protective Aid

Figure 9-12. Minimum bend radii—Teflon hose.



9-37 9-46.b. Replace heading of paragraph b. with:

b. Safety Belts shall be of an approved type. …

9-37 9-46.b.(3) Add new item (3) to subparagraph b., to read as follows:

(3) Safety belts shall be repaired in accordance with specifications approved by theresponsible FAA ACO.

9-41 9-51 Replace the introductory paragraph in 9-51 with the following:

9.51 SERVICE OXYGEN CYLINDERS REQUIREMENTS (Ref 49 CFR 173.34 e, 16).Standard-weight cylinders must be hydrostatic tested at the end of each 5-year period (10 yearsif it meets the requirements in 49 CFR 173.34e, 16). This is a Department of Transportation(DOT) requirement. These cylinders carry an ICC or DOT 3AA 1800 classification and aresuitable for the use intended.

Lightweight cylinders must be hydrostatic tested every 3 years, and must be retired from serviceafter 24 years or 4,380 pressurizations, whichever occurs first. These cylinders carry an ICC orDOT 3 HT 1850 classification and must be stamped with the approval after being inspected.(Ref. 49 CFR 173.34e, 15).

9-42 9-51.a.(1) Replace the text under subparagraph (b) with the following:

(b) Check the hydrostatic test date of the cylinder. DOT regulations require ICC or DOT3AA 1800 designation cylinders to be hydrostatic tested to 5/3 their working pressure, every 5years (10 years if they meet the requirements in 49 CFR 173.34e, 16).

Cylinders bearing designation ICC or DOT 3HT 1850 (Ref. 49 CFR 173.34e, 15) must behydrostatic tested to 5/3 their working pressure every 3 years, and retired from service 24 yearsor 4,380 filling cycles after the date of manufacture, whichever occurs first.

10-1 10-2 Add new item “c.” to “10-2. Terminology” to read as follows:

c. Negligible Weight Change is any change of one pound or less for aircraft whose weightempty is less than 5,000 pounds; two pounds or less for aircraft whose weight empty is morethan 5,000 and 50,000 pounds; and five pounds or less for aircraft whose weight empty is morethan 50,000 pounds. Negligible c. g. change is any change of less than 0.05% MAC for fixedwing aircraft, 0.2 percent of the maximum allowable c. g. range for rotary wing aircraft.

(Then, renumber d. – q. as required with the addition of c.)

10-7 Fig. 10-6 Correction to formula at the bottom of Figure 10-6:

Formula: C.G. = D –F x L

= 34” –454 x 67.8

= 34” – 18.4” = 15.6”W 1673

10-11 10-15.g. Add new text to follow the “NOTE”, to read as follows:

When weighed with full oil, actual empty weight equals the actual recorded weight less theweight of the oil in the oil tank (oil weight = oil capacity in gallons x 7.5 pounds). Indicate onall weight and balance reports whether weights include full oil or oil drained. (See figure 10-9.)

10-11 10-15a Add new section “10-15a” to read as follows:

10-15a. REPAIRS AND ALTERATIONS are the major sources of weight changes, and it is theresponsibility of the aircraft mechanic making any repairs or alteration to know the weight andlocation of these changes, and to compute the new CG and record the new empty (EW) weightand EWCG data in the aircraft flight manual.



10-11 10-15b Add new section “10-15b” to read as follows:

10-15b. ANNUAL OR 100-HOUR INSPECTION. After conducting an annual or 100-hourinspection, the aircraft mechanic must ensure the weight and balance data in the aircraft recordsis current and accurate.

11-11 11-33 Move this paragraph to the next page, to come under a new heading,“11-35 ACCEPTABLE MEANS OF CONTROLLING OR MONITORING THEELECTRICAL LOAD”, insert it as new subparagraph “a.” and modify it to read:

a. Output Rating. The generator or alternator output ratings and limits prescribed by themanufacturer must be checked against the electrical loads that can be imposed on the affectedgenerator or alternator by installed equipment. When electrical load calculations show that thetotal continuous electrical load can exceed 80 percent output load limits of the generator oralternator, and where special placards or monitoring devices are not installed, the electrical loadmust be reduced or the generating capacity of the charging system must be increased. (This isstrictly a “rule of thumb” method and should not be confused with an electrical load analysis,which is a complete and accurate analysis, which is a complete and accurate of the compositeaircraft power sources and all electrical loads) When a storage battery is part of the electricalpower system, the battery will be continuously charged in flight.

Then, renumber all the paragraphs in Section 3 accordingly (Pages 11-11 through 11-13).

11-16 11-51 Change last two sentences in the paragraph to read as follows:

… for protection of black boxes or components. Use of a circuit breaker as a switch is notrecommended. Use of a circuit breaker as a switch will decrease the life of the circuit breaker.

11-21 Table 11-6 Change the first item in the left column (“Nominal system voltage”) from “12” to “14.”

11-22 Table 11-7 Replace Table 11-7 with the following:

TABLE 11-7. Examples of determining required tin-plated copperwire size and checking voltage drop using figure 11-2



11-27 11-67.f. Replace the second sentence in the paragraph with the following:

The use of sizes smaller than #8 is discouraged (Ref. AS50881A).

11-27 11-67.f. Replace the fourth sentence in the paragraph with the following:

Use of aluminum wire is also discouraged for runs of less than 3 feet (AS50991A).

11-27 11-68.b. In the last paragraph on Page 11-27, in the fourth line, change “12V” to “14V.”

11-28 11-68.d. In the sixth line in this paragraph, change “12 volts” to “14 volts.”

11-36 11-77.d. In the third sentence which begins, “Wires are typically categorized…”, replace it and the nexttwo sentences with the following:

…Wires are typically categorized as being suitable for either “open wiring” or “protectedwiring” applications. MIL-W-5088L, replaced by AS50881A, wiring aerospace vehicle,Appendix A table A I lists wires considered to have sufficient abrasion and cut-throughresistance to be suitable for open-harness construction. MIL-W-5088L, replaced by AS50881A,wiring aerospace vehicle, Appendix A table A II lists wires for protected applications. …

11-36 11-77.e. Add new text to this paragraph, just after the first sentence, to read:

Characteristics should be chosen based on environment; such as abrasion resistance, arcresistance, corrosion resistance, cut-through strength, dielectric strength, flame resistant,mechanical strength, smoke emission, fluid resistance, and heat distortion.

11-41 Table 11-12b Insert a new table.

Table 11-12b. Comparable properties of wire insulation systems.



11-39 11-88 Correct the typo in the second sentence of this paragraph to read:

Insulation or jacketing will vary according to the environment.

11-40 Table 11-11 Add an asterisk and note to this table, in the “Insulation Type” column across from“MIL-W-25038/3/2/”:

[in the column] …See specification sheet *

[under the table] * Inorganic Fibers–Glass–TFE

11-41 Table 11-12 Add “PVF2” in two places to this table, in the “Insulation Type” column across from both“MIL-W-81044/12” and “MIL-W-81044/13”:

Crosslinked polyalkene – PVF2

11-44 11-96.w. Change this paragraph to read as follows:

w. Where practical, route electrical wires and cables above fluid lines and provide a 6-inchseparation from any flammable liquid, fuel, or oxygen line, fuel tank wall, or other low voltagewiring that enters a fuel tank and requires electrical isolation to prevent an ignition hazard.Where 6-inch spacing cannot practically be provided, a minimum of 2 inches must bemaintained between wiring and such lines, related equipment, fuel tank walls and low voltagewiring that enters a fuel tank. Such wiring should be closely clamped and rigidly supported andtied at intervals such that contact between such lines, related equipment, fuel tank walls or otherwires, would not occur, assuming a broken wire and a missing wire tie or clamp.

11-45 11-96.aa. Change the last sentence in this paragraph to read:

…The radius for thermocouple wire should be done in accordance with the manufacturer’srecommendation and shall be sufficient to avoid excess losses or damage to the cable.

11-46 11-97.l. Insert a new paragraph before the current paragraph “1.”, and redesignate current paragraph“l” as “m”:

l. Wire substitution. In the repair and modification of existing aircraft, when a replacementwire is required, the maintenance manual for that aircraft should first be reviewed to determine ifthe original aircraft manufacturer (OAM) has approved any substitution. If not, then the OAMshould be contacted for an acceptable replacement.

11-51 11.117 Change the second phrase in the introductory paragraph to read as follows:

… They may be bent at six times their outside diameters at breakouts or six times the diameterwhere they must reverse direction in a bundle, provided that they are suitably supported.

11-52 11.118A. Add new text, “11-118A. DRIP LOOP IN WIRE BUNDLE” and a new figure with it, to readas follows:

11-118A. DRIP LOOP IN WIRE BUNDLE. A drip loop is an area where wire is dresseddownward to a connector, terminal block, panel, or junction box. In additional to the servicetermination and strain relief, a trap or drip loop shall be provided in the wiring to prevent fluidor condensate from running into the above devices. (See Figure 11-9b on the next page.) Wiresor groups of wires should enter a junction box or piece of equipment in an upward directionwhere practicable. Where wires must be routed downwards to a junction box or unit of electricequipment, the entry should be sealed or adequate slack should be provided to form a trap ordrip loop to prevent liquid from running down the wires in the box or electric unit.

…Continued



11-57 11-146.c. Insert a new sentence after the first sentence in this paragraph:

… Stand-offs should be used to maintain clearance between the wires and the structure. …

11-68 11-175 Add a parenthetical statement to the end of this paragraph:

(See paragraph 11-178.)

11-69 11-178 Add new text to the end of the existing introductory text for paragraph 11-178:

… We recommend the use of the proper calibrated tool. Aircraft quality crimp tools aremanufactured to standards. Such tools are provided with positioners for the wire size and areadjusted for each wire size. It is essential that the crimp depth be appropriate for each wire size.If the crimp is too deep or not deep enough, it may break or cut individual strands, or it may notbe tight enough to retain the wire in the terminal or connector. Crimps that are not tight enoughare also susceptible to high resistance due to corrosion build-up between the crimped terminaland the wire. MIL-C22520/2 or MIL-T-DTl2250G specification covers in detail the generalrequirement for crimp tools, inspection gages and tool kits.

11-71 11-186.a. Replace existing paragraph “a.” and delete the “NOTE:” at the end of “a.”:

a. Types of Grounding. If wires carrying return currents from different types of sources,such as signals of DC and AC generators, are connected to the same ground point or have acommon connection in the return paths, an interaction of the currents will occur. Mixing returncurrents from various sources should be avoided because noise will be coupled from one sourceto another and can be a major problem for digital systems. To minimize the interaction betweenvarious return currents, different types of grounds should be identified and used. As a minimum,the design should use three ground types: (1) ac returns, (2) dc returns, and (3) all others. Fordistributed power systems, the power return point for an alternative power source would beseparated. For example, in a two-ac generator (one on the right side and the other on the leftside) system, if the right ac generator were supplying backup power to equipment located in theleft side, (left equipment rack) the backup ac ground return should be labeled “ac Right”. Thereturn currents for the left generator should be connected to a ground point labeled “ac Left”.

11-83 11-209 Change the introductory paragraph to read:

The preferred method is to mark directly on the wire. A successful requirement qualificationshould produce markings that meet the marking characteristics specified in MIL-W-5088 orAS50881A without causing insulation degradation. Teflon coated wires, shielded wiring, multi-conductor cable, and thermocouple wires usually require special sleeves to carry identificationmarks. There are some wire marking machines in the market that can be used to stamp directly

Figure 11-9b. Drainage hole in low point of tubing.

11-52 11.118A. continued…



on the type wires mentioned above. Whatever method of marking is used, the marking should belegible and the color should contrast with the wire insulation or sleeve.

11-84 11-210 Change the text in this paragraph to read:

Due to widespread use of hot stamp wire marking, personnel should refer to SAE ARP5369,Guidelines for Wire Identification Marking using the Hot Stamp Process, for guidance onminimizing insulation damage. Hot stamp process uses a heated typeface to transfer pigmentfrom a ribbon or foil to the surface of wires or cables. The traditional method imprints hot inkmarks onto the wire. Exercise caution when using this method, as it has been shown to damageinsulation when incorrectly applied. Typeset characters, similar to that used in printing pressesbut shaped to the contour of the wire, are heated to the desired temperature. Wire is pulledthrough a channel directly underneath the characters. The heat of the type set characters transfersthe ink from the marking foil onto the wire.

11-85 11-210.b. Change the “CAUTION” note to read as follows:

CAUTION: The traditional Hot Stamp method is not recommended for use on wire withoutside diameters of less than 0.035. (REF. SAE ARP5369). Stamping dies may causefracture of the insulation wall and penetration to the conductor of these materials. Whenvarious fluids wet these opening in service, arcing and surface tracking damage wirebundles. Later in service, when various fluids have wet these openings, serious arcing andsurface tracking will have damaged wire bundles.

11-91 11-230 Insert new text before the first sentence of 11-230, as follows:

11-230. GENERAL. There is a multitude of types of connectors. Crimped contacts are generallyused. Some of the more common are the round cannon type, the rectangular, and the moduleblocks. Environmental-resistant connectors should be used in applications subject to fluids,vibration, thermal, mechanical shock, and/or corrosive elements. When HIRF/Lightningprotection is required, special attention should be given to the terminations of individual oroverall shields. The number and complexity of wiring systems…

11-91 11-231 Change the first sentence in 11-231 to read:

Connectors should be selected to provide the maximum degree of safety and reliabilityconsidering electrical and environmental requirements.

11-103 11-260 Add new text to the end of 11-260, to read:

… Unused wires can be secured by tying into a bundle or secured to a permanent structure;individually cut with strands even with insulation; or pre-insulated closed end connector or 1-inch piece of insulating tubing folded and tied back.

12-4 12-9.b.(10) Correct the typographical error in subparagraph (a)(1) to read:

1 1502B Metallic Time Domain Reflectometer or equivalent.

12-5 12-11 Change the first sentence in this paragraph to read:

A VOR operates within the 108.0 to 111.85 MHz, and 112.0 to 117.95 MHz frequency bands.

12-6 12-14.a. Change the first sentence in this paragraph to read:

a. Localizer receiver operates on one of 40 ILS channels within the frequency range of108.10 to 111.95 MHz (odd tens).



12-7 12-19.a. Change paragraph “a.” to read as follows:

a. The tests required must be performed by:

(1) The manufacturer of the aircraft on which the tests and inspection are to be performed.

(2) A certificated repair station properly equipped to perform those functions and holding:

(a) An instrument rating Class I.

(b) A limited instrument rating appropriate to the make and model of applianceto be tested.

(c) A certified/qualified mechanic with an airframe rating (static system tests andinspections only). Any adjustments shall be accomplished only by an instrument shop certified/qualified person using proper test equipment and adequate reference to the manufacturer’smaintenance manuals. The altimeter correlation adjustment shall not be adjusted in the field.Changing this adjustment will nullify the correspondence between the basic test equipmentcalibration standards and the altimeter. It will also nullify correspondence between the encodingaltimeter and its encoding digitizer or the associated blind encoder.

12-8 12-21 Change the last two sentences in this paragraph to read:

… Tests should be conducted during the first 5 minutes after any hour. If operational tests mustbe made outside of this time frame, they should be coordinated with the nearest FAA ControlTower or FSS. Tests should be no longer than three audible sweeps.

12-11 12-28 Add new “12-28. ELECTRIC COMPATABILITY” to read as follows:

12-28. ELECTRIC COMPATABLITY. When replacing an instrument with one which providesadditional functions or when adding new instruments, check the following electrical [conditions](where applicable) for compatibility:

a. Voltage (AC/DC).

b. Voltage polarity (DC).

c. Voltage phase (AC).

d. Frequency (AC).

e. Grounding (AC/DC).

f. System impedence matching.

g. Compatibility with system to which connected.

12-13 12-37 Change introductory text of this paragraph to read as follows:

12-37. COMPASS SWING must be performed whenever any ferrous component of the system(i.e. flux valve compensator, or Standby Compass) is installed, removed, repaired, or a newcompass is installed. The magnetic compass can be checked for accuracy by using a compassrose located on an airport. The compass swing is normally effected by placing the aircraft onvarious magnetic headings and comparing the deviations with those on the deviation cards. Referto 14 CFR 23.1327, 14 CFR 23.1547, and the equipment or aircraft manufacturer’s manual.

12-13 12-37.b. Redesignate “Compass Swing Procedures” as subparagraph “c.” and insert a newsubparagraph “b. Precautions”:

b. Precautions.

(1) The magnetic compass must be checked for accuracy in a location free of steel structures,underground pipes or cables, or equipment that produces magnetic fields.

(2) Personnel engaged in the compensation of the compass shall remove all magnetic orferrous material from their possession.



(3) Use only nonmagnetic tools when adjusting the compass.

(4) Position the aircraft at least 100 yards from any metal object.

(5) All equipment in the aircraft having any magnetic effect on the compass must be securedin the position occupied in normal flight.

12-13 12-37.c. Change 12-37.b. to 12-37.c., delete the introductory text, and change subparagraph (1) to readas follows:

c. Compass Swing Procedures.

(1) Have the aircraft taxied to the NORTH (0°) radial on the Compass Rose. Use a hairlinesight compass (a reverse reading compass with a gun sight arrangement mounted on top of it) toplace the aircraft in the general vicinity.

12-13 12-37.c.(1) Add a new sentence to the NOTE paragraph, to read:

Remember the hairline sight compass is only intended to be used as a general piece of testequipment.

12-13 12-37.c.(2) Change subparagraph (2) to read:

(2) If the aircraft compass is not in alignment with the magnetic North of the mastercompass, correct the error by making small adjustments to the North-South brass adjustmentscrew with a nonmetallic screwdriver (made out of brass stock, or stainless steel welding rod).Adjust the N-S compensator screw until the compass reads North (0°). Turn the aircraft until it isaligned with the East-West, pointing East. Adjust the E-W compensator screw until it reads 90°.Continue by turning the aircraft South 180° and adjust the N-S screw to remove one-half of theSouth’s heading error. This will throw the North off, but the total North-South should be dividedequally between the two headings. Turn the aircraft until it is heading West 270°, and adjust theE-W screw on the compensator to remove one-half of the West error. This should divide equallythe total E-W error. The engine(s) should be running.

12-14 12-37.c.(3) Change subparagraph (3) to read:

(3) With the aircraft heading West, start your calibration card here and record the magneticheading of 270° and the compass reading with the avionics/electrical systems on then off. Turnthe aircraft to align with each of the lines on the compass rose and record the compass readingevery 30°. There should be not more than a plus or minus 10° difference between any of thecompass’ heading and the magnetic heading of the aircraft.

12-14 12-37.c.(4) Add text to the end of the NOTE paragraph, as shown:

…rather than brass hardware, magnetized control yoke, structural tubing, and improperlyrouted electrical wiring, which can cause unreasonable compass error.

12-14 12-37.c.(5) Change the first phrase in the first sentence to read:

(5) If the aircraft has an electrical system, two complete compass checks should beperformed, one with minimum electrical equipment…

12-14 12-37.c.(6) Add a new subparagraph to 12-37.c., to read as follows:

(6) When the compass is satisfactorily swung, fill out the calibration card properly and put itin the holder in full view for the pilot’s reference.



12-14 12-37.d. Add a new paragraph 12-37.d., to read as follows:

d. Standby (wet) Compass. Adjustment and compensation of the Standby Compass mayalso be accomplished by using the “compass swing” method.

12-19 Section 4 Change Chapter 12 Section 4, “Avionics Test Equipment” to Section 5, and insert a new Section4, “Pitot/Static Systems” to read as follows:

SECTION 4. PITOT/STATIC SYSTEMS

12-51. GENERAL. In order for the pitot-static instruments to work properly, they must beconnected into a system that senses the impact air pressure with minimum distortion and picksup undisturbed static air pressure.

Pitot pressure is ram air pressure picked up by a small open-ended tube about a 1/4-inch indiameter that sticks directly into the air stream that produces a pressure proportional to the speedof the air movement. Static pressure is the pressure of the still air used to measure the altitudeand serves as a reference in the measurement of airspeed.

Airspeed requires pitot, altimeter, rate of climb, and transponder-required static.

12-52. SYSTEM COMPONENTS. The conventional design of the pitot system consists ofpitot-static tubes or pitot tubes with static pressure parts and vents, lines, tubing, water drainsand traps, selector valves, and various pressure-actuated indicators or control units such as thealtimeter, airspeed and rate-of-climb indicators, and the encoding altimeter connected to thesystem. (See figure 12-5.)

Figure 12-5. Pitot/static system for a small aircraft.

12-53. PITOT/STATIC TUBES AND LINES. The pitot tube (see figure 12-6) is installed at theleading edge of the wing of a single-engine aircraft, outside the propeller slipstream or on thefuselage of a multiengine aircraft with the axis parallel to the longitudinal axis of the aircraft,unless otherwise specified by the manufacturer.

12-54. STATIC PORTS AND VENTS (more modern trend) should be mounted flush withfuselage skin. One port is located on either side of the fuselage, usually behind the cabin.

Inspect for elevation or depression of the port or vent fitting. Such elevation or depression maycause airflow disturbances at high speeds and result in erroneous airspeed and altitudeindications.

12-55. HEATER ELEMENTS. A heating element is located within the tube head to prevent theunit from becoming clogged during icing conditions experienced during flight. A switch in the



cockpit controls the heater. Some pitot-static tubes have replaceable heater elements whileothers do not. Check the heater element or the entire tube for proper operation by noting eitherammeter current or that the tube or port is hot to the touch. (See figure 12-6.)

Figure 12-6.

12-56. SYSTEM INSPECTION.

a. Inspect air passages in the systems for water, paint, dirt or other foreign matter. If wateror obstructive material has entered the system, all drains should be cleaned. Probe the drains inthe pitot tube with a fine wire to remove dirt or other obstructions. The bottom static openingsact as drains for the head’s static chamber. Check these holes at regular intervals to precludesystem malfunctioning.

b. Check to ensure the water drains freely. If a problem is experienced with the pitot-staticsystem drainage or freezing at altitude, and the tubing diameter is less than 3/8-inch, replace itwith larger tubing.

c. Check the pitot tube for corrosion.

(1) The pitot probe should not have any corrosion within 1/2-inch of the probe tip.

(2) Make sure there is no flaking which forms pits and irregularities in the surface of the tube.

NOTE: It is essential that the static air system be drained after the airplane has beenexposed to rain.

12-57. SYSTEM LEAK TEST.

a. Pitot-static leak tests should be made with all instruments connected to assure that noleaks occur at instrument connections. Such tests should be accomplished whenever a connectionhas been loosened or an instrument replaced.

…Continued



12-19 Section 4 continued…b. After the conclusion of the leak test, return the system to its normal flying configuration.Remove tape from static ports and pitot drain holes and replace the drain plug.

12-58. STATIC SYSTEM TESTS must comply with the static system tests required by 14 CFR91.411 and be performed by an appropriately-rated repair station with the appropriate testequipment.

If the manufacturer has not issued instructions for testing static systems, the following maybe used:

a. Connect the test equipment directly to the static ports, if practicable. Otherwise, connectto a static system drain or tee connection and seal off the static ports. If the test equipment isconnected to the static system at any point other than the static port, it should be made at a pointwhere the connection may be readily inspected for system integrity. Observe maintenanceprecautions given in paragraph 12-60 of this section.

b. Do not blow air through the line toward the instrument panel. This may seriouslydamage the instruments. Be sure to disconnect the instrument lines so no pressure can reachthe instruments.

c. Apply a vacuum equivalent to 1,000 feet altitude, (differential pressure of approximately1.07 inches of mercury or 14.5 inches of water) and hold.

d. After 1 minute, check to see that the leak has not exceeded the equivalent of 100 feet ofaltitude (decrease in differential pressure of approximately 0.0105 inches of mercury or 1.43inches of water).

12-59. TEST PITOT SYSTEM in accordance with the aircraft manufacturer’s instructions. Ifthe manufacturer has not issued instructions for testing pitot systems, the following may be used:

a. Seal the drain holes and connect the pitot pressure openings to a tee to which a source ofpressure and manometer or reliable indicator is connected.

b. Restrain hoses that can whip due to applied pressure.

c. Apply pressure to cause the airspeed indicator to indicate 150 knots (differential pressure1.1 inches of mercury or 14.9 inches of water), hold at this point and clamp off the source ofpressure. After 1 minute, the leakage should not exceed 10 knots (decrease in differentialpressure of approximately 0.15 inches of mercury or 2.04 inches of water).

CAUTION: To avoid rupturing the diaphragm of the airspeed indicator, apply pressureslowly and do not build up excessive pressure in the line. Release pressure slowly to avoiddamaging the airspeed indicator.

d. If the airspeed indicator reading declines, check the system for leaky hoses andloose connections.

e. Inspect the hoses for signs of deterioration, particularly at bends and at the connectionpoints to the pitot mast and airspeed indicator. Replace hoses that are cracked or hardened withidentical specification hoses. Any time a hose is replaced, perform a pressure check.

Warning: Do not apply suction to pitot lines.

12-60. MAINTENANCE PRECAUTIONS. Observe the following precautions in all pitot-static system leak testing:

a. Before any pitot/static system is tested, determine that the design limits of instrumentsattached to it will not be exceeded during the test. To determine this, locate and identify allinstruments attached to the system.

b. A system diagram will help to determine the location of all instruments as well as locatea leak while observing instrument indications. If a diagram is not available, instruments can belocated by tracing physical installation.

c. Be certain that no leaks exist in the test equipment.



d. Run full range tests only if you are thoroughly familiar with the aircraft instrumentsystem and test equipment.

e. Make certain the pressure in the pitot system is always equal to, or greater than, thatin the static system. A negative differential pressure across an airspeed indicator can damagethe instrument.

f. The rate of change or the pressure applied should not exceed the design limits of anypitot or static instruments connected to the systems.

g. When lines are attached to or removed from the bulkhead feed-through fitting or at aunion, ensure the line attached to the opposite end is not loose, twisted, or damaged by rotationof the fitting. Such fittings normally are provided with a hex flange for holding the fitting.

12-61. REPLACING LINES. If necessary to replace lines, observe the following installation:

a. Attach lines at regular intervals by means of suitable clamps.

b. Do not clamp lines at end fittings.

c. Maintain the slope of lines toward drains to ensure proper drainage.

d. Check the lines for leaks.

12-62. RELOCATON OF PITOT TUBE. If pitot tube relocation is necessary, perform therelocation in accordance with the manufacturer’s recommendations and consider the following:

a. Freedom of aerodynamic disturbances caused by the aircraft.

b. Location protected from accidental damage.

c. Alignment with the longitudinal axis of the aircraft when in cruising flight.

12-63. TROUBLESHOOTING THE PITOT/STATIC PRESSURE SYSTEM.

a. If instruments are inoperative or erratic operation occurs, take the following action:

(1) Check for clogged lines. Drain lines at the valves (especially after aircraft has beenexposed to rain). Disconnect lines at the instruments and blow them out with low-pressure air.

(2) Check lines for leaks or looseness at all connections. Repair as required.

b. If the pitot heating element(s) are [in]operative, check the following:

(1) Are circuit breaker(s) tripped?

Table 12-1. Color codes for pitot-static systems.

…Continued



12-19 Section 4 continued…(2) Reset the circuit breaker to determine if:

(a) The system is OK, or(b) The circuit breaker trips again, if so:

1. Check the wiring continuity to the ground. If the switch(s) is defective, repairas necessary.

2. Check the heating element; replace it if it is defective.

Chapter 12, Section 4 is now Section 5, “Avionics Test Equipment” and the paragraphs arerenumbered, starting with 12-70 GENERAL.

End of main text Add a new Chapter 13, “Human Factors” to follow the last section of Chapter 12:

CHAPTER 13. HUMAN FACTORS

13-1. HUMAN FACTORS INFLUENCE ON MECHANIC’S PERFORMANCE. Toaccomplish any task in aviation maintenance at least three things must be in evidence. Amechanic must have the tools, data, and technical skill to perform maintenance. Only recentlyhas the aviation industry addressed the mechanic job functions, pressures, and stress, byidentifying those human factors (HF) that impact the mechanics performance.

13-2. THE FAA AVIATION SAFETY PROGRAM has condensed these HF reports into apersonal minimums checklist, which asks the mechanic to answer 10 ‘yes or no’ questions beforethe maintenance task is begun and 10 ‘yes or no’ questions after the task is completed. If themechanic answers “NO” to any of the 20 questions, the aircraft should not be returned toservice. We have provided the checklist in figure 13-1 for your evaluation and review. A colorcopy of the checklist is available from any Flight Standards District Office. Just ask for theAirworthiness Safety Program manager.

Figure 13-1. Personal Minimums Checklist



Changes to APPENDIX 1. GLOSSARY

2 Add new term:

calibration— a set of operations, performed in accordance with a definite document procedure,which compares the measurements performed by an instrument or standard, for the purpose ofdetecting and reporting, or eliminating by adjustment, errors in the instrument tested.

3 Add new term:

crack —is a partial separation of material caused by vibration, overloading, internal stresses,nicks, defective assemblies, fatigue, or rapid changes in temperature.

6 Add new term:

inverter— a device for converting direct current to alternating current.

7 Add new term:

rectifier —a device for converting alternating current to direct current.

Changes to APPENDIX 2. ACRONYMNS AND ABBREVIATIONS

1 Replace the definition for “AFDS” as follows:

AFDS—autopilot flight director system

ac 43.13-1b update - ercoupe parts

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