Construction Types, AD's & SB's

Construction Types & Repairability

Goodyear / Loral / Engineered Fabrics / Meggitt (multi-ply urethane) Repairable?
Pre-1960 Pliocel All nylon construction, becomes very brittle No
1960-70 BTC-39 Condemned - AD 78-05-06 No
1970-72 BTC-54A Soft urethane similar to BTC-39 but thicker No
1973-78 BTC-67 Urethane becomes stiff & brittle, nipples break off No
1979-88 BTC-85 Better urethane construction with nitrile nipples Sometimes
1988-on BTC-99 Latest construction weakens in alcohol & aromatics Yes
A.I.R. / Duralite (1-ply urethane) / FFC MFG. (1-ply nitrile) Repairable?
1979-94 P-2315 Low-grade urethane, nipples break off body crumbles No
1994-99 P-2393 Similar to 1975-91 Uniroyal, weak nipples, seams Sometimes
2000-on P-2393 Better Usually
US Rubber (multi-ply nitrile) / Uniroyal (1-ply nitrile) / AmFuel Repairable?
1946-55 US-538N Durable military construction becomes stiff with age Rarely
1956-on US-566R Durable military construction Usually
1956-59 US-584 Nitrile coated cotton fabric, dries out, shrinks, and tears Rarely
1956-61 US-588 Durable military construction Usually
1959-62 US-907 Extremely thin material No
1963-74 US-943 Durable, gusseted corners, medium weight fabric Usually
1975-91 US-943 Less durable, stiff folded corners lower quality fabric Usually
Aero-Tech Services / A.T.S. (2-ply nitrile) Repairable?
1976-90 201 Blisters and separations, shrinkage, not ozone resistant Not worth it
1991-on 201 Shrinkage issue similar to US-584 Not Worth it
Graham Lott Ent. / Duraflex / A/C Fuel Cells Worldwide / A/C Team (1-ply nitrile) Repairable?
1985-2002 Thin material, leaks extensively, weak seams No

(Unapproved parts notice #96-269 April 13, 1999)

Eagle Technologies Co. (multi ply) Repairable?
2001-09 EMS7 Original nitrile susceptible to drying out in low fuel Usually
2010-on EMS7 New polymer developed to resist increased aromatics Yes

Maintenance Issues

AD 78-05-06 All Goodyear BTC-39 fuel cells: Condemned at removal
AD 84-10-01R1 Cessna 180 to 210 filler caps/ wrinkles/ quick drains
Check out our valve STC
AD 90-21-08 Cessna 180: add a left hand vent on early models
AD 90-23-18R1 Piper PA-23: Wedge kits field installed in inboard aft corner of fuel cells trap more water than original problem and should be removed!

Beech MSB 2109 Some Barons and Bonanzas equipped with baffle boxes must replace deteriorating brown safety foam with Type IV blue safety foam.

Venting Bent or broken vents or vents lines restricted by ice or insect nests cause a vacuum that unsnaps cell causing uneven flow and or false fuel quantity indications.

New Fuels Increased quantities of oxygenates, toluene, and other aromatics used to boost octane in auto gas, 100LL and new fuels degrade rubber parts like o-rings & hoses.


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