AD 82-18-09

82-18-09 AIRCRAFT TANK SERVICE, INC.: Amendment 39-4449. Applies to Lockheed Model 1329 series airplanes, Avions Marcel Dassault Model Fan Jet Falcon series airplanes, and British Aerospace (Aircraft Group) Model DH-125 series airplanes which have been modified in accordance with STC SA2603WE, SA3221WE, SA3324WE, SA1851WE, or SA3382WE, certificated in all categories.

Compliance required as indicated, unless already accomplished.

To prevent possible engine fuel starvation, accomplish the following:

A. Within the next 30 calendar days after the effective date of this AD, or before the accumulation of two years calendar time since the installation of tygothane tubing, whichever occurs later, inspect to determine the condition of the tygothane components in accordance with the appropriate service bulletin listed in the table below.

1. If there is cracking or brittleness, discontinue use of the single point refueling system and within 90 calendar days after the inspection, remove tygothane tubing systems components and replace with like serviceable components in accordance with Part III of the appropriate service bulletin. The appropriate service bulletin for each type airplane is shown below.

Model STC No. Aircraft Tank Service, Inc. Service Bulletin Fan Jet Falcon SA1851WE A28-01 Rev. 1 dated January 21, 1982 DH-125 SA3382WE A28-02 Rev. 1 dated February 5, 1982 1329 SA2603WE A28-04 Rev. 1 dated January 29, 1982, or A28-05 Rev. 1 dated February 5, 1982 (see Service Bulletin effectivity) 1329 SA3221WE A28-05 Rev. 1 dated February 5, 1982 1329 SA3324WE A28-05 Rev. 1 dated February 5, 1982

2. If there is no cracking or brittleness but a chocolate brown color noted, continue operation and repeat inspection at six months from initial inspection and replace tygothane components per appropriate service bulletin within one year from initial inspection.

3. If the tygothane components are light colored, continue toinspect in accordance with paragraph A. of this AD at intervals not to exceed six months until such time as the tygothane components are replaced in accordance with Part III of the appropriate service bulletin.

B. After the effective date of this AD, if difficulty in pressure refueling or spillage out of the vent line is encountered, inspect per paragraph A. of this AD, and:

1. If the tygothane tubing has started to break up and there is evidence of tygothane particles in the tank which could cause fuel system contamination, replace the tygothane tubing prior to next flight per Part III of the appropriate Service Bulletin.

2. If cracking or embrittlement is found without evidence of loose particles, discontinue use of the single point fueling system and replace the tygothane tubing within 90 days after the inspection in accordance with Part III of the appropriate Service Bulletin.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 tooperate aircraft to a base for the accomplishment of inspections or modifications required by this AD.

D. Alternate means of compliance which provide an equivalent level of safety may be used when approved by the Chief, Western Aircraft Certification Field Office, FAA Northwest Mountain Region, Hawthorne, California.

The manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1).

All persons affected by this proposal who have not already received these documents from the manufacturer may obtain copies upon request to Aircraft Tank Service, Inc., Product Support Engineering, P.O. Box 1307, Sun Valley, California 91352. These documents may also be examined at FAA Northwest Mountain Region, 17900 Pacific Highway South, C-68966, Seattle, Washington 98168; or Western Aircraft Certification Field Office, 15000 Aviation Boulevard, Hawthorne, California 90261.

This amendment becomes effective October 4, 1982.