AD 81-06-06

Airworthiness directive · Fuel Feed Lines · Garrett AiResearch TFE-731-3-1H engines (AlliedSignal Aviation Services STC SA3870WE)

Effective
March 26, 1981
Models
BH.125 Series 400A, BH.125 Series 600A, DH.125 Series 3A, DH.125 Series 3A/R, DH.125 Series 3A/RA, DH.125 Series 400A, HS.125 Series 600A
Data sheet
TCDSA3EU
Registered aircraft
4 matched by model
Product
Aircraft · Large airplane
Amendment
39-4065

Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed January 21, 2026.

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The airworthiness directive

81-06-06 BRITISH AEROSPACE: Amendment 39-4065. Applies to Model HS/DH/BH- 125 airplanes series -3A/R, -3A/RA, and -3A/RA with British Aerospace Modification 25/2600 installed; series -400A and -400A with British Aerospace Modification 25/2550 or STC SA3870WE installed; and series -600A and -600A with British Aerospace Modification 25/2468 installed, certificated in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent restricted movement of the flap control unit input lever and chafing of the left engine fuel line due to possible interferences, accomplish the following:

(a) Within 50 hours time in service after the effective date of this AD, inspect:

(1) For chafing of the left engine fuel feed line; and

(2) For recommended clearance between the fuel feed line and the flap control unit input lever in accordance with paragraph 2A(1), (2), and (3) of the Accomplishment Instructions of British Aerospace Service Bulletin28-69, Revision 1, dated June 25, 1979 (hereinafter referred to as the service bulletin) or an equivalent approved by the Chief, Aircraft Certification Staff, Federal Aviation Administration, Europe, Africa, and Middle East Office, Brussels, Belgium.

(b) If as a result of the inspections required in paragraph (a) of this AD -

(1) Chafing or other damage to the fuel line is found, before further flight, except that aircraft may be flown in accordance with FAR Section 21.197 to a base where the work can be performed, replace the fuel line with a serviceable fuel line of the same P/N.

(2) Clearance between the engine fuel feed line and the flap control unit input lever is found to be less than 0.15 inches, before further flight, increase the clearance in accordance with paragraph 2A(4) of the service bulletin.

(c) Upon completion of the actions required in paragraphs (a) and (b) of this AD, return the aircraft to service in accordance with paragraphs 2A(5) and 2A(6)of the service bulletin.

This amendment becomes effective March 26, 1981.

Affected TCDS · 1

The type certificate data sheets for the models this AD names, matched by model and maker.

Registered aircraft · 4

Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.

By aircraft maker
  • Hawker Siddeley4 aircraft
By year built
19681971
Registered aircraft by year built: 3 aircraft
19681
19701
19711

1 with no year recorded

By model

Aircraft