AD 76-06-08

76-06-08 HAWKER SIDDELEY AVIATION LTD: Amendment 39-2558. Applies to Model DH/BH 125 airplanes, all series, certificated in all categories.

Compliance is required as indicated.

To prevent possible failure of the original bolts attaching the outboard hinge bracket to the upper airbrake assembly (R/H and L/H) and loss of an airbrake in flight accomplish the following:

(a) For upper airbrake assemblies, within the next 10 hours time in service after the effective date of this AD or upon the accumulation of 500 hours total time in service on the airbrake assembly, whichever occurs later, unless already accomplished, remove installed bolts P/N S21A102-4E or A102-4EDHS614D (3 per bracket) and install new bolts -

(1) P/N S21A102-5E, or an FAA-approved equivalent, in accordance with paragraph A of the section entitled "Accomplishment Instructions" of Hawker Siddeley Aviation Limited Alert Service Bulletin 57 A49, dated July 1, 1975 or an FAA-approved equivalent; or(2) P/N S21DHS1432-5E or an FAA-approved equivalent in accordance with the section entitled "Accomplishment Instructions" (Part A) of Hawker Siddeley Aviation Ltd. Modification Service Bulletin 57 49 (2454) dated September 18, 1975, or an FAA-approved equivalent.

(b) Replace P/N S21A102-5E or FAA-approved equivalent bolts, installed as replacements in accordance with paragraph (a)(1) of this AD, at intervals not to exceed 500 hours time in service from installation until the bolts have been replaced with P/N S21DHS1432-5E bolts (3 per bracket) in accordance with paragraph (a)(2) of this AD or an FAA-approved equivalent.

(c) For upper airbrake assemblies held as spares, before installation on an airplane, replace the original bolts, P/N S21A102-4E or A102-4EDHS614D, (3 per bracket) with new bolts in accordance with paragraphs (a)(1) or (a)(2) of this AD.

This amendment is effective upon publication in the FEDERAL REGISTER as to all persons except those persons to whom it was made immediately effective by the airmail letter, dated February 9, 1976, which contained this amendment.