AD 78-09-04

78-09-04 HAWKER SIDDELEY AVIATION LIMITED: Amendment 39-3200. Applies to Model DH-104 "Dove" airplanes, all series, certificated in all categories, except those airplanes incorporating Hawker Siddeley Model DH-104 Modification 779.

Compliance is required as indicated.

To detect cracking and prevent possible failure of the lugs of the lower center section main spar wing to fuselage attachment, accomplish the following:

(a) Within one month after the effective date of this AD, unless already accomplished within the last month, and thereafter at intervals not to exceed two months from the last inspection, remove the lower wing to fuselage fairings and inspect the center section main spar bottom boom lugs for cracks using an ultrasonic inspection method in accordance with appendix 1 of Hawker Siddeley Aviation, Limited Technical News Sheet (TNS) 238, issue 2, dated January 24, 1977, or an FAA-approved equivalent.

(b) The repetitive inspections required by paragraph(a) of this AD may be terminated upon incorporation of a steel lower boom in accordance with Hawker Siddeley Model DH-104 Modification 779, or an FAA-approved equivalent.

(c) Within two months after accomplishing six repetitive inspections under paragraph (a) of this AD, a steel lower boom must be incorporated in accordance with Hawker Siddeley Model DH-104 Modification 779, or an FAA-approved equivalent.

(d) If any crack is found during an inspection required by paragraph (a) of this AD, before further flight, replace the boom with a steel boom in accordance with Hawker Siddeley Model DH-104 Modification 779, or an FAA-approved equivalent.

This amendment becomes effective May 24, 1978.