81-21-03 BRITISH AEROSPACE CORPORATION: Amendment 39-4229. Applies to all operators of DH-114 Heron Series 1B and all series 2 airplanes which have been modified in accordance with Modification 154 or 469.
To ensure wing leading edge access doors remain properly secured, accomplish the following unless already accomplished:
1. Within 350 hours time in service after the effective date of this AD, modify the wing leading edge access doors in accordance with British Aerospace Corp. Manufacturer's Technical News Sheet W.1 1, Issue 2, and Modification No. Heron 1171 (Amendment No. 1 incorporated) dated October 17, 1961, or a later FAA approved revision.
2. Alternate means of compliance may be used which provide an equivalent level of safety when approved by the Chief, Seattle Area Aircraft Certification Office, FAA, Northwest Region.
3. Airplanes may be flown to a maintenance base for repairs or replacement in accordance with FAR 21.197.
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 directive who have not already received these documents from the manufacturer may obtain copies upon request to the addresses listed above. These documents may also be examined at FAA, Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108.
This amendment becomes effective October 18, 1981.