77-01-06 PIPER: Amendment 39-2806. Applies to Models PA-31 and PA-31-325, Serial Nos. 31-7612060 through 31-7612080, 31-7612082 through 31-7612089, 31-7612091, 31- 7612096 and 31-7612099; Model PA-31-350, Serial Nos. 31-7652105 through 31-7652115, 31- 7652117, 31-7652118, 31-7652120 through 31-7652146, 31-7652148 through 31-7652162, 31- 7652164, 31-7652165 and 31-7652168 and above model aircraft which have had a replacement horizontal stabilizer installed in the field subsequent to April 1976, certificated in all categories.
To prevent possible hazards in flight associated with missing horizontal stabilizer skin- stiffener rivet attachments, accomplish the following within the next fifty hours in service from the effective date of this AD unless previously accomplished:
(a) Inspect and, if required, repair the horizontal stabilizer skin-stiffener rivet attachment in accordance with the "Instructions" section of Piper Service Bulletin No. 521 or equivalent procedures approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.
This amendment is effective January 19, 1977.