AD 87-03-12

87-03-12 DEHAVILLAND: Amendment 39-5549. Applies to DHC-6 Models 1, 100, 200, and 300 airplanes certificated in any category, when fitted with side folding cabin utility seats.

Compliance: Required as indicated, unless already accomplished.

To prevent disengagement of the utility seat forward legs from the floor mounting rail, accomplish the following:

(a) Within 50 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished within the last 25 hours TIS, and at subsequent intervals not to exceed 50 hours TIS thereafter, attempt to move the lower end of each forward leg sideways into the open part of the keyhole slot using as much force as can be exerted by hand. If the leg can be removed from the keyhole slot, remove the seat from service until Modification No. 6/1828 is incorporated in accordance with the ACCOMPLISHMENT INSTRUCTIONS of DeHavilland Service Bulletin (S/B) No. 6/447, Revision C, dated May 16, 1986.

(b) Repeat thecheck in paragraph (a) of this AD each time the seats are moved from stowed to deployed position.

(c) The check required by paragraph (b) of this AD may be accomplished by a flightcrew member, certificated under FAR 61 or FAR 63 rules, briefed on the procedure.

(d) When Modification No. 6/1828 is incorporated in accordance with the ACCOMPLISHMENT INSTRUCTIONS of DeHavilland S/B No. 6/447, Revision C, on each seat, subsequent checks required by this AD are no longer required on that seat.

(e) An equivalent means of compliance may be used when approved by the Manager, New York Aircraft Certification Office, Federal Aviation Administration, ANE-170, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581.

This AD supersedes AD 84-07-07, Amendment 39-4841.

This amendment becomes effective on February 13, 1987.