AD 80-13-13

80-13-13 DEHAVILLAND: Amendment 39-3816. Applies to all DHC-6 model airplanes equipped with floats, certificated in all categories.

To prevent spreader strut lug failure and interference between float fitting and front strut, accomplish the following:

(a) On aircraft Serial Numbers 1 thru 611 incorporating S.0.0. 6002 and 6082 float and chassis installation, within 100 hours in service or one month, whichever occurs first, after the effective date of this AD, unless previously accomplished, incorporate modifications in accordance with DeHavilland Service Bulletin 6/330, Revision "C", dated February 29, 1980, or approved equivalent modification.

(b) On all aircraft with front spreader struts P/N C6UF1014-1, within 200 hours in service or two months, whichever occurs first, after the effective date of this AD, unless previously accomplished, incorporate modification in accordance with DeHavilland Service Bulletin 6/357, Revision "C", dated February 29, 1980, or approved equivalent modification.

(c) Equivalent modifications must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

(d) Compliance times may be increased by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, upon receipt of substantiating data submitted through an FAA Maintenance Inspector.

This amendment is effective July 1, 1980.