AD 83-02-01 ACTIVE

83-02-01 DeHAVILLAND: Amendment 39-4551. Applies to Model DHC-3 (Military U-IA) airplanes certificated in any category.

COMPLIANCE: Required within 30 days after the effective date of this AD unless already accomplished in the last 11 months, and at intervals not to exceed each 12 months thereafter, unless already accomplished.

To prevent corrosive deterioration of the wing strut to fuselage attachment structure, accomplish the following:

a) Visually inspect each wing strut tie-bar for internal corrosion in accordance with paragraph 5 in the Inspection Section of Service Bulletin S/B No. 3/37 Rev. "A" dated May 14, 1982 (hereinafter referred to as the Service Bulletin).

1) If no corrosion is found, proceed to the inspection specified in paragraph b) of this AD.

2) If evidence of corrosion is found, prior to further flight, remove corrosion, check for depth of corrosion and inspect for cracks using dye penetrant methods as prescribed in paragraph 6 of the Replacement Section of the Service Bulletin.

i. If corrosion is within limits and no cracks are evident, proceed to the inspection in paragraph b) of this AD.

ii. If corrosion exceeds limits, or cracks are evident, replace the tiebar with an airworthy part in accordance with the Replacement Section of the Service Bulletin.

b) Visually inspect all tie-bar lugs for corrosion in accordance with paragraph 9 of the Inspection Section of the Service Bulletin.

1) If no corrosion is found and paragraph a) of this AD has been complied with the airplane may be returned to service.

2) If evidence of corrosion is found, prior to further flight, remove corrosion, check lug minimum thickness and, using a dye penetrant, check lug for cracks in accordance with paragraphs 9 through 11 of the Inspection Section of the Service Bulletin.

i. If lug minimum thickness is within limits and no cracks were found and paragraph a) of this AD above has been complied with, the airplane may be returned to service.

ii. If lug minimum thickness does not meet minimum specified thickness or, if cracks are found, prior to further flight, replace the tie-bar in accordance with the Replacement Section of the Service Bulletin.

c) The airplane may be flown in accordance with FAR 21.197 to a location where the requirements of this AD may be accomplished.

d) An equivalent method of compliance with this AD may be used if approved by the Manager, New York Aircraft Certification Office, ANE-170, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581.

This amendment becomes effective on February 3, 1983.