AD 86-20-04 ACTIVE

86-20-04 ARCTIC AIRCRAFT COMPANY: Amendment 39-5412. Applies to Arctic Model Interstate S-1B2 "Tern" (Serial Numbers 1001 through 1029) airplanes certificated in any category.

Compliance: Required within the next 100 hours time-in-service (TIS) or within 31 calendar days after the effective date of this AD, whichever comes first, unless already accomplished.

To preclude the possibility of catastrophic flutter of the ailerons and/or the elevators during flight at high speeds, resulting in possible loss of the airplane, accomplish the following:

(a) Re-mark the airspeed indicator by removing that portion of the yellow arc that presently extends from 142 miles per hour (123 knots) to 160 miles per hour (139 knots), and the red radial line presently located at 160 miles per hour (139 knots), and marking a red radial line located at 142 miles per hour (123 knots).

(b) Replace the existing Airplane Flight Manual (AFM) with the FAA approved Airplane Flight Manual forthe Arctic Model Interstate S-1B2 airplane, Revision 7 dated April 15, 1986. If the airplane is currently operated as a seaplane, detach the FAA approved Seaplane Flight Manual Supplement from the existing Airplane Flight Manual and attach it to the new Manual. Also, detach any FAA approved Airplane Flight Manual Supplements, required with currently-installed major alterations, from the existing Airplane Flight Manual and attach them to the new Manual.

(c) Check the airplane's instrument panel to determine if there is a placard reading "SEAPLANE MANEUVERING SPEED 105 MPH (CAS)" and "SEAPLANE MAXIMUM SPEED 142 MPH (CAS)". If so, remove the existing placard and replace it with the placard reading "SEAPLANE MANEUVERING SPEED 105 MPH (CAS)", supplied with Arctic Aircraft Company Service Bulletin No. 5.

(d) Accomplish the actions required in paragraph (a) of this AD at a certificated repair station with a Class 1 instrument rating or an appropriate limited instrument rating. The checks and actions required in paragraphs (b) and (c) of this AD may be accomplished by the owner/operator. Make the entries in the airplane's maintenance records documenting the accomplishment of the inspections, checks, and actions required by this AD as prescribed by FAR 91.173.

(e) An equivalent means of compliance with this AD may be used if approved by the Manager, Anchorage Aircraft Certification Office (ANM-100A); FAA; 701 C Street, Box 14; Anchorage, Alaska 99513.

All persons affected by this directive may obtain copies of the documents referred to herein upon request to Arctic Aircraft Company, Post Office Box 6-141, Anchorage, Alaska 99502; Telephone (907) 243-1580; or FAA, Office of the Regional Counsel; Room 1558, 601 East 12th Street, Kansas City, Missouri 64106.

This amendment becomes effective on October 12, 1986.