AD 81-06-07 ACTIVE

81-06-07 GULFSTREAM AMERICAN CORPORATION (formerly Grumman American Corporation, Grumman Aerospace Corporation): Amendment 39-4054. Applies to Gulfstream American Model G-1159, serial numbers 1 through 258, and 775, certificated in all categories.

Compliance is required as indicated, unless already accomplished. To prevent improper functioning of the landing gear system, accomplish the following:

Within the next 10 hours time in service after the effective date of this AD, inspect the landing gear selector valve to determine valve part number (Ref. Gulfstream II Illustrated Parts Catalog (IPC) Figure 32-23, Item 52).

(a) If P/N 1159SCH216-1 or P/N 1159SCH216-5 is installed, no further action is required.

(b) If P/N 1159SCH216-3 is installed, accomplish the following:

(1) Before further flight, install placard adjacent to the landing gear selector handle. The wording of the placard shall be: "INTERRUPTION OF LANDING GEAR RETRACTION OR EXTENSION PROHIBITED",using letters of 1/8 inch minimum height. Concurrently, FAA Approved Flight Manual Supplement No. GII-81-01, dated February 6, 1981, must be added to the Airplane Flight Manual. The Flight Manual Supplement may be obtained from Gulfstream American Corporation, P.O. Box 2206, Savannah, Georgia 31402.

(2) Within 60 landing gear operating cycles (one retraction and one extension) after effective date of this AD, replace P/N 1159SCH216-3 landing gear selector valves with either a P/N 1159SCH216-1 or a P/N 1159SCH216-5 valve. Remove the placard and the Airplane Flight Manual Supplement added in section (1) when either of the replacement valves is installed.

An equivalent method of compliance may be approved by the Chief, Engineering and Manufacturing Branch, FAA Southern Region.

NOTE: Information concerning replacement selector valves may be obtained from Gulfstream American Corporation Customer Bulletin No. 305, amendment No. 1, January 15, 1981.

This amendment is effective March 27, 1981.