AD 78-14-06

78-14-06 GULFSTREAM AMERICAN CORPORATION (GAC) (FORMERLY GRUMMAN AMERICAN AVIATION CORPORATION: Amendment 39-3261 as amended by amendment 39-3313. Applies to GAC Model G-1159, serial numbers 1 through 229, and 775, airplanes certificated in all categories.

Compliance is required as indicated, unless already accomplished.

To prevent cabin window pane failure and possible engine damage, accomplish the following:

1. Prior to the accumulation of 600 landings on any window, or within the next 10 landings after the effective date of this AD, whichever occurs later, accomplish the following:

A. Inspect and replace all outer cabin window panes in accordance with GAC Customer Bulletin 270A, dated September 18, 1978, or later revision approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Southern Region, or in an equivalent manner approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, SouthernRegion. The visual checks for cracks required by Customer Bulletin 270A may be performed by the pilot. The remaining provisions of this AD apply to aircraft with any reduced thickness outer cabin window pane installed with 600 or more landings.

B. Restrict airplane operations to a maximum cabin pressure differential of 8.0 psi and install one of the following placards on the instrument panel in full view of the pilot, or in an equivalent location approved by the FAA, utilizing a minimum of 1/8 inch high letters with the wording:

1. "DO NOT EXCEED A MAXIMUM CABIN PRESSURE DIFFERENTIAL OF 8.0 PSI. THE TABLE CONTAINED IN GAAC LETTER DATED JUNE 20, 1978, MAY BE UTILIZED. COMPLY WITH THE INSPECTION REQUIREMENTS OF AD 78-14-06 PRIOR TO EACH FLIGHT."

2. "DO NOT EXCEED A MAXIMUM CABIN PRESSURE DIFFERENTIAL OF 8.0 PSI."

C. Incorporate G-1159 Airplane Flight Manual Interim Revision No. 19-5 dated September 21, 1978, in the Basic Airplane Flight Manual dated April 1, 1969.

2. Repeat the inspection and replacement requirements of paragraph (1)(A) of this AD prior to each flight.

3. The inspection requirements and restrictions on operation may be discontinued, and the AFM Interim Revision removed once all affected outer cabin window panes are either replaced with full thickness outer panes identified in accordance with GAC Customer Bulletin 270A dated September 18, 1978, or later revision approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Southern Region; or replaced with windows with less than 600 landings.

4. For the purpose of complying with this AD, subject to acceptance by the assigned FAA maintenance inspector, the number of landings may be determined by dividing each airplane's hours' time in service by the operator's fleet average time from take-off to landing for the airplane type. Alternately, if an operator has recorded pressure cycles, the number of pressure cycles may be used in lieu of landings.

Amendment 39-3261 became effective July 20, 1978.

This amendment 39-3313 becomes effective October 9, 1978.