AD 81-13-07

81-13-07 GATES LEARJET: Amendment 39-4139. Applies to Models 23 (Serial Numbers 003 through 099), Model 24 Series (Serial Numbers 003 through 357), Model 25 Series (Serial Numbers 003 through 341 except 337), Model 28 (Serial Numbers 001 through 005), Model 29 (Serial Numbers 001 through 003), Model 35 Series (Serial Numbers 001 through 415) and Model 36 Series (Serial Numbers 001 through 047) airplanes.

COMPLIANCE: Required as indicated unless already accomplished.

To ensure operation without fuel starvation, within the next 50 hours time-in-service after the effective date of this AD, accomplish the following:

A) Insert in the Airplane Flight Manual the FAA Approved temporary changes shown hereinafter as Figures I, II, and III or the FAA Approved Flight Manual changes (temporary or permanent) supplied by the manufacturer and containing the same information as the above figures.

B) Operate the airplane in accordance with instructions in the Airplane Flight Manual changes specified in Paragraph A of this AD.

C) Any equivalent method of compliance with this AD must be approved by the Chief, Aircraft Certification Program Office, Room 238, Terminal Building 2299, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 942-4285.

This Amendment becomes effective on June 25, 1981.

FIGURE I

TEMPORARY FLIGHT MANUAL CHANGE Description of Change: Add Limitation to Section I of the Airplane Flight Manual. Filing Instructions: Insert this page adjacent to the "Takeoff and Landing operational Limits" in section 1 -Limitations in your Airplane Flight Manual:

Amend Section I - TAKEOFF AND LANDING OPERATIONAL LIMITS by adding the following Limitation:

FUEL LOAD - MINIMUM 600 POUNDS IN EACH WING REQUIRED FOR TAKEOFF AND INTENTIONAL GO-AROUND.

FIGURE II

TEMPORARY FLIGHT MANUAL CHANGE Description of Change: ADD Minimum Fuel Quantity Warning to Section II of the Airplane Flight Manual Filing Instructions: Insert this page adjacent to the "After Takeoff checklist of Section II - NORMAL PROCEDURES in your Airplane light Manual. Add the following warning:

AFTER TAKEOFF:

WARNING: When the fuel quantity gage indicates 600 pounds of less remaining in either wing tank, prolonged nose up attitude of 10 degrees or more may cause fuel to be trapped in the aft area of the wing tank outboard of the wheel well. Fuel starvation and engine flameout may occur. Reducing pitch attitude and thrust to minimum required will prevent this situation.

FIGURE III

TEMPORARY FLIGHT MANUAL CHANGE Description of Change: ADD Minimum Fuel Quantity Warning to Section II of the Airplane Flight Manual Filing Instructions: Insert this page adjacent to the "Go-Around/Balked Landing" checklist of Section II-NORMAL PROCEDURES in your Airplane Flight Manual. ADD the following warning:

GO-AROUND/BALKED LANDING (ONE OR TWO ENGINE):

WARNING: When the fuel quantity gage indicates 600 pounds or less remaining in either wing tank, prolonged nose up attitude of 10 degrees or more may cause fuel to be trapped in the aft area of the wing tank outboard of the wheel well. Fuel starvation and engine flameout may occur. For go-around conditions with low fuel, on first steady indication by the LOW Fuel warning light, reduce climb attitude and thrust to minimum required.