# AD 81-13-07: Change to AFM Fuel Starvation - Type: Airworthiness directive - Status: Current - Products: Learjet 23, 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25 and 11 more - Effective: June 25, 1981 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-4139 - Registered aircraft: 286 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A71FF78F7C60128F862569F10073C228.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/81-13-07 ## The airworthiness directive 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. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A10CE](https://openairdocs.org/tcds/A10CE): Learjet Inc.; names 22 of 29 models: 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E… - [TCDS A5CE](https://openairdocs.org/tcds/A5CE): Learjet Inc.; names 1 of 1 models: 23 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 286 (286 by airframe model, 0 by engine model) - Makers: Gates Learjet 156, Gates Lear Jet 80, Learjet 50 Models with the most aircraft: - [Gates Learjet 35A](https://openairdocs.org/model/gates-learjet-35a): 135 aircraft (airframe model) - [Learjet 35A](https://openairdocs.org/model/learjet-35a): 24 aircraft (airframe model) - [Gates Lear Jet 36A](https://openairdocs.org/model/gates-lear-jet-36a): 21 aircraft (airframe model) - [Gates Learjet 25D](https://openairdocs.org/model/gates-learjet-25d): 20 aircraft (airframe model) - [Gates Lear Jet 35](https://openairdocs.org/model/gates-lear-jet-35): 16 aircraft (airframe model) - [Gates Lear Jet 36](https://openairdocs.org/model/gates-lear-jet-36): 13 aircraft (airframe model) - [Gates Lear Jet 25B](https://openairdocs.org/model/gates-lear-jet-25b): 12 aircraft (airframe model) - [Learjet 24](https://openairdocs.org/model/learjet-24): 7 aircraft (airframe model) - [Gates Lear Jet 24D](https://openairdocs.org/model/gates-lear-jet-24d): 7 aircraft (airframe model) - [Learjet 23](https://openairdocs.org/model/learjet-23): 6 aircraft (airframe model) - [Learjet 24D](https://openairdocs.org/model/learjet-24d): 4 aircraft (airframe model) - [Gates Lear Jet 24F](https://openairdocs.org/model/gates-lear-jet-24f): 4 aircraft (airframe model) - [Learjet 24B](https://openairdocs.org/model/learjet-24b): 3 aircraft (airframe model) - [Gates Lear Jet 28](https://openairdocs.org/model/gates-lear-jet-28): 3 aircraft (airframe model) - [Learjet 24A](https://openairdocs.org/model/learjet-24a): 2 aircraft (airframe model) - [Gates Lear Jet 24E](https://openairdocs.org/model/gates-lear-jet-24e): 2 aircraft (airframe model) - [Learjet 25](https://openairdocs.org/model/learjet-25): 2 aircraft (airframe model) - [Gates Lear Jet 25](https://openairdocs.org/model/gates-lear-jet-25): 1 aircraft (airframe model) - [Gates Lear Jet 25C](https://openairdocs.org/model/gates-lear-jet-25c): 1 aircraft (airframe model) - [Learjet 25D](https://openairdocs.org/model/learjet-25d): 1 aircraft (airframe model) All 23 models: https://openairdocs.org/ad/81-13-07/models.md Every aircraft: https://openairdocs.org/ad/81-13-07/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.