# AD 84-19-06: Tab Control System - Type: Airworthiness directive - Status: Current - Products: Learjet 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E, 24F, 24F-A, 25, 25A and 13 more - Effective: October 22, 1984 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small/large airplane - Amendment: 39-4919 - Registered aircraft: 347 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D964B530898F72A6862569880076048B.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/84-19-06 ## The airworthiness directive 84-19-06 GATES LEARJET: Amendment 39-4919. Applies to the following model/series airplanes certificated in all categories except airplanes modified in accordance with Supplemental Type Certificate SA944NW (Dee Howard XR Modification). Compliance required as indicated unless already accomplished. MODEL SERIAL NUMBERS 24 100 thru 357 25 003 thru 369 28 001 thru 005 29 001 thru 004 35 001 thru 514 36 001 thru 053 55 001 thru 105 To prevent aileron/trim tab flutter due to a failure or disconnect of the tab control system, accomplish the following: A. Within the next 600 hours time in service, or the next aileron/trim tab removal or rebalance, whichever occurs first, replace the trim tab balance weight and rebalance the left aileron in accordance with the instructions in Gates Learjet Corporation Airplane Modification Kit Number AMK 83-3 for Models 24, 25, 28, 29, 35, and 36; and AMK 55-83-3 for Model 55. B. Special flight permits may be issued in accordance with FAR 21.197 to operate airplanes to a base in order to comply with the modification requirements of this AD. C. Alternate means of compliance with this AD which provide an equivalent level of safety may be used when approved by the Manager, Wichita Aircraft Certification Office, FAA, Central Region. All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Gates Learjet Corporation, P.O. Box 7707, Wichita, Kansas 67277. These documents may also be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington. This amendment becomes effective October 22, 1984. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A10CE](https://openairdocs.org/tcds/A10CE): Learjet Inc.; names 25 of 29 models: 24, 24A, 24B, 24B-A, 24C, 24D, 24D-A, 24E… ## 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: 347 (347 by airframe model, 0 by engine model) - Makers: Gates Learjet 219, Gates Lear Jet 80, Learjet 48 Models with the most aircraft: - [Gates Learjet 35A](https://openairdocs.org/model/gates-learjet-35a): 135 aircraft (airframe model) - [Gates Learjet 55](https://openairdocs.org/model/gates-learjet-55): 54 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) - [Gates Learjet 55C](https://openairdocs.org/model/gates-learjet-55c): 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 55](https://openairdocs.org/model/learjet-55): 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) - [Gates Learjet 55B](https://openairdocs.org/model/gates-learjet-55b): 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) All 26 models: https://openairdocs.org/ad/84-19-06/models.md Every aircraft: https://openairdocs.org/ad/84-19-06/aircraft.md ## Related documents - [STC SA944NW](https://openairdocs.org/stc/SA944NW): Installation of the XR Drag Reduction System. Avcon Industries Inc, Named in the applicability --- 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.