84-19-06: Tab Control System

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.