Airworthiness Directive · Amendment 39-19404 · Te flap control system
Learjet, Inc. Airplanes
(1) This AD applies to the Learjet, Inc. model airplanes that are certificated in any category, as listed in table 1 to paragraph (c) of this AD.
We are adopting a new airworthiness directive (AD) for certain Learjet, Inc. Models 28, 29, 31, 31A, 35, 35A, 36, 36A, 55, 55B, 55C, and 60 airplanes. This AD was prompted by fatigue cracks initiating in the flap support structure due to repetitive flap loads, which has caused flap nose roller support bracket failure. This AD requires replacement of the flap nose roller fitting, nose roller support bracket, and adjacent rib support structure with improved components. We are issuing this AD to address the unsafe condition on these products.
(1) For Models 28 and 29 airplanes:
(i) Within 24 months after October 23, 2018 (the effective date of this AD) or within 400 landings after October 23, 2018 (the effective date of this AD), whichever occurs first, replace the nose roller fitting, nose roller support bracket, and adjacent rib support structure with replacement parts by following the Accomplishment Instructions in Bombardier Learjet 28/29 Service Bulletin SB 28/29-27-31 Recommended, dated September 11, 2017.
(ii) Although Paragraph 3.B.(1) of the applicable SB for these models that have modified flap roller assemblies requires the operator to contact Learjet Inc. for repair instructions, this AD requires that you do the repair using a method approved by the Manager, Wichita ACO Branch, FAA. For a repair method to be approved by the Manager, Wichita ACO Branch, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
(2) For Models 31 and 31A airplanes: Within 24 months after October 23, 2018 (the effective date of this AD) or within 400 landings after October 23, 2018 (the effective date of this AD), whichever occurs first, replace the nose roller fitting, nose roller support bracket, and adjacent rib support structure with replacement parts by following the Accomplishment Instructions in Bombardier Learjet 31 SB 31-27-35 Recommended, dated September 11, 2017.
(3) For Models 35, 35A, 36, and 36A airplanes: Within 24 months after October 23, 2018 (the effective date of this AD) or within 400 landings after October 23, 2018 (the effective date of this AD), whichever occurs first, replace the nose roller fitting, nose roller support bracket, and adjacent rib support structure with replacement parts by following the Accomplishment Instructions in Bombardier Learjet 35/36 SB 35/36-27-50 Recommended, dated September 11, 2017.
(4) For Models 55, 55B, and 55C airplanes: Within 24 months after October 23, 2018 (the effective date of this AD) or within 400 landings after October 23, 2018 (the effective date of this AD), whichever occurs first, replace the nose roller fitting, nose roller support bracket, and adjacent rib support structure with replacement parts by following the Accomplishment Instructions in Bombardier Learjet 55 SB 55-27-41 Recommended, dated September 11, 2017.
(5) For Model 60 airplanes: Within 12 months after October 23, 2018 (the effective date of this AD) or within 200 landings after October 23, 2018 (the effective date of this AD), whichever occurs first, replace the nose roller fitting, nose roller support bracket, and adjacent rib support structure with replacement parts by following the Accomplishment Instructions in Bombardier Learjet 60 SB 60-27-39 Recommended, Revision 1, dated January 15, 2018.
(6) For all airplanes: Some compliance times in this AD are presented in landings. If you do not keep a record of the total number of landings, then use a 1-to-1 conversion for hours time-in-service (TIS) to landings. Example: 20 hours TIS = 20 landings.
(7) For Models 31, 31A, 35, 35A, 36, 36A, 55, 55B, 55C, and 60 airplanes: Although Paragraph 3.B.(2) of the applicable SB for these models that have modified flap roller assemblies requires the operator to contact Learjet Inc. for repair instructions, this AD requires you do the repair using a method approved by the Manager, Wichita ACO Branch, FAA. For a repair method to be approved by the Manager, Wichita ACO Branch, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
