Airworthiness Directive · Amendment 39-15175 · Learjet Model 31, 31A, 35, 35A (C-21A), 36, 36A, 55, 55B, and 55C Airplanes, and Model 45 Airplanes
Learjet Model 31, 31A, 35, 35A (C-21A), 36, 36A, 55, 55B, and 55C Airplanes, and Model 45 Airplanes
This AD applies to Learjet Model 31, 31A, 35, 35A (C-21A), 36, 36A, 55, 55B, and 55C airplanes, and Model 45 airplanes; certificated in any category; as identified in the service information specified in Table 1 of this AD.
| Learjet airplane model | Service Bulletin | Revision level | Date |
|---|---|---|---|
| 31/31A | Bombardier Service Bulletin 31-54-2 | 1 | August 21, 2006. |
| 45 | Bombardier Service Bulletin 45-54-3 | 2 | August 15, 2003. |
| 35/35A (C-21A) and 36/36A | Learjet Service Bulletin 35/36-54-3 | Original | March 16, 2001. |
| 55/55B/55C | Learjet Service Bulletin 55-54-3 | Original | March 16, 2001. |
The FAA is adopting a new airworthiness directive (AD) for certain Learjet Model 31, 31A, 35, 35A (C-21A), 36, 36A, 55, 55B, and 55C airplanes, and Model 45 airplanes. This AD requires inspecting for unsealed gaps on the pylon side of the engine firewall and cleaning/ sealing any unsealed gap; and, for certain airplanes, inspecting for unsealed gaps of the pylon trailing edge and cleaning/sealing any gap. This AD results from a report that unsealed gaps (penetration points) of the engine firewall were discovered during production. We are issuing this AD to prevent penetration of flammable liquids or fire through the engine firewall into the engine pylon, which could lead to fire inside the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Within 12 months after the effective date of this AD, do the actions described in paragraphs (f)(1) and (f)(2) of this AD, in accordance with the applicable service information specified in Table 1 of this AD.
(1) For all airplanes: Inspect for unsealed gaps on the pylon side of the engine firewall and clean and seal any unsealed gap.
(2) For Learjet Model 45 airplanes only: Inspect the engine pylon trailing edge for unsealed gaps, and clean and seal any unsealed gap.
Actions accomplished before the effective date of this AD according to Learjet Service Bulletin 31-54-2, dated March 16, 2001; or Bombardier Service Bulletin 45-54-3, dated March 16, 2001; or Revision 1, dated December 12, 2001; as applicable; are considered acceptable for compliance with the corresponding action specified in this AD.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
