Airworthiness Directive · Amendment 39-11950 · Learjet Model 45 Series Airplanes
Learjet Model 45 Series Airplanes
Superseded. A later AD replaced this one: AD 2003-17-08. Comply with the one in force.
Model 45 series airplanes, serial numbers 45-001 through 45-114 inclusive; certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD), applicable to certain Learjet Model 45 series airplanes, that requires repetitive application of grease to the rotating disk assembly of the nose landing gear squat switch mechanism. Application of grease to the squat switch assembly is necessary to prevent moisture contamination and subsequent formation of ice. Such ice formation could result in bending or damaging of the nose landing gear squat switch assembly, which could drive the nose wheel to an uncommanded angle against the force of the steering system. This condition, if not corrected, could result in the airplane departing from the runway at high speeds during landing.
To prevent the airplane from departing the runway at high speeds during landing due to bending and damage to the squat switch assembly of the nose landing gear, accomplish the following:
(a) Within 30 days after the effective date of this AD, apply grease to the rotating disk assembly of the squat switch mechanism of the nose wheel in accordance with Bombardier Aerospace Service Information Letter SIL 32-016, dated March 30, 2000. Thereafter, repeat this application at intervals not to exceed 30 days.
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.
Aircraft
