Lear 40/45 MLG Cylinder Inspection

April 2011

There has been a lot of discussion and confusion in regards to the inspection of the MLG Cylinder forging parting line and lower service port on the Lear 40 / 45 models.

When complying with Service Bulletins (SB) 45-32-30 or 40-32-13 (Landing Gear, Nondestructive Inspection (NDI) of the Main Landing Gear Shock Strut Cylinders), it is NOT required or advised to sign-off on the related IRNs that are referenced in the SBs themselves.

Compliance of the SB has NO EFFECT on the frequency or interval of the Inspection IRNs. The SB stands on its own merit and is a one-time inspection only. If the IRN was inadvertently signed off, the operator is NOT penalized and the initial inspection threshold stays the same. In discussions with Learjet, a letter of explanation can be obtained if needed.

The “Initial” interval for the applicable IRN stays the same. For reference purposes, the applicable IRNs and associated dash numbers and intervals are listed below. The base P/N is the same for all of them, which is 200-0201-XXX

IRN # P/N  Interval
3220118  -105 & -106   3,300 Ldgs Initial/ 600 Ldgs repeat
3220136 -101,-102,-103, -104,-107,-108 4,800 Ldgs Initial/ 600 Ldgs repeat
3220146 -109, -110 4,800 Ldgs Initial/ 600 Ldgs repeat