Learjet Winter 2007

• Classic Lear 12-Year Inspections
• 40 Series Window Combings
• Be Proactive with Recommended Service Bulletins

Classic Lear 12-Year Inspections

— David Schiver

There is or will be a new revision of the 12-year inspections on all the Learjet line except for the 40 series A/C. This is to perform a detailed visual inspection of the mounting areas and doublers of all antennas and electrical equipment that penetrates the pressure vessel. This entails removing ALL antennas and electrical equipment that penetrates the press vessel. Depending on how your aircraft is equipped, this could add an additional 30 to 50 hours of labor to the 12-year inspection. Another addition to the 12-year inspection is to NDT the upper attach point for the nose gear actuator. This will add an additional 4.5 to 6 hours as well.

40 Series Window Combings

— David Schiver

Duncan Aviation has investigated the inspection item on the 40 series A/C that involves visually inspecting the polished window combings (IRN A5323031 on both models in the B1) with a 10X magnifying glass. In working with one of our core customers and the OEM, we have concluded that the best way to approach this item is as follows:

1. Clean each combing thoroughly with alcohol prior to inspecting. This will get any dirt, wax or polishing compound from the surface that could possibly appear as corrosion.
2. Inspect, per the maintenance manual with a 10X magnifying glass.
3. Identify suspected areas.
4. Use a “Q-Tip” and dab the suspected pit with chem film (Alodine 1200 or 600) and let it sit approximately 2 minutes to activate.
5. If the suspected spot is an active cell of corrosion, it will turn dark. You will then have to remove the spot through light blending. If it does not turn dark, just polish out the alodine and you are done.

Hopefully this will reduce the amount of blending on the combings to reach the expected life. There are discussions about a two-step ceramic coating that will protect the bare aluminum better as well. Stay tuned!

Be Proactive with Recommended Service Bulletins

— Brad Lennemann

Periodically, Bombardier releases Recommended Service Bulletins (S/B) that apply to the Learjet. These S/Bs are used to inform operators of modifications, substitutions or special checks required to maintain the aircraft, powerplant or equipment in safe operating condition.

There is usually no charge for parts and labor to comply with these S/Bs if your aircraft is under the five-year manufacturer warranty AND the S/B work is performed within 12-months of the date the bulletin was first released.

It is very important that you be proactive and comply with these S/Bs. Not only will your aircraft operate more efficiently and safely, but your Learjet will maintain its value if there comes a time when you are thinking about selling it.

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