Learjet Spring 2008

• Planning a Successful Maintenance Event
• Lear 40 & 45 Starter / Generator

Planning a Successful Maintenance Event

— Cary Loubert

Good planning can go along way in making a maintenence event a success. The larger the event and the older the aircraft the more important planning becomes. Downtime is a precious commodity with many owners and we, as maintenance professionals, are asked to use it wisely. Here are a few questions to ask yourself as you plan.

1. Are there items that should be addressed with the main inspection?
   
2. Is there a benefit to performing another inspection early to reduce the downtime in the coming year?
   
3. Are there any stand-alone or out-of-phase inspections that are coming due?
   
4. What life-limited components are nearing the end of their usefulness?
   
5. Does your aircraft have STCs with ICAs (Instructions for Continued Airworthiness) that are due?
   
6. Do you have any paint or interior discrepancies needing repair or maintenance?
   
7. Are there warranty considerations your ­maintenance vendor should know about?

Complying with Service Bulletins (SBs) should also be a part of your planning process. Many SBs can be performed at a lower cost if done soon after their release. Bombardier often offers parts and/or labor coverage on select SBs. If this applies to your aircraft, the kit is free if ordered during the free period. The labor is covered also, if applicable, when the SB is completed before the labor coverage expires. Always read the section of the SB on expense coverage carefully.

If your aircraft has an STC for RVSM due, you will need to bring your RVSM manual and its ICA. If the STC holder revises the ICA, you may need to revise your STC manual to use the revised ICA.

Lastly, as you ready the aircraft to go to your maintenance provider, remember to send your logbooks, any ICAs, custom completion manuals and custom wiring diagrams.

Lear 40 & 45 Starter / Generator

— Jerry Cable

Presently Lear 40 and 45 Starter/Generators have an Overhaul and Brush replacement time of 600 or 1200 Hours. Most of us know that these units rarely make it to this scheduled maintenance and are removed early for failure; normally due to bearing failure caused by overheating.

Learjet and Goodrich have recently released service bulletins to address this issue. Service Bulletins 23080-023B-24-8 and 23080-059-24-8 (Lear S.B. 40-24-7 and 45-24-12), provide improvements to the Starter/Generator. (Concurrent requirement that Lear S.B. 45-71-6 or 40-71-03; Installation of Exhaust Scupper; be incorporated as applicable).

A new Ceramic Hybrid Ball Bearing is the key ingredient to this modification. The new bearing withstands the high temperature of operation these units encounter. This allows the units to run their full scheduled duration, which means increased reliability, decreased maintenance costs and downtimes.

The bulletins can be accomplished during normal overhaul without the need for additional labor and will update the P/N of the unit to 23280-066 or 23280-067, respectively. Please contact Duncan Aviation for more details about this cost-savings modification.

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