Learjet Summer 1999

• Chapter 5 Changes (35 Maintenance Manual MM-99)
• Duncan Satellites Have Your Install Needs Covered
• Cut Your Expenses
• Fan Failure?

Chapter 5 Changes (35 Maintenance Manual MM-99)

In the latest chapter 5 revision, Learjet has changed the IRN (inspection reference number). Example: The first item in the Inspection/checks with special requirements or inspections/checks due at other intervals (section 5-10-24) is perform inspection of life vest. The old IRN was 25-61-00; the new IRN is C2561000. The only change is the addition of a letter on the front and an additional number (usually 0), in the number itself. The letter is the revision level of the item, which is used by Learjet Maintenance Engineering. The number is added to give them more flexibility in the numbering system.

Duncan Aviation uses the IRN as a reference in the log book entry to reduce confusion in similar items. We feel this will help reduce confusion when a log research is required at a later date.

Note: G2130007 The Cabin Pressurization System—Perform Cabin Leak Rate Check—has been added to the inspections/checks with special requirements or inspections/checks due at other intervals (section 5-10-24). Learjet has a revision in work to add this inspection/check (effective on aircraft 35-107, 35-113 and subsequent, and 36-032 and subsequent). The cabin pressurization system functional test (IRN E123004) is still in the Phase C1 inspection/check. It is our understanding that E123004 is the electrical portion of the cabin pressurization system functional test only.

For more info, contact Bill Schroeder in LNK at 800.228.4277 or contact Pete Kilmartin in BTL at 800.525.2376.

Duncan Satellites Have Your Install Needs Covered

Duncan-Las Vegas, a full-service avionics shop located at McCarran Airport, joins a growing list of facilities that provide full installation service for avionics systems from a variety of manufacturers, including FMS, TCAS, GPWS, GPS, AFIS, RVSM upgrades, inflight telephones and AirShow.

Other Duncan satellite avionics facilities with installation capabilities include Van Nuys (VNY); Teterboro (TEB); Dallas (DAL); and Denver (SDN). Installation activity at Duncan satellite facilities is supported by the engineering experience of Duncan’s major aircraft maintenance and modification facilities in Lincoln, NE, and Battle Creek, MI. Duncan holds more than 400 STC’s and has a wide range of experience in avionics system installations and design.

Cut Your Expenses

Learjet 30/50 series hydraulic pumps 6600301-3 are expensive to overhaul. Duncan’s Accessory shop is working to reduce the repair and/or overhaul costs for this pump and has developed and received FAA approval on a cost-saving repair procedure. The 20 series Learjet hydraulic pumps, p/n 2317087-8, have also recently become much less expensive to overhaul.

For more info, contact Chris Gress in LNK at 800.228.4277 or contact Pete Kilmartin in BTL at 800.525.2376.

Fan Failure?

Learjet 30/50 series generators 6608201-9 operate at high RPM’s. There is a tendency for the generator fan to crack after extensive operation at high RPM’s and because of exposure to ice induction. Duncan’s Accessory shop has developed and received FAA approval on the repair of this fan which will allow for a considerable savings over replacing it.

For info, contact Chris Gress in LNK at 800.228.4277 or Pete Kilmartin in BTL at 800.525.2376.

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