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December 2011 Intelligence Newsletter

Learjet 20/30 Series: Un-Commanded Aux Cabin Heat

Duncan Aviation has recently observed an aging aircraft issue in regards to the Aux Cabin Heat in 20 & 30 Series Learjets not equipped with a Meggitt freon system.

PW500 Series Compressor Bleed Control System

The compressor bleed control system on the PW500 series engines provides surge-free operation throughout the entire engine operating range.

Cessna 525: Troubleshooting the Temperature Control System

The temperature control system on the Cessna 525 can be rather difficult to troubleshoot considering the many components involved.

Challenger 604 Saddle Tank Corrosion

It has been several years since we’ve observed saddle tank corrosion aboard the CL604; however, we are beginning to see it more often in the field.

Autopilot-Induced Control Surface Oscillations

During autopilot-engaged flight, oscillations can occur in the roll, pitch or yaw axis. The most commonly squawked oscillation occurs in pitch and is often referred to as porpoising.

Universal FMS Support Coming to an End

According to Service Letter (SL) No. 2843 and 2844, Universal Avionics has announced they will cease repair, support and the navigation database updates for the UNS-1M and UNS-1Msp series Navigation Management System, effective January 1, 2013.

Radar Unit Chamber Testing Advantages

When a radar unit is in for repair, having it tested in an environmental/altitude chamber assists in duplicating ‘no fault founds’ and finding intermittent squawks.