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Astra / Westwind Summer 2002
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Garmin Update
- Curt Campbell
We would like to announce that Duncan Aviation-Battle Creek has successfully installed a dual Garmin GNS-430/530 GPS/Nav/Com interfaced with a Honeywell FZ-500 flight control system in a Citation 551 aircraft. The Garmin GAD-42 Adapter was used, and the Honeywell flight control system was upgraded to accept roll steering.
As reported in an earlier Duncan Intelligence newsletter, previous field reports from operators indicated an incompatibility between the Garmin and the Honeywell Flight Director systems. However, no compatibility issues were encountered during Duncan Aviation’s installation.
With the Cessna RVSM service bulletin and the GPWS that was also installed during the visit to Battle Creek, this aircraft is ready for the future. The Garmin radios provide 8.33kHz channel spacing, FM Immunity and are BRNAV (RNP-5) capable.
Questions About Prebuys?
- Tom Burt
Duncan Aviation will be hosting a symposium in Lincoln on October 1 & 2, 2002. Classes will be held on Effective Prebuys, and many other customer-requested topics. Many of the classes will be offered for IA renewal credit. Log on to DuncanAviation.com/Conference for more information.
Keeping Cool
- Tim Garity and Mike Junker
With the hot summer upon us, concerns about keeping the passengers and crew cool are paramount. If your cooling system just doesn’t seem to be keeping up, here are a few things to check.
Begin by checking the temperature of the air coming out of the water separator. With system in Manual, full cold, and the right engine slightly above idle, it should be about 35 degrees Fahrenheit. If it is much warmer, check the turbine bypass valve by removing its connector. If this makes the air colder, the 35 degree switch is probably defective. This test can also be done by pulling the auto temp circuit breaker in the cockpit.
Ineffective cooling can be caused by the cooling turbine running slow, due to low pressure output from the engines. Pressure to the cooling turbine is regulated by the fluid pressure regulating valve. Astra Maintenance Manual 21-50-00, page 501(Westwind 21-50-00, pages 501 & 502 ), details how to check the output, which should be 22-26 PSIG with the right engine at 90%. If this is low, but more than 16 PSIG, the bleed switching valves could be at fault, and their pressures can also be checked. Refer to Astra Maintenance Manual 21-11- 01, pages 501-503 (Westwind, 21-11-00, pages 5 & 6). Pressure should be 25- 30 Psi. If the fluid pressure regulator is reading 16 PSIG, check the reference pressure regulator, and pneumatic thermostat. The reference pressure regulator may be cracked and failing to regulate. Check the dorsal fin air inlet and heat exchanger for debris, which may cause reduced cooling of the bleed air.
Lastly, the cooling turbine itself can be removed and borescoped for blade damage and the rotating group checked for high torque. Aircraft with APUs should use max airflow for best ground cooling. Note: The guarded switch is located on the right forward pedestal by the copilot’s left foot.
Service Where You Need it - Rapid Response
- Tim Garity
If you find yourself in the middle of nowhere with a broken aircraft, don’t feel helpless. Dial 877.522.0111(toll-free) to reach Duncan Aviation’s Rapid Response Hot Line. For engine or airframe support, you’re just minutes away from technical help, or a few hours away from having technicians arrive at your location and get you back in the air. Service is available 24/7, 365 days a year, for nearly all types of corporate aircraft. Specialized services such as fuel leak repairs, Permaswage tubing repair, Astra aileron bearing replacement or preparing damaged aircraft for a ferry flight are available from our Rapid Response technicians. If there is a service you need help with, and you don’t wish to move the aircraft, please call.
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