TFE731 Engine Anomalies & N1 DEEC Downloads

June 2010

As flying hours have been trending upwards during the past few months and with summer temps increasing, so are TFE731 engine anomalies. The N1 DEEC will automatically perform an event record if any of the following operations occur:

• Uncommanded DEEC transfer to manual mode
• Type 2 engine exceedance
• Uncommanded engine shutdown

An “event record” is a 5-minute scan of engine parameters and ambient conditions. This event record can be an invaluable tool to maintenance personnel troubleshooting engine problems. An event record can be initiated by the Pilot whenever abnormal engine conditions are observed by the crew on an aircraft equipped with an SPR/Fuel Enrich Switch. A pilot-initiated event should only be used once between DEEC downloads as the N1 DEEC only records one event at a time. If the event record is initiated more than once between DEEC downloads, only the most recent event is recorded.

It is also highly encouraged to perform an event record on all engines at the same time even if only one engine is experiencing anomalies. This allows maintenance personnel to view both sets of data and compare outside ambient conditions and engine parameters to find the problem in a timely manner.