An Air Canada Air bus commuter plane from Calgary to Vancouver had to turn back after 20 mins in flight as there was a "power surge" at first report.

Passengers were emergency exited and a fire broke out in one engine after a safe landing. Can anyone speculate on what would cause a power surge, and why a fire would start in an engine after it had landed? Smoke in the cabin and a chemical smell reported by passengers. Is this a normal reason for a return to base or could it be computer related?

-- Laurane (familyties@rttinc.com), December 24, 1999

Answers

Airplanes create their own power just like a car. In all probability they were getting ammeter spikes and decided to return anticipating electrical problems. The fire resulted from overcharge most likely. And this is a very good reason to do a 180.

-- av8r (av8r@theglobe.com), December 24, 1999.

This does not sound computer related at all.

Probably an unusual mechanical/electrical failure in the engine accessory pad area. Depending on the type of failure, a power surge could have resulted. At 115 volts AC and 400 cycles per second (hertz) a sudden change of more than about 10% or so would be noticeable. Lucky the fire started on the ground. In flight, the burn through rating on the engine pylon is about 10 to 15 minutes. 'Smoke' in cockpit and cabin was probably due to one of the pressurization air inputs being located in the stream of the 'smoke'. Aircraft hydraulic fluid (Skydrol) might have become an aerosol mixed with the same smoke and then entered the pressurization system, also. Skydrol is considered to be benign, although it can cause irritation.

The jet engines and auxilliary power unit (a small jet engine powered generator) all provide compressed air to pressurize the aircraft at altitude. Some of this pressurized air is used to cool or heat the air in the aircraft, also. A fire/or other source of air contamination near an intake to the engines or a.p.u. could be a source for 'smoke' in the cabin or cockpit.

-- snooze button (alarmclock_2000@yahoo.com), December 24, 1999.