APU

[Guest glenally]

Is it true that the engines fan should spin when the apu is on and the main engines are off.When i was coming back from my holiday in gran caria the main engines were switched off and the apu was on and the engine fans were still spiningGlenally

[Guest vrandar]

Just having the APU on does not cause the fan blades to spin. For starting the engines, initially the APU bleed air starts the starter motor which starts the engine by spinning the N2 up to the optimum speed, the air that is forced through the compressor spins the turbine at the rear-end of the engine which in turn spins the N1 fan at the front part of the engine. Don't forget that on shutdown of the engines the fan blades will keep spinning for a while because they are very very efficient. Wind can also cause the fan blades to spin (windmilling). So can/will will the pilot doing the walkaround.Rob Elliott, EGPE InvernessPSS Airbus Support andAirbus Fleet Training Captain, British Airways Virtual airbus@speedbirdonline.co.ukhttp://www.speedbirdonline.co.uk/airbus.htmlhttp://www.bavirtual.co.uk

[Guest rcmonster99]

It's the wind going thought the fans... next time you are bored at the airport check out the fans on each plane, they will all be spinning with the wind;)

[Guest diesel1964]

>It's the wind going thought the fans... next time you are>bored at the airport check out the fans on each plane, they>will all be spinning with the wind;) The Fans on all turbines are wind driven Only Normally refered to as N1 or Fan