737 APU start switch

[Sean]

Does the APU start switch in the NG's hold itself in the START position before automatically switching back to ON (a bit like the ENG START switches)?

You can see in this video...

http://www.angelfire.com/il2/aphs/FilmAPU.wmv

I didn't think it did. If not, was this a feature of earlier 737's or not at all?

Sean

[fordgt40]

Sean

The "start" position is momentary and the lever returns to "on" when released

Regards

David

[Sean]

Thanks Dave, any ideas which type the switch in the video is from. I've checked the 737 cockpit companion, and it doesn't make it clear whether this is a feature of the classics.

Sean

[fordgt40]

Sean

Sorry, but I do not know. My earlier response is based on the 737 600/700/800 Boeing manual as:-

6 APU Switch
OFF – normal position when APU is not running
• positioning switch to OFF with APU running trips APU generator off the
bus(es), if connected, and closes APU bleed air valve. APU continues to
run for a 60 second cooling period
• APU air inlet door automatically closes after shutdown.
ON – normal position when APU is running.
START (momentary) – positioning APU switch from OFF to START and
releasing it to ON, initiates an automatic start sequence

Regards

David

[philb737]

Sean,
As David stated the APU switch is momentary held on start position and the lever returns to "on as soon as you release the switch !The switch in the video is not from a 737 OH panel it is probably from a  727 oil cooler CSD panel being used as a APU switch. 
Phil

[jetpilot]

I have the real switch and it is lock in OFF position (You need to pull it to been able to move it) , Lock in ON position, and momentary START (Immediately goes back to ON, no delay).
Roberto

[Sean]

Thanks for the replys everyone. Confirms my thoughts about the NG.

Sean

[XOrionFE]

I happen to have the same switch as the one in the video.   It has a solenoid to hold it.  I also have the right switch which does not have the solenoid.  I think the solenoid one as stated is from some other function on a 727.   If anyone is looking for a solenoid operated one though let me know.

Scott