Dash-8 Aux. power unit

[High-wing]

Hi guys,

To those who know the Dash-8, in particular the 300-series with an APU, you will know that its weight-on-wheels logic circuit prevents any starting of the APU in flight.
I colleague an I were discussing whether there was a possibility to override this function for eg. pulling circuit breakers etc. to get the APU started in flight (because it will be a good thing to have in an emergency such as total electric failure).

Any knowledgeable folk out there with ideas ?

Thanx.

[2reds2blues3greens]

from memory( long time ago )the pseu controls all that such as the weight on wheels and thats not overrideable. :confused:

[Capt Claret]

High-wing,

The 'APU' sensor, senses nose wheel oleo extention, via the PSEU. To the best of my knowledge it is not overridable.

Nor would you want to start the APU in the air as it is not placed inside a fireproof 'container', hence you might get more than you bargained for.

The DH8 with 2 x DC Gen and 2 x AC Gen has very good electrical redundancy as it is.

I have seen instances of DH8-100s (28 seat combi pax/frt) being loaded such that without pax, the nose oleo was so extended that the APU shutdow. About a dozen guys into the flight deck compressed the oleo enough to restart the APU, but when the dozen left ..... :D

[ 22 November 2001: Message edited by: Capt Claret ]