(Mods - hope this is on-topic for here; it's probably the place to find the people with the answers)
I recently bought a KHD T312 on ebay; this is a Tornado APU. See:
http://www.corestore.org/turbine.htm
I'd be interested in any inside info the people who actually use & maintain the damn things can give me about these - are they reliable? What tends to go wrong with them?
I haven't seen one in situ on a Tornado so I'm making assumptions about how they work. I'm presuming they're coupled to some kind of transfer gearbox between the two engines, so they can run either as an APU, motoring the accessories and providing bleed air for the packs, or in 'engine start' mode, where the APU is accelerated and the drive transmitted (how? is there a clutch in the system?) to the engine being started.
Is the above vaguely correct?
I was puzzled by the fact that it wasn't a two-shaft design, like the units with which I'm familiar (Lucas starter on the Pegasus, Plessy Solent on the Spey).
Many thanks.
Mike