By the way the unducted fan (UDF) did actually work and worked quite well.
an3_bolt, thnx. Indeed there is renewed interest in UDF. I think UDF are a bit further awaythen e.g. the TP400. Noise / resonance / gearbox cooling / mechnical complexity need time to sort out. Still in the background I have been working on something UDF above 200 seats with Henry Lam, stay tuned..
Might have posted a little bit hasty..
......
Nevertheless ATR believes strongly in this system:
Bald_Eagle, thanks for your input. I doubt a system based on Hotel mode would be able to take a slope / bridge at MTWO and maintain a speed of 20 mph over longer taxi times. The Turboliner would be much heavier then an ATR too.
Keesje the ATR in Hotel mode is supplied by the same engine driven generators so can supply normally 400A DC
Kiwilad, thnx. I took a closer look at the TP400. Its a big 3 shaft engine. It has a dedicated microturbine starter integrated that needs limited power to start itself.
http://www.microturbo.fr/article.php...le=181&lang=en. It weighs 15.5 kg.
I think an APU optimized for moving the aircraft around could be equally limited in size and weight. Its doesn't have to produce the bleed air to start up a big turbo fan engine. An serious effort to really reduce noise to a minimum by means of a silencer would add some weight.
Your experience on flying ATR versus 737 on short routes confirms my airline experience. The shorter the flight the less difference between gate to gate times between props & jets. Props are often allowed to use secondary runways too.
This week-end I'll try to summarize & do a Turboliner mark III based on all input
rgds