Peter

As I have posted before. On the early Jets (F-80A/B) it took 21
seconds to accelerate from idle rpm to full rpm. You made your go
around decision on base leg.

In actul practive, we only reduced rpm to around 65% (idle was 35%) in
the pattern until "we had the runway made", to reduce the spool up
time.

Since those days, they have decreased the spool up time to a pittance
..

On turbo props however, they run the engine at a constant rpm during
flight and all you do with the throttle is change the prop pitch. With
this you can go from no thrust to full thrust instantly.

Fly safe.

Big John

On Mon, 24 May 2004 14:50:46 +0200, Peter Hovorka
wrote:

Hi tony,

I'm ignorate of the technology, but seem to remember the airlines went to
jets
because fuel costs were lower and they were lest costly to keep running.

... and because passengers appreciated not to arrive in a three-engine
Connie after departing in a four engine a few hours ago. Enginge failures
were a main issue on that.

If they scaled down well, I expect we'd see them in hybred cars long
before they'd be in general aviation aircraft. You don't need rapid
response times in a hybred, but the 'spool-up' time in a small plane could
take a lot of getting used to by pilots who need lots of throttle
jockeying to land their airplanes.

I take that back -- it wouldn't take a lot of time, there'd be aluminum
junk that used to be airplanes near the approach end of lots of airports.

I don't think so. Spool up time on modern turbines is marginal compared with
early turboprop/jet engines. Compared with the workload a high power piston
is causing, every turbine would be much safer. I bet on that.

Regards,
Peter