Perry Mick wrote:

Paul:

This is not the data you requested, but it's what I have so far:

static rpm: 4200
rpm @ 80 knots:  4400

Once at 65 knots, takes about 3000 rpm to maintain that speed,
and hold the nose off, which I can do at that speed.

I never saw 4400 rpm with the prop unducted, not sure I even
saw 4300.

Here it is in my notes, 1-26-99, unducted rpm @ 80 knots: 4260

Approximate HP at 3000 rpm: 75
@ 4200 rpm:  105
@ 4300 rpm:  108
@ 4400 rpm:  110

I now have 32.0 hours on the Hobbs, all engine tests and taxi
tests.

Runway data to be used to calculate position of runway markers:

beginning of threshold:  45 deg 11.41'N, 123 deg 09.06'W
beginning of runway 4:  45 deg 11.49'N, 123 deg 08.89'W
end of runway 4:  45 deg 11.98'N, 123 deg 07.85'W

In response to your response to Marc de Piolenc:  I'm not sure
I'll even get to 6000 rpm, maybe 5500, with a corresponding reduction
in speed from 200mph.  Perhaps with more HP (by adding a turbo)
I could get there, but then it may mean that the duct needs to be
redesigned slightly so that the air is not accelerated to 267 mph,
but some lower number.  Like I said before, the current shape of the
duct just maximizes mass flow up to the limit of an 8 degree tail
cone shape, assuming my 24 inch duct chord.

That is tricky to use that data as you need to be competent
in spherical trig. Plus the lat/long resolution is not the greatest.

Easier way is to sneak out there in the middle of a foggy moonless night 
with a 100 foot tape and a spray can of white paint :-)

Or talk to the airport manager and ask him how far apart are the 
runway lights. 

I see no problem carrying an observer as you don't need to take
off. A simple stop watch will do. Make separate runs to each
100 foot marker so the observer has only one time to record
during each run. Too bad I don't have one of my computerized fifth
wheels lying around like they used on the Rutan Voyager.

Once we have a plot of acceleration up to 85 Kts we can extrapolate
that to 100 Kts or so hopefully things are roughly linear up to
at least that speed. I suspect however as the fan tips approach
mach .8 or above things get decidely non-linear.

Paul
 
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