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Outer Space....

RV9798

RV9798

Well Known Member
Yesterday I tested my RV9A on the edge of outer space ;) at 17500 ft. Density altitude was 18900 ft @-6 C. I had oxygen on and the engine at full throtle was 2460 RPM and 16.2"Map @ aprox 6 gal/hr. Speed TAS 145KTS (Dynon is great for displaying TAS...no calculations). It still would climb at 300ft/min. (2persons). Control felt solid. Pilots are gassed out....

13500ft gave the 9A her best performance. 160Kts TAS firewalled.

Guess where I would cruize

Pete
 
Wow Pete, that is really up there! How long did it take for you to climb to that altitude? I'll bet coming down was quicker. ;)

What engine/prop combo are you running?
 
Cruising altitude in my RV-9A...

You verified what I have been seeing for the past year. I regularly cruise at 12,500 and 13,500 MSL with my O-320, C/S prop, full power, 6 gallons per hour, 160 MPH TAS on the Dynon. It works out to be around 25 MPG with zero wind. One of these days, I will get oxygen on board and get up there when crossing the Rockies in Colorado, etc.

The Hobb's has 207.3 hours on it going to Oshkosh twice, the upper Great Lakes, NYC, New England, Texas, LOE5, and Florida several times. I have seen tail winds up high of 30 and 50 MPH during some of those trips. When I find headwinds, I try different altitudes to keep them down to 10 to 15 MPH if possible. I made one return trip from Florida at about 1,000 feet AGL to keep out of high headwinds. Part of that "low-flying" even had a slight tail wind when I compared TAS to GPS ground speed.

Jerry K. Thorne
East Ridge, TN
RV-9A N2PZ
www.n2prise.org
 
Units

n2prise said:
You verified what I have been seeing for the past year. I regularly cruise at 12,500 and 13,500 MSL with my O-320, C/S prop, full power, 6 gallons per hour, 160 MPH TAS on the Dynon. It works out to be around 25 MPG with zero wind. One of these days, I will get oxygen on board and get up there when crossing the Rockies in Colorado, etc.


Jerry K. Thorne
East Ridge, TN
RV-9A N2PZ
www.n2prise.org
Click to expand...

Jerry.... Pete's original posting was in KTS TAS.... are you guys speaking the same units??

Is he faster with a FP prop over your CS one?

gil in Tucson .... got to keep those units straight.... :)
 
Last edited:
az_gila said:
Jerry.... Pete's original posting was in KTS TAS.... are you guys speaking the same units??

Is he faster with a FP prop over your CS one?

gil in Tucson .... got to keep those units straight.... :)
Click to expand...


I am in KTS TAS. That's what my Dynon is setup for.

John ask me how long it took to 17.5.....I did not record that, but the whole trip took 1.2 hrs. For that altitute you need good Oxygen system.

I think cruizing at 11.5 to 13.5 is probably the best for my 9a.

Pete
 
Since we are talking about RV9/9A speeds, here is what I did yesterday... went to 7500 msl, did four full power runs (360,90,180,270) then averaged the GPS ground speed for a result of 163 kts/hr.

RV9, 160hp, f/p wood prop, 2600rpm, 1021 empty weight, pants and fairings on.

The wood prop probably costs some speed, but looks great!
 
real numbers

That's what I've been waiting to see. A number for GROUND speed. A number to use to calculate the time from pt A to pt B. Finally, meaningful data. Three years of reading about TAS, IAS, CAS, OAT, level of the lake, position of the planets, etc.

beginning the slide canopy effort,
Steve
 
Steve said:
That's what I've been waiting to see. A number for GROUND speed. A number to use to calculate the time from pt A to pt B. Finally, meaningful data. Three years of reading about TAS, IAS, CAS, OAT, level of the lake, position of the planets, etc.

beginning the slide canopy effort,
Steve
Click to expand...
Ground speed doesn't mean that much. I could have a ground speed of 200 knots in a 172, and someone in an rv be at 80 knots on the same day with both planes at full power. Winds will affect the readings.

TAS is the speed # I want to see. It tells me what I should fligth plan for.
 
Speeds....

I have done quite a few long cross-country trips since my first trip to Oshkosh one day out of the paint shop. http://www.n2prise.org/rv9a151.htm

During every flight, I look at the GPS ground speed, the true air speed calculations from my Dynon D10-A, and the true airspeed reading from Van's TAS airspeed indicator. The GPS ground speed is the one that tells me how long I will be flying to my next stop. That is the speed that keeps my eyes on the fuel flow sensor readings and the amount of time the engine has been running at cruise power settings. I made it a point during phase one testing to keep meticulous log entries on the fuel amounts and time flown between fuel fill-ups. I continue to keep those fuel records to this day.

I met a guy who did not manage his fuel properly. The first time he had a new RV-9A at Oshkosh 2002. The second time I met him at OSH was two years later. He had new RV-9A and the first one was "no more".

Jerry K. Thorne
East Ridge, TN
RV-9A N2PZ
Hobbs = 207.3 hours
 
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