VAF Forums

VAF Forums (https://vansairforce.net/community/index.php)
-   RV-9/9A (https://vansairforce.net/community/forumdisplay.php?f=5)
-   -   Performance RV-9 (https://vansairforce.net/community/showthread.php?t=58513)

apkp777 02-17-2011 01:28 PM

Quote:

Originally Posted by tsneidin (Post 514532)
Thats great Tony, now show us your nickel leading edge on your prop.

Hey Todd, lets go flying on Saturday. I will get some prop photos up soon. I only had my phone yesterday and it wouldn't have done the prop justice. It really looks good.

apkp777 02-21-2011 02:28 PM

Here's a quick pic of my Catto nickel leading edge.


Hatch11h 06-18-2011 05:39 PM

RV-(A with 200HP
 
Van's doesn't want 200HP on the 9A's, however, I have installed an Eggenfellner E6/200 which is only rating that kind of power at 2700 rpm. My takeoff setting is 2500 and cruise is usually 1900 to 2000rpm. The prior engine I had was a max 160HP Egg H-6 and I would get 130kts every time with those low cruise power settings. At 12,500 I got the gph down to 5.9. at 1900.

I will post my performance numbers this week once I get them together. Using a brand new three blade MT.

- Aaron
Austin TX

apkp777 08-24-2015 03:44 PM

Those of you flying the tailwheel -9, I am looking for comparisons for Vx and Vy and Best Glide. I have done several tests and get different numbers each time. Just curious what your flight test numbers are?

Right now I have Vx at 64 KIAS and Vy KIAS at 75 KIAS BG at 75 KIAS.

alpinelakespilot2000 08-24-2015 05:15 PM

Quote:

Originally Posted by apkp777 (Post 1008593)
Those of you flying the tailwheel -9, I am looking for comparisons for Vx and Vy and Best Glide. I have done several tests and get different numbers each time. Just curious what your flight test numbers are?

Right now I have Vx at 64 KIAS and Vy KIAS at 75 KIAS BG at 75 KIAS.

Tony-
I agree with getting different numbers. I don't yet have an autopilot installed so that makes it a bit difficult as well. I've always understood that Vy and Vglide should be about the same, but can't confirm that in my tests. In short I would not recommend anyone take my numbers as gospel.

That said, the numbers I use: Vx about 65KIAS, Vy about 85KIAS, Vglide = 75-80.

What I think I've found with the lack of consistency in my numbers (mostly Vy and Vglide) is that there very well may be a wide range here (i.e. a very flat part of the curve) that we are dealing with. I too though would be very interested what the "average" may be among a wide variety of 9/9A's. I would bet that would get us close to the ideal, at least for those of us you are using the recommended 160-hp. I suspect combining the 160hp numbers with the occasionally used 180hp numbers would not be very helpful toward this end.

apkp777 08-24-2015 05:50 PM

Thanks Steve,

I am looking at the CAFE RV9A testing. They came up with 95MPH (82KTS) Vy and 82 MPH (71KTS) Vx.

*"Vy, speed for best climb rate, CAS, 5500? dens.alt, @103 mph TAS 95 mph.

Vx, speed for best climb angle, CAS, 5500? dens., @88.3 mph TAS 81.6 mph"


Interesting that they found the best descent rates at 82 MPH (71KTS)
"Min. sink rate, idle power, coarse pitch, 1725 lb, 81.7 mph TAS 664.2 fpm" and the best Glide at 95MPH (82kts) 12:1

http://cafefoundation.org/v2/research_aprs.php

alpinelakespilot2000 08-24-2015 06:16 PM

Yeah, I just looked that up too, Tony. Interesting. I maybe flying Vx and definitely best glide 5 or so knots too slow. Otherwise am pretty close. Need to get the autopilot servos installed. I can't hand fly well enough to get repeatable numbers.

BTW, good to have you in this part of the country. Look forward to meeting up finally!

apkp777 08-24-2015 06:25 PM

Definitely let's get together. I am loving the PNW!

My original numbers were close to the CAFE numbers, but started doing some testing again recently as my prop is pitched differently and W&B different than my flight testing basis. I think I will stick with the CAFE till I get some good science.

Greg Arehart 08-24-2015 09:39 PM

For what it's worth, my numbers are Vx=76 mph, Vy=92 mph. That's with the IO360. I absolutely agree that it is difficult to get consistent numbers hand-flying this stuff.

Greg


All times are GMT -6. The time now is 08:38 AM.