Speeds

cwreeves · #1 08-08-2009, 08:15 PM

Anyone willing to share their RV-7 best angle and best rate of climb speeds?
I'm doing my flight testing RV-7, TMX-360, 2 blade fixed pitch Cato prop. I'd like to have a base line of what to expect. It's been very hot here in Tucson so I'm waiting for cooler weather.
Charlie

hevansrv7a · #2 08-08-2009, 09:16 PM

My IO-360 180 HP with Catto 3-blade only turns about 2200 static and climb. Thus my best rate and best angle are close - around 105-110 kts. The best way to test best rate is to fly the VSI, but if you have a good hand held GPS you can use the VSI on that for greater accuracy. For best angle, if you have a GRT, you can fly the path indicator. If not, perhaps some other EFIS can do that. If not, you are going to find that the best angle of climb will vary considerably with density altitude and with weight.

You can also find your best endurance and best glide speeds with the GPS but that's another subject..

pierre smith · #3 08-09-2009, 05:56 AM

It was near 100 here yesterday, but I use 140-150 MPH climb speeds and still go over 1000FPM with my three bladed Catto...visibility is good, CHT's stay down. 110 has a steep attitude with little to no forward visibility. Try varying cruise/climb conditions and you'll be pleasantly surprised.

Regards,

cwreeves · #4 08-09-2009, 05:55 PM

Thanks guys for the data. I'm going to use suggested method for arriving at the best rate and angle in the AC 90-89A. For best rate the AC says to use 15 mph/knots above the predicted best rate of climb speed. I'd like to know what the predicted speed would be? based on your input's the best predicted would be in the neighborhood of 110 knots. The AC method has you start at a given altitude, stabilize the speed at the predicted speed while climbing and make a note of how high you climbed in 1 minute. You continue doing this procedure at by reducing your speed by 5 mph for each test until your speed is 10 mph above the stall speed. The greatest gain in altitude of the tests is the best rate of climb. Per the AC of course. The best angle is plotted on the graph made while doing the best rate testing. I prefer waiting until cooler weather because my oil temp is running 210 degrees in cruise.
Thanks again!
Charlie