Several months ago I purchased an RV-6A. The owner claimed 170 mph while sipping gph. I did my homework prior to the purchase and understand those numbers to be common. I love the plane and it does sip 7 gph however the only time I can get 170 mph is i a decent. Typical numbers are closer to 154. Any suggestions for drag points i could look at. The IA on my field is familiar with RV's and feels like the prop ( wood Fixed) is pitched correctly.
Van's Air Force
Don't miss anything! Register now for full access to the definitive RV support community.
Common Drag locations?
- Thread starter kdedmunds
- Start date
dedgemon
Well Known Member
African or European?
mph or kts.
mph or kts? The only reason i ask is thats almost the exact difference between the two numbers. If 7gph is only giving 154 mph than that is draggy. If its 154 kts than thats in line with what i get in my Rv6a with old pants.
mph or kts? The only reason i ask is thats almost the exact difference between the two numbers. If 7gph is only giving 154 mph than that is draggy. If its 154 kts than thats in line with what i get in my Rv6a with old pants.
Yep. For sure. I now see on my newly flying RV-9A that I have about 1/4" to 3/8" of elevator counterweight fwd edge showing when trimmed in full cruise. Ugh. Found it only because the spouse took some photos with her iPad and the aftward views showed the elevator culprit.
Sid Lambert
Well Known Member
This depends greatly on things other than weight. All airplanes are built a little different. Especially before pre-punch.
Also, I think it's been said that Van's put a little extra angle in there to keep a slight load on the elevator in cruise.
Also, I think it's been said that Van's put a little extra angle in there to keep a slight load on the elevator in cruise.
rv7boy
Forum Peruser
Would the original poster return and post some answers to some of the questions you've been asked?
The original post may have been a legitimate question, but does it bother anybody when one of these questions is asked by someone and we never hear from them again?
Please, Mr. Edmunds, join in the thread you created and tell us more about your RV-6A.
The original post may have been a legitimate question, but does it bother anybody when one of these questions is asked by someone and we never hear from them again?
Please, Mr. Edmunds, join in the thread you created and tell us more about your RV-6A.
This is correct.
If an RV is built as the original design details intended, there will be a very slight down elevator displacement at typical cruise flight C.G. positions.
It enhances dynamic pitch stability.
If a builder chooses to make adjustments to remove the need for down elevator, they are trading some pitch stability for a small airspeed increase.
walkman
Well Known Member
Just needed to gather a little info so I could respond. BTW Thanks for all the interest. I have been using the indicated airspeed in MPH on the installed Dynon 10A The engine is a Lycoming IO 320. I cant swear to the accuracy of the airspeed indicators although I know the static system has been checked recently and told that all was fine. I"m sure the wheel pants are the old style. i took some pictures of the the pants as well as the elevator but need to figure how to get them in here to show you . Again thanks for the help
Kent
Kent
speed
Kent,
The next time we are at 2J9 together we can go up to altitude (about 8500) and fly along side each other. At that altitude and WOT leaned properly I bet you'll see close to the 170MPH claim. It'll be fun to do and we can get true ground speed from the GPS. Call me sometime if you are interested and want to do it after 5pm during the week.
David Watson
508-3067
Kent,
The next time we are at 2J9 together we can go up to altitude (about 8500) and fly along side each other. At that altitude and WOT leaned properly I bet you'll see close to the 170MPH claim. It'll be fun to do and we can get true ground speed from the GPS. Call me sometime if you are interested and want to do it after 5pm during the week.
David Watson
508-3067
rv7charlie
Well Known Member
Speaking of static ports...
What does your GPS say, on a calm early morning flight before thermals start? (Don't use an evening flight; cooling air will force you into a constant climb to maintain altitude.)
Are your static ports flush, or raised above the fuselage surface? My 1st -4 was about 10 kts slow until Kevin Horton told me about needing a 'bump' at the static port.
BTW, the reason I noticed it was that I did a high speed pass down (excuse me; aborted approach) my home runway & noticed that my altitude was about 40 feet below field elevation. After installing the bumps (big pop-rivet heads RTV'd over the ports), the altitude during high speed passes returned to above ground level and speed went up 10 kts.
Charlie
What does your GPS say, on a calm early morning flight before thermals start? (Don't use an evening flight; cooling air will force you into a constant climb to maintain altitude.)
Are your static ports flush, or raised above the fuselage surface? My 1st -4 was about 10 kts slow until Kevin Horton told me about needing a 'bump' at the static port.
BTW, the reason I noticed it was that I did a high speed pass down (excuse me; aborted approach) my home runway & noticed that my altitude was about 40 feet below field elevation. After installing the bumps (big pop-rivet heads RTV'd over the ports), the altitude during high speed passes returned to above ground level and speed went up 10 kts.
Charlie
