Don

Don

Well Known Member
One of the things I've wondered about is how comprehensive the flight testing was on MY plane in Phase I. My guess is, there's no way to know for sure. Some folks explore the envelope carefully and fully and others, well maybe not so thoroughly - or so I hear. How do you know which category the airplane you just bought falls into? My guess is, if you can talk with the builder you can get a sense but you never know for sure. If the folks that build N257SW were as careful testing it as they were building it, I've got nothing to be concerned about. All of my testing will just be practice for test flying my 9A when it's done. What concerned me is there are builders, there are pilots, and then there are builder-pilots. Clearly, the guys that built my 9A were top notch builders but I don't know much about what kind of test pilots they were. It's not that I doubt the work was done - rather I need to know first hand that the plane flies like Van says it should.

With that in mind, I decided to start exploring the envelope on the 9A that I recently purchased. Yesterday I took the plane up and did some power-off stalls, clean and dirty. I discovered you can "sneak up" on a stall and have the stick full back, power at idle, and the plane wallows at 43 knots dirty, falls about 100'/minute (not sure how accurate that is but its not far off) and the nose never breaks. That surprised me until I ran into an RV-6 pilot who said the same thing. When I didn't sneak up on it I could get a break at Van's published 41 (maybe 42) knots. It surprised me how 'alert' I was doing this. Maybe 'alert' isn't the right word - nervous or concerned might be closer to the truth. I didn't know for sure anyone had actually stalled THIS 9A before and just maybe I'd discover something I didn't expect. Logic said the possibility was small but not zero. Stalling the Cherokee was never a concern - but I was confident that it had been tested.

It was a non-event.

So far I've only stalled the plane at solo weight with full fuel (and nearly full). But based on that experience I dropped my final approach speed to 57 knots (between 55 and 60) and landings are a joy - albeit, a slow joy. Final approach seems to take 10 minutes getting to the runway. I've also made a habit of entering the pattern at less than 80 knots to make slowing down to final approach speed possible.

Tomorrow I will see what the stall speed is at gross and then I'll start moving the weight further back - as far aft as I can within W&B limits and see what that does. I am still getting used to the speed and the efficiency of this plane but what a pleasure it is to fly - I love seeing the earth moving more quickly underneath my wings. A whole new world of opportunities is opening up.
 
Don said:
But based on that experience I dropped my final approach speed to 57 knots (between 55 and 60) and landings are a joy - albeit, a slow joy. Final approach seems to take 10 minutes getting to the runway. I've also made a habit of entering the pattern at less than 80 knots to make slowing down to final approach speed possible.
... I am still getting used to the speed and the efficiency of this plane but what a pleasure it is to fly - I love seeing the earth moving more quickly underneath my wings. A whole new world of opportunities is opening up.
Click to expand...

Couldn't have said it better m'self. :D I too have discovered how s-l-o-w the pattern is when you get used to cruisin' around at 145kts +. Funny ... the pattern didn't used to seem this slow in a 172. ;)
I'm using exactly the pattern speeds you mentioned ... the tough part is gettin' her slowed down to flaps speed ... I need an anchor or a drag chute!
 
I dropped my final approach speed to 57 knots (between 55 and 60) and landings are a joy - albeit, a slow joy. Final approach seems to take 10 minutes getting to the runway.
Click to expand...


It's so non-RV I was told :D
 
like it

Rupester said:
Couldn't have said it better m'self. :D I too have discovered how s-l-o-w the pattern is when you get used to cruisin' around at 145kts +. Funny ... the pattern didn't used to seem this slow in a 172. ;)
I'm using exactly the pattern speeds you mentioned ... the tough part is gettin' her slowed down to flaps speed ... I need an anchor or a drag chute!
Click to expand...

I think I am going to like cruising at 145 and landing at 60 kts. I hope the variable pitch prop helps to slow it for landing.
 
Steve, the constant speed prop allows you to enjoy the full range of RV speeds. You can sizzle into the pattern and have it slowed to final approach speed as you turn base.

Don, the "model" has been proven. There should be no fear but I understand what you are going through. In a year you won't doubt that plane one iota! I listened to every noise and bump (probably even imagine some that weren't there) but now I trust and love my "Tweety" 100%!!
 
Steve Melton said:
I think I am going to like cruising at 145 and landing at 60 kts.
Click to expand...

It may be sacrilege but that's pretty close to how I fly my RV-8 :)


Don - your experience reminds me so much of my primary training. I was initially nervous about stalls in the various configurations. Finally, my instructor said to me "you're so afraid of spinning that you fear the stall". He was right. We went and did spin training and I never feared stalls after that.
 
Last edited:
I'm just saying...

humptybump said:
... At some point, I highly recommend you get an instructor who is competent to do spins in the RV-9A and gets some experience at the edge of the flight envelope.
Click to expand...

For some reason Van's does not recommend spins in the -9's. I'm not exactly sure why but it is in the builder's manual.
 
Bill - thanks for pointing out Vans does not recommend spinning the -9. I was not aware of that or else I would not have suggested it. Apologies all around.
 
Last edited:
There have been lots of threads on flight testing a proven design, but I would not be comfortable fkying an experimental plane to redline if I had not seen it go that fast myself. If I ever buy and experimental airplane I will put a chute on and test it to the corners of the flight envelope.

My $.02
 
tkatc said:
I listened to every noise and bump (probably even imagine some that weren't there) but now I trust and love my "Tweety" 100%!!
Click to expand...

I'm j-u-s-t emerging from the "heavy listening stage" and starting to trust her more and more. Hadit not been for strong fuel smells - emanating from the ever-leaking Red Cube - I would be in trust mode already. Everything else on the aircraft flies and performs as expected/hoped/advertised.
 
Glen, my concern wasn't spinning per se. I've had spin training and I could recover in a Pitts. Not as big a deal as I thought it would be but the perspective on the world was different. The instructor used the Eiffel Tower at Kings Dominion for a point of reference - we'd count it going around and then I'd recover - after 3 turns. Its probably time to take that training to the next level.

I think part of my concern was remembering an ancient post here (by Andy Karmy I think) about when he was doing stall testing on his 9A. As I recall he was at gross weight, with the CG as far aft as he could get it, when the plane approached a stall it flipped over on its back. His only comment about recovery was something to the effect of "normal recovery methods worked" or something like that. I've wondered what he meant, exactly. I also think it was Kahuna here who within the past week talked about there being variability in the flight characteristics of RVs - and I think he was talking about within the same model. I was wondering if I'd get some unexpected surprise that would challenge my ability to recover. Stalls and stall recovery per se are well within my comfort level.

And while I understand the envelope of the 9 is pretty well defined and tested, I'm just wanting to make sure the 9 I'm flying fits the norm and so far it seems to. Did you verify the envelope on your 8 after you bought it? What do others do when they buy a used experimental plane?
 
Don,

Yes, I did go through much of the RV-8 envelope test within the first year of owning the plane. The exception has been CG range. I have not had a suitable solution for adding enough weight to fully test the extreme aft CG envelope.

I do have an advantage when it came to the evaluation of the build - I bought the airplane from the builder and had the opportunity to both fly with him and discuss the phase-1 materials. I continue to stay in regular contact with him and we discuss all aspects on the airplane.

For whatever reason, I never fully trust the plane. The slightest change is sound or feel and I'm on high alert. Then again, I think I've been this way with every airplane I've flown.
 
Last edited:
Test Flights

You should be very well prepared to test the 9a you are still building. Not many of us have that opportunity.

I find that I enter the pattern at 1700 RPM, about 95 knots, slow to flap down at idle, then fly final at 60 knots. I have been cruising at 145 knots true airspeed at 2400 rpm.

IO 320 with Sensenich FP prop. 70 dia. 79 pitch. Wt empty 1071 lb.
 
I have to admit that I have not flown my 9A to the corners of the envelop and don't intend too. I was apprehensive during my first 100 hrs or so. Initially every bump made me worry that wings might fall off. Eventually I felt comfortable to fly it over high mountains and ocean. However, I still don't feel comfortable landing on grass although I have done several. I did not gain all that confidence through flight testing but by flying it often.

My 9A has fixed pitch Sensenich standard prop (between climb and cruise) and two Odyssey 680 batteries on the firewall (slightly nose heavy). I normally enter pattern at 120+kts. Pull power to slow to 100-110 kts on downwind. Too fast to slow down, fly a wider pattern (never the 747 pattern). Idle abeam the number and hold altitude to slow to 90 kts. Trim and add first 10 degree flap at 90 kts. Base at 80 kts and 20 degree flap. 70 kts turning final and full flap down. Drop to 65 kts at short final. Over the threshold at 60 kts. If too high on short final, slip it at 70 kts. If too low, add power. Below 65 kts I don't really have a floating problem over the runway. I do give myself a big stall margin on final.
 
Great information gentlemen. This afternoon I did some T&Gs - I think I was flying slower than most of you. The Dynon was reading 57-58 on base and I added the last 10 degrees of flaps. I held that until short final and I let the speed down to 55 knots - it was fairly smooth air but 5-7 knots of cross wind. I could land on the mains every time and I figure I must have been fairly slow because even with the stick full back the nose wheel didn't stay up long.

I also tried landing at 57-58 knots - the plane seems to "like" that speed with full flaps and full up trim. It was a longer roll out and the nose stayed up longer. I know flying with Vlad the nose wheel stayed up for ever - that wasn't my experience this evening. Two landings in the 60-62 knot range were modest floaters. I landed shorter that the 172 that were landing but not by a lot.

What is escaping me is how to get that 350' landing Van's advertises.

At 55 knots turning base I feel like a helicopter - just turning in place, little or no apparent forward motion....clearly at 55 knots there is forward motion but gosh, that's slower than the manual says to land the Cherokee and it sure wasn't a speed demon! On a really smooth day with no wind, I may drop to 53 knots and see what it results in (hopefully a 350' roll out I hope). That's 1.3 x Vso and that's as low as I'm going. If that doesn't give me 350' I'm going to find out how Van's does it.
 
Don said:
I also tried landing at 57-58 knots - the plane seems to "like" that speed with full flaps and full up trim ...

At 55 knots turning base I feel like a helicopter - just turning in place, little or no apparent forward motion....clearly at 55 knots there is forward motion but gosh, that's slower than the manual says to land the Cherokee ....
Click to expand...

I'm close to that ... I find a sweet spot at 52-56 touchdown.

I fully agree with your "helicopter" feeling ... (heck, I feel that way at 65kts!) Turning base at 55 would scare the snot outta me. :eek:
 
You must log in or register to reply here.