RV-9 vs. RV-7???

[N200PF]

...want to get your thoughts!

What are the advantages that the RV-9 has over the RV-7? I would love to hear reasons from building to cost to flight handling to safety. The bottom line is why did you choose to build the RV-9?

THANKS!!!

- Peter

[Spike]

For me there is no such thing as advantages or disadvantages. For me it was what fits my type of flying the best. I want to put the wife in the airplane, and go places in comfort, decent speed, and the best stability possible since it might end up being an IFR aircraft. Aerobatics was on the absolute bottom of the list. I also am a real fan of the O-320 and its fuel burn. That screams the RV-9 to me. I guess for me it was very intellectual. The speed difference really isnt anything to make note of, etc. The hardes part is the decision is where to put the third wheel.


-- John

[N200PF]

See now all that make PERFECT sense and will be a large percentage of the flying that WE do! However, I am balancing that with the times that I am flying alone and want a bit more performance...

OK, I can accept the fact that there is no easy answer!

Maybe if I look out even further (and VERY optimistically) building a 7 now and maybe putting a 10 together 7 or 8 years from now would be the best of both worlds...

I'm a big talker for someone who has not even put one rivet in a real airplane surface yet!!!

- Peter

[Spike]

...However, I am balancing that with the times that I am flying alone and want a bit more performance

You said it yourself. The difference between the two is "a bit more of performance". Check out the time difference between the two aircraft at cruise speed over a 250 mile non-stop trip. So, other an being able to go upside down (for a very very short period of time), what does that performance get you ?

-- John

[nightflyer]

I concur with Spike's comments completely. Ask yourself one other question: are you a low-time pilot? I am, which is one reason the -9A appeals to me. The wider wingspan equals slower roll rate equals great stability. I have NO interest in aerobatics, so the aero capability of the 7 doesn't appeal. They're both excellent airplanes, as are all the RVs; it's just that the 9 fits my "mission profile" better.
Hard to go wrong with either !

[N200PF]

OK, OK I need to fly them both...

Spike - Upside down does appeal to me even if it's for a very short period of time...because I can't do it now in our Arrow! ...but I can't say that it appeals to me more than the amount of stability I would loose with the shorter wings.

Thanks for the help!!! This is just what I am needing right now befor our trip to Aurora!

- Peter

[guest]

RV9A: tricycle insurance is cheaper
RV9A: lowest stall and sink rate
RV9A: side by side is better for wife or friends
RV9A: great cross country handling
RV9A: great speed.

end of discussion. period.

[N200PF]

OK - I've said all along that I'm leaning 7 and these are all valid points for the 9! Let me play devils advocate:

1. Either 7 or 9 I'm building a tail dragger
2. I can deal with 5kts faster stall speed to be able to roll & loop
3. Side by side - same
4. X-Country handling - Don't know how this would be between the two???
5. Speed - Advantage 7 but not by much (~15kts)

I hope when I fly them back to back in Aurora one of them will speak to me!

- Peter

[jim_geo]

I may be dead wrong……….well maybe dead isn’t the right choice of word. I’ve said this elsewhere on this board so I’ll say it again here. Given the power options of the 9 I think that rolls and loops are easily possible in the 9. When my pappy and I ventured into aerobatics I rarely experienced more than two g’s and that was only for very short periods of time (I usually had him stop soon after that). All the aerobatics I’ve experienced were in a Citaborea, no Hershey bar wing there and when it comes right down to it Citaboreas’ are an aerodynamically inferior design compared to RVs’. What I’m trying to say is that I can’t discard the 9 simply based on the notion that I can’t do aerobatics in it because I don’t believe that it can’t. Maybe the 9 just isn’t the best of the line for aerobatics.

[SonoraMike]

was wondering about this subject too, thought I'd resurect this old topic.

are the published speeds on the 9 due to engine size? with a larger engine I'm assuming that you'd increase airspeed, but what is the structural Vne?

Is the lack of aerobatics due to the different wing vs the 7? specifically, what standard aerobatic manuvers would be off limits in the 9?

what are the G loads on the 9?

would it be correct to assume that the 7 handles crosswind takeoff and landings (xw> 15kts) better given the wing it uses?

I've heard rumors that the 9 will a 200hp motor deals well with the possible higher Va/Vne speeds

[bmurrish]

Upsidedown

Go get an intro to aerobatics flight and you will build the 7

[captain_john]

I will second that motion.

Stick to the published horsepower and mission.

I am building the -7 for the "sport" of it. It will do most of what I want out of a plane.

Hope this helps!

CJ

[g_e_young]

The RV-9 has the docile handling of a Cessna with the great flying qualities of an RV. Unless you're a high time pilot or really want to do aerobatics, I would get the -9. If you main goal is long cross country then I would definitely recommend a -9. An RV-7 is a Porsche and an RV-9 is more like an MB E-320.

My 2 cents.

gy

[Bob Barrett]

If you go to vansaircraft.com you will get VNE speeds, recomended engines and Van strongly discourages builders from exceeding those. You need to worry about flutter, exceeding VNE, being over designed weight specs etc. Exceeding VNE or G limits can and have been fatal! Some builders exceed both engine horsepower and VNE etc however you then become the one and only test pilot for a different combination. Some may get away with it for a while but it may catch up to them later. Follow Van's recomendations!

[arffguy]

Well put Bob.

[prestwich]

I just went through this agony for the last two months, as I discussed on another forum (thanks for this link, Capt'n John!) and I've looked into it in detail.

Here's my view: DO NOT do aerobatics in the 9, unless you're proficient in flying with detached wings, horizontal stabilizer, or control surfaces. It may have enough speed, but Van's does not publish G-ratings on this plane for a very, very good reason. You may get away with it a few times, but as soon as you screw up one of those maneuvers and pull a few too many Gs getting her back to straight and level, something important is going to come off.

I asked a lot of questions and talked with a lot of people and met many builders and saw many planes. Mostly I got answers that sounded like forked tongue: "The 7 is easy to fly, no problem, not squirrely at all." Followed by "You need a wing leveler, or you'll be flying it every second" and "It's not stable enough for an IFR platform."

Well, Van's will give you a demo ride. One. Pick the plane you want to try. Not too conducive to comparison. So I hung around some builders and the EAA folks near me until they either liked me enough or were sick of me enough to offer me a ride.

I went up in a 6A, which is essentially the same airplane as a 7A. I had 2 1/2 hours of sleep the night before, terrible diahrrea that morning, not enough food, the sun was getting pretty hot inside the bubble even though I had the vent open, and the ex-military pilot demonstrated quite a few aerobatics.

And, it had been about five years since I'd been in a plane at all. I've got about 150 hours, about 147 of which are in a Cessna 150. I went up in a Citabria for an hour once (loved it) -- if you have trouble remembering how to spell it, look at the word backwards -- and a couple of hours in a 172.

Now, bear all that in mind when I tell you, the RV-6/7 is DUCK SOUP. The guy at the factory told me over the phone that most pilots have trouble with it for five minutes or so until they get used to it and stop overcontrolling it. I have no idea what he was talking about. It didn't take me two seconds to get used to it. Point and shoot. I don't know how the 9 could be any easier. I'm baffled. And, I'm getting the 7A, because, yes, I do want to turn the world upside down on occasion.

One other thing: The largest engine you can put in the 9 is 160 hp. The smallest engine you can put in the 7 is 160 hp. Look at the numbers, and you'll see that performance is essentially identical. Do a little arithmetic and you'll see that the 7 actually gets slightly better gas mileage. So don't buy a 9 for economy. Buy the 7 and put the smaller engine in it, or put in the big one for when you need it and fly it at half power most of the time. Those few extra knots are the most expensive ones, anyway.

[cjensen]

Nice write up prestwich! I am going to build a -7 for similar reasons. I like to go upside down sometimes too.

Good luck in your project!

[captain_john]

U R Welcome!

Make yourself at home! I do!



That was a good write up for those contemplating which design to go with!

It is interesting to see what is important to people and what isn't.

-7 drivers are different than the rest I think!

CJ

[Spike]

Welcome to the group Prestwich, glad you decided to participate. Stick around and bring some friends Glad to have you.