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RV-9A Performance

aarvig

aarvig

Well Known Member
So, I am back and forth between the 9A and the 7A. A member of the local MN wing of the VAF, Pete Howell, was kind enough to give me a ride in his beautiful 9A last night and actually turn the plane over to me for quite awhile. I have to say, I loved the stability and smoothness of the plane, especially as a low time pilot. Very smooth, nice flying airplane. He demonstrated slow flight, just above stall speed and we performed some maneuvers at that speed. Also did stalls and no flap landings. I quickly realized the 9 had very predictable handling qualities and was very easy to fly. Needless to say, previous to riding in his plane I was pretty fixed on the the 7A being the plane I want to build. But after last night, I am starting to lean towards the 9A because of its stability and lower cost to fly. We were burning 4.5gph at 108 knots last night. For local flights that is quite affordable. I like aero but that isn't a deal breaker. What I like about the 7A is the higher cruise speed since my wife and I will be flying back and forth to North Dakota all the time. So the question I have is this...could you folks report in on your 9A performance? Specifically, with a fixed or constant speed prop, what are your cruise speeds, at what RPM and/or MP and what type of fuel burn are you getting for a specified altitude? I appreciate the data. By the way, a big thanks to you Pete for taking me up.
 
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If you build an RV, you AREN'T going to be flying around at 108 kts.. I can promise you that..
 
RV-9a perf

bkilby said:
If you build an RV, you AREN'T going to be flying around at 108 kts.. I can promise you that..
Click to expand...


...true, going a-to-b. But I DO throttle back to 2200 and only 120 kts. just to enjoy the scenery, or the lower noise level, or to give myself time to think and look at the chart before entering unfamiliar airspace or fields.
The option to go faster is nice, but may not be for everyone.

I was most comfortable with the -9 in the pattern and landing, over the -6/7, as I'm a low-time pilot.
Perhpas that's why people build 2 or more RV's, as experience grows, so do expectations, and mission's change, kids grow up, and you grow in and out of need for speed, space, seats etc.
 
Aaron,

Lots about this in other threads. A search should give you heaps of information. You started at the right place with Pete Howell. He would be the 9A performance guru and can tell you everything you need to know.
My 9A performs similar to Pete's although I think he has a slight edge with fuel consumption, most likely due to his dual electronic ignition. My typical cruise at 8,500 ft DA is about 150 kts TAS using just over 6 g/h. The fastest I cruise is about 160 kts TAS (at 8,500 ft DA) using around 7.3/7.4 g/h. These are accurate figures verified using the 4 leg NTPS spreadsheet and actual physical measurement of fuel used (not from the FF gauge).
Now, I can go about 170 kts TAS at 8,500 ft DA WOT and 2,700 rpm but I would need to run at about 150 ROP and use lots of fuel. My 160 kts TAS mentioned above is the fastest practical speed that I would cruise at as any faster would require more than approx 63% power which is my self imposed limit for Best Economy mixture settings (Lycoming allows 75%). A 9A or a 7A with the 0-360 would be able to cruise a bit faster before needing to go ROP, but 160 kts TAS is a pretty good speed and I think the increase in drag at higher speed would start to make it impractical (from a fuel consumption point of view) to cruise much over 160 kts even with a 0-360 7A (or a 9A with the bigger engine). Others may disagree!

Fin
9A. 0-320. LS Plasma III and mag. Hartzell C/S prop
 
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Fuel Efficiency, 9 vs 7

I have the 7A and it was the right choice for me, but for others the 9's are correct. CAFE tested a 6A and a 9A. The 6A's performance is very, very close to the 7A's. You should read the reports, but I'll summarize on this one point. The 9A when tested by CAFE was significantly more fuel efficient. Van's numbers do not reflect it, but CAFE found it to be true.
 
Speed Demon!

Aaron you are welcome! You were a great stick last night. We did a bit of everything and Arron flew it really well, stalls, steep turns dead on altitude, and approaches right to the threshold where upon I donkeyed up the landings!

Speeds are a bit higher than he quoted - we were climbing much of the time. 123ktas is about right for level LOP local cruise on 4.5gph - you can get 128-130 on 5 at 3500ft or above. I spend 60+% of my time at low cruise @ 4.5 gph flying with Kate and taking pics. (boring, I know)

Fin's cruise numbers are right on mine - he is a touch faster (and I dislike him for it!) I shoot for ~150kt on 6gph up at 7500 and above and it works well. For the Grand Forks trip(if you must see UND:eek:) is 1.6 hrs at 150kts and 1.4 at 170kts. Not a huge diff. Maybe the EVO is for you! Very nice.

Hard to go wrong with the 7 or 9. I fly em both,and like them for diff reasons. Just dont build an 8 (ducking and just kidding;))
 
The secret

The secret to going fast is never slowing down.

There is a local RV-9A with a 108 hp O-235 up front. (This is a replacement for an O-320 powered -6A he had previously built.)

He thinks the -9A is a much better plane than his -6A which he still flies because his uncle now owns it.

He will fly nonstop 910 miles from OKC to HKY with reserves at 150 mph. He said that with the -6A he would have to make a fuel stop along the way.

It is all about your mission profile.
 
Uhm.. do you need a better example of why believing everything you read on the internet is not a good idea? ;)
 
Engine size, performance, & fuel usage

The question always arises regarding engine size in relation to performance and fuel usage. It's been said that throttling back an 0360 as used in a RV7 can get the same fuel savings as an 0320 in a RV9.

Well............I'm here to tell you it's true! A friend who owns a very nice and extremely well built RV9A, which is about 50 lbs. less weight than my 6A; prefers to fly his plane at "econo-speeds" to use much less fuel. He arrives at the destination later, but usually uses several gallons less than I do.

Lately, he flew my 6A while another friend flew his 9A. By again flying at "econo-speed", my 6A took a bit less fuel than his 9A. This last weekend, after a fill up on a cross-country, we both again flew at these fuel saving speeds home. Turns out my 6A took on 5.7 gallons, and his 9A filled at 5.9.

Proof----------that my 180 HP RV6A can actually beat, or at least stay with the 160 powered 9A (fuel wise) if I/we try. I was also flying at 155 mph, 7500'.

As to preferences, I prefer my 6A. It has a lighter touch on the controls, climbs faster, and has a 20 mph faster top speed. We both have constant speed props.............which we feel is mandatory. Others may differ on that subject.:) He prefers his 9A, which has a dual Dynon glass panel versus my six pac. His interior also is the full Classic Aero interior. I only have the Classic Aero seats.

But.............. because the way my 6A performes in comparison, he'd actually like a 7A. However, the 9A does land 10 mph slower, and has less of a descent rate. I've got a lot of 9A hours, and don't feel that either is harder to land. It wouldn't take many hours to feel as comfortable in the 7 as a 9.
Both are just about the same in turbulence. I've made wise cracks, that if blind folded on a cross-country, that you wouldn't know the difference between riding in my 6A versus the 9. It's true, as they feel much the same.

I know I'm talking a lot about my 6A versus the 9A, but I've been up in the 7 too. It's not really much different than the 6A.

edit: PS, we both have carbs and don't run LOP.

L.Adamson -- RV6A
 
The performance charts on Van's site make it appear that the 9 is much more efficent at altitude though. I have a 9 empennage kit and am thinking about listing it in the classifieds section and trading it with someone for a 7 empennage kit.

However if my assessment is correct then maybe I should stick with the 9.

RV-7 18,500 ft (160 HP)
RV-9 24,500 ft (160 HP)

But even at 200 HP the RV-7 shows a service ceiling of 22,500 ft -- still lower than the 9. Is it reasonable to assume that up at O2 altitudes, the 9 really starts to shine?
 
petehowell said:
Aaron you are welcome! You were a great stick last night. We did a bit of everything and Arron flew it really well, stalls, steep turns dead on altitude, and approaches right to the threshold where upon I donkeyed up the landings!

Speeds are a bit higher than he quoted - we were climbing much of the time. 123ktas is about right for level LOP local cruise on 4.5gph - you can get 128-130 on 5 at 3500ft or above. I spend 60+% of my time at low cruise @ 4.5 gph flying with Kate and taking pics. (boring, I know)

Fin's cruise numbers are right on mine - he is a touch faster (and I dislike him for it!) I shoot for ~150kt on 6gph up at 7500 and above and it works well. For the Grand Forks trip(if you must see UND:eek:) is 1.6 hrs at 150kts and 1.4 at 170kts. Not a huge diff. Maybe the EVO is for you! Very nice.

Hard to go wrong with the 7 or 9. I fly em both,and like them for diff reasons. Just dont build an 8 (ducking and just kidding;))
Click to expand...

Sorry on the numbers. I thought we were 108Kts, I maybe should have been paying attention to the airspeed indicator but I was having to much fun flying your airplane!:D
 
mculver said:
The performance charts on Van's site make it appear that the 9 is much more efficent at altitude though. I have a 9 empennage kit and am thinking about listing it in the classifieds section and trading it with someone for a 7 empennage kit.

However if my assessment is correct then maybe I should stick with the 9.

RV-7 18,500 ft (160 HP)
RV-9 24,500 ft (160 HP)

But even at 200 HP the RV-7 shows a service ceiling of 22,500 ft -- still lower than the 9. Is it reasonable to assume that up at O2 altitudes, the 9 really starts to shine?
Click to expand...

I talked to Ken Scott at Vans regarding this very subject. He told me that because of the efficiency of the RV-9A wing it does fly better at higher altitudes...
 
But is it faster? Sounds like it could be above ~15,000 ft

I talked to Ken Scott at Vans regarding this very subject. He told me that because of the efficiency of the RV-9A wing it does fly better at higher altitudes...
Click to expand...
 
mculver said:
But is it faster? Sounds like it could be above ~15,000 ft
Click to expand...

I honestly doubt it! But don't know for sure. I've only been to 14500' in my 6A, while the 9A that I've flown has been to 17,500 ( but not with me). And we have not flown these altitudes in the two planes together. However, since we do start at 4200' & regularly get into the 10,500' altitudes, my 6A will out climb the 9A, and is faster all around. But should the 9A get some better fuel savings & speed at 17500.......... then so be it. Just fly the 9 at 15000' to 17500' and bring the oxygen! :D

L.Adamson --- RV6A
 
But even at 200 HP the RV-7 shows a service ceiling of 22,500 ft -- still lower than the 9. Is it reasonable to assume that up at O2 altitudes, the 9 really starts to shine?
Click to expand...

At gross weight, Van's specs show the 7/200HP at 22,500 verus the 9/160HP at 19,000. A models are slightly less.
 
L.Adamson said:
I honestly doubt it! But don't know for sure. I've only been to 14500' in my 6A, while the 9A that I've flown has been to 17,500 ( but not with me). And we have not flown these altitudes in the two planes together. However, since we do start at 4200' & regularly get into the 10,500' altitudes, my 6A will out climb the 9A, and is faster all around. But should the 9A get some better fuel savings & speed at 17500.......... then so be it. Just fly the 9 at 15000' to 17500' and bring the oxygen! :D

L.Adamson --- RV6A
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Larry,

I know your plane has 180 hp but doesn't your friend's plane have only 160? If so, this comparison isn't valid.

Mike,

As for the speed difference between the 160 -7 & -9, they are so close that it comes down to how the pilot flies, power settings, etc. Notice on Van's web site, that it takes 200 hp before a -7's ground roll is shorter than a -9.

The truth is, they are both RV's, both fly like RV's, and you will be happy with either one and hard pressed to tell the difference between the two.

My 135 hp RV-9 gets off the ground in about 250 feet, solo. On long trips, over 200 miles, with other RV's I'm the first to take off and when we reach our destination I'm the last to arrive BUT when I enter the pattern the 2nd to last RV is usually rolling out on the runway. Thus I'm really not that slow. The down side is the rest of the gang gets to watch and critique my landings. The upside is there usually isn't a long wait for the fuel pumps.
 
I'm baffled......

I've been flying since 1971, and despite a long flying layoff period, have over 6000 hrs logged. The first 500 hours was logged in my Ercoupe, which I used to get my private and commercial tickets.
During this 38 years of aviation adventures, I've always heard pilots state how much they love to fly. Yet in the next breath, they love to brag how fast their plane is, and how fast they get to where they're going.
Could someone please explain this thinking to me?

Oh, BTW, my loaded 9A, 3 blade MT, IO-360 180 hp, cruises at 193 mph true, at 9500, 8 gph, WOT-2400 rpm.
With this bigger engine, my 9 will fly fast, will fly slow, will climb like a scalded eagle, or climb at cruise setting.
For cross country flights, I just wish it had 10 more gallons of fuel.
Great plane!!
Jack
N99552
135 hours
 
USCANAM said:
I've always heard pilots state how much they love to fly. Yet in the next breath, they love to brag how fast their plane is, and how fast they get to where they're going.
Could someone please explain this thinking to me?
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I don't know....

But when we slowed down to 155 mph for "econo cruise", my wife thought we were going to fall out of the sky...

But in reality, with all the excellent scenery around here; we can just see more of it, with higher speeds.... if desired. The ground doesn't appear to move all that fast at 200+ mph either.

L.Adamson --- RV6A
 
Do both, Jack

On a Friday, when my wife is off, she loves a fast day-trip to the coast, so we get there as quick as we can....the days are getting shorter.

Later, if she wants to go sight-seeing the beautiful inlets, suspension bridges and rivers, we do that at 100 MPH....usually the speed I give joyrides at...it all depends on the mission.

I wouldn't think of going to LOE at 100 in an RV! Nor would I go 200 down low while my wife is trying to take pictures.

......aaaah the versatility!
 
-7 vs -9

I've flown one example of each. We have both in the hangar. Side by side race, the 160HP / FP -9 walked away from the 170HP / FP -7 by about 5 mph at WOT and 2,000 feet.

That's certainly not a scientific report, but what I saw that time.

I really like the way the -9 flies. Not sure 5 or 10 or 15 mph really makes the deal one way or the other. Can't go wrong. Get the one you think is cool when you get ready to write the check.
 
RV-9A for me

JDRhodes said:
I've flown one example of each. We have both in the hangar. Side by side race, the 160HP / FP -9 walked away from the 170HP / FP -7 by about 5 mph at WOT and 2,000 feet.

That's certainly not a scientific report, but what I saw that time.

I really like the way the -9 flies. Not sure 5 or 10 or 15 mph really makes the deal one way or the other. Can't go wrong. Get the one you think is cool when you get ready to write the check.
Click to expand...

Jeff is right. If you feel the need for a roll or gentle loop, get the RV-7 or -7A. I don't like aerobatics, so I got the RV-9A. When I went to LOE5, I had the lowest horsepower at 160 than the other RV's in the group. We came along later at the gas pumps in Andrews, TX. We flew higher and stayed out of the turbulence along the way.

Jeff, I am looking forward to your fly-in on October 24th. I hope the weather is good that day.
 
-9 acro video

Am I the only guy wondering if that -9 with the VS sliced off was the same one doing the acro on youtube?
 
Steve said:
Am I the only guy wondering if that -9 with the VS sliced off was the same one doing the acro on youtube?
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What -9 with the VS sliced off?

Remember, after some testing Van's started putting the -9 VS and rudder on the -7, so that part can handle some acro.

As for the -9 being looped and rolled. As has been discussed, yes it will loop and roll very nicely from what I have been told, although I haven't tried a loop to verify. The thing is, if you get over aggressive or botch a maneuver, you could over stress the plane.

When done right, those are very low G maneuvers. Heck, watch the acro routines at the big airshows where they use non-acro planes. All they are is positive G maneuvers going back and fourth down the show line.
 
N941WR said:
What -9 with the VS sliced off?...
Click to expand...
wehgr.jpg


From http://vansairforce.net/
 
RVnoob said:
there's a video on YouTube about someone rolling and looping in a RV-9
is that real?


Many acro maneuvers are 1G actions. Are they safe to perform on the RV-9?
Click to expand...

This has been whipped to death many times. You could probably search the forums for the many comments on RV-9 acro, but I'll say that "safe" aerobatics in any airplane depends on the pilot. There is nothing magical about the 6G stress rating. Some pilots may not be safe doing aerobatics in an aircraft rated for 8G.

However, the FAA requires an aircraft mfg. to meet the +6/-3 G rating before allowing aerobatic maneuvers. Vans Aircraft it not the legal mfg. of a completed RV-9, but they adamantly state the RV-9 is not suitable for aerobatic flight due to the fact that the ultimate load testing does not meet the FAA requirement for aerobatic aircraft.

Aside from legality, an aircraft stressed for 6G (RV-7) simply provides more margin for error than an aircraft approved for 4.4G operations (RV-9). An RV-9 can easily be looped and rolled well within the utility category (4.4G) limitation. However, this requires the pilot to be well past the point in the aerobatic learning curve where blown maneuvers and mistakes are made.

I'm don't know much about this aspect, but there may also be insurance/liability risks associated with accidents involving non-approved maneuvers.
 
RVnoob said:
there's a video on YouTube about someone rolling and looping in a RV-9
is that real?


Many acro maneuvers are 1G actions. Are they safe to perform on the RV-9?
Click to expand...

This has been whipped to death many times. You could probably search the forums for the many comments on RV-9 acro, but I'll say that "safe" aerobatics in any airplane depends on the pilot. There is nothing magical about the 6G stress rating. Some pilots may not be safe doing aerobatics in an aircraft rated for 8G.

However, the FAA requires an aircraft mfg. to meet the +6/-3 G rating before allowing aerobatic maneuvers. Vans Aircraft it not the legal mfg. of a completed RV-9, but they adamantly state the RV-9 is not suitable for aerobatic flight due to the fact that the ultimate load testing does not meet the FAA requirement for aerobatic aircraft.

Aside from legality, an aircraft stressed for 6G (RV-7) simply provides more margin for error than an aircraft approved for 4.4G operations (RV-9). An RV-9 can easily be looped and rolled well within the utility category (4.4G) limitation. However, this requires the pilot to be well past the point in the aerobatic learning curve where blown maneuvers and mistakes are made.

I don't know much about this aspect, but there may also be insurance/liability risks associated with accidents involving non-approved maneuvers.
 
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Flying Upside down in a 9

I'm a newbie and have been rading the list for several months. I'm trying to decide between the 7 and 9, so I have a question about the discussion regarding doing loops and rolls in a 9. Can you loop or roll a plane with a carb? From my reading on this list, one of the advantages people list for FI is the ability to fly upside down. Do they mean for extended periods?
 
Welcome to VAF Joe!

No offense, but I think you should forget about loops and rolls as they apply to the RV-9. But to answer your question, you can loop and roll a plane with a carburetor. They can be completely positive G maneuvers, meaning the carb will continually deliver fuel. The engine will immediately quit with the onset of negative G, but will immediately restart (assuming brief exposure) when positive G is restored. This is not a problem. Loss of oil pressure if the main problem. Fuel injection doesn't rely on gravity, so it takes care of the fuel delivery...except you also need a flop tube in your fuel tank so that fuel can be retreived from the tank regardless of how the fuel is sloshed about. To take care of the oil pressure problem, you need an inverted oil system. Unless you're interested in competition aerobatics, I wouldn't bother with inverted systems. It's not about upright or inverted, it's about pos/neg G. You can pull negative G's upright and positive G's inverted. Plenty of recreational acro can be done at positive G.

Take some introductory acro instruction and find out if you like it. If so, think RV-7.
 
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SlowJoe said:
... one of the advantages people list for FI is the ability to fly upside down. Do they mean for extended periods?
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Yes, for extended periods of time but you will also need flop tubes in the tanks and an inverted oil system.

sandifer said:
.... It's not about upright or inverted, it's about pos/neg G. You can pull negative G's upright and positive G's inverted. Plenty of recreational acro can be done at positive G...
Click to expand...
On occasion I would hit a negative bump in my carb'ed -9 and the engine would stumble. The same thing would happen with an over agressive pushover to level flight from climb. Not a big deal but it did it once while giving a member of this forum a ride and is something you should be aware of.
 
VS sliced off

N941WR said:
What -9 with the VS sliced off?QUOTE]

Does anyone know what the deal was here or if it made it on the NTSB accident listing? Very nice to see the aircraft is flyable with some of the VS and all the rudder missing...but I don't necessarily want be the guy who demonstrates that!

Doug Lomheim
RV-9A, OKC / Mazda 13B/ FWF /Electrical
Click to expand...
 
dlomheim said:
N941WR said:
What -9 with the VS sliced off?QUOTE]

Does anyone know what the deal was here or if it made it on the NTSB accident listing? Very nice to see the aircraft is flyable with some of the VS and all the rudder missing...but I don't necessarily want be the guy who demonstrates that!

Doug Lomheim
RV-9A, OKC / Mazda 13B/ FWF /Electrical
Click to expand...
Doug,

Take a look at the "PU" number, it will not hit the FAA/NTSB database as it doesn't look like it happened in the states.

PS. "PU" is for aircraft registered in Brazil.
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PU 09A

Hi guys,

that?s right. PU is the brazilian registration for ultralights. The nine is the only RV (no RV 12?s here yet) that may be registered like that down here. It?s something like the LSA, but it does not have a max speed limit, only weight and stall. On the other hand, It doesn?t matter how well equiped or constructed your plane is, experimental cannot be IFR, and VFR is limited to FL075:mad:
I will try to get some more information about the VS incident in the local news and keep you up to date.

Cheers
 
MTOW for an RV-9/9A is 1750 lbs (794 Kg).

That weight can be lower for -9's with smaller engines but with my O-290 I set it at 1750 and don't really see a reason why the the GW should be reduced based on the performance I saw.
 
Corrections

Thankx Pete. the (640 lb) was a mistyping.
I'm not sure if the authorities here check on every plane's configuration to see if they still keep the numbers below the limits. I've never seen a 09 with an 0-235 and they still get the PU registration. Brazilian flight authorities can be really incoherent.
 
I got to fly a 6A last week with an eggenfeller conversion and then just got back from flying a 9A this morning (160/fixed pitch). Handling, trim, etc was similar but the 9A was quicker on takeoff, better on speed and I landed about 10knots slower than I landed in the 6A. I think the best benefit for the 7 vs 9 would be the larger engine, otherwise the 9 is as good a choice. I'm in the same predicament, looking at either trading my Velocity for an RV? or building a 7 or 9 kit from scratch..Tom
 
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