RV-7 or RV-6

[Humrnv]

I took a flight in a -7 a couple of days ago and now I have to have one. I’m debating on looking for a kit to finish or order a new kit from Vans. However I have noticed several really nice flying-6’s for sale that seem to be priced good. I haven’t flown in a -6 so I’m not sure the difference in the flying. I know the -7 has longer wings, higher gross, more fuel and more engine options. Should I buy a flying-6 or hold out and build a -7.

Any information would be greatly appreciated.

 

[bjdecker]

-7

Ken,

The -7 is the way to go --- it has all the excellent flying qualities of the -6 but with a little more room, more fuel, accepts a bigger engine, higher Vne, etc.

There's a great -7 project that's almost completed that you can look at - get a feel for the whole experience.

Contact Bobby Lucroy at 5I2-657-6I67 for details. It's been listed for sale here.

Cheers,

Brian

 

[Mike S]

Welcome to VAF

Ken, welcome aboard the good ship VAF

 

[Untainted123]

Should I buy a flying-6 or hold out and build a -7.

Yes!

Buy a 6 for flying while you build the 7. Not entirely kidding, I know several who have done the same.

RV-6's are still the best deal going, there are quite a few of them, and they can get you flying now instead of several years from now. Nothing wrong with buying, building or buying and building.

 

[blaplante]

I took a flight in a -7 a couple of days ago and now I have to have one. I’m debating on looking for a kit to finish or order a new kit from Vans. However I have noticed several really nice flying-6’s for sale that seem to be priced good. I haven’t flown in a -6 so I’m not sure the difference in the flying. I know the -7 has longer wings, higher gross, more fuel and more engine options. Should I buy a flying-6 or hold out and build a -7.

Any information would be greatly appreciated.

With full fuel I doubt the useful load in the 7 is actually much/any more than in the 6.
Most 7's are o-360 180 HP and CS props, which ups the empty weight as well.
"more room" in the 7 is about 1" of headroom only. If you are under 6' it should be a non-issue in the 6 (redo the bottom cushion if need be).

Owning a 6 and having flown 7 a couple times I find the 6 to be lighter on the controls.

 

[Dan 57]

Should I buy a flying-6 or hold out and build a -7

Do you want to build, or do you want to fly? That is the question you wanna ask yourself.

I spent years building (not assembling as in today's modern kits) an RV-4, and did not enjoy the process. Even finishing a project is a task not to be underestimated.
Others will of course disagree, and do enjoy the building process enough to build several of these machines.

Most of the differences between a -7 and a -6 have already been posted above, nothing to add.

 

[BillL]

I took a flight in a -7 a couple of days ago and now I have to have one. I’m debating on looking for a kit to finish or order a new kit from Vans. However I have noticed several really nice flying-6’s for sale that seem to be priced good. I haven’t flown in a -6 so I’m not sure the difference in the flying. I know the -7 has longer wings, higher gross, more fuel and more engine options. Should I buy a flying-6 or hold out and build a -7.

Any information would be greatly appreciated.

If you are considering building - look at the classifieds NOW!!

https://vansairforce.net/community/showthread.php?t=219694

 

[sailvi767]

One consideration is there are no inflight airframe failures on the RV6 that I can find. That’s not the case with the RV7 where there have been multiple failures.

 

[Snowflake]

Are you and your passenger below ICAO standard weights? 350 lb or less total? If so a -6 will do you fine.

Would you and your passenger total closer to 400lb? Maybe a -7 would be better.

Is the total significantly over 400? Start looking at the -14.

I started a -7 build many years ago, and along the way after changes to job and free time profile I bought a flying -6 with the intention of finishing the -7 and selling the -6. But the -6 turned out to be an excellent choice and everything I wanted, so I sold the -7 kit and just kept flying. 650lb of useful load in mine (1000 empty) is plenty for me+wife+fuel+baggage.

 

[echostar7]

I have enjoyed flying in my lightweight rv-6 the most with O320, i have flown RV-6 and RV-7 with 360's and they dont feel as agile and are more of a handful imo. I would opt for a 950-1000~lb RV6-7

 

[longranger]

It’s my project in the classifieds that BillL referenced in post #7 (sale pending BTW). I’ve never actually been at the controls of a 7 so I can only say I chose it mostly due to the ease of building the prepunched kits, and somewhat due to the slightly higher fuel capacity. I have flown a friends 160hp RV-6A slider about 30 hours, and for what I’d want in an airplane at this point in my life I’d seriously consider buying it if it ever comes up for sale.

 

[DeltaRomeo]

I took a flight in a -7 a couple of days ago and now I have to have one. I’m debating on looking for a kit to finish or order a new kit from Vans. However I have noticed several really nice flying-6’s for sale that seem to be priced good. I haven’t flown in a -6 so I’m not sure the difference in the flying. I know the -7 has longer wings, higher gross, more fuel and more engine options. Should I buy a flying-6 or hold out and build a -7.

Any information would be greatly appreciated.

5’10” 173.2 (this morning) lbs and been flying my -6 for 21 years. Kinda a fan. The diff between a 7 and 6 isn't that much - 7 slightly more stable in yaw due to larger rudder. 6 a little more 'sporty' with the original size tail. I prefer it to be honest.

And welcome to VAF!

v/r,dr

 

[rv6n6r]

You can't really go wrong either way

RV-6s (kits or built) are going to be less expensive so probably a better value, though flying models are more likely to have some hours on them. The -7 is basically a "new and improved" -6 so if you want those incremental improvements (slightly bigger, more refined design & mfg.) and aren't as concerned about cost, then do a -7. Either way you can't really go wrong.

 

[JonJay]

The 6 was Vans last “hand designed and manufactured” kit. The 7 wasn’t a redesigned 6, it is a whole different product, designed to take advantage of the automated equipment Vans was using for the 8 and subsequent models. Vans matched some of the 6 specs, motor mount, firewall profile, gear, etc… so there was some commonality, thankfully.

Building any airplane is a daunting project. However the early RV’s, 3,4,6 required a bit more builder engagement. Jigging, laying out rivet lines, locating ribs, laying up the spar, etc…. As a result, you can get a wide variance in build quality. That said, I have seen many 7’s that missed just short of the mark with the little things, like edge finishing, FWF installs, etc…. They seemed to attract some builders who thought they could just throw them together and have an airplane.

Most 6 owners wouldn’t consider trading for a 7. We are jealous of what we have. I like the slightly sportier feel of the shorter wing. I even like the quirky tail wag cruising in turbulence. It would be nice to have the higher gross, VNE, fuel, etc…. but that has never affected how I use my airplane. As Randall put it, small incremental improvements between the 7 and 6. I love them both.

I would probably be buried in my 6 when I pass but that would be a waste of a great airplane.

 

[Duncannon]

One question I have is: At high altitude x-country flights (10-12k feet), does the 7 do any better than the 6, assuming they have the same engine, prop and weigh roughly the same?

The 9 is said to be a bit slower than the 6/7/8’s at lower altitudes, but the difference diminishes the higher up you climb. And at high enough altitudes, will even cruise faster, though you have to be up at hypoxia levels.

 

[RV8JD]

Here are links to the RV-6/6A and RV-7/7A performance data for comparison:

https://www.vansaircraft.com/rv-6/#aircraft-details-2

https://www.vansaircraft.com/rv-7/#aircraft-details-2​

 

[Desert Rat]

I've never flown a 6 so I can't really speak to that, my buddy had one and he loved it, but I never got to fly it before he wrecked it.

I'm building a 7, but I would have no problem at all buying a nice 6. It's not like there is a deal breaker either way.

Here are the technical issues I considered when I decided to build a 7 vs actively look for a 6 to buy;

The 7 has about an inch more headroom because you sit that much lower in the cockpit. Other than that, the cockpits are dimensionally almost identical.

The 7 has a 200 lb higher gross weight, but it also carries more fuel so if you top it off don't expect to be able to cram another suitcase in there. I'm not suitcase dependent but I like the idea of carrying more fuel.

The 7 has a higher Vne, and a higher Va, but more importantly, Vno is about 12kts higher on the 7 which is a big deal for me because I'm shoving an IO390 under the hood and it will most definitely cruise in the yellow if I shove the black knob in. This way as long as I don't mind burning some extra Dino-juice I can bomb along air 164 knots indicated without having to worry about bending something if I hit some bumps.

The 7 is mostly prepunched parts, vs the 6 which was had a bunch of hand layout. If I ever need a new skin or whatever on the 7 I can drill off the old one and have some level of assurance that the new one will match without a lot of rework.

 

[jrs14855]

RV

Something to consider: there has never been an inflight structural failure of a RV6. There was one registered as an RV6 but it was not built to plans.
There have been several inflight structural failures of RV7's, the latest Feb 19, 2022. Still no final report on that one. Use of RV9 rudder on some RV7's may be an issue but nothing definite that I have seen. At least some of the RV structural failure accidents started with rudder failure.

 

[dreed]

Welcome aboard- RV's are all awesome.

They are both great airplanes- if you find a reasonable 6, go for it. Fly now! Then, if finances allow it, build the plane you want.

I have a 7A, she's a bit of a plus size model (just under 1200#) with a 390, full interior, IFR panel, all the accoutrements, etc.. Still pretty sporty compared to most aircraft out there (i did up gross to 1850#). I fly a 6 occasionally too and I love it, it is a little more docile, but not a ton more.

If I had to chose, I'd take my 7 most of the time as I find her a bit more suited for all missions- but the six is a heck of a lot of fun to fly and a little lighter on the controls.

 

[ChiefPilot]

One question I have is: At high altitude x-country flights (10-12k feet), does the 7 do any better than the 6, assuming they have the same engine, prop and weigh roughly the same?

Vans own specs suggest the 6 will do better at altitude than the 7, given equal horsepower etc. For example, the solo weight ceiling for a 180hp RV-6 is listed as 25,700 while that of the 180hp 7 is 23,000.

All else is rarely equal, however. Individual builds may be better or worse.

 

[Jpm757]

I have enjoyed flying in my lightweight rv-6 the most with O320, i have flown RV-6 and RV-7 with 360's and they dont feel as agile and are more of a handful imo. I would opt for a 950-1000~lb RV6-7

RV-7 a handfull?

 

[Snowflake]

One question I have is: At high altitude x-country flights (10-12k feet), does the 7 do any better than the 6, assuming they have the same engine, prop and weigh roughly the same?

A "comparable" -7 will be 100lb heavier than a -6, so the comparison becomes apples to oranges. The extra weight means a -6 performs better at altitude on the same engine, as someone mentioned.

A proper comparison would be an O-320 powered -6 against an O-360 powered -7, I think. Those are the engines those airframes were designed around.

 

[ChiefPilot]

A "comparable" -7 will be 100lb heavier than a -6, so the comparison becomes apples to oranges. The extra weight means a -6 performs better at altitude on the same engine, as someone mentioned.

A proper comparison would be an O-320 powered -6 against an O-360 powered -7, I think. Those are the engines those airframes were designed around.

Even comparing a solo weight -6 at 180hp against a solo weight -7 at 200hp shows the -6 to still have a slight ceiling advantage. But again, differences between individual examples is probably more important. A light weight 7 will almost certainly outperform a chubby 6 and vice versa.

None of the documentation I have from building mine suggests the -6 was designed around the 320; there is certainly nothing in the builders manual that suggests that. It was designed to support parallel valve O/IO-360 models whereas the -7 additionally officially blessed the angle valve variants.

 

[gasman]

I have enjoyed flying in my lightweight rv-6 the most with O320, i have flown RV-6 and RV-7 with 360's and they dont feel as agile and are more of a handful imo. I would opt for a 950-1000~lb RV6-7

Almost impossible to find or build. My 6A is 1050 lb and it has nothing in it.
But it does handle GREAT!

 

[RV7A Flyer]

Something to consider: there has never been an inflight structural failure of a RV6. There was one registered as an RV6 but it was not built to plans.
There have been several inflight structural failures of RV7's, the latest Feb 19, 2022. Still no final report on that one. Use of RV9 rudder on some RV7's may be an issue but nothing definite that I have seen. At least some of the RV structural failure accidents started with rudder failure.

We went through this in another thread. IIRC, those failures were caused by grossly exceeding Vne. Hardly a design fault, IMO.

A little learning is a dangerous thing...

 

[RV8JD]

RV-7/7A In-Flight Breakup Accident Information

To increase the strength and flutter margins of the RV-7/7A, remove the RV-9/9A rudder (which is used on the -7/7A) and install an RV-8/8A rudder. The RV-7/7A with the RV-8/8A rudder is a Van's approved configuration.

Instead of rehashing it all again in this thread, newer forum members can view this thread:

https://vansairforce.net/community/showthread.php?t=209131​

The post linked below, within that thread, explains why the the RV-8/8A rudder on the RV-7/7A provides larger strength and flutter margins:

https://vansairforce.net/community/showpost.php?p=1627863&postcount=16​

 

[Snowflake]

Almost impossible to find or build. My 6A is 1050 lb and it has nothing in it.
But it does handle GREAT!

There was a thread a while ago asking about -6(/a) empty weights and there were quite a few below 1000lb. Mine is 999lb.

There was another thread quite a while ago now by someone who built a -9 and somehow got it registered (or was trying to) as a light sport. He had empty weight down in the low 900's.

 

[sailvi767]

We went through this in another thread. IIRC, those failures were caused by grossly exceeding Vne. Hardly a design fault, IMO.

A little learning is a dangerous thing...

The failures were generally exceeding VNE. The Utah inflight breakup does not appear to be VNE related. Regardless I suspect there have been just a many RV6’s that have exceeded VNE without a catastrophic result. I purchased a RV6 built by a noted individual in the RV community. He built it for racing and commented how hard it was for him to find an untouched RV6 kit. I asked why he did not simply get a RV7 kit from Vans. He said he would not have been comfortable running the speeds he was planning on in a RV7. I think the 7 is a great aircraft but care needs to be used near the margins.

 

[RV7A Flyer]

The failures were generally exceeding VNE. The Utah inflight breakup does not appear to be VNE related. Regardless I suspect there have been just a many RV6’s that have exceeded VNE without a catastrophic result. I purchased a RV6 built by a noted individual in the RV community. He built it for racing and commented how hard it was for him to find an untouched RV6 kit. I asked why he did not simply get a RV7 kit from Vans. He said he would not have been comfortable running the speeds he was planning on in a RV7. I think the 7 is a great aircraft but care needs to be used near the margins.

The probable cause in the Utah case says abrupt control inputs above Va in mountain wave and turbulence. And the original statement about rudder failures in *this* thread broke the rules and speculated on an accident cause int he absence of *any* information about the cause or a Final report from the NTSB.

(From the earlier post) At least some of the RV structural failure accidents started with rudder failure.

Wrong. They started with exceeding Vne by significant amounts. Or, to do an even deeper failure analysis, they started with pilots making decisions that put them in that regime in the first place.

Yep, you're right, though...exceed Vne and you're outside of the design envelope, on your own, and guessing at what the margins might be, or hoping you don't use all the margin. Hard to blame any design for a pilot failing to exercise good airmanship.

 

[sailvi767]

In the Utah accident they actually have zero idea what happened other than Mountain wave and turbulence that day. Both occupants were highly experienced pilots and I doubt they made abrupt inputs. The level of turbulence could have been extreme but no one really knows.

 

[RV7A Flyer]

In the Utah accident they actually have zero idea what happened other than Mountain wave and turbulence that day. Both occupants were highly experienced pilots and I doubt they made abrupt inputs. The level of turbulence could have been extreme but no one really knows.

Postaccident examination of the airplane revealed damage to the horizontal stabilizers and elevators that was consistent with a downward failure in positive overload. The loads required to fail the horizontal stabilizers and elevators cannot be generated from normal flight or control movements. Such failures would have required an abrupt pull back on the stick and corresponding movement of the elevator to a trailing-edge-up position, at speeds greater than the airplane's maneuvering speed. Failure of the horizontal tail first would have caused the airplane to pitch down rapidly, producing air loads on the upper surface of the wing that were sufficient to fail them in negative overload. The damage observed on the wings was consistent with a downward failure in negative overload. Additionally, there were no indications of any pre-existing cracks or anomalies with the horizontal stabilizers, elevators, or wing structures, and no pre-accident anomalies were observed that would have precluded normal control of the airplane.

Probable Cause and Findings
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's abrupt flight control inputs, likely above the maneuvering speed, in severe winds and turbulence conditions, which resulted in an in-flight breakup.

Given that they're the ones who did all the analysis, including examination of the wreckage, metallurgy, whatever, and nobody here did, this is the best we can do...but they certainly didn't have *zero idea* what happened. In any case, claiming that this was because of rudder failure, contradicting the NTSB report, without any evidence is misinformation at best.

 

[sailvi767]

Given that they're the ones who did all the analysis, including examination of the wreckage, metallurgy, whatever, and nobody here did, this is the best we can do...but they certainly didn't have *zero idea* what happened. In any case, claiming that this was because of rudder failure, contradicting the NTSB report, without any evidence is misinformation at best.

I never claimed it was rudder failure. I simply stated it was an accident that was not caused by a VNE over speed. I suspect as I pointed out extreme turbulence might have been a factor. Inflight breakups of airframes without a known underlying cause are fortunately one of the things that does get NTSB attention. This was as you mentioned properly investigated unlike most light aircraft accidents. What caused the overstress was however supposition on the part of the NTSB. I lived and flew extensively in the area years ago so it hit close to home. The part that really got my attention is the forecast only called for moderate turbulence. Still mountain wave is nothing to take casually in the area. I once was descending into the valley 20 miles south of SLC and we lost 50 knots of airspeed in about 5 seconds. It was a eye opener!

 

[RV7A Flyer]

I never claimed it was rudder failure. I simply stated it was an accident that was not caused by a VNE over speed. I suspect as I pointed out extreme turbulence might have been a factor. Inflight breakups of airframes without a known underlying cause are fortunately one of the things that does get NTSB attention. This was as you mentioned properly investigated unlike most light aircraft accidents. What caused the overstress was however supposition on the part of the NTSB. I lived and flew extensively in the area years ago so it hit close to home. The part that really got my attention is the forecast only called for moderate turbulence. Still mountain wave is nothing to take casually in the area. I once was descending into the valley 20 miles south of SLC and we lost 50 knots of airspeed in about 5 seconds. It was a eye opener!

But why even bring it up? Per the NTSB, someone yanked the snot out of the stick while over Va and tore things off the plane. That could happen in ANY aircraft, and it's not a design problem. It's a PILOT problem.

The OP was asking about a 6 vs a 7, and some people here have resurrected the thinking that changing a well-built 7's rudder based on TLAR "engineering" is somehow something the OP should do lest he kill himself by exceeding Vne by 1 knot and inducing flutter.

It's *misinformation* at best, fear-mongering at worst. *Stay within the envelope*.

Based on the results of our various design and testing programs, we determine and publish do-not-exceed limits for calculations such as max gross weight, max G-loading, etc. When we publish specification numbers for our aircraft designs, we expect that people will stick by those limits when they build, certify and fly their airplanes. While we do, of course, build in a certain safety margin or “buffer,” it’s very important to understand that these margins “belong” to the engineer – not to the builder. Pushing the limits is just that. So, unless you are fully and uniquely qualified to assess your own custom design (in which case you’re on your own, of course) we will tell you — quite directly — that the published limits are the limits. Period.

Van's Aircraft (emphasis added)

 

[sailvi767]

I believe the aircraft was possibly overstressed. I don’t believe a highly experienced pilot yanked the **** out of it. I suspect they encountered severe turbulence that induced high vertical G loads. In another life I pulled a lot of G. The aircraft should have taken 6 G’s without a failure and should been able to go beyond that without a inflight breakup. 6 G’s is a very high loading to intentionally pull in a RV. The 9 G ultimate load is extreme G to pull. This pilot should have been well versed on how to handle an aircraft in a turbulence encounter. The NTSB makes no mention that this was a pilot induced accident or that the aircraft was above VA. The last radar track had a max groundspeed of 133 knots. In the end the report basically has no solid conclusions.

“A review of the weather information indicated that there were likely low-level winds gusting from 26 to 46 knots at the time of the accident and that moderate-to-severe turbulence likely existed at the accident site. The weather conditions likely contributed to the in-flight breakup by either aggravating a flight maneuver or preventing a recovery from a loss of airplane control.”

 

[RV7A Flyer]

I believe the aircraft was possibly overstressed. I don’t believe a highly experienced pilot yanked the **** out of it. I suspect they encountered severe turbulence that induced high vertical G loads. In another life I pulled a lot of G. The aircraft should have taken 6 G’s without a failure and should been able to go beyond that without a inflight breakup. 6 G’s is a very high loading to intentionally pull in a RV. The 9 G ultimate load is extreme G to pull. This pilot should have been well versed on how to handle an aircraft in a turbulence encounter. The NTSB makes no mention that this was a pilot induced accident or that the aircraft was above VA. The last radar track had a max groundspeed of 133 knots. In the end the report basically has no solid conclusions.

“A review of the weather information indicated that there were likely low-level winds gusting from 26 to 46 knots at the time of the accident and that moderate-to-severe turbulence likely existed at the accident site. The weather conditions likely contributed to the in-flight breakup by either aggravating a flight maneuver or preventing a recovery from a loss of airplane control.”

Probable Cause and Findings...The pilot's abrupt flight control inputs, likely above the maneuvering speed

NTSB (emphasis added)