[Mike0726]

I am building an RV-7 and would like to use the small rudder originally supplied with the older RV-7 kits. This rudder had the folded trailing edge instead of the blind riveted trailing edge. It should also be the same rudder as the RV-8. Just wondered if anyone had one of the originals that they didn’t use and would be interested in selling.

Thank you for your help!

 

[SwimmingDragonfly96]

I am building an RV-7 and would like to use the small rudder originally supplied with the older RV-7 kits. This rudder had the folded trailing edge instead of the blind riveted trailing edge. It should also be the same rudder as the RV-8. Just wondered if anyone had one of the originals that they didn’t use and would be interested in selling.

Thank you for your help!

I don't have anything for sale but I do have the small rudder on my 7A. Curious why you want to go with the small one?

 

[Mike0726]

I don't have anything for sale but I do have the small rudder on my 7A. Curious why you want to go with the small one?

Good question. I like the folded trailing edge as opposed to the riveted trailing edge. Thought about fabricating the larger rudder with a folded trailing edge but the small rudder seemed to have some other advantages as well.

 

[bjdecker]

I am building an RV-7 and would like to use the small rudder originally supplied with the older RV-7 kits. This rudder had the folded trailing edge instead of the blind riveted trailing edge. It should also be the same rudder as the RV-8. Just wondered if anyone had one of the originals that they didn’t use and would be interested in selling.

Thank you for your help!

22 years is a long time to hold on to a rudder...

 

[SwimmingDragonfly96]

Good question. I like the folded trailing edge as opposed to the riveted trailing edge. Thought about fabricating the larger rudder with a folded trailing edge but the small rudder seemed to have some other advantages as well.

Gotcha. A lot of people blame the RV7 in flight breakups on that newer, bigger rudder. I remember some time ago, there was actually a thread on here of people retrofitting the older smaller rudder. I, personally, do find the rudder authority a little weak with the smaller rudder, but the plane flies great still and I don't really have a comparison as I've never personally flown the bigger rudder.

 

[jrs14855]

Gotcha. A lot of people blame the RV7 in flight breakups on that newer, bigger rudder. I remember some time ago, there was actually a thread on here of people retrofitting the older smaller rudder. I, personally, do find the rudder authority a little weak with the smaller rudder, but the plane flies great still and I don't really have a comparison as I've never personally flown the bigger rudder.

A lot of people would include the NTSB final reports that show rudder/rudder parts the first items in the breakup sequence.

 

[Walt]

I'm one of the guys that installed the original small rudder a few years ago, stronger and looks better.
I built it back around 2000, then they sent me the 9 rudder so I used it thinking it must be 'better'.
Very happy with the 'new' smaller rudder.

 

[jrs14855]

The story that I heard was that the 7 with the original rudder was ok on spin recovery but the people involved felt it could be improved. I have watched video of a small rudder 7 doing spins and don't see anything that would concern me.
So we have a solution in search of a problem that has been the starting point for several in flight structural breakups.
Setting aside the RV3 problems in early history and examining only the aerobatic models, structural failures:
RV4 zero
RV6 zero
RV7 seven
RV8 one
RV14 too small a sample to be accurate.
The RV8 was an AG pilot on the controls who was likely used to much heavier control forces. Vans Aerobatic Epistle details how easy it would be to put a G load in excess of 10 G and maybe closer to 20 G on any of these airplanes.

 

[bjdecker]

The story that I heard was that the 7 with the original rudder was ok on spin recovery but the people involved felt it could be improved. I have watched video of a small rudder 7 doing spins and don't see anything that would concern me.
So we have a solution in search of a problem that has been the starting point for several in flight structural breakups.
Setting aside the RV3 problems in early history and examining only the aerobatic models, structural failures:
RV4 zero
RV6 zero
RV7 seven
RV8 one
RV14 too small a sample to be accurate.
The RV8 was an AG pilot on the controls who was likely used to much heavier control forces. Vans Aerobatic Epistle details how easy it would be to put a G load in excess of 10 G and maybe closer to 20 G on any of these airplanes.

RV-7 -- Eight; at least according to the exemplary work by Carl @RV8JD

RV-7:7A In-Flight Breakups.xlsx

Sheet1 RV-7/7A In-Flight Breakups No.,Model,Accident Date,Registration Number,Location,Fatalities,References,Accident Number,Preliminary Investigation Report,Final Investigation Report,Docket 8,RV-7A,02/19/22,N787NV,White Hills, AZ,1,<a href="https://aviation-safety.net/wikibase/275672">https://...

docs.google.com

 

[RV7A Flyer]

So we have a solution in search of a problem that has been the starting point for several in flight structural breakups.

Funny...I thought the starting point for most of these was people exceeding Vne by as much as 40 knots or more.

 

[jrs14855]

White Hills AZ was the latest one. One of the most incompetent final reports I have ever seen. NTSB says a split s at excessive speed. I have serious doubt the writer of that report could even describe a split s using a model. Local witnesses described a spiral descent that accelerated in speed. The final part of the video shows a steep descent with almost 90 degree stable bank angle and the entire tail missing. One of the puzzles is the relatively stable pitch angle. With the horizontal tail gone the airplane would be expected to pitch nose down.
The Atlantic City RV7 pitched down violently enough to fail the wings downward after the tail departed. It that accident there were witnesses who viewed the pilots botched aileron rolls from another airplane. The other airplane was not present for the fatal flight. Also that airplane had rudder wind damage that was repaired by the non builder pilot. The really sad part to me is that it is likely that a RV4, 6 or 8 would likely have survived those same scenarios.

 

[jrs14855]

Exceeding Vne: I previously posted about a RV6 owner that I flew with in the Pitts. He admitted to a botched aileron roll in the RV6 that resulted in speed close to 300, a lot of G load and nearly hitting the ground. I talked that pilot thru his first successful aileron roll in the Pitts without demonstrating the maneuver, only describing it in a briefing. Two years of doing that with a success rate of near 100%. A number of times with non pilots.
The point is if a RV6 can survive near 300 m/h why can't the RV7?

 

[andoman]

I built an early -7A with the small rudder. Flew it for about 100 hrs before Van’s sent me the free larger rudder to build and install. I had spun her many, many times and the less than 1 turn improvement (iirc) in spin recovery was not worth the effort to build the new rudder.
In fairness, 1 turn less rotation is 1500‘ of altitude lost, yes?
The small rudder looks MUCH better imho.
A question no one has answered is: does the larger rudder give the aircraft increased yaw authority so it will be MORE prone to enter a spin?
I believe this is a great question since most RV’s spin eagerly…
To the OP: I think enough of the early -7(A) builders shelved the small rudder and built the large one. You might get lucky if you keep on the hunt for a mothballed kit. I bet more than one ended up as a donation to a local EAA chapter. Mine large one was used up as handy and valuable scrap 2024 over the decades of subsequent building.
Good luck!!

 

[PhatRV]

Exceeding Vne: I previously posted about a RV6 owner that I flew with in the Pitts. He admitted to a botched aileron roll in the RV6 that resulted in speed close to 300, a lot of G load and nearly hitting the ground. I talked that pilot thru his first successful aileron roll in the Pitts without demonstrating the maneuver, only describing it in a briefing. Two years of doing that with a success rate of near 100%. A number of times with non pilots.
The point is if a RV6 can survive near 300 m/h why can't the RV7?

Pure luck can be an option too.

 

[RV7A Flyer]

Pure luck can be an option too.

No, no...do some TLAR armchair engineering, put a bigger or smaller something on the plane, tell yourself it's "better" and has "more margin" and go out and exceed the new margin by 20% or so, rip some other part of the plane off and then blame THAT part for not "giving enough safety margin".

 

[RV7A Flyer]

RV-7 -- Eight; at least according to the exemplary work by Carl @RV8JD

RV-7:7A In-Flight Breakups.xlsx

Sheet1 RV-7/7A In-Flight Breakups No.,Model,Accident Date,Registration Number,Location,Fatalities,References,Accident Number,Preliminary Investigation Report,Final Investigation Report,Docket 8,RV-7A,02/19/22,N787NV,White Hills, AZ,1,<a href="https://aviation-safety.net/wikibase/275672">https://...

docs.google.com

And here's what I wrote a while back, to dispel the falsehood that all of the accidents listed were due to, or in some cases even *known* to have had, empennage/rudder failures. Hell, in one case he listed the plane *wasn't even recovered from underwater*.

1. Preliminary report only, cause undetermined yet.
2. Preliminary report only, in-flight break-up, weather involved, cause undetermined yet.
3. Exceeded Vne by > 20% (44 knots).
4. "There were no clear indications that any of the [empennage] components that fractured in overstress did so before ground impact or independently of the bird strike."
5. "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."
6. Probable cause undetermined because wreckage was not recovered (sunk in 500' of water).
7. "At the time of the inflight breakup, the airplane was traveling 20 knots above the published never exceed speed."
8. Exceeded Vne by 34 knots.

We should at least debate based on FACTS.

 

[Kaffer62]

Speaking of holding onto things. I have an early unbuilt small rudder for the 7.

 

[Scott Hersha]

Exceeding Vne: I previously posted about a RV6 owner that I flew with in the Pitts. He admitted to a botched aileron roll in the RV6 that resulted in speed close to 300, a lot of G load and nearly hitting the ground. I talked that pilot thru his first successful aileron roll in the Pitts without demonstrating the maneuver, only describing it in a briefing. Two years of doing that with a success rate of near 100%. A number of times with non pilots.
The point is if a RV6 can survive near 300 m/h why can't the RV7?

Pure luck may be an option, but I question the “speed close to 300” part of that one without inducing some sort of flutter, especially on the non-counterweighted rudder. An observation of airspeed, feeling, assumption……. mph or kts, doesn’t matter, that is very far outside the designed performance envelope for an RV6. I think the RV6 is the safest design that Van has made (I’ve built 2), but I think the RV7 is safe too, if operated within the design envelope. It might be a little easier to exceed that envelope due to its slippery design, and maybe a possible assumption that the improvements made in the design gives you some sort of extra margin. Bad assumption, especially if you consider the paring of the weight margins when you build a heavy RV7. Aerobatic gross weight margins disappear pretty quickly when you add all the personal amenities like a heavy BMW interior, multi-redundant IFR panel, etc. Nothing wrong with all that stuff, but it affects other aspects of the airframe that might be limiting. That big rudder on the RV7 had more to do with allowing the airframe to handle a bigger engine, and that can lead you into the limiting edge of your design envelope much quicker if you’re not careful, and well trained in aerobatic flying.
My RV6, with its BEAUTIFUL small tail, is limited in certain aerobatic areas, namely in spin maneuvering and recovery. Van recommended in many articles, to limit turns in a spin to three turns maximum in the RV6. If you do three full turns, realize that it will take at least three turns to recover from that spin. My RV8’s could do more than that with no problem, but I don’t really like spins anyway. The RV7 can handle similar spin characteristics to the RV8 because of that larger rudder and vertical (less attractive) tail. But that larger tail can more easily exceed the designed structural limitations of the structure when you exceed the speed and G limits as designed. Nothing wrong with the RV7 when flown as designed.

 

[alcladrv]

On my -7A, I built the large rudder as it was supplied with my kit. Re-skinned it 9 years later prior to paint because of cracking from some of the forward stringer rivets. After painting, it looked pristine and flew fine for 10 years when it got tweaked by strong aft quartering winds even with a gust lock on each side. That's when I learned how much flex it had even with rudder stops keeping it 1-1/2 inches away from the elevator.

Built a new early -7/-8 rudder a couple of years ago, which looks great and flies with little, if any, difference with the large rudder. It is so stiff, compared to the large rudder, that it appears to have minimal flex. I use the plane for cross-country flights and no aerobatics. Point of reference: I noted at Airventure 2023, that Vans' RV-7A demonstrator had the early -7/-8 rudder installed on it.

 

[Thermos]

Trying to recenter the thread...WRT small versus large rudder, flutter, and the rest of this discussion, there's far better information in this VAF thread.

Mike0726, I hope you're able to find a rudder kit. Just curious, did you ask Van's what a -8 rudder would cost? I'd be interested in finding out as well.

Dave

 

[plehrke]

A question no one has answered is: does the larger rudder give the aircraft increased yaw authority so it will be MORE prone to enter a spin?

Another question does the larger rudder give any more yaw authority at low speed for landing in a cross wind?

 

[Mike0726]

Excellent points!

 

[Mike0726]

Trying to recenter the thread...WRT small versus large rudder, flutter, and the rest of this discussion, there's far better information in this VAF thread.

Mike0726, I hope you're able to find a rudder kit. Just curious, did you ask Van's what a -8 rudder would cost? I'd be interested in finding out as well.

Dave

They are unable to provide shipping quotes at this time so a little unknown.

 

[Mike0726]

Speaking of holding onto things. I have an early unbuilt small rudder for the 7.

Mike********@yahoo.com
*zero seven two six two zero zero zero

Phone: Five one zero eight two eight 7602

Give me a shout if you’re interested in letting it go.

 

[JonJay]

I built an early -7A with the small rudder. Flew it for about 100 hrs before Van’s sent me the free larger rudder to build and install. I had spun her many, many times and the less than 1 turn improvement (iirc) in spin recovery was not worth the effort to build the new rudder.
In fairness, 1 turn less rotation is 1500‘ of altitude yes?

I spun tested my 6 before they started championing against it. If I recall correctly loss is about 500’ per turn, but then you have to recover.
What will forever be etched in my mind is how quickly the 6 spun up from a relatively benign stall and wing drop to a wickedly tight spin and tunnel vision of the earth growing larger. Then, a nervous wait after correction for the airplane to react. That was about a turn and a half for me. I did a few fully developed spins then decided that was enough.
So, ya, I’ll believe 1500’ total all things equal.

 

[jrs14855]

I spun tested my 6 before they started championing against it. If I recall correctly loss is about 500’ per turn, but then you have to recover.
What will forever be etched in my mind is how quickly the 6 spun up from a relatively benign stall and wing drop to a wickedly tight spin and tunnel vision of the earth growing larger. Then, a nervous wait after correction for the airplane to react. That was about a turn and a half for me. I did a few fully developed spins then decided that was enough.
So, ya, I’ll believe 1500’ total all things equal.

Regarding Vne: Prior to the involvement of RV's i the Sport Class at Reno there were two exceptionally fast RV's. Dave Anders RV4 and Tracy Saylor's RV6. Both were likely exceeding Vne in SARL Races. The RV6 was destroyed after being sold. Some kind of ground accident not involving a pilot. With more and more RV's in the Sport Class the faster airplanes are almost certainly exceeding Vne.
These are just a couple of examples of RV's that have been operated well beyond Vne. It is inexcusable that RV7's are being allowed to operate with the RV9 rudders. Those rudders simply are not airworthy on the RV7.
The FAA took action with the early RV3 issues. Why not the RV7??

 

[maxmirot]

The story that I heard was that the 7 with the original rudder was ok on spin recovery but the people involved felt it could be improved. I have watched video of a small rudder 7 doing spins and don't see anything that would concern me.
So we have a solution in search of a problem that has been the starting point for several in flight structural breakups.
Setting aside the RV3 problems in early history and examining only the aerobatic models, structural failures:
RV4 zero
RV6 zero
RV7 seven
RV8 one
RV14 too small a sample to be accurate.
The RV8 was an AG pilot on the controls who was likely used to much heavier control forces. Vans Aerobatic Epistle details how easy it would be to put a G load in excess of 10 G and maybe closer to 20 G on any of these airplanes.

I find hard to believe the RV4 and RV6 have had zero structural failures

 

[RV7A Flyer]

It is inexcusable that RV7's are being allowed to operate with the RV9 rudders. Those rudders simply are not airworthy on the RV7.

Oh, come on..."not airworthy"? Prone to hyperbole, are we?

 

[Sam Buchanan]

I find hard to believe the RV4 and RV6 have had zero structural failures

I'm not going to state there has never been an airframe failure of the RV-4 or RV-6, but during the 27 years I've been in the RV community I don't recall any failures and haven't seen historical data of a failure. These aircraft have totally different spars from the later models and the legacy small tails apparently can tolerate more loads than the more modern versions. Perhaps Scott or Mel can recall a failure but I can't.

 

[sailvi767]

I find hard to believe the RV4 and RV6 have had zero structural failures

I researched RV6 accidents extensively. I could not find a single inflight breakup even though at the time I looked the RV6 fleet had more flight hours.