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RV-4 "Size" Question

VF84Sluggo

Well Known Member
Folks,

I'm looking at buying a new-to-me RV-4. I've never sat in a -4, wondering just how cramped the back seat is, max height/weight for a rear seat passenger. I've heard the aft cg is also a concern if the rear passenger is on the large side.

I used to own an RV-3, and it's always looked to me like Van took a -3 canopy and squeezed two people under it with the -4.

Any advice/info is appreciated!
 
Short trips are best

My better half is 5'7" and 145-ish pounds. She is very comfortable in the back seat and we have stayed an entire week at OSH with luggage we carried in the plane. That being said, she does not volunteer to come along on 'just for fun' flights and prefers jaunts straight and level and under one hour. With a 'big' motor and CS prop up front, the CG issue is much more manageable. My record, because of an emergency ranching situation, was I carried our foreman to a location. He was 6'6" and 300 pounds. Not gonna lie, it SUCKED for both of us- his comfort and the flying qualities of my -4. But we did it. The four is not as roomy as the -8 but having owned both, I went back to the -4 because it just flies and feels better. No, it really does. And remember, >69% of the time you WILL be solo, so buy the plane YOU like......No really �� And yes, the RV-4 is considerably roomier than the -3. But the -3 is a great solo bird too��
 
I've carried a 6' 4", 260 lb passenger in the back of my -4. He fit but it was tight. This was beyond the envelope for a proper W&B so the handling qualities were poor to awful. When it comes to the back seat of a -4, passenger height surprisingly doesn't seem to be an issue. But maybe that depends on the passenger's ability to scrunch down.

Alan
RV-4
 
Lots of threads on this already

There are several threads on this same question, but here is my usual response from experience. I have a -4 I built and love it..95% of my flying is 2 up (wife loves to fly). I am 6'1", 200ish, and she is 140something and 5'11". No problems with fit/comfort or flying qualities. I have the rear footwells which should be standard anyway, an O320/wood prop, 950ish# airframe. All -4s are not equal, but all -4's will become pitch "twitchy" with AFT CG. This can be a surprise on first landing and over rotation in the flare. I always take off with some downtrim or you'll be stick pushing in the initial climb aggressively. I have a personal backseater weight limit of 200# and a 3.5 gal smoke tank in rear baggage I will keep below half with a 200# backseater. Full fuel makes things much better, and I seldom go below half tanks with heavy PAX. While this seems a bit limiting, it accommodates most passengers without an issue.
 
Run a W&B on the particular -4 you are considering, they all differ, some considerably. Also check the gross weight advertised for that specific airplane. I have seen several -4's that have big engines and c/s props that have the G.W. bumped up to accommodate the heavier aircraft. In some cases the G.W. was increased above the original #1500 AFTER the original airworthiness certification (not legal). The RV-4 is a terrific machine designed for 150-160 hp f/p prop, some owners try to turn them into something they were not originally designed for. Van recognized this, and hence the RV-8 was born. Don't try to make an RV-4 into something it is not, if you need more room/power/useful load then maybe an -8 is a better choice.
 
With my 980# empty weight, 125 pound wife, and full fuel, I can only have 20# of luggage (in the back), and the airplane still flies nice, but is definitely tail heavy - but within limits, as long as I have 8+ gallons of fuel on board. It’s just not a really good cross country airplane for two adults with lots of luggage, and it wasn’t designed to be. The RV8 was. I’ve had 2 RV8’s, and 2 RV4’s. I couldn’t believe all the stuff I could squeeze in to that RV8, along with a passenger, and still be within designed limits. The RV4, although capable to a lesser degree for two people, wasn’t designed to have the expanded capability that the RV8 has.
Having said that, I realize that for me, 95% of my flying is solo, and there isn’t another RV (or any airplane available to the common man) that flies as wonderfully as a light weight RV4. For the cost, I can’t think of any airplane anywhere, that can compete with an RV4 in terms of flying qualities, fun factor, or any sort of cost/benefit analysis. If it fits your mission profile within the designed limits, you can’t go wrong with a well built RV4.
 
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Thanks for all the great input!

What I'm afraid of is that the -4 I'm looking at is on the beefy side. The fit and finish is outstanding, plush interior, IO-360/constant speed prop. While all that sounds great, it just screams "heavy." So now you bring into play aerobatic weight limit, and overall structural loading limits.

I know my -3, while not spartan, was not fitted out with fancy upholstery and gizmos and gadgets. I'd even talked with Van 1 on 1 about this, and he said while those Cadillac interiors and full panels look nice, it's added weight he never intended for the design. I recall him saying, with these -3s and -4s coming in at 100+ lbs over his design empty weight was just never part of what was intended or designed for.

Here's the -4 I have a Letter of Intent for buying. She IS a beauty:
 

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I have seen the picture of this one online, and I agree, she is a real beauty. Maybe you should ask yourself what your requirements are, and then do an actual weight and balance calculation with the owners accurate data to see if it works. The design gross weight of the -4 is 1500#, as you know. I have an O-360 in my RV4 which might be slightly lighter than the injected engine in this example, provided it’s a parallel valve engine. My carbon Sensenich is lighter than the Whirlwind, but not by much, so it might work for you. When I have full fuel on mine (980# + 190#), I’m left with 330# of useful load for me, my passenger, and luggage.
Some builders have claimed a higher gross weight through phase 1 flight testing, but make sure that is what it says on your Operating Limitations, and also understand this is outside the design limitations of the airplane from Vans Aircraft. If you end up eating up some runway lights, or worse, you want to make sure your insurance policy is still valid. I’ve never had an insurance company ask me for a copy of my Op Lims, but the FAA has a copy of it if there is an accident.
 
Thanks, Scott. Good info.

I asked for a copy/pic of the W&B earlier today. I can't see ANY way this plane comes in near Van's design empty weight (903-913, from the specs from the -4 on Van's Aircraft website)

Frankly, I bet I'd be solo 95% of the time (like in other planes I've owned). I also plan on doing "Sunday afternoon" acro. And with the wife onboard, it would be to go somewhere, or just a local sight-seeing flight.

However, from doing more reading here on the -4 forum, it sounds like with two onboard the -4 is outside aerobatic limits. It would be nice to take a passenger "over the top" on a loop, or other mild acro stuff. If the -4 is not capable of that, that just might be a deal-killer.
 
I don’t know of any RV4’s that have an empty weight within that range. I’m not saying that they don’t exist, because they do, but I don’t know of any. If your airplane you are considering weighs 1,000#, with 100# of fuel (1/2 tanks), you will have 275# for you and your passenger (that includes chutes if you plan on acro and go by the book). The aerobatic GW doesn’t change because of a phase 1 claim on the Op Specs. For the most part, acro in an RV4 is a solo experience, legally, unless your passenger is light, and you obey the restricted CG envelope.

That being said, loops in my airplane results in 3.0-3.5 G’s. The kinds of rolls that I do are 1G maneuvers for the most part. The RV4 rolls like none other, in fact, it almost does it by itself. It is totally a visual maneuver. With my grandkids on board, I’m within the aerobatic limitations, and my grandkids love it. I haven’t done loops with them, even though I am within the aerobatic gross weight and CG limits. I don’t want them to get sick or scared, but they love rolls, wingovers, and any low G maneuvering. They also love being strapped in like a Top Gun pilot.

If this airplane that you’ve shown doesn’t meet your requirements, keep looking. You’ll find what you want eventually, and there isn’t a better bang for your buck, generally speaking, than a Vans RV4.
 
Scott,

Thanks for the info. Appreciate it.

In my -3 I found 3.5 g was a nice spot for vertical manuevers. More than that tended to scrub off knots for no real gain. Managing power/pull down the back side was key to keeping speed and g under control.

I'm sure a -4 handles crisply. But as Van told me, in his shop, one-on-one, the -3 flies/handles how he "intended the breed to fly. Anytime you stretch a plane, you lose a little performance." Problem is, with a -3 you can't share the fun! I'd go for a -3 again, but the wife says no more "me only" toys...LOL

I'd love to get an -8. I think that would be better for load-carrying ability and any aft cg concerns, but with triple-digit prices on them (ones I'd want, anyway), it ain't happening.
 
...
I'm looking at buying a new-to-me RV-4. I've never sat in a -4, wondering just how cramped the back seat is, max height/weight for a rear seat passenger. ...
I've had a short ride in an RV-4 in the back and it was surprisingly roomy and comfortable. I'm not that big - about 5'9" and 175 lbs but extremely muscular and good-looking - oops, wrong forum.
 
The RV-4 is the best flying model. It will carry anything that you can put in it, legal or not. I have the fast back modification with the 180HP which gives you much more storage space and keeps the breeze on the passenger’s neck to a minimum. I can get two carry ons and emergency equipment in the baggage compartment. A properly built airframe and equivalent engine, the RV-4 will have better performance than any other model with 2 or more seating. I see 180 knots at altitude and 7GPH.

I talked with one builder that built every model that Van produced and he said that the only one he regrets selling was the 4.

The problems with the 4 and 6 are that they are getting old. Good examples of the 4 are not easy to find because they are mostly sparsely equipped and in all conditions. If you can find a well equipped 180HP model with CS prop that was taken good care of buy it because you won’t regret it.
 
Size Matters

I recently sold my beloved RV6A "Stubbs" with the goal in mind of picking up a -6 (tailwheel) with an O360 and a constant speed prop. That will take some time it appears, so in the mean time I'm considering other options. Are there any 6'2" RV4 drivers out there? I have a long lower torso and would like some feedback on the comfort on a cross country trip.
More information: when I bought my RV6A it did not have the "Almost a 10" modification. After approximately 45 minutes of flight time, my knee and hip joints wold start to burn from being at the wrong angle.
After I performed the seat modification moving the last piano hinge row on the bottom back 11'4" and the upper sear rail back according to the modification specs (appoximately 2"), I was able to ride in the plane for hours with no ill effects.
So if any tall pilots have experience with the RV4, your input would appreciated.
 
I'm 6'3" 240, and I built an 8 back in the late 90s. I sold it as a complete airframe, but never flew it. I had no issues with room though I was 40 lbs lighter...

Fast forward 20 years, and the flying bug has bit me again. I'm looking at 4's, and sat in one the other day. I can report that I fit ok, leg room was fine, 3 fingers above my head, shoulders barely touching on either side. After sitting in it, I'm now sure I want one. I'm evenly proportioned, if it matters.

I wouldn't want to sit in the thing for 4 hours without a break, but how long can you really go before you gotta pee?
 
2 dumb questions.

Would a 40lb dog and small bag fit in baggage of a 4?

Would someone be comfortable sharing their BEW and arm with me to run a trial Calc?
 
Dog would not be happy!

I'm not sure any dog would be happy in the baggage compartment, but 40 lbs. wouldn't be a problem. If no rear passenger is in this scenario, the rear seat back can be quickly removed and a properly sized dog crate would probably fit in the back (secured of course).
 
2 dumb questions.

Would a 40lb dog and small bag fit in baggage of a 4?

Would someone be comfortable sharing their BEW and arm with me to run a trial Calc?

Here’s mine:

BEW 979.2; Empty CG 69.45”

Maximum Gross Weight 1500 lbs.
Aerobatic Gross Weight 1375 lbs
Datum 60” forward of wing leading edge
Forward CG Limit 68.7” aft of datum (15% MAC)
Normal Aft CG Limit 77.4” aft of datum (30% MAC)
Aerobatic Aft CG Limit 75.9” aft of datum (27.5% MAC)
 
I'm not sure any dog would be happy in the baggage compartment, but 40 lbs. wouldn't be a problem. If no rear passenger is in this scenario, the rear seat back can be quickly removed and a properly sized dog crate would probably fit in the back (secured of course).

Is the baggage area not open at the top beg hind the back seat? Or is it like under a turtle deck? No one ever posts pics of the baggage area
 
Fully closed off

It is completely closed in the RV-4 as the closure is the seatback. Good amount of room, but cant load heavy with heavy rear passenger. In this picture, I have seat folded forward and a 3.5 gallon smoke oil tank in place. I can still throw in a couple medium size duffels on top.
 

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Thank you, that tells me a -4 won't fit my mission. I was trying to expand my search from the -6 because the market is so tight right now.
 
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