Cockpit size

Adam Weiss

Pre-takeoff checklist
Joined
Aug 10, 2017
Messages
468
Location
KLXT
Display Name

Display name:
kcmopilot
Mission:
2 seats and a little baggage.
300+ nm X-Country + IFR.
The most bang-for-the-buck seem to be experimentals.

I thought the Thorp T-18 was the perfect answer: great performance, simple, low cost of entry...
Until I sat in one recently.
I'm not huge...6' and 180lbs, but my knees were pegged under the panel. I literally couldn't move once I was in and forget trying to operate the pedals.

Based on this, I'm hoping you guys can tell me if I'd fit in any of the other planes on my short-list:
Lancair 320/360
Glasair I RG or II RG
Vans RV-6/6A
Last choice: Mooney M20E

Thanks!
 
Mission:
2 seats and a little baggage.
300+ nm X-Country + IFR.
The most bang-for-the-buck seem to be experimentals.

I thought the Thorp T-18 was the perfect answer: great performance, simple, low cost of entry...
Until I sat in one recently.
I'm not huge...6' and 180lbs, but my knees were pegged under the panel. I literally couldn't move once I was in and forget trying to operate the pedals.

Based on this, I'm hoping you guys can tell me if I'd fit in any of the other planes on my short-list:
Lancair 320/360
Glasair I RG or II RG
Vans RV-6/6A
Last choice: Mooney M20E

Thanks!

Try out a Vans RV. The 8 is the most comfortable for the pilot, but the passenger seating isn't in on par with the side-by-side 6/7/9.

I am 6'4" well over 200 lbs and I can fit in an RV no problem.
 
I put this data together ~25 years ago, but it might help:

http://www.wanttaja.com/avlinks/cockpit.htm

Ron Wanttaja
Thanks Ron.
That's really good data!

What I can't reconcile is that a 172 has 50", and is more than enough.
The Thorp was 40" and nowhere near enough.
But would 42" or 43" in a Glasair or RV-6 do the trick?

And in the Thorp, the issue wasn't really that the pedals were so close to the seat.
I can bend my knees and be comfortable.
It's just that with my knees bent, there was nowhere for them to go.
They were pinned up under the panel.

I think I may just have to find some folks willing to let me sit in them!
 
I have a Sierra for sale ;) 44" wide and 48" height.
I owned a Super Musketeer (A23-24) for 5 years...basically a fixed-gear Sierra.
Great plane...but sloooooooowwww :)
 
You didn’t state a budget and I’m assuming you want to buy an already flying model, but the RV-7/7A is a little bigger all the way around than the 6.

F08C8902-34D8-42A0-8D71-544E75C3D00F.gif
C60DBB1B-8194-40ED-B21E-24AD5F8D6813.gif

If the budget is no limit, then RV-14/14As are starting to show up on the used market and are bigger still:

C73325F3-0B54-4B4E-B819-72B2E8365FD0.gif
 
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I forgot to add that the RV-9/9A has the same cockpit dimensions as the 7/7A. Bottom line is there’s lots of options out there that meet your mission requirements.
 
Thanks Ron.
That's really good data!

What I can't reconcile is that a 172 has 50", and is more than enough.
The Thorp was 40" and nowhere near enough.
But would 42" or 43" in a Glasair or RV-6 do the trick?

And in the Thorp, the issue wasn't really that the pedals were so close to the seat.
I can bend my knees and be comfortable.
It's just that with my knees bent, there was nowhere for them to go.
They were pinned up under the panel.

Well, that's anthropometrics for you (the science of measuring the human body and its parts). We do not have the same proportions; for the same height, one of us may have longer legs and a shorter torso. I'm six feet, but broader-on-the-barstool than tall in the saddle.

A while ago, the military built airplanes for the "average" human frame. Thus no one was comfortable. Around 1950 someone got around to making a study on how bad-fitting cockpits was contributing to aviation accidents. From that point, they started working to make cockpits more adjustable to allow the pilots better leverage on the controls, etc.

Back about 25 years ago, I was working on the Boeing Space Station proposal. One of our requirements was that the station be compatible with the 95 percentile male, and 5 percentile females. So a bunch of us volunteered as guinea pigs. At the Boeing Renton plant was an Anthropomety machine; basically an iron maiden that measured the bejesus out of someone. This card is how I came out:

anthro.jpg

I had too many measurements in the >99% category to qualify for the test team.

Ron Wanttaja
 
Thanks Ron.
That's really good data!

What I can't reconcile is that a 172 has 50", and is more than enough.
The Thorp was 40" and nowhere near enough.
But would 42" or 43" in a Glasair or RV-6 do the trick?

And in the Thorp, the issue wasn't really that the pedals were so close to the seat.
I can bend my knees and be comfortable.
It's just that with my knees bent, there was nowhere for them to go.
They were pinned up under the panel.

I think I may just have to find some folks willing to let me sit in them!

Important to differentiate between a Glasair I and II. The II has 3” over the I in width. Would definitely recommend the II over the I just for cabin size. Two people in a I are touching shoulders sitting semi reclined. Comfortable for one person but not two.
 
6'3" here, 200 lb. and 36" inseam (long legs/medium torso build) and I have plenty of room in my RV-9A.

My fist will fit between the top of my headset and the canopy. I went for the standard panel, as the extended one can hit the tops of your thighs. And with no center tunnel or console to speak of, on longer stints I can fully extend my right leg to the right of the rudder pedals, or into the right seat footwell when flying solo. Being able to stretch out like this can sure make a 3-hour leg of an x-country more comfortable.

IMG_3653.JPG
 
6'3" here, 200 lb. and 36" inseam (long legs/medium torso build) and I have plenty of room in my RV-9A.

My fist will fit between the top of my headset and the canopy. I went for the standard panel, as the extended one can hit the tops of your thighs. And with no center tunnel or console to speak of, on longer stints I can fully extend my right leg to the right of the rudder pedals, or into the right seat footwell when flying solo. Being able to stretch out like this can sure make a 3-hour leg of an x-country more comfortable.

View attachment 64692
That’s really helpful!
Nice plane too!
 
If there’s anyway you could make it to a major fly-in like OSH or Sun-n-Fun you could try them all on for size. Barring that, check out your local EAA chapter as I’m sure the local builders would be more than happy to show your their planes/ projects.
 
Where are you?
Try to sit in one like you did with the Thorp.
I think you can fit in any of these but may find one more comfortable than the other. Our RV9a was larger than the lancair but I found the lancair much more comfortable. of course they are very different aircraft and you would be well advised to consider that in choosing between them.
 
I know I'm a fanboy, but the fact is the biggest bang for your buck will be the Mooney. I just did your 300nm trip with two and bags in two hours in my M20c. And Mooneys fit tall pilots just fine.
 
I know I'm a fanboy, but the fact is the biggest bang for your buck will be the Mooney. I just did your 300nm trip with two and bags in two hours in my M20c. And Mooneys fit tall pilots just fine.

Not this tall pilot. I get scrunched in the side, and I have to cock my head like Dustin Hoffman in RainMan.
 
Try on the -6, which are plentiful and the same cockpit dimensions as the -7. The rudder peddle mounting can be adjusted for your height (maybe the Thorpe can too?), the seat back is adjustable and there is a mod by Anti-Splat, Aero called the Almost -14 mod that can be performed to provide even more seat adjustment options. I own a RV-7A and plan to do this mod for taller passengers since my rudder peddles are mounted for my 5' 8".

You'll want a newer -6 with higher gross weight and rudder peddles mounted on the longerons rather than the floor.

I just did a 580 NM trip in my plane. Non-stop from KLHW to KAXQ, cruised at 11.5k, 155 KTAS @ 7.5 GPH in 4 hours. The -6 will do the same or better but doesn't have the 1800 lb gross weight.
 
I thought the Thorp T-18 was the perfect answer: great performance, simple, low cost of entry...
Until I sat in one recently.
I'm not huge...6' and 180lbs, but my knees were pegged under the panel. I literally couldn't move once I was in and forget trying to operate the pedals.
One thing to remember - unlike an RV where someone will wack your pee-pee if you deviate from what God Richard VanGrunsven ordained, T-18s were individually built from plans and sheet stock. And, for something like a panel, the original builder probably sat in it, measured where his/her knees came to and set the bottom of the panel accordingly.

I'm 6', my brother is a bit taller, but (and this shouldn't be a surprise) there is room for our knees in the T-18 that he built.

On the other hand, the overall width is pretty much similar for most T-18s because the big structure tends to be per drawings but even then there is the Lou Sunderland variations that are a couple inches wider just to add to the fun.
 
One thing to remember - unlike an RV where someone will wack your pee-pee if you deviate from what God Richard VanGrunsven ordained, T-18s were individually built from plans and sheet stock. And, for something like a panel, the original builder probably sat in it, measured where his/her knees came to and set the bottom of the panel accordingly.

I'm 6', my brother is a bit taller, but (and this shouldn't be a surprise) there is room for our knees in the T-18 that he built.

On the other hand, the overall width is pretty much similar for most T-18s because the big structure tends to be per drawings but even then there is the Lou Sunderland variations that are a couple inches wider just to add to the fun.

The last part of your post is the most relevant. Yes the RV community tends to be anal about structural mods but thats partly because the RV builders manual is an assembly manual and not a construction manual as by and large they lack engineering drawings with dimensional data. That being said, despite the lack of support from the factory for mods, they are done all the time. But with more than 10,000 flying, mods are inevitable whether Vans likes it or not.
 
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I should have clarified.
Ron’s data shows a 172 is 50” from seat to pedals.
That’s the measurement giving me trouble.
 
Not this tall pilot. I get scrunched in the side, and I have to cock my head like Dustin Hoffman in RainMan.

"Podunk traffic, Mooney 1234, taking runway 24 for straight out departure...10 minutes to Wapner!!...Podunk" :)
 
You and I are the same size. I love my 7a! Your mission is an hour and a half in my plane. Here are some videos on it:


 
Mission:
2 seats and a little baggage.
300+ nm X-Country + IFR.
The most bang-for-the-buck seem to be experimentals.

I thought the Thorp T-18 was the perfect answer: great performance, simple, low cost of entry...
Until I sat in one recently.
I'm not huge...6' and 180lbs, but my knees were pegged under the panel. I literally couldn't move once I was in and forget trying to operate the pedals.

Based on this, I'm hoping you guys can tell me if I'd fit in any of the other planes on my short-list:
Lancair 320/360
Glasair I RG or II RG
Vans RV-6/6A
Last choice: Mooney M20E

Thanks!

RV-14
 
You and I are the same size. I love my 7a! Your mission is an hour and a half in my plane. Here are some videos on it:


Looks like a great plane! Thanks for sharing.
I agree. I think it hits my sweet spot for just about everything.
 
Hello everyone, I'm building Pietenpole. My height is 194 centimeters. How high should the cockpit be so that the wind does not blow in the face?
 
Based on this, I'm hoping you guys can tell me if I'd fit in any of the other planes on my short-list:
Lancair 320/360
Glasair I RG or II RG
Vans RV-6/6A
Last choice: Mooney M20E

RV-6 and Mooney will work. I'm 6'5", 230 lbs, 36" inseam. But for Lancair money, I'd rather get an RV-8.

BTW, I could not get into Liberty XL2 at all. One of the tightest airplanes I've ever been in. It's about Sonex sized, or maybe even worse. The first chief pilot and co-founder of a local flight school had one of those. Man it was a dog. Absolutely unusable with 2 people onboard. They struggled with that airplane for a while, and gave up, bought a hershie-bar Cherokee with an overheard crank. Saved the school from bankruptcy. Years later the guy was still trying to sell that Liberty, but there were no takers.
 
RV-6 and Mooney will work. I'm 6'5", 230 lbs, 36" inseam. But for Lancair money, I'd rather get an RV-8.

BTW, I could not get into Liberty XL2 at all. One of the tightest airplanes I've ever been in. It's about Sonex sized, or maybe even worse. The first chief pilot and co-founder of a local flight school had one of those. Man it was a dog. Absolutely unusable with 2 people onboard. They struggled with that airplane for a while, and gave up, bought a hershie-bar Cherokee with an overheard crank. Saved the school from bankruptcy. Years later the guy was still trying to sell that Liberty, but there were no takers.
Good info! Thanks.
 
what's the budget. The price swings are more than 50K from all the stated options. Kinda worthless.
 
Yeah, that's not RV-8 kind of money. Even RV-6 might be difficult.
 
Yeah, that's not RV-8 kind of money. Even RV-6 might be difficult.
Agree.
The original list I had seems to have some (but not a lot of) decent examples in that price range.
That’s why I was asking about cockpit size.
I’d love to have an RV-7, but that’s not going to happen without a partner.
 
Speaking of RV-7s, a builder/owner in our EAA chapter just completed a trip to all 48 states in 7 days. Not just touch and goes, he powered off and took a picture on the ground in each state.
 
RV-6 and Mooney will work. I'm 6'5", 230 lbs, 36" inseam. But for Lancair money, I'd rather get an RV-8.

BTW, I could not get into Liberty XL2 at all. One of the tightest airplanes I've ever been in. It's about Sonex sized, or maybe even worse. The first chief pilot and co-founder of a local flight school had one of those. Man it was a dog. Absolutely unusable with 2 people onboard. They struggled with that airplane for a while, and gave up, bought a hershie-bar Cherokee with an overheard crank. Saved the school from bankruptcy. Years later the guy was still trying to sell that Liberty, but there were no takers.

I'm surprised you would say that. I've flown in a Liberty XL, and it had plenty of head, leg, and shoulder room. If I remember correctly, it has a 48" wide cockpit, and while I haven't flown a Sonex, I remember the cockpit width being considerably narrower, according to its specifications. I will agree the XL isn't the fastest plane in the world, but slightly faster than a LSA, and with the increased gross weight increase, somewhat more useful load than most LSAs.

I think part of the problem with the useful load is the plane was originally designed around the certified version of the 100 HP Rotax 912, but it was replaced by the more powerful, and heavier IO-240F Continental. That change alone cost 100# of useful load. I don't know if the Rotax is compatible with the gross weight upgrade, but for me it's a moot point.
 
You just need to sit in them all as the ones listed all have very different ergonomics. While I easily fit in an RV 6/6 I find them claustrophobic feeling. Just feels like the panel and windshield are right in your face. The 8 and even 4 feel better if you can go tandem. The Glasair I is tiny on the inside. Can’t comment on the Lancair. Both of those will be much more of a recliner type seating position than a chair type position of the RV and Mooney. All of them are plenty wide for all but the most husky of guys. My preference would be in order RV8 Mooney Glasair II side by side RV.
 
Might also try a Mustang II if you fit the RV6. Its a smidge smaller but are usually cheaper to purchase and just as good in performance.
 
I know I'm a fanboy, but the fact is the biggest bang for your buck will be the Mooney.
Horses for courses of course; for money, speed, fuel burn, etc., the Mooney certainly is in a league of its own, but I just don't find them comfortable

I get scrunched in the side
Same. I know Al Mooney was a big guy and people will talk about leg room, etc., but I don't like how you feel like you're strapped into a luge..



Also, someone posted this image above. Marketing stuff like this is annoying, because WHO actually is "Brand X" ..? I've never sat in a plane where part of my buttock was hanging outside the aircraft and my head was that far cranked over, and I doubt anyone else has. Hyperbolic marketing like that seems cheap
upload_2018-12-6_13-22-2.png
 
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