Ironflight

Ironflight

VAF Moderator / Line Boy
Mentor
On another thread, I was talking about how I don't like to fly into rough gravel fields for fear of damaging my pretty (but tight) wheel pants. AT the same time, I don't want to travel without the pants, as it takes away a big chunk of cruise speed. SO I wondered if anyone had thought about what a "rough field pant" would look like, if you wanted to make up a special set to install for that kind of trip.

Rather than let the question get buried in a trip report thread, I'll start this one, and see what kind of ideas get generated!

My first thought is....I'd keep the wheel to pant clearances large, and probably not spend much on paint! :p

Paul
 
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I'm planning on 6.00x6 wheels and opening up the openings more... It'll cost top end, but it will fit my off-field missions better... I think anyway.
 
I've been experimenting with an old set of Cessna pants. I have not finished yet, but the ground clearance and clearance around the tire look good for rough field operations. The pants also have an adjustable "scraper" in the back half, which helps to keep mud from accumulating. I've got a bit more fitting and glassing to go, but I'll keep you posted on the progress.
 
Rough Field pants idea.

You know I've been thinking of the same thing. After reading horror stories of rough field damage to pants by stones/sod caught between the tire and pants or of the nose wheel catching a tight fitting pant and riping it off on a hard handing I was wondering if a soft sealing strip would work. Sort of like engine baffling seal material filling a larger cap all around the tire and pants. They make a white Teflon material very similar to the engine baffle seal that is used in USDA food prep machinery and pharmaceutical applications. You could probably make a pretty nice tight installation with almost no gap at all but have the ability to flop out of the way if things did get tight. I know its a rough idea but something to think about.
NYTOM
RV-6A N822PM (res)
 
A rocket builder/owner at a field near me uses the red silicone material
to fill the gaps around the wheel opening. Looks pretty good. Don't know
if it's flexible enough for the wind to push it around or wheather it works
as a speed enhancer but in theory I guess it might work.

He has them attached on the inside of the pant, not sure exactly how.
 
osxuser said:
I'm planning on 6.00x6 wheels and opening up the openings more... It'll cost top end, but it will fit my off-field missions better... I think anyway.
Click to expand...

There is a -6 pilot who has done this using the 5" axles. He made some bushings that slipped over the axle and the 6" wheels fit. I exchanged e-mails with him about 2 years ago but do not have his address anymore.

Actually, I am glad I did not do it. The limiting factor for me is the nose wheel, but if you are with TD, it is no factor.

I find around here I do just as well as the guys with the bigger tires, and we have a Bonanza, a Comanche, and a couple Cherokee operating out of this 2200' strip, which is rather squishy now and then. The trick is to keep moving....with full aft stick at all time.

With regard to wheel pants, I've about given up on keeping them pretty. We do not have a rock problem but semi tall grass and weeds do a real job on the paint. I suppose one could use something like auto under coating, but that would look worse than paint and be draggy.
 
osxuser said:
I'm planning on 6.00x6 wheels and opening up the openings more... It'll cost top end, but it will fit my off-field missions better... I think anyway.
Click to expand...
There is a -9 builder up in AK who just ordered custom gear legs to fit these wheels. In place of wheel pants he is going put mud flaps. Not pretty but functional and as he said, functional is what counts up there.

He told me that this longer axel is the same one the Supper cub guys use for their tundra tires and that he might fit a pair to his plane just to get picture to send to Van's. That's I've got to see.

Also, some time back I posted a thread asking if anyone had tried the Maule type wheel pant that just whent behind the wheel. No one replied so I suspect it hasn't happened yet.
 
Yeah, But.....

....I want my cake, and to eat it too!! ;)

1) I don't want to change tires
2) I want to keep some sort of wheel pant so as not to take a huge drag penalty if I'm flying a long way, but acknowledge that we'll have to give up SOME speed....
3) I want something that will protect the rest of the airplane from rocks and stuff
4) I guess I don't care what they look like, as I want to keep my really nice wheel pants for normal use anyway....


Maybe the answer is just some regular Van's pants with wide from and rear opening so you don't catch rocks int eh openings, a plain-jane paint job (or just primer), higher ground clearance, and an "undercoating"-like material on the bottoms to take rock impacts without chipping.....

what else?
 
This is forum is great for the exchange of ideas.

I just asked a question in the Big Bend thread about rough field pants, Glad to see it has taken on a thread of its own.

I am just working on starting the emp at this point and I hope yall get this sorted out by the time i get to the wheel pants.

I was thinking the same as you Paul, the pants might extend from just below the axel leaving more of the wheel hanging out, and not have as close fit.

My Cessna pants have a thick aluminuml scrapper just behind the wheel, and a hole behind that to allow debris to fall out of the pants. If it costs me a couple of knots so be it, landing on gravel is somthing i do frequently and hope to be able to continue doing with the -8
 
Paul,

I fly my RV6 off of a relatively short Grass trip, and routinely fly off of my dads strip which is 100% gravel.

The long and short of it is, just open up the clearances a little bit (doesn't seem to affect speed much, but then again I'm not that scentific).

Just be prepared that every year at annual when you remove the pants that the bottoms will be really chewed up...I lay up a new strip of carbon fiber or glass on them, slather on some paint and go flying. FYI...some time ago I ripped the holy heck out of one of them, but it wasn't on the gravel or sod...it was on pavement. One of those REALLY gusty xwind days (when I shouldn't have been flying) where everthing was ok on final, but caught a nice sideways gust just as the wheel touched....well, the left tire caught the wheel pant - (the plane tried like heck to hit a runway light and go around), so for a few seconds I was scared @#%$, but in the end no ground loop...just a messed up pant. It was then that we opened up the gap a bit larger so no more tires catching the pants!

I also have a lower chewed up outer right wingtip with "road rash" scars from a different xwind experience and a gravel strip, but that's another story all together (at the time, I didn't realize I had the wing THAT low)! :)

In the end, I'd just open up the pants a bit, go fly and schlop on some paint/glass/epoxy when needed to clean up the bottoms.

Cheers,
Stein.
 
How about open wheel pants, like fenders? You can think of them as just the inboard half of the wheel pants. That'll leave the landing gear and front of the tire faired, but the outboard part of the tires would be left alone. I'm thinking this would give at least some drag reduction but minimizes the chances of getting anything caught in there. Also, most of the wheel pant is facing in so no one will notice if it gets chewed up.

You can finish it off by sticking a hubcap on the wheels.

Okay, okay...it's a whacky idea but this isn't called "experimental" for nothing, ya' know. :D
 
Undercoating

Paul's suggestion of undercoating reminded of a product I bought a few years ago to protect the lower panels of a very expensive car I had no business of owning. Running on gravel roads would leave paint chips behind the tires where the body curved underneath. To solve this problem I lightly wet sanded the affected surface and masked off any untreated areas. Then the "stuff" was applied just like spray paint. It came in a over sized can and after drying left a thin transparent coating that had a satin finish. It was extremely tough and flexible and the stones just bounced off it. From a few feet away it was invisible. As I recall it was called "Chip Guard" or something "Guard". Might help on the rear bottom of the pants behind the tire opening. Just another rough idea.
Tom
RV-6A N822PM (res)
 
Aluminum Doubler?

Great ideas guys!

Has anyone tried an aluminum doubler plate riveted to the fiberglass to strengthen the opening? Especially around the rear? I agree that is where the pants seem to get torn up first - the tire kicks or lifts something into th opening and rips up the glass. How about reinforcing it with metal? Maybe that's what the scraper thoughts are really about....

I've "been there, done that" on tearing up a pant do to close tolerances and a blown tire (as many others have...) during phase 1. Fortunately, it was still in primer, and a couple of hours glass work fixed it up. Now with the really nice paint, I'd hate to have to have Grady re-do them...

Paul
 
Ironflight said:
Has anyone tried an aluminum doubler plate riveted to the fiberglass to strengthen the opening? Especially around the rear? I agree that is where the pants seem to get torn up first - the tire kicks or lifts something into th opening and rips up the glass. How about reinforcing it with metal? Maybe that's what the scraper thoughts are really about....
Click to expand...
Imho, adding any reinforcement to this area is just going to cause a LARGER area to break when it breaks.
 
C'mon fellers

Airplanes are designed as a system. If you want to fly into and land on rough fields, think about the whole system.

Change the wheel pants.
Bigger wheels and tires.
Stronger axles. (don't just shim them to size)
Stronger gear legs.
Stronger gear boxes to hold the gear legs.
Beef up skin thicknesses around the gear boxes.
Thicker tail wheel spring, bigger tire, axle, fork.
Beef up the mounting for the tail wheel spring.

Then, think about...
The effect of all that banging on the rest of the fuselage, wing mountings.
Stones etc. hitting your tail feathers.

After you do all that, how much does your airplane weigh?

There are super cub kits out there. They are designed as a system for rough fields.
 
dan said:
Imho, adding any reinforcement to this area is just going to cause a LARGER area to break when it breaks.
Click to expand...

I thought about that later Dan - you could very well be right. My old Grumman pants (plastic, if I recall) had been patched and reinforced several times with aluminum - and they always started cracking again right at the edges of the aluminum patches - just created stress risers....

OK, so maybe we open up the rear opening all the way to the bulkhead?

Of course, I agree with Nuisance that if you're gonna do gravel strips all the time, why not have the right airplane? Jay Pratt let me fly "Shooter", his Tundra-tired Northstar (experimental Cub-type airplane). Those monster cartoon tires were the best - absorbed what would have been a bounced landing and could probably roll over coconut-sized rocks!

Paul
 
Wheel Pants

Paul,
Look to Vans for the answer!
I was fortunate to be able to buy an already flying RV-6.
Then proceeded to upgrade it to the newer pants and leg fairing.
The original design sits higher on the wheel and isn't designed too tight either.
I don't think the -8 had the older design but I bet there are lots of guys around your area with the original design sitting on the shelf like I do.
Remember Van was a grass field kinda guy before the masses pushed him into thinking about speed.
Just a thought!
 
Nuisance said:
C'mon fellers

Airplanes are designed as a system. If you want to fly into and land on rough fields, think about the whole system.

Change the wheel pants.
Bigger wheels and tires.
Stronger axles. (don't just shim them to size)
Stronger gear legs.
Stronger gear boxes to hold the gear legs.
Beef up skin thicknesses around the gear boxes.
Thicker tail wheel spring, bigger tire, axle, fork.
Beef up the mounting for the tail wheel spring.

Then, think about...
The effect of all that banging on the rest of the fuselage, wing mountings.
Stones etc. hitting your tail feathers.

After you do all that, how much does your airplane weigh?

There are super cub kits out there. They are designed as a system for rough fields.
Click to expand...
Rough fields are relative. I don't think that 5.00x5 tires are adaquate for the mains for anything but hard surface, and maybe groomed turf. The system that the TD RV's used (Except the -8) is pretty good as it is, I'd be planning on 6.00x6, which aren't that much heavier with the 5.00x5 (but they definitly are heavier). The gear legs might have to be beefier, and i'd be going with normal 6.00x6 axles (Which are stronger). The gear goes into the engine mount, not a gear box. Then I'll have a set of well fit wheelpants and a set of deflectors so if I go onto gravel, I give up the speed, and keep from damaging the stabs and flaps.

RV is the jack-of-all-trades airplane. I don't want to go Supercub speeds... I'd just fly my dads C177.
 
Here's an idea...

Why not take the RV-9 wing, add a strut, build the -9 empennage, and bolt it to the top of a -9 fuselage?

Maybe add a 2nd row of sets and an O-360.

Hello Van's, are you listening?

It might be appropriately called an RV-13
 
Old style RV-6 wheel pants

Paul,
maybe the old style RV-6 wheel pants are the solution of your problem.
I believe they have more ground clearance.
 
How to not Tear the Arse out of your Pants

I have the 'old' style 'pants, and fly off a grass strip. I too caught the tyre on the pants a few times and just had to keep opening up the hole. The flexible strip around the opening is a good idea, and I think I will try it. Also you neeed to keep the pressures up to reduce tyre deflection. Another 'trick' is to balance the 'pant by adding mass in the 'pant nose so that it is 'balanced' about the mounting plate. This way when the wheels are hammering up and down on a rough 'strip you don't get a twisting moment on the mounting system that, in my case, kept loosening the bolts and wearing the holes.

RV-4
VH-PIO
 
Obviously, we're not flying these RV's with small wheels up and landing on glaciers or in the tundra. So there's no point in considering Super Cub with 3' tire missions. But I do consider landing on smooth gravel surfaces.

Let's regroup. What's the point? Is it to deflect/prevent rocks from flying up into the fuse and empennage? Or to keep material out of the wheel pants?

From my experience on mud and gravel, I worry much more about gravel impingement. Without larger tires, the RV's just don't do well in mud. Although I've taxied (inadvertently) through some pretty serious mud and my -8 was literally partially supported by the wheel pants in the mud! Not a plan, but it happened and no damage resulted. The mud collected in the wheel pants was minimal - not even requiring immediate cleaning to keep going.

The times I've landed on gravel, I've ended up with some dings. I would like some flaps or, say, a fin of sorts on the aft-bottom side of the wheel pant that would serve to deflect the gravel.

Something like one of these anti-cavitation plates mounted on the outdrive of a boat. Wouldn't add much drag.
 
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