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Pants and Fairings

wirejock

Well Known Member
Does anyone have a write up on how to install the pants and gear fairings? Any mods or tips?
The idea of clamping a piece of fairing with a hose clamp seems like a failure waiting to happen.
I appreciate any ideas whatever the model. Thx
 
Wheel pants

If you have the Vans drawings for the pressure recovery wheel pants that is a big help. The intersection fairings at the wheel pants will keep the gear leg fairing from moving downward and the upper intersection fairings will locate the gear leg fairing.
The wheel pant brackets will need some "adjustment" to fit the wheel pants correctly.
Check the tire pressure, chock the wheels securely and level the airplane. Make some marks on the floor to establish alignment. Mark the center of both ends of the main pants vertically and horizontally. Make some kind of simple jig for quickly establishing the aft end of the main pants.
PM me as you progress and I will have more suggestions.
Wheel pants are a lot of work if you haven't figured that out already.
 
Drawings

If you have the Vans drawings for the pressure recovery wheel pants that is a big help. The intersection fairings at the wheel pants will keep the gear leg fairing from moving downward and the upper intersection fairings will locate the gear leg fairing.
The wheel pant brackets will need some "adjustment" to fit the wheel pants correctly.
Check the tire pressure, chock the wheels securely and level the airplane. Make some marks on the floor to establish alignment. Mark the center of both ends of the main pants vertically and horizontally. Make some kind of simple jig for quickly establishing the aft end of the main pants.
PM me as you progress and I will have more suggestions.
Wheel pants are a lot of work if you haven't figured that out already.

I have the usb for RV7, 14 and 10. Which drawings specifically and what is a pressure recovery wheel pant?
I also have RV Bits Upper and Lower Gear fairings. Sure hope they are better than the plenum. Looks like I get to sand off more gel coat. Hate that stuff.
 
I have the usb for RV7, 14 and 10. Which drawings specifically and what is a pressure recovery wheel pant?
I also have RV Bits Upper and Lower Gear fairings. Sure hope they are better than the plenum. Looks like I get to sand off more gel coat. Hate that stuff.

The plans for the -10 are very good, imo, but those pants are sized for the larger wheels/tires on the -10, so you’ll need to adjust some dimensions, I imagine. IMO, the key is having the wheels off the ground and the fuse in flight attitude so the pants and fairings are aligned for flight, not for when the airplane is sitting on the ground.
 
The gear leg fairings creep downward because the hose clamps are located on a tapered section of the legs. I put 2 layers of 1” fiberglass tape epoxied to the gear legs just below the clamps. Another thing I found was the powder coating on the gear legs was wearing off where the fairings rub up and down the legs. I applied 3M Teflon tape as a bearing surface. No more creeping down or wear.
 
I used a hose clamp for the lower portion of the NG leg fairing and it works very well. I put wood dampers on the MG legs and did not use any clamps, they just ride free. No issues here, BUT the dampners keep them from moving around much. The upper and lower IX fairings lock in the alignment.

The RVbits fairings are WAY LESS work than the kit stuff. Personally I don't take off all of the gel coat and have no paint adhesion issues.
 
I just repainted my wheel paints and fairings.
I hate this design.
I replaced the 7As nose gear bracket with the new design.
This allows taking off the wheel pants without raising the wheel off the ground.
I thought it would be a good time for the upgrade.

I am not the builder, now I have a taste of the process.
Boy what a headache. I wish I had left it alone.

I think it cost me three weeks delay trying to retro fit.
 
Larry, the Van's RV-7 construction manual has a pretty good write-up with photos on how to do the gear leg fairing and wheel pants alignment. They also go into a lot of detail on how to make your own intersection fairings, but I opted for buying pre-made versions and that worked out well. I think I got mine from Fairings Etc.; the fit & finish were excellent.

The manual describes how you go about reinforcing the finger joint on the gear leg fairing where the hose clamps grab the upper end--you absolutely want to do that. I'd recommend using some carbon fiber strips there for the extra strength. Don't be stingy here. But the other guys are correct in their replies here, as the intersection fairing will hold it all in place.

And the "pressure recovery" wheel pants are what Van's supplies with kits these days (at least for the better part of this century). I followed their instructions and it all came out fine.
 
For my RV8, the wheel fairings and leg fairings were completed using the plans build instructions. The left and right wheel fairings were aligned using the simple contraption in the picture below, keeping the left and right ends in alignment and the cant angles the same on both sides. The holes for the clecos were closed with micros when done.

I decided to mold the intersection fairings myself instead of buying from the suppliers. For the negative mold, I use the soft non-hardending modeling clay from https://smile.amazon.com/Sargent-Art-Plastilina-Modeling-2-Pound/dp/B00FR7TQOM/ref=sr_1_4?crid=2L3IUY1UIHWFV&keywords=modeling+clay&qid=1656598702&s=arts-crafts&sprefix=modeling+clay%2Carts-crafts%2C586&sr=1-4. I tried to use the window sealant foam but it was messy and difficult to clean.

This stuff doesn't harden but you can shape it and it keeps it shape firmly enough for molding. I used 3 layers of fiberglass after a few liberal coatings of PVA mold release. After demolding, I had to coat the exterior with epoxy and micro and sanded smooth. The added thickness smooth out the bumps and added additional stiffness to the intersection fairing. The last picture shows the intersection fairing pieces after they were painted with primer.
 

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Manual

Larry, the Van's RV-7 construction manual has a pretty good write-up with photos on how to do the gear leg fairing and wheel pants alignment. They also go into a lot of detail on how to make your own intersection fairings, but I opted for buying pre-made versions and that worked out well. I think I got mine from Fairings Etc.; the fit & finish were excellent.

The manual describes how you go about reinforcing the finger joint on the gear leg fairing where the hose clamps grab the upper end--you absolutely want to do that. I'd recommend using some carbon fiber strips there for the extra strength. Don't be stingy here. But the other guys are correct in their replies here, as the intersection fairing will hold it all in place.

And the "pressure recovery" wheel pants are what Van's supplies with kits these days (at least for the better part of this century). I followed their instructions and it all came out fine.

Thanks
I plan to follow Vans but I've learned there are often other ways to do things and sometimes better.
 
My Approach

I fixed the leg fairing at the wheel pant and planned for relative motion at the intersection fairing.

Initially I had the leg fairing fixed at the intersection, but quickly discovered there is significant relative motion there whenever landings require the gear to flex. Perhaps this is why people find that the Van's approach of hose clamping some glass from the leg fairing results in broken glass.
 
For my RV8, the wheel fairings and leg fairings were completed using the plans build instructions. The left and right wheel fairings were aligned using the simple contraption in the picture below, keeping the left and right ends in alignment and the cant angles the same on both sides. The holes for the clecos were closed with micros when done.

I decided to mold the intersection fairings myself instead of buying from the suppliers. For the negative mold, I use the soft non-hardending modeling clay from https://smile.amazon.com/Sargent-Art-Plastilina-Modeling-2-Pound/dp/B00FR7TQOM/ref=sr_1_4?crid=2L3IUY1UIHWFV&keywords=modeling+clay&qid=1656598702&s=arts-crafts&sprefix=modeling+clay%2Carts-crafts%2C586&sr=1-4. I tried to use the window sealant foam but it was messy and difficult to clean.

This stuff doesn't harden but you can shape it and it keeps it shape firmly enough for molding. I used 3 layers of fiberglass after a few liberal coatings of PVA mold release. After demolding, I had to coat the exterior with epoxy and micro and sanded smooth. The added thickness smooth out the bumps and added additional stiffness to the intersection fairing. The last picture shows the intersection fairing pieces after they were painted with primer.

Phat,
I have t sets of pre built fairing junctions and both are ****. I was going to try the window foam but your use of clay looks good. I worry about making both sides the same so it doesnt induce any yaw or weird flying properties. How did you make sure they were the same?

Maybe Im more worried than I need to about it - I do mount a gopro on the top of my wing and it doesnt appear to make a difference so maybe a slight difference in shape is ok. I think making sure the leg fairing is mounted the same is more critical. How did you make sure they were both aligned the same? If you have more pictures I would love to see them.
 
Phat,
I have t sets of pre built fairing junctions and both are ****. .

The 1st set of fairings were scrapped. I was using the window foam for these

The 2nd set was too heavy and they were scrapped.

For the 3rd set, I used 2 layers of fiberglass and an extra layer at the leading edge. They came out okay but they were on the flimsy side. After I coated them with micro and sanded smooth, they became stiffer and I stopped at it. I am sure the intersectional fairings are NOT symmetrical, accounting for the hand mold modeling clay, and hand sanded micro.

I think the major contributors for the flight quality are the symmetrical alignment of the wheel-pants and the leg fairings. I hope that I got them right.
 
Cracking

I found that the fiberglass tabs at the top of the fairings cracked so I embedded a piece of aluminum to strengthen that area. For intersection fairings I purchased a set from fairings-etc. They just about fit perfectly out of the box.
 
The tab and the hose clamp? Yeah, the one time I tried it, the thing was cracked off at the first inspection.I generally just let the leg fairings float, captured by the upper and lower intersection fairings. But I have seen it done with wood stiffeners where a single screw into the wood holds the leg fairings from sliding up and down. You could easily come up with something as clever if you use metal stiffeners….
 
I tried to use the window sealant foam but it was messy and difficult to clean.

Spray can foam is near useless. Miserable stuff for making forms.

What works is high density pour foam. Big items without much detail can be done with 2 lb density (example; cowl exit panel below), although more dense is way better.

Something like these gear fairings is best done with 4 lb or 6 lb. Google will turn up plenty of sources.

Tip #1: Never try to spread or move the stuff when wet. Just make up some quick dams with paper and masking tape, pour it, and don't touch it. If you do, the density gets scrambled. Result is hard spots which don't contour evenly.

Tip #2: remove the foam from inside the flight part. If left in place it tends to expand and contract with changes in altitude, which makes the glasswork do funny things.

Whenever possible, make your lower fairings integral with the wheel pants. Less drag, fewer parts. Smaller is better.
-
 

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<snip>

Whenever possible, make your lower fairings integral with the wheel pants. Less drag, fewer parts. Smaller is better.
-

Dan
Edit...Disregard. I found one.
Do you have a finished photo? I would like to see how/where the two halves of the fairing/pant is split.
 
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LifThet

Finally. Fuse is up and stable. Photo is probably enough, but here's parts and details.

One HF Motorcycle lift with a home made cradle.
Two welding Jack Stands from Amazon
One Farm Equipment weight
One 500lb mini hoist from Amazon
Hunk of chain
Klein Laser level
4x6x8
2x6x8
Scraps of 1/4 plywood
Fiberfrax
1/4x36 all thread
Nuts, washers, homemade shims and brackets

I fabricated two wood blocks for the jack stand saddles.
Some leftover Fiberfrax was used for padding.
This set up is really stable. I will keep it at the hangar for future use.
The hydraulic lift was needed to get the fuse high enough to slip the stands under. The cradle is all bolted together with all thread and bolted to the jack.
From there, the stands are easy to adjust precisely to level the fuse. They have a screw type post with a big handle.
The farm equipment weight weighs about 200lbs. The weight has been buried on our property for over 20 years. I knew it would come in handy some day.
Mini winch easily pulls the tail down to level the longerons. Plus it wratchets in both directions. No sudden release like web wratchets.
I slip the hydraulic back under after the day is done, just for an added insurance but I doubt it's needed.
Here's the links.
https://www.harborfreight.com/1500-...l0JcJGem8O4xtGa62PZGQGrknDPorlqxoCBwIQAvD_BwE
Mophorn V Head Pipe Stand... https://www.amazon.com/dp/B07HNLGJMZ?ref=ppx_pop_mob_ap_share
Mophorn 0.25T Lever Block Chain... https://www.amazon.com/dp/B07N2LVMB8?ref=ppx_pop_mob_ap_share
Klein Tools 93LCLS Laser Level,... https://www.amazon.com/dp/B0753K7XQF?ref=ppx_pop_mob_ap_share

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I hate to be the one to ask the stupid question, but for those of you who fabbed your own lower intersection fairings, how did you get the lower half to remain tight against the gear leg? I just tried and tried, but somehow you're hoping/expecting wet layups to remain in position against a surface ABOVE them? The upper lays nicely, but it's resting on top. How on earth can you get the lower to stay?

Baffled, and I don't mean all that sheet metal around the engine.
 
Continued...

So, unless there's a secret Van's Anti-Gravity kit I can order, I'm considering aftermarket lower leg fairings. I see Fairings Etc and RV Bits as sources so far. Any others I should check out?
 
Clay,
Im not sure I understand your question so this may be not what you were asking. The intersection fairings I got were ****. I dont know who made them but they didnt fit at all. I used aluminum tape and bondo to do the layups. That worked reasonably well but still a pain. If you can find some good ones that fit - but them. It will save you grief and time.

To get the intersection fairing to be tight against the leg fairing, I did the layup and then used clear packing tape to hold it tight. It was pretty messy getting the tape off and the intersection transition ended up being too tight to the leg so use caution and maybe wrap a couple layers of tape in the leg to pad it.

Mine didnt turn out great but look OK from 10' so it matches my paint job!!
If I rebuild, I will make the lower intersection fairing go under the leg fairing. It would require taking the hinge pin out to take the wheel pant off but it would look better in my opinion. I am having too much fun flying that I really dont see me making the mod anytime soon.

Good luck with them.
 
If at first you don't succeed...

I guess I'm down two strikes, is what I'm saying.
Strike 1. The Van's lower intersection fairings did not work well. The forward section was okay, but the aft sections needed so much work to align, etc, that we tossed them.

Strike 2. I attempted to fab from scratch the aft fairings to match the forward section I was retaining. This got ugly fast, and I never did find out how to get the lower side of the aft fairings to remain in close contact with the underside of the gear leg. Gravity is a B%$&h.

So, I'm preparing for the third pitch, Non-Van's pre-made intersection fairings. I see Fairings Etc and RV Bits selling fairings. Looking for feedback or suggestions on them or others. I have the Grove Airfoil Gear, so their profile is actually different from a standard faired Van's legs.
 
I guess I'm down two strikes, is what I'm saying.
Strike 1. The Van's lower intersection fairings did not work well. The forward section was okay, but the aft sections needed so much work to align, etc, that we tossed them.

Strike 2. I attempted to fab from scratch the aft fairings to match the forward section I was retaining. This got ugly fast, and I never did find out how to get the lower side of the aft fairings to remain in close contact with the underside of the gear leg. Gravity is a B%$&h.

So, I'm preparing for the third pitch, Non-Van's pre-made intersection fairings. I see Fairings Etc and RV Bits selling fairings. Looking for feedback or suggestions on them or others. I have the Grove Airfoil Gear, so their profile is actually different from a standard faired Van's legs.

I installed RV Bits intersection fairings on my RV-12 years ago before Van's started offering them (I also made leg fairings, but that's a different story...) and found they fit perfectly out of the box and were a fairly simple install. Based on that experience, I bought RV Bits (Jan Hanekom) intersection fairings for my -10. I'm just now fitting them, but initial check is that they are a good fit with no trimming required.

RV Bits quality is good.
 
RV Bits

I guess I'm down two strikes, is what I'm saying.
Strike 1. The Van's lower intersection fairings did not work well. The forward section was okay, but the aft sections needed so much work to align, etc, that we tossed them.

Strike 2. I attempted to fab from scratch the aft fairings to match the forward section I was retaining. This got ugly fast, and I never did find out how to get the lower side of the aft fairings to remain in close contact with the underside of the gear leg. Gravity is a B%$&h.

So, I'm preparing for the third pitch, Non-Van's pre-made intersection fairings. I see Fairings Etc and RV Bits selling fairings. Looking for feedback or suggestions on them or others. I have the Grove Airfoil Gear, so their profile is actually different from a standard faired Van's legs.

I installed the RV Bits upper and lower intersection fairings and was pleased with the fit. The only issue is my hatred for gel coat. In fact my beautiful paint job cracked because the gel underneath cracked. I would sand it off and apply micro.
I also added an overlap to the lower forward fairing top and bottom to cover the seam.
 
I installed RV bits with little to no working of the shape. They aren't perfect but they fit pretty well. I'm more interested in flying than closing up minuscule gaps to get the show look.
 
Regarding Larry's original observation that the "hose clamp seems like a failure waiting to happen," I was thinking about somehow attaching the gear leg fairing to the lower intersection fairing with screws through the intersection fairing into nut plates on the inside of the gear leg fairing. I don't have my plane here to visualize whether that would work or not, but I know after only 1 flight with the fairings on I'm already developing stress pre-cracks on those fiberglass "tongues" that you hose clamp to the legs.
 
Fairing clamp

Regarding Larry's original observation that the "hose clamp seems like a failure waiting to happen," I was thinking about somehow attaching the gear leg fairing to the lower intersection fairing with screws through the intersection fairing into nut plates on the inside of the gear leg fairing. I don't have my plane here to visualize whether that would work or not, but I know after only 1 flight with the fairings on I'm already developing stress pre-cracks on those fiberglass "tongues" that you hose clamp to the legs.

I drew this up. If you want the pdf. Shoot me an e-mail (below).
20220812_152639.jpg
 
Regarding Larry's original observation that the "hose clamp seems like a failure waiting to happen," I was thinking about somehow attaching the gear leg fairing to the lower intersection fairing with screws through the intersection fairing into nut plates on the inside of the gear leg fairing. I don't have my plane here to visualize whether that would work or not, but I know after only 1 flight with the fairings on I'm already developing stress pre-cracks on those fiberglass "tongues" that you hose clamp to the legs.

I watched upper fairing failures happen on many builds here (posts) and decided to make a stronger connection. It looks (very) similar to wirejocks. The gear fairing takes a beating as the wheel end of the gear deflects to braking and landing forces. It should fit loosely or forces will be generated along the gear axis. The lower end should allow for some floating axially as well or the fairing will be loaded between the upper attachment and lower compression from gear flexure. It seems to like floating within the upper and lower intersection fairings but must be prevented from excessive motion axially. Having rigidly fixed my upper end, i conclude that if it had some elasticity to it's axial position it would (might) be ideal.

I have a vision that if it were held axially by a strap of baffling only preventing travel downward, it might remain happy and live long. Could be wrong.

IMG_2094.jpg

IMG_2095.jpg
 
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Fairing clamp

Follow up. A few builders asked for the plans.
It's intended to mimic the shape of the inside of the fairing.
Installation is easy. Figure out about where it will land on the gear leg with a little room to move up or down. Mark that location on the fairing. Remove everything from the airplane.
Slip in into the fairing and drill the holes for the screws. Drill an access hole for the breeze clamp screw on tbe inboard side.
Reinstall the clamp leaving the breeze clamp loose.
Secure the fairing with the four screws then position the fairing and tighten the breeze clamp. Now the fairing can go off or on and the four screws will go in the same place.
 
A couple things from experience

I've been kinda following this thread because its a challenge for many, and is one of the "stand out" finish details when a person looks at fit and finish details. Besides the looks, there is a lot of dynamic function that goes on and must be accommodated. take a look at a slow motion video of an RV landing gear just taxiing on grass..whole lot of shakin! Keep in mind, the intersection fairings must allow some movement of the leg fairing or everything will be wrecked in short order. The tapered leg aircraft suffer much worse than the RV-8 type due to the fore-aft movement in the tapered legs. When the gear legs splay open/closed, the leg fairing moves vertically in the cuffs, with the upper leg fairing being the only "restrained" point at the clamp. The lower must float freely, and not be attached to the pant cuff. Also, the upper end of the leg fairing needs the aft side trimmed to just barely be covered by the upper cuff at the aft most end, otherwise when the leg flexes aft, the leg fairing will contact the fuselage skin thus denting it, as well as sliping and damaging the retainment tabs...I had to make this trim after finding my leg fairings migrating downward. My upper cuffs are split at the aft side, as are most to allow the installation and the leg fairing for-aft movement. I have attached a couple pictures of the fairings (home made using the clay method). I applied teflon infused urethane anti-chafe paint (PPG) to the unseen matting surfaces where movement occurs for wear protection.
 

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Yes, the tongue and clamp is due for failure. Probably other solutions too. The leg fairing flexes quite a bit with the gear leg. On landing for example, compression on top and tension on the bottom. I re-glassed the tongues a couple times, then just gave up since it would always crack after 100 hrs or so.

Turns out, the intersection fairings at each end hold things just fine. No more cracks or stresses on any of the fiberglass parts. Seems it works well to just let the gear leg fairing 'float' between the other two. YMMV.


Regarding Larry's original observation that the "hose clamp seems like a failure waiting to happen," I was thinking about somehow attaching the gear leg fairing to the lower intersection fairing with screws through the intersection fairing into nut plates on the inside of the gear leg fairing. I don't have my plane here to visualize whether that would work or not, but I know after only 1 flight with the fairings on I'm already developing stress pre-cracks on those fiberglass "tongues" that you hose clamp to the legs.
 
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