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Installing leg fairings and wheel pants

Scott Will

Well Known Member
Now that it's finally flying, it's time to install the fairings and pants. No more people asking me why I have so many spinners in my hangar! (they are all in the back of my hangar and sorta look like spinners standing on the end)

For some reason, I have reservations about doing this. How hard is it, really? My biggest questions are:

- how do you jack up a 7A so you can get the weight off the wheels?
- having bought the intersection fairings from Bob @ Fairings ETC, do you really need to jack up the plane because the upper intersection fairing sets the proper angle?
- does the plane need to be off the ground to do just the wheel pants?
- anything else to look out for?

My speed right now is only about 140 kts and my rpms on the engine are slightly above 2500. So I need to get the speed up to get the rpm's up on the engine. My static RPM on the engine/prop is 2200 rpm, which is right where Craig Catto said it'd be. So it's sorta like chicken and egg - can't get the rpm's til I get the speed and vice-versa. Guess it all comes down to drag.

Any good builder websites that detail this process?

Thanks!
 
Get a set of wing jacks and get the hard points from Van's to put into the wing tie down holes to jack up on. Then you will need several building blocks and a chain to hold the tail down.

Roberta
 
Scott, I'd try not to rely on the upper intersection fairings setting the alignment of the leg fairings. They'll get 'em pretty close, but imho it's definitely worth jumping through the hoops to achieve that last bit of perfection. Get the weight off the gear when you do the alignment of main leg fairings and wheel pants, you'll be glad you did! Less drag = more mpg at every power setting.
 
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Here are some pics of my 7A jacked up. Wing jacks are about $175.00 a piece, but you can try to borrow or share with other low wing owners.

Roberta

planejack2dx2.jpg



planejack1ss5.jpg
 
Roberta... those look like jacks from www.jackhouse.com. What model are they (12)?

Can you do the wheel pants without jacking the aircraft?

Man, I wish some airplane fairy would come along and do all this at night.

Thanks!
Scott
 
Scott Will said:
Roberta... those look like jacks from www.jackhouse.com. What model are they (12)?

Can you do the wheel pants without jacking the aircraft?

Man, I wish some airplane fairy would come along and do all this at night.

Thanks!
Scott

On the 6A, I used what amounts to a sawhorse but with more structure, and carpet padding to support the fusealage under the spar. I could jack up each side of the sawhorse a bit at a time with a floor jack, and then slip blocks of wood under it.

I think that what's most important, is how the gear legs/ wheels align with the fuselage when compressed on the ground or free hanging as in flight. In other words, will there be toe in or toe out on the ground, and fairings that don't align perfectly with the airstream in flight, because they were installed while the legs were under load sitting on the ground.

I don't know the exact answer, as I've seen fairings installed while jacked up, and on the floor too. However, using the jacked up method, I still did it over a weekend, and it wasn't too killer. The pants were the newer two-piece type.

I could also swear that my wheel pants don't perfectly align with the fuse, while sitting on the ground, but am not sure without chalk lines and re-measuring. That would be because of the toe-in while compressed, possibly. And different RV models may very too.

Confused? :D

L.Adamson
 
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Yes, They are Jackhouse Jacks. I would not recommend doing any of the fairings or pants on the ground. The jacks are a very good investment. You will not need them often, but they are the safest and quickest way to get the plane off all wheels and level it out. I use them several times a year for annuals, wheel pant removal and install ( I remove mine for winter flying off our grass strip), and adusting break out force on the nose wheel. If you can share a pair with other owners, that helps take the sting out of buying a set.

Roberta
 
Wheel pants

Would anyone give an aprox. amount of time this should take for all new pants and fairings.
Thanks
 
Timeframes

The longest part was filling the pinholes. The alignment and attchment is pretty simple. Need to do some minor layups on the inside of the fairings where the screws come thru.

6-8 hours for the mains and 4 more for the nosewheel should do it. Intersections fairings will take a few days due to multiple layups. Lots of time to fill the pinholes....
 
Just do it....

Hi Scott,
It really isn't as bad or difficult as you think, nor very time-consuming. It is, however, very important to have the main gear dangling free and care taken for very good fairing and wheelpant longitudinal alignment. It will definitely pay off in good cruise speeds.

Just use a couple of cheapo bolts in the tie down holes for jacking points. Cut their heads off and round them a bit on your bench grinder. We used two bottle jacks on a couple of concrete blocks and a 2 X 6 on top of them to jack on. Go with the snapped string procedure, down the middle of the fuselage onto the concrete floor and measure from there. Call me if you wanna talk about it.
Regards,
 
I guess it depends on your skills and what kind of 'finish' and alignment you're looking for. :) Looks like Pete did his in 12ish hours. I have 56 hours into the 3 wheel pants, the nose strut fairing, and the main gear leg fairings on my RV10....(this is working straight through, no sitting and thinking time) for fitting and mounting with no primer/pinhole work. I'll start the main gear intersection fairings today. Will probably end up with another 20 or so hours there. I'll also mention that I've done my share of wheel pants and fairings in the past so this isn't my 1st go-round, it's just how long it takes me to get the fit and finish that I want.

As you can see from 2 perspectives (mine and Petes)...times will vary.....just do the best job you can.....as far as how long it takes....'it is what it is' :). Good Luck.

Rick in Ohio at the Buffalo Farm
http://rv6rick.tripod.com/ohiovalleyrvators/

The longest part was filling the pinholes. The alignment and attchment is pretty simple. Need to do some minor layups on the inside of the fairings where the screws come thru.

6-8 hours for the mains and 4 more for the nosewheel should do it. Intersections fairings will take a few days due to multiple layups. Lots of time to fill the pinholes....
__________________
Cheers,

Pete
RV-9A
St.Paul, MN
 
Fairings-etc

Scott,
The fairings etc, intersection fairings are the way to go.....no layup and they fit really well.

If the plans don't show it for the nosewheel, leave the brackets attached by the wheel bolt and add nutplates,
Regards,
 
Aligning Fairings

I spent over 100hrs on the U/C fairings......... and it's a tail dragger. I'm either dumb, slow or fussy?
Absolutely detest GRP.

I did come up with an excellent solution for alighning the Gear Leg Faairings.
Pete.
legalignzn5.jpg
 
results

Wanted to post an update. After installing the main gear leg and upper intersection fairings only (no wheel pants, no nose gear leg fairing). A hangar neighbor of mine lent me 'proper' aircraft jacks.

I picked up about 100 rpm and about 20 mph! Just those things alone. My problem before is that my engine was only getting up to 2500 RPM with the Catto propeller. Both Catto and Aerosport said the RPM and speed will come up with fairings. Well here are my readings on Saturday:

5500' 2600 rpm... GPS speeds of 165/155/156 on headings of 0/120/240. 158.7 kts or 182.5 mph
5500' 2450 rpm... GPS speeds of 156/146/148 on headings of 0/120/240. 150.1 kts or 172.5 mph

Can't wait to get the rest of the fairings on. Then I should be in the same league as 'normal' RV's. I knew it was a whole new airplane when the vertical speed on climbout was a whole lot higher at the same airspeed.

Best,
 
Does anyone have a picture of the lower intersection fairing for the nose wheel? (wheel pant to leg fairing). I have the Fairings Etc set but it came with no instructions. Obviously it has to allow the wheel to pivot, do you have to cut the leg fairing back?

Thanks, Larry
 
Here are a couple pictures of my installation. Really had to cut the top part down ALOT before there was enough clearance for the pant to swivel from full left to right. Don't know if this is the correct way to install it but from the photos I've seen of other installations, they all appear to have removed a lot from the top of the fairing.
dsc00742mediumev8.jpg

dsc00743mediumkd4.jpg
 
Thanks Joe, pretty much what I envisioned. I'm thinking I may raise the 3/16 leg fairing to pant clerance callout to 5/16 or so, that would leave a little more front fairing, we'll see. Yours pant's look good! My front to back pant fit was awful, like they came from different planets. I had to fill over 1/8 inch top and bottom to get a nice fit. Oh well, the beauty of glass as they say.

Larry
 
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another alternative?

I have the same setup on my plane and I was under the impression (maybe wrongly) that the little "extra piece" was attached to the gear leg fairing and left to float above the actual wheel pant so that it hid the opening in the wheel pant below. Anybody install them this way? Am I nuts?
 
Here is a hint for the gear leg fairings.

I came up with this after my band clamp attach tabs started breaking off.

Use you tube of boelube and warp it with wax paper and insert it into the top of the gear leg fairing. Add a couple of plys of fiberglass cloth.



This is the same size as the gear leg and makes it easy to make and nice attach tab for the band clamp.



This way the tabs won't be under stress when the bands are tightened down.

A little sanding and your ready to go.

Kent
 
How to lift my plane...

is the 'how to lift the plane' discussion complete???

I'm at the thinking point of adding Leg Fairings & Wheel Pants on my 7

I was planning to lift it from the engine mount or hoist point on the engine,
any of you guys see a problem with this? Having it lifted from the bottom gives me visions of jack stands protruding up through the wings... (ouch)

of course engine cowling would be in the OFF Position

I happen to have an engine hoist, so no 'new, non-flying equipment' needed.

Thanks for continuing the discussion...
-Rich
 
Do not lift the plane by the hoist point on the engine!

Tie a heavy strap or heavy rope around the engine mount, or lift by some other system.
 
is the 'how to lift the plane' discussion complete???Thanks for continuing the discussion...
-Rich

Probably not just yet. For the best results, consider leveling the fuselage. Hard to do with an engine hoist. But easy to do with a sawhorse.

http://picasaweb.google.com/tonyboytoo/RV3BMiscellaneous/photo#5136896404528711634

There needs to be just enough daylight between the engine mount cross tube and saw horse to allow the sawhorse to slide under the cross tube. Pick the tail up and the wheels will come off the ground, then put a second sawhorse under the aft fuselage. And the Peter James method for aligning the gear fairings works great. Post #14 in this thread.

Tony
 
Elegant Solution

Nice thought Tony!
I will use the method, slight modifications needed,
as Engine & Exhaust are installed

anyone have a pic of the setup for a taildragger
& the lines extending back to the Horiz. Stab.
Are all measurments from a chalk line snaped on the floor?

I've never seen the fairing alignment done & can't envision the set-up

thanks,
 
Rich,

Peter's method for aligning the gear leg fairings was in an RVator. Can't lay my hands on it right now, but maybe Peter will see this and explain. Here's how I did the rest of it. Once the fuselage is level draw a fuselage centerline on the floor. Measure the distance from the centerline to the center of each tire, then draw the tire centerlines parallel to the main centerline. Draw a horizontal and vertical centerline on the front and back of each wheel pant, then drill a small hole and insert a nail. You'll have a nail on the front and back of each pant. Clamp the pant in place, then adjust until the front and back nail are equidistant from the floor. Then slide a square lightly against each nail and adjust the pant in/out until the spaces between the bottom of the squares and the centerlines are the same.
Look at these to see how I held the gear fairing and upper intersection fairings in place. I've made some horrendous landings and nothing has busted loose yet.

http://picasaweb.google.com/tonyboytoo/RV3BMiscellaneous/photo#5136870677674608194

http://picasaweb.google.com/tonyboytoo/RV3BMiscellaneous/photo#5140988652686351650

http://picasaweb.google.com/tonyboytoo/RV3BAllThePartsInCloseFormation/photo#5171415848001449074

http://picasaweb.google.com/tonyboytoo/RV3BAllThePartsInCloseFormation/photo#5171415886656154754

Tony
 
getting the center lin on the ground...

is the firewall rivet in the center...
or, how do you find the center to put the first line down

Feeling pretty silly here, I just dropped some lines &
the center rivet of firewall
TO center rivet of wing spar
TO tail wheel fitting
does not appear to give me a line!!!

I did this at 6:30am, then had to get to work, so I need to double check..
thought you guys could chuckle at the easy stuff, then provide direction

LUCY's up to 15hrs, 155kts w/o fairings
 
Since you haven't done this yet, may I offer a little advice?

i would align the gear leg fairing and wheel pants without the weight of the airplane on the gear, but I would then load up the airframe on the ground to simulate fuel to fit the upper and lower gear leg fairings.

If you fit them all up without weight, then when the gear sags on the ground, these intersection fairings will gap. It won't be by much, but it can be noticeable (by everyone who stops by to look at your airplane at AirVenture).
 
Finding level and straight on wheel pants?

I've got weight off wheels and fuselage level. Now, how on earth do you guys find level and centerline on these fully rounded wheelpants? I can eyeball it, but I'm trying to do better than that?
 
Pants and fairings

I've got weight off wheels and fuselage level. Now, how on earth do you guys find level and centerline on these fully rounded wheelpants? I can eyeball it, but I'm trying to do better than that?

Easy peasy. Shoot me an e-mail (below). I wrote an article for Kitplanes. I can send the draft.
The short answer is the aft end can be measured. Forward end is easy. Lay a piece of sandpaper on the floor. Holding the pant near the aft center point, swing it side to side lowering slowly. When it hits the sandpaper, take a look and make a mark. Repeat at 90 degrees. That's the forward center. Now just set up a laser level and connect the dots.
 
Pete's Laser Leg Faring Alignment

I can't find my original posting so I'll repost it.

It's years since I posted Pics, but if you want them I'll try.

Here's the Post.

Pete.

Pete James Method for Aligning fairings with ‘Streamline’.
[email protected]

First a word on using the string to establish the fairing parallel with the ‘steamline’.
The string thing is standard Vans procedure. My variation is the 1/4" poly tubing. Without the poly tubing bring the two strings together it is impossible to measure the distances between each string and the trailing edge, as you cannot get you head in at right angles to read a ruler. But if you just slide the poly tube along the sting until one string is touching the fairing you can eyeball the gap to the other- say 1/16"- and rotate the fairing to make the equal gaps. See Picture “Leg String align” and “Impossible measuring.jpg”
How to set up the streamlines.
I have a laser level that projects both a Horizontal and a Vertical line. It is not an expensive unit and is only powerful enough to use in doors, but it was invaluable for aligning the legs.
Establish Centre Line.
1. First I jacked the aircraft so that it was level and the wheels were about 1/4" off the floor.
2. Next you need to establish a line on the floor exactly under the centre line of the fuselage.
3. To do this I placed my Laser level on the floor under the tail and moved it until it shone down the centre of the fuselage underside. Where the laser shone on the floor, I then marked with a bricklayers chalk line and then permanently marked it with a marker pen. See picture “Fuselage Centre line.jpg”
Establishing streamline
1. A string needs to be placed around the leg fairing with the two ends running back to a support near the tail, such that it is parallel with the streamline of the airflow in flight.
2. To obtain the streamline the string needs to be parallel with the centre line and horizontal to the floor.
3. In order to establish the horizontal position from the centre line, I measured and mark a line on the floor approx 3’ out from the centreline. I then placed a chipboard box with one face on this line near the tail to support the aft end of the string. See picture “Horiz/Vert from Centreline”
4. To establish the level that the string needed to be above the floor at this point, I sat the laser in front of the gear leg, over the 3’ offset line on the floor and raised the laser until the cross-lines of the laser impinged dead centre on the front of the gear leg and taped the string at this point. I then marked where the horizontal line impinged on the chipboard box at the rear and duct taped the string at this point also. See Picture “Streamline on Leg.jpg” and “Laser Position.jpg”
5. It was then fairly easy to rotate the leg fairing until it was equi distant between the two strings. See Picture “Leg String align”.

Wheel Fairing aligning.
Aligning the wheel fairing was relatively easy by marking a line on the floor, in front and behind the wheel, parallel with the centre line and carrying the line up to the fairing with a carpenters square. See picture “Wheel Fairing align.”

Other uses of Laser Level
Attached are other pics showing how the laser level can be used to:
• Establish the leg fairings are straight before drilling for hinges.
• Levelling the engine cowl
• Aligning the elevators

Good luck.
Pete.
 
close

As far as the wheel pants go, I think close is good enough; I don't think the air flows straight around the wheel pants anyway. And the wheel pants are more tear dropped shaped, so probably can't drag the plane around if they are a little off.

But we know that the gear leg fairings do make a difference in trim. This is most likely due to the fact that they are a mini control surface.

I spent a lot more time on my gear leg fairings getting them perfectly aligned to the centerline; hope it is good enough.
 
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