SECTION 48: GEAR LEG & WHEEL FAIRINGS
Build Instruction Updates
- 05/21/19 48_10.pdf
Check for more recent updates here
Properly aligning wheel pants and gear leg fairings is a tedious procedure. For maximum in-flight drag reduction, final alignment must be done with the aircraft’s weight off the wheels.
General
- For identifying hinges, see Van's hinge FAQ
Before You Start
Special/New Tools/Supplies
- A #40 adjustable rivet spacer is a nice way to make evenly-spaced holes in your gear leg fairings. Not mandatory you can always do it by hand.
- A laser level that can produce both horizontal and vertical laser lines is probably easier than chalk lines and plumb bobs.
- Many people use Tinnerman Washers on their fiberglass components and you may want them on your wheel pant #6 and #8 screws now or one day in the future. You could consider planning around them from the start or just wait until screws start to pull through the fiberglass in the future.
- It's probably the only place you'll need it so you can work around it with a Dremel, but a 1/4" CS bit is handy here.
Modifications to Consider
- The plans have you build your own front wheel spacers (48-16 Step 3) but you can also buy nice pre-made ones from Aircraft Spruce. You'll need these regardless of the types of wheels you have on your plane (assuming you are using the standard wheel pants at least).
- Consider making or buying Tug Guards
- It's easy to do this at any time in the future, but some people like longer bolts for the nose wheel towbar attachment. This option provides a more secure attachment but does stick out past the wheel pants by a little bit.
- Note that you will need to remove your wheel pants every time you want to check your tire pressure or add air to your tires. There are two common modifications to make this easier in the future:
- Create a strategically-placed hole that allows you to unscrew the tire stem cap and check/fill the tire without removing the wheel pants.
- Adding a door in each wheel pant to allow access to the tire stem. See Wheel Pant Doors for one method.
- Some people choose to split the wheel pant/gear leg intersection fairing into two pieces and permanently attaching each piece to the wheel pant. This can provide a cleaner look and it makes it a bit easier to remove the wheel pants. Here are a couple blogs that show that process:
Notes
Page 48-4
- Step 2: note that there may be a seam on the top of each wheel pant but that seam is NOT centered.
- Step 3: if the opening doesn't line up between the front and back pieces go ahead and trim one of the pieces until they have a similar-sized opening. You'll be trimming the opening more once you have it installed on the wheel.
- Step 4: it might seem that the only important dimension on this block is the 1-1/4 height but you'll be using it later for the nosewheel where the height needs to be 7/8". So if you make this block exactly as described you can use it for all three wheels.
Page 48-5
- Figure 1: consider screwing a taller block directly into the rear point of the wheel pant (at the approx. 9-5/16 mark referenced in the drawing). You'll need to take the wheel pants on and off quite a few times and once screwed in you will set a constant vertical alignment.
Page 48-6
- Step 1: Countersinking the 1/4 inch hole is discussed on this FB thread
Page 48-8
- Step 1: Most likely the trailing edge of your fairings will extend 1/2" or more past the cut line and you'll want to trim that later (even though the plans never mention to do that). What's useful here, though, is you can install some Clecos along the trailing edge aft of that cut line and it will maintain the shape much better than using tape, etc.
- Step 4: For opaque fairings, there are several ways to deal with the problem of how to make matching holes. Marking on the hinge will probably not be useful.
- You can Cleco the trailing edge of the fairing together (past the cut line) and then rest the hinge inside. Mark on the outside of the fairing where the hinge sits, then use those marks to draw a center line on the outside of the fairing. Clamp the hinge in place and drill from the outside into the hinge.
- See this FB thread for additional options.
Page 48-9
- Step 3: If you put a hole in the fiberglass for the safety wire it is easy to rip that hole open when using standard safety wire pliers. Consider putting a hole in the flange of the hinge pin for the safety wire.
Page 48-10
- Step 2: The plans make it sound like you can just pick any arbitrary point on the step and drop a plumb bob, but that won't work. You need to figure out how far in/out on the step will line up with the correct height on the gear leg fairing. In other words, you need a point on the leading edge of the gear leg fairing that is the same vertical and horizontal (inboard/outboard) point as a second point on the step. The easiest way to do this is to use a laser level or a string line with a bubble level. Using the step as a reference, move the line up/down the gear leg fairing until the two points are level. Now you have identified the height on the gear leg (which matches the height on the step) and the inboard/outboard point on the gear leg fairing. Now all you need to do is use a laser level or other method to find the inboard/outboard point on the step that is the same distance out as the point on the gear leg. In other words,
Page 48-16
- See this FB thread on fitting the nose wheel fairing.
Page 48-17
- Step 2: Screw 3/8-24 x 1 3/4 is an RV-10 problem point. The steel bolt in the aluminum fork may eventually strip the thread and come loose. Consider evaluating measures to prevent this. See also
- this FB thread
- this VAF thread
- this Youtube
- this FB thread
- this FB thread
- Step 3: It can be tricky to make sure the front wheel pant is straight for all directions. Consider using a laser level to make sure a laser line that follows the centerline of the belly of the aircraft also lines up with the rear of the front wheel fairing and the nose gear leg and the center of the tire.
