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Metal v glass leg fairings

Coling955

Member
I fly from a bumpy grass strip and my leg fairings are now trash. I'm thinking of using the old style metal fairings in the hope that they can stand up to the beating better.
I've never seen the metal type. They're cheaper which is one attraction. I wonder if anyone has any comments? Should I stick with glass fibre? Has anyone seen any fairings made from carbon fibre or kevlar?
 
The FIX:

The fiberglass covers will not flex (for very long). So, you need to allow room inside the fairing to let the leg do it's dancing/wobble without actually touching the fairing.

Generally speaking, the leg should bend towards the tip, so the fairing can actually lay on the outside sfc of the leg in flight. The extra room on the underside of the leg should be enough for things to work out.

In other words, do not put the leg in the center of the leg airfoil. Put the leg in the upper area.

I would suggest at min 1/2" wobble room, measured between the bottom of the leg and the inside of the fairing. I use these dims on the Rockets with their 4' leg, and unless someone really drops it in, the fairings will take all normal operations - even on my rough grass strip.
 
Early aluminum leg fairings being stiff tend to crack at the top. Their top & lower piece arrangement with the overlap joint mid way down can be unsightly when the aluminum overlap eventually starts wearing, picture a 3" wide 'smoking rivet stain' !!
 
Grove landing gear for the 6, 7, and 9.

It's too bad that Grove doesn't make landing gear for the 6, 7, and 9 like they do for the 8 that has the airfoil built in to them and doesn't need the fiberglass fairings.

Mark
 
The fiberglass covers will not flex (for very long). So, you need to allow room inside the fairing to let the leg do it's dancing/wobble without actually touching the fairing.

Generally speaking, the leg should bend towards the tip, so the fairing can actually lay on the outside sfc of the leg in flight. The extra room on the underside of the leg should be enough for things to work out.

In other words, do not put the leg in the center of the leg airfoil. Put the leg in the upper area.

I would suggest at min 1/2" wobble room, measured between the bottom of the leg and the inside of the fairing. I use these dims on the Rockets with their 4' leg, and unless someone really drops it in, the fairings will take all normal operations - even on my rough grass strip.

Thanks, Now I know why mine (RV7) cracked, it is tight. Creased the right fairing. It is mounted pretty stiff to the gear at the top and the wrap for the brake line (at top, center and bottom) is snug. Any special thin tape for that?
 
Stiffeners

I was chasing main gear vibration and I glassed-in the wooden gear leg stiffeners. The fairings are now a force fit but I have not experienced any problems in 400+ hours.
 
What Airplane do you have? Model and tail dragger or tricycle gear?

I had metal on my first RV-4 and the big difference is they are not as aerodynamic, not as wide, narrow chord. Never had a lick of problem. I think you can make your own, but I don't think that is necessary. There are other things I would try first.

Do you have gear stiffeners. bonded (glassed) onto the gear to lower gear movement. These tapered wood strips bond and glass onto gear to dampen the spring back and spring forward whipping that can happen. This will help a lot. There are threads on this.

Crack of fiberglass fairing is the least of your worries. The overhanging prop and engine cantilevered off of engine mount and ALL gear loads, go into four bolts in firewall. This structure can, does and will crack with abuse of constant rough operation. For tricycle gear "A" models the main gear loads go into spar, but the weak link is the nose gear. Personally I would not fly off a soft "bumpy grass strip" with a trike A model. The nose gear problem has been mitigated with fixes and awareness, but the nose gear is still a potential fold-O-matic. Smooth firm dry grass, light weight, no gofer holes, sure the dash 'A' models are fine with good pilot technique.

Smoothing out the field and taxiway, or at least the 800' to 1000' of runway you use... I recommend taxi as slow as possible. Use soft field technique and takeoff in ground effect.

Bigger tires would help and they are possible without changing tire size from 5 x 5.00. 5x5.00 tire outside diameters (OD) vary by a large amount by make and model. The standard spec in many books is maximum OD of 14.1" for 5 x 500 tires. The larger OD 5x5's are typically high quality and multi ply tires. Most of the 5 x 5.00 we use are the least expensive smaller OD 5 x 5.00 (some are as small as 13.25" OD). I measured a bunch of different brands/models in a warehouse to verify this. The larger the tire the better rolling on rough surfaces, which reduces gear movement. If you have your wheel pants tight on a smaller OD tire, you might have to adjust the pants to fit the bigger OD. There is a thread where people have put larger tires than 5 x 5.00 for soft field operations (on these forums). Some are still 5" rim some 6" rim. If your field is rough this modification would be great.

Look at videos of gear movement of RV planes taxing, landing and taking off. They attach a GoPro to belly, focused on gear. it's shocking how much it moves and vibrates on asphalt runways and taxiways. I can only imagine on rough fields what they do. RV's don't have aircraft carrier landing gear, durable, plenty strong for intended use, but they're not a back country STOL tundra tire airplane. *Attn Doug: Case for RV Cub* Ha ha
 
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