Gear Drag

For general discussion of the Just Aircraft family of aircraft.
Includes: Highlander, Escapade, Summit and SuperSTOL.
Post Reply
EchoWhiskey
Seasoned Member
Posts: 63
Joined: Tue Sep 18, 2018 9:15 pm

Gear Drag

Post by EchoWhiskey »

This video is a mind blower,

The drag on a rod is almost 10 fold to an airfoil

https://www.youtube.com/watch?v=ftq8jTQ ... e=youtu.be

Why not install airfoil fairings(vocab?) on the gear to reduce drag?
Ed Whitaker
Humble Novice

What do you get when things don't go as planned? Experience.
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Gear Drag

Post by BDA »

Alan Ronk did that several years ago in Aus. Says he loves it

Look him up on Facebook
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Gear Drag

Post by BDA »

Better pictures of allan’s plane

@ronkstol
On instagram
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
SheepdogRD
Proprietor
Posts: 930
Joined: Tue Nov 30, 2010 5:41 pm
Location: West of Atlanta, GA

Re: Gear Drag

Post by SheepdogRD »

I'm not on Instagram, so I can't see what's presented there. For those in the same situation, here's some information I saved about 18 months ago:

Allan Ronk bought his SS through Steve Henry, and built it in Australia. It's VH-YOS. The covered landing gear and faired shock strut are only two of the many modifications he made.
VH-YOS-14.jpg
VH-YOS-08.jpg
VH-YOS-05.jpg
VH-YOS-17.jpg
VH-YOS-12.jpg
Here's a Western Australia news article from November of 2017: https://www.abc.net.au/news/2017-11-22/ ... ra/9163602.
You do not have the required permissions to view the files attached to this post.
Richard Holtz
Highlander N570L -- Ms. Tonka -- in gestation

If just enough is really good, then too much ought to be perfect.
jzawodn
New Member
Posts: 7
Joined: Wed Jan 11, 2017 12:42 am

Re: Gear Drag

Post by jzawodn »

Did he ever discuss the improvements in cruise speed he saw?

I'm sorta tempted to try this, assuming I ever find enough spare time...

Jeremy
User avatar
Tralika
Veteran Member
Posts: 385
Joined: Thu Oct 08, 2009 12:49 pm
Location: Wasilla Alaska

Re: Gear Drag

Post by Tralika »

I've been thinking about giving this a try as well. I left my gear uncovered with the theory that I want to see any cracks that start to develop rather than having to wait until the gear fails. I have the Extreme Gear on my Highlander with three tubes and 6" longer than the standard gear. That's a lot of drag. I have lots of fabric left over so I may just cover the gear and not paint it so I can do a test flight and see if there is much difference. If the results are positive I'll have to weigh the advantages against the risk of an undetected crack in the gear. I'm not aware of any problems with the Extreme Gear but more research would be needed.
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
User avatar
danerazz
Veteran Member
Posts: 1240
Joined: Tue Aug 18, 2009 9:33 pm
Location: Bangor

Re: Gear Drag

Post by danerazz »

I’m not going to say that not cover your gear to look for cracks is wrong...but...by that logic you shouldn’t put a cowl on, or cover the fuselage.

I think there are better reasons not to cover your gear (lazy, looks cool, operate on terrain that is likely to punch holes in it) but unless you are REALLY pounding on it the crack issue should not be a serious consideration.

YMMV
Dane

Paralysis by analysis
#242
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Gear Drag

Post by BDA »

I have had many (half a dozen or more) friends had gear legs fail leaving them stranded on a glacier or river where walking out was not an option.
Failed due to cracks from previous abuse.

Not saying you will always catch a crack, but if covered, you dont have the chance to look.

I will try some aero on the tubes at some point but not going cover the welds for that reason.

When I do my preflight, I dont lay down and inspect every weld, but I do look for rust stains at the welds, cracks usually leak rust.

And at annual, all welds on the gear are crack ckecked carefully.
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
Tralika
Veteran Member
Posts: 385
Joined: Thu Oct 08, 2009 12:49 pm
Location: Wasilla Alaska

Re: Gear Drag

Post by Tralika »

I have similar experience with gear failures. Never happened to me but I know several people who have and mechanics shown me cracks in gear legs discovered during inspection on several aircraft. I know there have been gear failures on Just aircraft but I don't know of any that resulted from undetected cracks. My gear, like most of the Just aircraft, are powder-coated which can hide cracks and corrosion. I like the powder-coated airframe but that is one of the drawbacks. I would like to keep the gear legs uncovered but if the drag reduction is significant I may do it.
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
User avatar
SheepdogRD
Proprietor
Posts: 930
Joined: Tue Nov 30, 2010 5:41 pm
Location: West of Atlanta, GA

Re: Gear Drag

Post by SheepdogRD »

Maybe an option here would be to create a removable aerodynamic fairing that would allow for crack-checks at maintenance intervals. Perhaps some epoxied-on fittings would provide mount points that wouldn't obscure any welds.

I haven't seen the Beringer Alaskan gear fairings except in pictures, but I suspect they're removable. It would be interesting to get a report from a Beringer user on how much the fairings helped.
Richard Holtz
Highlander N570L -- Ms. Tonka -- in gestation

If just enough is really good, then too much ought to be perfect.
User avatar
BucF16
Veteran Member
Posts: 463
Joined: Sun Mar 23, 2014 11:47 am
Location: Alexandria, Ohio

Re: Gear Drag

Post by BucF16 »

Go over to Mike Patey's YouTube channel and watch him build the fairings for Draco. Of course he has the time and resources, but Carbon-fiber fairings would be my choice.
Bruce
Bruce Johnson Highlander # 393
"Because I fly, I envy no man on Earth"
Builder web site:
http://www.bruceshighlander.blogspot.com
User avatar
Tralika
Veteran Member
Posts: 385
Joined: Thu Oct 08, 2009 12:49 pm
Location: Wasilla Alaska

Re: Gear Drag

Post by Tralika »

Carbon fiber would be nice. I've made small fiberglass fairings which were pretty simple but I've never worked with carbon fiber. I think the learning curve might be pretty steep and expensive. I thought about making gear leg fairings out of fiberglass or aluminum. The advantage over fabric is making the trailing edge aerodynamic for less drag. With fabric the shape will match the round rear tube causing more drag but less drag than three round tubes. I'm concerned about weight using aluminum or fiberglass but it might be worth some experimentation. I think attaching the fairings to the gear legs with adel clamps would work fine. I guess the thing to do is make a template to determine the overall size of the fairing and calculate the weight in aluminum and fiberglass. Oh Boy, another project!
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
User avatar
BDA
Veteran Member
Posts: 707
Joined: Mon Aug 22, 2016 11:25 am
Location: Kenai Alaska

Re: Gear Drag

Post by BDA »

My pacer had 3” long aluminum sheet metal angled trailing edge off the back tube that I think at one time had been fabric covered.

But when I had it the rest of the gear legs were wrapped in sheet metal with screws.
SuperStol XL Alaskan With Titan 340
N331AK. Shawn Taplin
Wing extensions,Symetrical Airfoil tail ribs (NACA 21)
Mods in progress: Heavier struts, Double slotted flaps
Goal: 15mph no wind
User avatar
Tralika
Veteran Member
Posts: 385
Joined: Thu Oct 08, 2009 12:49 pm
Location: Wasilla Alaska

Re: Gear Drag

Post by Tralika »

My Stinson had single piece aluminum gear fairings that wrapped around the gear and were secured at the trailing edge with screws and tinnerman nuts. There were formers on the gear to maintain the proper shape and the fairings attached with a few screws. I'm pretty sure something like that would work on the Highlander gear. Not sure what gauge aluminum they were made from. I'd be inclined to try .020. I'll have to make a template if I cover the gear with fabric so I guess I'll see how big a piece of aluminum it would take.
John Nealon
Wasilla, Alaska
Highlander Extreme #191
mykitlog.com/jnealon
av8rps
Veteran Member
Posts: 480
Joined: Thu May 12, 2011 5:01 pm

Re: Gear Drag

Post by av8rps »

I remember reading somewhere on this forum that Steve Henry gained 10 mph by covering the gear legs on his Highlander, so I covered mine with fabric. I just wrapped the leg, but in hindsight should have probably streamlined the leading and trailing edges for more effective drag cleanup.

I have never done a real serious test of mine, but believe I gained about 8 mph. With an uncovered gear at 5500 rpm it would go 108 mph, and now it will go 115mph at the same power setting. (Fwiw, this is with the larger 8.50 tires and a stock 95 hp 912uls turning a 70 inch 2 blade Sensenich carbon prop). They also say a cleaner airframe will climb and cruise better, or more efficiently than a dirty airframe. So there are most likely benefits like less fuel and longer range I will enjoy from this simple option.

If I were building another Highlander I would definitely put some sort of covering on the gear that would be removeable for inspection. I'm not hammering my plane like a lot guys do in the back country, so I'm ok with having it covered.
Post Reply

Return to “Just Aircraft”