Gear width mod?

[kauaicuda]

It looks to me like the patrol landing gear track width is kind of narrow, perhaps by about a foot. I’ve seen some owners point this out as a factor of ground handling.

Has anyone considered modifying the gear layout to be wider?

[Archer39J]

Not that I've heard of. That seems like it would be a pretty significant modification to a complex system for "ground handling". Anyone undertaking that would need to really understand what they are doing and how the frame will handle the different loads. It would be a hard case to make for reducing the stroke of the gear as designed.

[whee]

Dave pretty much covered it, seemingly small changes can significantly alter the load paths. I have no Patrol experience but I suspect the Patrol handles as good on the ground as the BH does. It's pilots wrecking the airplanes not the other way around.

[Patrol28]

"perhaps by about a foot"

How did you determine this?
Were these Bearhawk owners?

[JimParker256]

It's always interesting to me how firmly our opinions on "what looks right" are established by "what we've been flying"... And I'll admit that my initial of the Bearhawk airplanes was that the gear appeared to be somewhat on the narrow side.

BUT, that initial impression was forged by flying "very wide-stance" low-wing airplanes for many years. In a low-wing airplane, a crosswind landing on the upwind wheel first might well have dragged a wingtip if the gear was the same width as the Bearhawk gear. The low-wing designers have to consider that "one wing down crosswind stance" when setting the gear width. I realised that with the high-wing design of the Bearhawk, that is not a factor.

And after seeing the Patrol "in person" and going for a demo flight, any concerns I might have had about ground handling issues are gone. I've also read a bunch of "first flight" reports, and watched every "first flight" video on the internet... Those reports seem to indicate that even the very first landing (always a high-anxiety moment in a first flight) went very well, and the pilots generally note that the ground handling is outstanding.

I'm very comfortable with having made the decision to just trust Bob's design, and build according to the plans. As others have pointed out, re-designing the landing gear would have a HUGE ripple-effect throughout the entire airplane.

[svyolo]

Bob's designs are strong and light. They are not overbuilt. There are for sure some places where the fuselage tubing is bigger than it needs to be (rear longhorns) because it is too expensive to make them optimal. Same with the wing spars and skins.

But I would guess the landing gear attach is one of the "defining" components that you design to the strength you want, but not more. Also the wing and strut attach points.

You don't design and build light by "adding a little extra" here and there. I would definitely ask Bob about it.

[Archer39J]

I suspect this comes from the comment made about the gear width of the Patrol in the latest fly8ma video, without explanation or substantiation.

[zkelley2]

It looks to me like the patrol landing gear track width is kind of narrow, perhaps by about a foot. I’ve seen some owners point this out as a factor of ground handling.

Has anyone considered modifying the gear layout to be wider?

Go fly one. If you still think the ground handling is too touchy the two things that cause that is gear width and wheelbase length. The latter is probably harder to change than the former, but either way you'll be doing some engineering to change it. Experimental is all about making the plane work for you, not how someone tells you it needs to work. Just do it right.

On the gear side I bet the easiest way to make it wider would be to go with a set of grove spring gear. They'll make them to any dimension you want and they are crazy strong. Spring gear attach points are easy to fabricate. Generally they're less drag to. You'll just have to deal with having spring gear, for it's drawbacks.
You could probably get it wider with a cabane vee(cub style) as well since that halves the forces on the tubes. Good bit of fabrication needed on the fuselage for that, but it's been done.

[whee]

Related data point. I recently had Grove design and quote me some spring gear for my 4-place. I wanted it 3” taller so to maintain geometry they would be 6” wider I think it was. I had them designed for 2900lbs gross. Quote was $2500 which I thought was pretty great.

[zkelley2]

That's a steal compared to their 10" wheels and brakes!

[Rollie]

I've flown two Patrols and an LSA and didn't find any issues with the ground handling. They are all easy to keep heading straight down the runway. I wouldn't put any effort into changing anything about the gear.

[Battson]

I suspect this comes from the comment made about the gear width of the Patrol in the latest fly8ma video, without explanation or substantiation.

Sounds like fly8ma needs to do some more time in the saddle.... More flying less talk'n.

[kauaicuda]

All great responses guys, thank you.

[Shovelguy79]

I had wondered the same thing. I love everything about the Patrol except the gear width. I have no experience flying one but I have noticed that the wings tend to rock pretty bad on a rough airstrip. I am sure they handle great otherwise. I wish that the width could be properly increased to that of the Supercub. I think it might be more stable. That being said I am not an authority at all on the subject. Would be cool if Bob would weigh in on it or create a mod that could be purchased. Beautiful aircraft for sure.

[zkelley2]

It has been done. I know of one bearhawk with a cabane vee and wider gear. It's not even terribly difficult to engineer and do, but you're going to probably have to do all that yourself.

[Pbruce]

When I was young I read a number off articles on the Bucker Jungman and Jungmeister. Just about everyone who flew them described them as the most delightful aircraft they had ever flown. I wish I could have one, just for fun. Sadly, they are antique, and even in their day pretty complex to build, so few remain.

The Bearhawks have a gear width which is also on the narrow end of normal, reminiscent of the Buckers. I really like the (Bucker Jungman-esque) look of the BH since reminds me of my dream plane. However, I understand how it might be a stretch for some.

Back to the flying characteristics: form should follow function. If you made a Bucker look like a Pitts, it would be as handsome a Corvette crossed with a K-car, in my opinion. Similarly, you take what is by all accounts a magnificent flying and somewhat unique looking Bearhawk and after modifying it you end up erasing not only the aesthetic character of the plane, but it’s functional character as well. I suspect that gear was designed to avoid the maintenance hassle and bouncy handling of the cub gear, and the weight and bounce of spring gear, but at a strength and weight which supports the design mission of the plane.


Make sure you are proceeding for the right reasons. If it wasn’t working, like the C-120 gear which everyone added extensions onto to move the main wheels forward, then yes, I’d say fix it. But this is a good design. So what if it rocks on landing? It’s a quirk. It doesn’t tip over, does it? The Spitfire had this characteristic too, courtesy of its narrow gear, also designed that way with good reason. Be proud. You too are flying a thoroughbred with wings, not a nag! Think like a Spitfire Pilot. Reach up and touch the face of a God, and then return to earth with the grace of a gazelle, because you can in a Bearhawk

[Shovelguy79]

It is a great design and I love them mechanically, I suppose if it isn't broke don't fix it would apply. I need to keep it simple. The aircraft is a work of art.

[Bdflies]

The Patrol gear, as designed, is nothing short of delightful. If anyone desires to 're-engineer' an aspect of the aircraft, I’d suggest looking for another detail.
Just my opinion.

Bill

[geraldmorrissey]

New Jundmans are being built in Europe. I know of at least one that was imported into the US and powered with an 0-360. For the fat of wallet. See type group for details. Downside, like owning a Faberge egg. Need hanger, open cockpit, spares issue. Bearhawk, leave it outside, cabin heat, play in the mud, build your own spares. Be fun to have both plus a 250 LM just to round it out.
Gerry
Patrol #30