Wing hard points

[Luke68]

Just got the latest issue of sport aviation and on the cover is what looks like a carbon cub on steroids but what really caught my eye was the motor cycles hanging off the wings. I’m not saying I want to strap motor cycles to my wing but I’m wondering if anyone has looked into hard points incorporated into the wings for attaching small objects like skies, gun cases or the like.
Thoughts?

[zkelley2]

You can fit multiple bikes, hundreds of skis and guns in the back of a bearhawk. Don't think I could fit my 450 through the door or inside the cabin though.
I do put an inflatable boat and outboard in the back quite often.

[alaskabearhawk]

That's Scrappy. Mike Patey's newest creation. Super Cub folks have been hanging things off of struts for years. If you look there are two struts. They come from a common attach point at the fuselage and attach at about the middle of the wing, front and rear spar. The reason that works with the bikes is he utilized the front and rear strut/spar attach points as hard mounting points. Not something that would be possible with the BH unless you make a separate attach point at the rear spar for attaching that kind of thing. Zac is right. Why put all that drag out there when you can fit all and more inside the BH? It would be interesting to see how that would glide with all that stuff hanging off of the wings if the engine ever quit.

Rural Alaska photo _ Alaska bush plane photo, Super Cub and a bicycle, McCarthy, Alaska_.jpg94B89883-C789-4CAF-9FF0-707C31E06017.jpg

[jaredyates]

Interesting how practicality isn't what gets your picture on the cover...

[TimTall]

A buddy built one of these Murphy Radicals... There's a few extra pounds of aluminium between the spars to pick up the load but it's a pretty slick design. The hard points are threaded holes so you can attach basically any type of rack to it.

I called Bob and discussed it with him. He's not a fan. If I remember correctly, he wasn't too worried about making the wing strong enough to take the loads but he didn't like the idea of that much drag and airflow disruption hanging there. He figured not too big of a deal on a slower plane like the Radical, but at a BH at VNE with two bikes hanging down it might cause problems.

Screenshot 2022-01-08 160720.png

[marcusofcotton]

Thanks for sharing Bob's perspective on it.

[zkelley2]

A buddy built one of these Murphy Radicals... There's a few extra pounds of aluminium between the spars to pick up the load but it's a pretty slick design. The hard points are threaded holes so you can attach basically any type of rack to it.

I called Bob and discussed it with him. He's not a fan. If I remember correctly, he wasn't too worried about making the wing strong enough to take the loads but he didn't like the idea of that much drag and airflow disruption hanging there. He figured not too big of a deal on a slower plane like the Radical, but at a BH at VNE with two bikes hanging down it might cause problems.

Screenshot 2022-01-08 160720.png

You could always limit the airspeed when running like that. Just put a 100kias or maybe 85kias limitation on external wing loads.

[TimTall]

That's what I thought too. Bob still wasn't interested in talking about it much. I've got QB wings so I wasn't very interested in pushing the issue. I'd absolutely figure out how to do it if I was scratch building though. Bikes take up a massive amount of space inside. For shorter trips, wing mounting would be awesome.

[Luke68]

I also have quick build wings and if bob isn’t interested in talking about it i will leave it at that, I’m sure he has good reason

[svyolo]

There is thread drift, and then there is forum drift....................................

[Gerhard Rieger]

A good sized cargo pod makes much more sense, I made ten attach point on the bottom of my fuselage and have already talked to a AMO that does carbon fibre to make me one, the target is 200-250 lbs and their estimated weight for the cargo pod is 20-25 lbs. no extra loads, and much better balanced load under the wing. Behind the seat will be left for light bulky stuff.

[whee]

I don’t have my issue of Sport Aviation yet but if it’s the same pic from social media those motorcycles are electric. So basically a powerful ebike and not like hanging a couple 450s from the wings.

We’ve discussed this before and I’ve posted the pic of a C185 in NZ hauling 4 bikes on its wings in a commercial operation. Making hard points on a BH would be pretty easy depending on the chosen load. I planned to add hard points for cargo pods but haven’t done it yet.

[Bcone1381]

We are experimental. We are utility. Seem like Bob and Mark need help here. How can we combine creativity with safety. Belly Pods, cargo area extensions like our Super Cub brethren have done are proven utility expansion areas for us. I forecast the more Patrols that are built, the more we'll see of this.

I think when my Patrol is flying, I'll keep finding ways to improve it.

[Battson]

While the plane is experimental, you can go experiment. It's on you though...

From an aircraft designer's perspective, or Bearhawk Aircraft's perspective, this kind of modification would be 100% risk and 0% reward. It's not going to sell planes and it's fraught. It someone gets it wrong and crashes or worse, then they stand to suffer major brand / reputational damage. It's not surprising nobody is lining up to advise or on effectively endorse / approve such a mod.

Personally, I wouldn't be doing that kind of thing with the bikes, there are so many aggravating factors and unclear risks. I would hate to be flying in moderate to severe turbulence and seeing those things waggling on my wings. Thinking about how well they are strapped on and who they might fall on, or whether I am going down with them...

I would rather work on attaching a pod or something that increases utility in a more conventional way, and can carry all kinds of cargo. But that said, the internal cargo area is big enough on 999 flights out of the last 1,000. If you need more, get a Model 5.

[Mark Goldberg]

There is a Patrol being finished up with a nicely designed cargo pod. This plane is being built by an aeronautical engineer who spent most of his career at Boeing. Very capable guy. I bet his cargo pod will be nice., Mark

[Gerhard Rieger]

Love to see that, always a lot to learn

[svyolo]

I can think of a couple of real good reasons not to hang bikes off the wings. One is wing flutter, and the other is external load "flutter". Either could be catastrophic. Hanging external loads is something that is very thoroughly tested, on things that hang external loads. The tests are often not successful.

[alaskabearhawk]

Some options for tires

Cub.jpg