Bike Rack

[TangoAlphaWhiskey]

Hello Kitfoxers..
I am currently in the process of selling my Cessna 177RG with plans of building a bush plane. As an avid mountain biker, one of the things that I will miss about the Cardinal is the ability to remove the rear seat and load two full-sized bikes. While the Kit Fox is currently at the top of my list for a potential build, I am not quite ready to give up the ability to take along a bike or two. I have seen a couple of under-wing bike mounts (like the one below on a Murphy Radical) and wondered if anyone had explored this with a Kit Fox? I am considering building the STI version with the 914 turbo, so it seems like the added drag would be manageable...
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[Esser]

Hello Kitfoxers..
I am currently in the process of selling my Cessna 177RG with plans of building a bush plane. As an avid mountain biker, one of the things that I will miss about the Cardinal is the ability to remove the rear seat and load two full-sized bikes. While the Kit Fox is currently at the top of my list for a potential build, I am not quite ready to give up the ability to take along a bike or two. I have seen a couple of under-wing bike mounts (like the one below on a Murphy Radical) and wondered if anyone had explored this with a Kit Fox? I am considering building the STI version with the 914 turbo, so it seems like the added drag would be manageable...
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It’s been brought up a few times but no one that I know of has taken the plunge yet. You can find more if you use the search function but bottom line, it should be very doable.

[HighWing]

I too think it's doable. When we used to fly the Idaho Back Country, one of the guys would strap a camp chair in the V at the jury strut / lift strut junction using bungee cords. Definitely not a bicycle, but the idea.... When I was planning on my camera mount on the lift strut, I decided to put in hard points that I could use after the inspection - didn't want to trigger questions from the DAR with the camera already mounted. The first picture is of the hard points after lift strut fairings and paint, but the hard points were fabricated before covering using a section of tubing with smaller tubing welded parallel to each other and at right angles to the larger tubing. The part was then cut so that the large tube could fit over the lift strut. The smaller tubing was threaded on the top half and reamed to accept socked head bolts. One of the cross tubes was cut short so when installed before the fairing it would not interfere with the fairing. The other was longer so it did protrude through the fairing as the hard point.

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The second picture shows the camera mount framing bolted to the lift strut.

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I don't think I would recommend something as heavy or with as much drag as a bicycle being mounted mid span of the lift strut, but hard points mounted to the lift strut attach brackets might work. This would have to be done before wing rigging to avoid welding heat to the spar. I think what I would do is weld Nuts inside and concentric to appropriate sized - fairly heavy walled tubing and then strategically welding the tubing to the lift strut brackets - One (or two, see below) - on each bracket with gussets between the tubing and the external parallel gussets that the lift strut is attached to. Probably some sort of support should then be made to reduce the side to side - flexing - forces on the bolts, maybe two of the tube/nut combinations welded as far apart as possible.

Not an engineer here - Just some thoughts.

[David47]

Just following on from Lowell's comments, I'm putting mounting points on my plane for external cameras, but I'm including them (with cameras attached) in my flight test program so that I can demonstrate safe handling etc with and without. I want to be able to use them without getting awkward questions from Australian regulatory surveryors if they do a ramp check, and also for insurance purposes. The same thing would apply for slinging bikes or anything else off the wing struts or anywhere else for that matter. External attachments can cause handling problems, depending on their form factor, and where and how they're attached. Recommend that you do some homework and understand what the risks and potential safety implications may be before you proceed. Consider also the insurance implications if it was to go south for any reason. It may be worth talking to your DAR to see what additional testing would be required. Just an opinion

[av8rps]

If a person was to carry external baggage such as a bike I think it should be attached in a sort of streamlined pod so as not to create so much drag.

In addition to my Kitfox I also have a Lake amphibian, and it has pretty large wing floats that we have tested flying with and without the floats attached and found the drag is so minimal that it is hardly noticed. So maybe one could make a pod that could hold a bike and get the same effect. I would think a bike with spoke wheels and round tubing would be huge drag without some sort of additional streamlining.

The biggest factor to me with doing something like this is that you have to be careful about putting weight far out on the strut where the wing flexes the most. I think if you could possibly get the load to fit inboard of the jury struts it would be better as that part of the wing and strut is quite sturdy with minimal (or no) flexing. Maybe a folding bike in a smaller pod?

Just my two cents worth... free internet advice ;)

[Esser]

There are also lots of hard points already on the bottom of the fuselage.

[avidflyer]

A guy from Washington flew his tri gear Avid MK IV a lot with a kayak strapped to the bottom of his plane. If you don't know, the Avid MK IV is comparable to the Kitfox 3 in many respects. If it can be done with a kayak, a bike should be possible. JImChuk

[HighWing]

Just following on from Lowell's comments, I'm putting mounting points on my plane for external cameras, but I'm including them (with cameras attached) in my flight test program so that I can demonstrate safe handling etc with and without. I want to be able to use them without getting awkward questions from Australian regulatory surveryors if they do a ramp check, and also for insurance purposes. The same thing would apply for slinging bikes or anything else off the wing struts or anywhere else for that matter. External attachments can cause handling problems, depending on their form factor, and where and how they're attached. Recommend that you do some homework and understand what the risks and potential safety implications may be before you proceed. Consider also the insurance implications if it was to go south for any reason. It may be worth talking to your DAR to see what additional testing would be required. Just an opinion

David,
Your thoughts are appreciated and a fresh approach to what had driven me originally. My concern seemed to be always focused on the prohibition mentioned in our FARs regarding experimentals being used for compensation or hire. I always intended my camera to be for personal use only. Modifications after the initial airworthiness inspection are pretty much dictated by whether they are major or minor. Major requiring an additional 5 hours of test flights.

My first camera mount on the 1998 Model IV began as this:

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And ended up as this"

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Regarding insurance, sadly this became a reality when I initiated an emergency landing after an oil pressure issue that destroyed the airplane. No problem regarding insurance - full hull coverage. During a subsequent interview with the FAA investigator he mentioned the camera in passing, but declined to address any questions about it because he said he had, "too much on his plate right now". This was due to him also investigating the fatal takeoff accident from the same airport we had left that morning. My thinking was that he was concerned about the possible commercial use of the video camera - it was not in record mode during our emergency. The camera set-up in all iterations had a total of over 400 hours of flight time

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Current Mount


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[David47]

Sounds like you've been through the meat grinder with this in the past Lowell. It must have been heartbreaking to lose that first aircraft. I don't know that I'd have the ticker to start over again ... So my input comes from many years as a consulting engineer working in GA where every time we hung something off an airplane, I had to write a test schedule and go fly the thing. Our Regulator in Aus was very strict about it and beat up those that tried to hang external stuff without "proper paperwork". It was surprising to me how some of the most innocuous additions caused some kind of issue, whether it was separated flow giving unwelcome buffet or panel drumming somewhere or excessive trim corrections etc. There was nothing that I would consider a risk to flight safety in any of these tests, just more of an annoyance. But you're right about the "minor vs major" question. In the past, I've had to jump through all sorts of hoops to try and justify the lesser of the two. So I thought instead of stuffing around arguing the point with some Regulatory type about external additions to my plane, I'd simply include tests with and without, including various combinations in between. This way, problem goes away. Must admit though, I've never thought about filming from any of these aircraft being considered commercial until you mentioned it. I know if that were the case it would become a bucket of grubs. Maybe I'll have to sign some form of waiver to satisfy the doubters !. And finally .... those fairings on your camera equipment are really neat. I'm guessing you have more than a little experience with composites.

[HighWing]

It took me a couple of years until the build again bug hit me - then finding another IV to build was a challenge until I mentioned to a friend about a planned drive to Indiana to pick up a V. He led me to a IV a couple of hours away and the deed was done. I started playing with fiberglass in the early 80s and graduate school began in the early 2000s when a neighbor asked me to help him finish a Lancair IV. After 20 hours a week for a year and a half, I was really hooked.

[Rooster]

I Also love Mountain biking, and while there's no problem putting one in the plane (The wheels get cable tied to the roof inside the cabin), there is a problem to get my wife's bike in there as well.
When I brought it up with the factory of the Bushbaby / Kitplanes for Africa Safari, Stefan Coetzee said that he would be concerned with flexing forces as the speed built up, risking the wing developing washout or increased angle of attack or flutter?
I realize that Kitfox fuselage strength is very high compared to other makes, but are my thinkings valid?

http://saplanes.co.za/

Looking forward to a solution being found.
Reid

[ken nougaret]

As Paul mentioned, keeping the weight inboard.

[Ale]

I flew the Murphy Radical in Chilliwack, with a mountain bike under each wing, the plane handled great, I felt no effect on rudder, elevator o aleiron, the test pilot in the plane with me told me they stole about 10 mph.
I would love to add those to a Kitfox 5, but I am concerned about strength and location. If the racks are installed outside the struts, as in the Radical or the 185 operating in NZ, would that put excessive stress on the bolt of the front spar? The two planes I mentioned don't have folding wings, so in theory they are stronger there. If I install the racks slanted inside the jury struts, that would significantly reduce the stress/moment/torque on the holes through which the bolt that holds the front spar goes through, but the turbulence created by the bicycles would be a lot closer the the tail surfaces, possibly affecting handling.
One bicycle can probably be attached under the fuselage with no issues, but it might affect the airflow on the tail surfaces slightly. I think two bikes under the fuselage is not possisble.
I'm willing to hear the thoughts of the more experienced Kitfoxers. Thank you.

[txsailor]

Looks like nobodoy has opinions to my concerns and doubts...