Does anyone have experience with the Aluminum Landing Gear legs? Do they change the landing characteristics of the plane? Have a '77 GCBC with the steel spring type gear and eventually will be putting on some larger wheels for off airport work. As the wheel package will weigh a few pounds more, looking to save some of the weight back with the aluminum gear.
Aluminum gear
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Bob Turner
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I have them on my Decathlon. Change was trivial, except for the fabric attach loop. I did a minor alteration and bolted my new fabric attach in - did not want to get a torch in there.
If you don't buy the entire kit, look for less expensive bolts. When I did mine, ACA wanted $130 each for the bolts. I got them from Genuine for $28 each. There are six of them.
Lands fine. Slightly more rigid during taxi. Look way better without those ugly brake line fairings.
If you don't buy the entire kit, look for less expensive bolts. When I did mine, ACA wanted $130 each for the bolts. I got them from Genuine for $28 each. There are six of them.
Lands fine. Slightly more rigid during taxi. Look way better without those ugly brake line fairings.
Is there any limit on which airframes the aluminum legs can be put on?
Bob Turner
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No, because they are on the type certificate. It would be very expensive to retrofit to an oleo-type Champ. Cheaper to buy a new fuselage probably.
Bob, what did the gear legs cost you?
Bob Turner
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Gear legs are very expensive. I do not recall; it has been four or five years. I love them.
I saw a figure quoted for $6500, but that was from 2013. That is a lot of money. I could get the fuselage recovered for not much more than that. OTOH presumably the gear upgrade would increase the value of my plane, especially if I later got the wings for the gross increase.
If my current legs are damaged, the alternative would be a replacement spring steel set from Rainbow. Those are $800 on exchange, with an $800 core charge. I suppose the question would be what kind of labor cost am I in for.
I started paying attention to stories about Citabria spring steel gear legs bending. Turns out it happens a LOT. I found 6 or 8 instances on the internet with a cursory search.
If my current legs are damaged, the alternative would be a replacement spring steel set from Rainbow. Those are $800 on exchange, with an $800 core charge. I suppose the question would be what kind of labor cost am I in for.
I started paying attention to stories about Citabria spring steel gear legs bending. Turns out it happens a LOT. I found 6 or 8 instances on the internet with a cursory search.
Bob Turner
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The steel gear legs are apparently straightened cold. I would have none of that - steel has a fatigue life. The aluminum legs are formed soft, then heat treated for temper. I don't know what their lifetime is (I could find out) but it is way longer than mine.
I suggested an airfoil shape, but I assume there are cost and engineering considerations that argue against it.
I suggested an airfoil shape, but I assume there are cost and engineering considerations that argue against it.
Service manual says steel legs are heat tempered. Rainbow Ron supposedly anneals, reshapes to specs, then tempers again. If properly annealed, there would be no negative impact on service life.
I would prefer aluminum because of weight savings and corrosion resistance, but ouch on cost.
Speaking of cost, I priced a new Cleveland wheel today.
I would prefer aluminum because of weight savings and corrosion resistance, but ouch on cost.
Speaking of cost, I priced a new Cleveland wheel today.
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Bob Turner
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Check out Grove for wheels.
Good on Ron - heat treating makes them good as new.
Good on Ron - heat treating makes them good as new.
Do the aluminum gear legs increase gross weight by any chance?
Bob Turner
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They increase useful load by, I think, 14 lbs.
New ACA Super D gross is 1950, acro gross is 1800. Bellanca 8kcab gross is 1800. the metal wings increaese the allowable max gross in the utility category by 100 lbs, do the aluminum gear make up the additional 50? they take 14 lbs off the empty weight, got that part.
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do they put the plane at the same height as the steel legs?
aftCG
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Don't forget that your wallet is also lighter.
Factory metal wings and aluminum gear TOGETHER increases max gross by 150. Either component alone does nothing, legally. Prior to the aluminum gear in 2004, there was a period where the max gross increase could be obtained with metal wing, extended spring steel gear, and upgraded bolts.
ACA webpage lists nominal empty weight for current 8KCAB as 1304 lb. My 1978 model has nominal empty weight of 1330 lb. The max gross increase plus weight decrease would result in a useful load increase of 175lb, enough to legally take off with 2 grown men and full fuel.
From what I have read, the max gross is determined at least partially by a drop test. The aircraft is loaded and dropped from a height of 4 feet to see how much weight would cause a prop strike. Since ACA only supports metal wing aircraft, they have never done the drop test for wood spar aircraft. If they did, they would likely get the same improvement. The fact that aerobatic max gross is unchanged suggests that the wing is not the limiting factor.
I believe, but do not know, that the aluminum gear are longer, stronger, stiffer, and lighter. The aluminum (or extended steel) gear also permits a 2" longer prop, such as the Extreme Decathlon uses.
ACA webpage lists nominal empty weight for current 8KCAB as 1304 lb. My 1978 model has nominal empty weight of 1330 lb. The max gross increase plus weight decrease would result in a useful load increase of 175lb, enough to legally take off with 2 grown men and full fuel.
From what I have read, the max gross is determined at least partially by a drop test. The aircraft is loaded and dropped from a height of 4 feet to see how much weight would cause a prop strike. Since ACA only supports metal wing aircraft, they have never done the drop test for wood spar aircraft. If they did, they would likely get the same improvement. The fact that aerobatic max gross is unchanged suggests that the wing is not the limiting factor.
I believe, but do not know, that the aluminum gear are longer, stronger, stiffer, and lighter. The aluminum (or extended steel) gear also permits a 2" longer prop, such as the Extreme Decathlon uses.
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Bob Turner
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Then including the metal spar wings was just to sell wings?
The aluminum legs do not allow the aircraft to "rock around" during taxi, but I cannot find any real difference in landing. I haven't done any off-airport landings since I put them on, though.
The aluminum legs do not allow the aircraft to "rock around" during taxi, but I cannot find any real difference in landing. I haven't done any off-airport landings since I put them on, though.
Yeah, that's the thing, isn't it?
I am at least going to consider the aluminum gear if I have to replace the leg. The camber on my other wheel suggests the spring is nearly sprung. From an investment standpoint, upgrading to aluminum legs opens up a path to get full value from a later upgrade to metal wings and factory restored fuselage.