Help with floats please.
02-28-2009 | 07:46 PM
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From: Oklahoma City,
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Help with floats please.
I just got my floats put on the plane, and when I sit it down it rests on the back of the floats. I got the step about a 1/2 inch forward of the cg. Will this be ok, or do I need to relocate the floats? They're on my trainer, a Skyraider mach 1. Thanks!
02-28-2009 | 08:59 PM
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From: Chester,
NS, CANADA
RE: Help with floats please.
brett65
From everything I have read or been told, the step should be on the CG or only as much as 1/2 inch aft of the CG. This rule has always worked for me, but you never know, your setup might work fine. Just my 2 cents.
Lm
From everything I have read or been told, the step should be on the CG or only as much as 1/2 inch aft of the CG. This rule has always worked for me, but you never know, your setup might work fine. Just my 2 cents.
Lm
02-28-2009 | 11:27 PM
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RE: Help with floats please.
Brett,
Lordmerhen is right, I would move the step back to between the CG and 1/2" behind. The reason for this is that when you get up in on the step, you want the incidence to match the bottom of the float in front of it, not a line between the two heights. Check out the Seaplane forum and they have a few threads on this one.
Good Luck and I hope it is not too much of a problem.
Curtis
P.S. Did you check incidence from wing chord and the top of the floats?
Lordmerhen is right, I would move the step back to between the CG and 1/2" behind. The reason for this is that when you get up in on the step, you want the incidence to match the bottom of the float in front of it, not a line between the two heights. Check out the Seaplane forum and they have a few threads on this one.
Good Luck and I hope it is not too much of a problem.
Curtis
P.S. Did you check incidence from wing chord and the top of the floats?
03-01-2009 | 12:37 AM
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From: Oklahoma City,
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RE: Help with floats please.
I measured it, and I have between 1/2 and 3/4 inch incidence in it. I did relocate them too, and found the faq post in the seaplanes forum before I did. I added a piece to the front mount to give me the correct incidence. I think it is about right now.
03-01-2009 | 12:45 AM
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RE: Help with floats please.
[quote]ORIGINAL: brett65
I got the step about a 1/2 inch forward of the cg. Will this be ok, or do I need to relocate the floats?
[quote]
No this will present extremely unstable directional control during takeoff and likely not to get airborn before water loop and digging a float.
locating a step forward of the flight CG is just like locating taildragger main get to far forward
Always locate the CG at the same point at which it flys the best on wheels. To do this ballast the floats not the airplane (most often a couple of ounces in the nose of the floats) do not change anything in the airplane or weights. Doing this will allow very quick changes between floats and wheels with no rebalancing required.
On the important CG\step relationship with a typical 40\60 size float plane locate the step either at the CG or no more than a quarter inch aft of the CG. The step should never be placed in front of the CG This will always cause directional instability on the water. With the step aft of the CG it will be stabile in the same manner as tricyle gear is.
The next important item is the wing/float decaledge. Typically the wing should be around two degrees positive to the top decks of the floats. This will appear to be just slightly tail low when the floats are propped up with the top decks level. This is important if the airplane is level or worse tail high when the float decks are level then before the airplane can acheve a sufficient angle of attack for takeoff the heels (stern) of the floats will dig into the water and you will not get off the water, it just like slamming on the brakes.
John
I got the step about a 1/2 inch forward of the cg. Will this be ok, or do I need to relocate the floats?
[quote]
No this will present extremely unstable directional control during takeoff and likely not to get airborn before water loop and digging a float.
locating a step forward of the flight CG is just like locating taildragger main get to far forward
Always locate the CG at the same point at which it flys the best on wheels. To do this ballast the floats not the airplane (most often a couple of ounces in the nose of the floats) do not change anything in the airplane or weights. Doing this will allow very quick changes between floats and wheels with no rebalancing required.
On the important CG\step relationship with a typical 40\60 size float plane locate the step either at the CG or no more than a quarter inch aft of the CG. The step should never be placed in front of the CG This will always cause directional instability on the water. With the step aft of the CG it will be stabile in the same manner as tricyle gear is.
The next important item is the wing/float decaledge. Typically the wing should be around two degrees positive to the top decks of the floats. This will appear to be just slightly tail low when the floats are propped up with the top decks level. This is important if the airplane is level or worse tail high when the float decks are level then before the airplane can acheve a sufficient angle of attack for takeoff the heels (stern) of the floats will dig into the water and you will not get off the water, it just like slamming on the brakes.
John
