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aerocet amphibs

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vetdrem

Joined: 20 Nov 2007
Posts: 62

Posted: Fri Sep 19, 2008 5:30 am Post subject: aerocet amphibs

I finally got the installation of the aerocet 1100 amphibs on my model 3 completed and took my first lesson.



Things didn't go as well as they should have.  after landing on the water, with the engine at idle, the plane moved slowly forward as expected, but the nose of the floats were submerged.  That was a big concern for the instructor, since this was his first time in a kitfox on floats.  We taxied around for a few minutes and then did a takeoff.  the nose comes out of the water when power is applied and the takeoff worked OK.  



We landed again and shutdown the engine, and the plane settled on the water in a nice level attitude.  the amount of freeboard on the floats was constant for the entire length, then after starting the engine again, the nose was again submerged.



Sitting on the ramp at the airport, the angle of attack of the plane is very low, to the point that I was concerned that it wouldn't get off the runway, but it did get off OK.  But everyone that looks at it sitting on pavement says it looks like the nose is too low.



The question to those of you that have or have had aerocets on a kitfox, does this sound normal, or does it sound like the forward float struts are too short, causing the angle between floats and plane to be too small.



Thanks for any info.

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Fri Sep 19, 2008 7:53 am Post subject: aerocet amphibs

Do you have the angle of incidence between the plane and the top of the

float?



Noel



--

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

vetdrem

Joined: 20 Nov 2007
Posts: 62

Posted: Fri Sep 19, 2008 2:18 pm Post subject: Re: aerocet amphibs

That is exactly where I think my problem is, but I don't know how to check it.  



I talked to the guy that I bought the floats from, and he said that he didn't have that problem when they were on his plane, so I don't know where to go from here.



The rigging came with the floats and were designed for the kitfox, and the previous owner said that he didn't modify them.  I think that I am going to add a 1" alum. block under the front float struts to increase the angle a few degrees, and hope for the best.  I thought about replacing those struts, but that would require replacing the cross bracing, also, so I think that just lifting the struts will do the same thing with out going through a bunch of trouble.  It is also easy to put it back if it doesn't work.



If you have any info on the angle of incidence, I sure would like to see it.



Thanks, Louie

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Fri Sep 19, 2008 2:47 pm Post subject: aerocet amphibs

I'm not sure of this but I think the Kitfox levels by a straightedge under the second or third rib from the fuse.  It may also be levelled by the bottom of the plane just aft of the firewall.  I also think 3 deg of incidence from the top of the floats is considered optimal.  Dave Fisher would know for sure.  

   

[img]cid:image003.jpg(at)01C91A94.A8DB0DE0[/img]  

   

Noel Loveys  

Campbellton, NL, Canada  

CDN AME intern, PP-Rec  

C-FINB, Kitfox III-A  

Aerocet 1100 floats  

[url=noelloveys(at)yahoo.ca]noelloveys(at)yahoo.ca[/url]  

   

   

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_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

paul(at)eucleides.com
Guest

Posted: Fri Sep 19, 2008 6:45 pm Post subject: aerocet amphibs

On Fri, September 19, 2008 6:30 am, vetdrem wrote:

 	  Quote: 	
		   


	


 	  Quote: 	
		   We landed again and shutdown the engine, and the plane settled on the water in a nice

 level attitude.  the amount of freeboard on the floats was constant for the entire

 length, then after starting the engine again, the nose was again submerged.


	


That implies that the static balance is good. What you're saying is idle thrust is

dipping the nose. Where was the stick and elevator? I believe it should be only

slightly back from normal cruise position to keep it level in the water. At engine

idle can you pull the stick back enough to keep the floats level?



 	  Quote: 	
		   Sitting on the ramp at the airport, the angle of attack of the plane is very low, to

 the point that I was concerned that it wouldn't get off the runway, but it did get off

 OK.  But everyone that looks at it sitting on pavement says it looks like the nose is

 too low.


	


If the angle between the level flight line on the fuselage and the waterline of the

floats is too small then you plow too much water because you have to have the stick

too far back. If it is too large you introduce a lot of extra air drag in flight frpm

the floats.



 	  Quote: 	
		   The question to those of you that have or have had aerocets on a kitfox, does this

 sound normal, or does it sound like the forward float struts are too short, causing

 the angle between floats and plane to be too small.


	


If you block it up a little and that makes it take less back stick pressure to keep

the floats out, then determine if your speed (drag) is affected in flight.



 	  Quote: 	
		  

 Thanks for any info.





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 5051#205051






	




-- 

Paul A. Franz, P.E.

PAF Consulting Engineers

Office 425.440.9505

Cell 425.241.1618

vetdrem

Joined: 20 Nov 2007
Posts: 62

Posted: Sat Sep 20, 2008 4:16 am Post subject: Re: aerocet amphibs

I'm holding the stick full aft the whole time, but it still isn't enough to keep the float tips from submerging.



I agree that the static balance is close, so I think that the next move is to try to increase the angle of incidence.  



Thanks for the response.



Louie

paul(at)eucleides.com
Guest

Posted: Sat Sep 20, 2008 9:05 am Post subject: aerocet amphibs

On Sat, September 20, 2008 5:16 am, vetdrem wrote:

 	  Quote: 	
		   



 I'm holding the stick full aft the whole time, but it still isn't enough to keep the

 float tips from submerging.



 I agree that the static balance is close, so I think that the next move is to try to

 increase the angle of incidence.



 Thanks for the response.



 Louie


	


I'm not sure what is correct but I'd have reservations about increasing the the angle

between the float water line and the apparent attitude since this might have a big

effect on drag in flight. I think I'd move the plane c.g. back on the floats a little

first. You certainly don't want those floats to dig in on landing, you'd risk flipping

on your back. Normally while taxiing on the water, you should need only a slight back

pressure on the stick. Increasing the attitude of the plane on floats will effect the

take-off run length too. I know you need to consider the weight and balance between

allowable limits too. My guess is that with the plane loaded to gross weight right in

the middle of the cg limits, the front of the floats should be a little higher.

Definitely should not be submerged when taxiing.



If it were me, I'd try to get hold of Al Pike who is currently an instructor at



Merritt Island Air Service

900 Airport Rd

Merritt Island, FL 32952

(321) 453-2222



 or Ron Lueck, owner of CompAir (321) 452-7168, (321) 453-6641



CompAir is a successful business that started by building floats and float kits.



Al Pike has built quite a number of float kits and really has experience flying them.

If at all possible, he'd be the one to talk to. Might be tough to get hold of either

because they are so busy. But asking for setup advice for balance and attitude might

be a quick answer.



You can get a pretty good idea of how this works and setup instructions here.



<http://www.seminolerc.com/float_flying_basics.html>



Keep in mind when reading dimensions, in some cases they are for model airplanes.

(i.e. wing chord of 12 inches).



-- 

Paul A. Franz, P.E.

PAF Consulting Engineers

Office 425.440.9505

Cell 425.241.1618

paul(at)eucleides.com
Guest

Posted: Sat Sep 20, 2008 9:36 am Post subject: aerocet amphibs

On Fri, September 19, 2008 3:18 pm, vetdrem wrote:

 	  Quote: 	
		   



 That is exactly where I think my problem is, but I don't know how to check it.



 I talked to the guy that I bought the floats from, and he said that he didn't have

 that problem when they were on his plane, so I don't know where to go from here.



 The rigging came with the floats and were designed for the kitfox, and the previous

 owner said that he didn't modify them.  I think that I am going to add a 1" alum.

 block under the front float struts to increase the angle a few degrees, and hope for

 the best.  I thought about replacing those struts, but that would require replacing

 the cross bracing, also, so I think that just lifting the struts will do the same

 thing with out going through a bunch of trouble.  It is also easy to put it back if it

 doesn't work.



 If you have any info on the angle of incidence, I sure would like to see it.


	


Louie,



The starting configuration is to have the balance point at the step and the top of the

floats parallel with the plane of the stabilizer. As I quoted in a previous post,

here's how it works and how to proceed with fine tuning.



<http://www.seminolerc.com/float_flying_basics.html>



I'm very interested in your trials. I am going to be going through this myself.



-- 

Paul A. Franz, P.E.

PAF Consulting Engineers

Office 425.440.9505

Cell 425.241.1618

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Sat Sep 20, 2008 2:18 pm Post subject: aerocet amphibs

Before messing with the float struts why not try putting a bit of weight in

the tail of the floats for taxi testing.  If it is inside the balance

envelope you may even want to try a couple of circuits.  The3 only time I've

seen a plane float level was when it was totally empty...  most of the time

they float slightly nose high or tail low.  I flew with my father for close

to ten years and to be honest never once did I see the tails of the floats

above the water while taxiing...Then again our "normal" takeoff weight was

close to 100 lb. over weight   (C - 170B )  The only time we approached

MTOW was when we were just about out of gas.



I worked on a Champ once that would do nothing but plough water until a ten

lb. canvas bag was put in the aft cargo bin.  Getting on step was near

impossible with the pilot alone but it could easily handle up to the listed

gross once a bit of weight was put in the back.  Ten lb. of clothing or

fishing gear in the back and she flew like a homesick angel.



Noel



--

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

vetdrem

Joined: 20 Nov 2007
Posts: 62

Posted: Tue Sep 23, 2008 4:42 am Post subject: Re: aerocet amphibs

I give up,I quit, UNCLE, enough.



I added the length to the front struts, and took it out to the lake for a test.  It is a lot better, but I think that it could also use a few pounds in the tail to raise the tips of the floats a little higher.



It was good enough that we did an hour or so of take-offs and landings with no problems.



THEN IT WAS TIME TO HEAD BACK TO THE AIRPORT.



As I touched down on the runway, the thing started to veer off to the left and I couldn't do anything about it.  The plane slide on the grass and finally stopped in some bushes.



We used a tractor to get it back to the hanger, and found that the left main gear mechanism had popped out of the bearing mounted on the wheel well wall (I know, I didn't think that it could happen either) and the left float came into contact with the grass, causing drag.



There is very little damage, nothing that can't be straightened with a small hammer, but I'm pretty fed up with this amphib thing.



I seriously considering removing the amphib mechanism, glassing up the wheel well holes, and turning them into straight floats.



Any comments?

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akflyer

Joined: 07 May 2007
Posts: 574
Location: Soldotna AK

Posted: Tue Sep 23, 2008 9:05 am Post subject: Re: aerocet amphibs

as with anything, when you start getting more complex you have more things that can go wrong.  I would say dont give up so easy.   I have been doinking with the floats for 2 yrs on my brothers plane trying to find the "perfect" setting, not just one that works ok.  



Hang in there, and really give the rigging and all mechanical parts a good going over to make sure every part of the system is within tolerance.

_________________
DO NOT ARCHIVE
Leonard Perry aka SNAKE
Soldotna AK
Avid "C" / Mk IV
582 (147 hrs and counting on the rebuild)
IVO IFA
Full Lotus 1450
#1 snake oil salesman since 1-22-2009

I would rather die trying to live, than to live trying not to die....

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Tue Sep 23, 2008 10:19 am Post subject: aerocet amphibs

Comment... Sure, no sweat!



You're almost there, why quit now.  The main axels and actuators are

something that you have to keep up on...  See if there is a way you can

reinforce the bearing cap  so it can't slip out again. 



Be careful how much weight you put in the tail...  it shouldn't take much.  



On the outside chance you do remove the landing gear, try to make it

reversible and you might find you won't need the aft ballast. 



Noel



--

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

dholly

Joined: 19 Dec 2006
Posts: 40
Location: Upstate NY

Posted: Tue Sep 23, 2008 4:47 pm Post subject: Re: aerocet amphibs

 	  vetdrem wrote: 	
		  We used a tractor to get it back to the hanger, and found that the left main gear mechanism had popped out of the bearing mounted on the wheel well wall (I know, I didn't think that it could happen either)... 	
 Louie - Do you feel this particular failure is a result of a rough turf strip landing or an unrelated mechanical failure? Referencing part #'s from the "1100 Series Floats Group Assembly Part Numbers #1102 Amphibious Floats" .pdf document, exactly which parts failed? I'd like to check mine for unusual signs.. Oh, and I would also be curious what S/N's your floats are? Keep the faith, Doug

_________________
-Kitfox III 582 Blue/C Grove Spring / Aerocet 1100 Amphibs
-Airdale Avid+ (project) TD / W.I.B. Gear

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