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Flaps and Ailerons

PostPosted: Sat Dec 01, 2007 5:31 pm
by Uwe Jens
I have a question for you, maybe a little crazy... I am starting on building the ailerons and flaps, I can see they have the same construction, the only difference are about 4" in the length.  According to the building manual the ailerons are larger.   My runway is at 9000 ft above sea level, this is the reason I need more sustenance.  The question is, could I exchange the ailerons for the flaps?  Maybe doing this will help me on my takeoffs and landings.  What do you think?


PostPosted: Sat Dec 01, 2007 11:20 pm
by Gary H
I would say follow the instructions!!  :)


PostPosted: Sun Dec 02, 2007 12:20 am
by scubarider
  Not sure you can do that due to the position of the connection tabs to trailing edge.  They have to fit a certain way.  Anyway the only authority that you would gain by adding length to the ailerons is more roll.  This would not matter for take-offs.  The size of your elevators would give you better.  Did you get the larger tail?

PostPosted: Sun Dec 02, 2007 11:14 am
by Uwe Jens
Hi guys,
In the building manual says the measurements are:  72 1/2 for the ailerons and 68 7/8 for the flaps, I think this is for the Escapade since the real meausurements I have are 82 for the ailerons and 78 for the flaps. ( I pressume this is for the Highlander).
The supports to the trailing edge do not have any problem with the exchange.  Since it has a bigger flap it will improve the stoll speed, that at my operating altitude is critic.  Maybe if I have a smaller aileron I will loose roll reaction but it is not as important as reduce the landing speed, I am trying to optimize my aircraft for this type of operation, I am also placing the Vortex Generators, I am using them on my actual aircraft and really work great!  They reduced the stoll speed in aprox  7 miles.
Please give me your opinions,

PostPosted: Mon Dec 03, 2007 2:49 am
by Dave Krall CFII SEL SES
A turbo/intercooler on the engine would do you more good at typical equatorial DA @ 9000 MSL.
Any PIX of your airport?


PostPosted: Wed Dec 05, 2007 11:33 am
by billy5823
have you had a chance to fly a highlander? my opinion is that you want have any performance problems. I have flew with gary of just several times and we usually grab a notch of flaps for the heck of it but have never needed to. I understand i am at 3000 and that does make a big difference.but i still think you will be fine.are you using the jabaru or rotax ? the rotax slings alot bigger prop even though the hp numbers are lower, so there for getting a lot better climb performance. so thats my 2 cents thanks billy

PostPosted: Wed Dec 05, 2007 1:06 pm
by Uwe Jens
Hi guys,
I will use the Rotax 912 S (100 HP) with a 72" three blade prop.  When I am referring on using more flaps surface is because I need to reduce the stoll speed.  To just mention an example,  at this altitude (9000 ft) the ground speed aproach increases about 30%, the aproaching spped to the ground is very fast,  even though the air speed is the same than the aproaching speed at sea level than at this altitude.
This is the reason why I need to reduce the stoll speed with any trick ( vortex generators, bigger flaps, light weight, etc).  My problem is not based on take-off for which I will need more power and will be solved the problem.  My problem is in the landing.  The runways that I will be using are very short in distance ( 1200 ft or less).  The type of operation I use is very similar to the one the Bush Planes in Alaska use.  Can anyone tell me how sensitive is the roll?  (Aileron function in a Highlander).  I don´t have a chance of flying a Highlander yet.  The one I bought is the first one in Ecuador.
I decided to buy this kit after doing a lot of research on kits that have the Highlander´s performance.
I am open to suggestions.


PostPosted: Wed Dec 05, 2007 3:57 pm
by Roger
I would think that would be a good exchange. As you observed, if you just change the position of the hinge pivot on the ailerons and flaps, and perhaps the position of the attach point of the pulleys, I'd see no problem and of course the longer flaps would be very useful in landing distance. (Why didn't I think of that?) I also fly out of a relative high runway (6500 ft.) and I know I'd rather have a larger flap and slightly less roll authorithy for shorter landing distances. If I were you, I'd call Troy at Just though and ask him what he thinks as he's the one that engineered the Highlander and is very astute when it comes to changing things.


PostPosted: Wed Dec 05, 2007 7:44 pm
by billy5823
what do you think of extending the width of the flaps verses lenght . just a thought . the roll rate is just a little more than a cub or taylorcraft.  thanks billy