Should GP Viper have 2 Degrees positve incedence on tail ?
07-01-2010, 10:09 PM
#1
Should GP Viper have 2 Degrees positve incedence on tail ?
I have a new Great Planes Viper. The tail has 2 degree positive incendense to the wing. Is that normal? Also has the new kits been updated and do not need all the modifications that are posted? Thanks Dan
07-08-2010, 12:02 PM
#4
RE: Should GP Viper have 2 Degrees positve incedence on tail ?
Ed thank you for that information. Do you know if the New Great Planes viper needs the modifications that have been posted in the distant past.
I plan on using plastic bolts to mount the wing. The question is should I strengthen the tail section? Thanks again. Dan
I plan on using plastic bolts to mount the wing. The question is should I strengthen the tail section? Thanks again. Dan
07-08-2010, 02:30 PM
#5
Join Date: Dec 2001
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RE: Should GP Viper have 2 Degrees positve incedence on tail ?
Hi!
I have built two Vipers!
The first one 4-5 years ago and the second 3 years ago. The first one powered by a Webra GT .40 required only slight up trim on the elevator (1-2,5mm). The second one powered by a LS Nelson required 3-4mm up trim.
I nearly lost the second Viper due to a tail braking just in front of the V-stab ( You can see the crack in the fuselage in one of the pictures below ) I was very lucky as I had flown the plane twice and was about to fly a third time when it suddenly began to rain...and when the rain shover had stopped I decided to wipe the plane clean for third flight. Then I noticed the crack in the fuselage...
So I decided to strengthen the area inside the fuselage with a layer of 3mm balsa and 25g glassfiber/epoxy on the out side, and at the same time lower the V-stab up front 3mm to get ride of the undesirable elevator up trim.
Luckily for me the plane flew with no up trim at all after the fix.
So I expect all Vipers have a slight up trim problem as standard.
I have built two Vipers!
The first one 4-5 years ago and the second 3 years ago. The first one powered by a Webra GT .40 required only slight up trim on the elevator (1-2,5mm). The second one powered by a LS Nelson required 3-4mm up trim.
I nearly lost the second Viper due to a tail braking just in front of the V-stab ( You can see the crack in the fuselage in one of the pictures below ) I was very lucky as I had flown the plane twice and was about to fly a third time when it suddenly began to rain...and when the rain shover had stopped I decided to wipe the plane clean for third flight. Then I noticed the crack in the fuselage...
So I decided to strengthen the area inside the fuselage with a layer of 3mm balsa and 25g glassfiber/epoxy on the out side, and at the same time lower the V-stab up front 3mm to get ride of the undesirable elevator up trim.
Luckily for me the plane flew with no up trim at all after the fix.
So I expect all Vipers have a slight up trim problem as standard.
