Hover,
I went looking for the post on the 3305 and I found one in 2004 that Krysta says you can use it in airplanes, then I found a post in 2008 that she said they are not recommended in planes due to deadband issues. Then I found this post which might explain your problem better,

http://www.rcuniverse.com/forum/m_22...tm.htm#2211319