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Old 04-29-2011 | 11:38 AM
  #193  
Dave Wilshere
 
Joined: Jun 2002
Posts: 13,258
Received 788 Likes on 571 Posts
From: Watford, UNITED KINGDOM
Default RE: DerJet DH Vampire build thread-

Christian.

Like most new models, as I finished the install, there were a couple of things I would change next time! Thank you anyway.

So, the Vampire has flown!
Last night...this morning! I found a small problem, all the testing I did on the gear, I was pumping to around 60-70PSI which functions the gear fine. I knew that for flight and with the doors more pressure would be needed. So last night I started using 95-110psi to fully pressure test things. At these pressures, occasionally one leg would stick up. The extra pressure meant the leg door was hard against the shut in the wing and like this the leg would not release. A light press "in" would allow the cylinder to release and the leg would come down. So..I added 0.4mm ply packers under the leg door mount and the operation seemed reliable...but I had a thing in the back of my mind.
Balance was achieved with 1120 grams lead in the nose. I balanced it on the wood former, UAT full, some fuel in the main tanks.
My movements and expo suited my flying needs perfect, so will assemble and measure/note in a while.
Take-off roll was 100m on tarmac without flap ( I will now use some flap as the ground speed was higher than I expected on rotation ) Rock solid feel, few peeps of aileron trim and it was perfect. Rolls are axial with my aileron set up ( will measure) and as expected power with the P-120SX meant most of the flight was with the throttle at 1/3-1/2 stick position. I did one full power loop which was 600' (200m) dia and you can throttle back at 3 oclock. We had a 8 knot cross wind today and again as expected the Vampire fish-tails slightly with the big pod and small boom/fins. Nothing nasty though. Flap test showed no pitch with no down elevator on TO flap, and 3% down on landing (I like a slight nose down sit on full flap)
Flight time was set for 9 minutes, but I expect 11-12 with my power settings. So at 9 minutes I hit the gear switch, the sticky main leg had stuck again [:@] Great! Several fast rolls, and rebound rolls were tried to release the leg but nope []
So I cleaned up and made a grass landing. Obviously I touched the leg and it popped down [>:] Luckily no damage and I have the vampire back in the workshop to re work the gear door (like I should have before I flew her! Lesson 1!!)

Hope to fly again on Sunday

Dave
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