Last weekend I helped my son maiden his ElectraJet. He flew - I launched. When he powered it up for a range check, I felt a large negative pitching moment due to the offset thrust line. He checked everything and said it was O.K., so I gave it what I consider a normal straight ahead toss. It went into a downward trajectory and hit the ground about 10 feet away. Fortunately, nothing was hurt, so we tried again. THis time he put in full up trim and I gave it a HARD heave a little above horizontal. This time by giving it full up elevator he managed to level it out about a foot off the ground, then it started climbing. Once it got going, it flew O.K., except it wouldn't loop - just a quick stall and recovery. We tried a couple of more times and both times it was a toss up whether it would level off before it hit the ground, but it did. It appears that it has to have a lot of speed before the elevators can overcome the negative moment from the offset thrust line. I don't think one person could both launch and fly it, unless he can launch with one hand and control with the other. Is this launching problem a standard problem with the ElectraJet, or can it be fixed with thrust line/elevator/ C.G. adjustments?

Check that C.G. again. Sounds like it is too far forward.
Also, is the battery firmly mounted, so it stays put during the launch?

...and build a sdmall catapult, as I show on my site (under bungee). It's too sad to loose a plane due to a bad toss.
Bungee is much much safer
http://www.geocities.com/lucchev/

DLC,

I agree that either your CG is off or you have the reflex set wrong on the elevons. If those are correct you might double check that you got the motor mounts seated all the way in the foam sockets and that the motor is resting on the rails and not some how cocked off at an odd angle. I hand launch mine myself with no problem. Just an eazy toss and it flys away level.

What battery pack are you using with it?

Dru

DLC,

I fly my Electrajet with a few different battery types, but I ensure that it balances about 5/8" forward of the + marks under the wings. This is with elevons adjusted level. It launches well with power on and an easy throw, straight out. With 8 x KR1100AAU batteries it climbs away quickly and reasonably steeply.

Seems your C of G is too far forward, or possibly your motor is somehow angled down (towards the prop).

Good luck,

Brian

Thanks for the responses. Brian, I don't know what C.G. setting he was using - I will pass your info on to him.