I had the same problem with a plane and was at the point were I was puting down trim on launch and it still was hit and miss on launches. Then one of the members in our club in Bakersfield asked is your tow hook open or closed? What he ment was is the angle of you the hook portion of the hook more than 90 deg. (open) or les than 90 deg. (closed) to the bottom of the fuse. If the hook is open (more than 90) it's possible to pop off every time even though the plane is set up correctly. I now have bent my hooks to about 80 deg. to the bottom of the fuse and can go up with the nose pointing up with out fear of a pop off. I hope this helps.
Maurice --- In [EMAIL PROTECTED], "Dave Seay" <[EMAIL PROTECTED]> wrote: > I am flying (or possibly more correctly, trying to fly) a high quality open > class TD ship (no names as it has nothing to do with that). It really is an > excellent flyer, when I can get it in the air. However, in the many months > that I have had it, I've had about 75% of my launches end in pop- offs. I am > fast reaching a point of total disgust. I must be doing something wrong but > have not a clue as to what. The guys in the club are helping all they can > but we're not making any progress. > > The spec calls for a 5-1/6" CG (from LE) with a conservative position being > 5-1/16". I started out there and over time I ended up with the CG at 4-7/8" > with the tow hook about 1/4" in front of that. Getting tired of the > pop-offs, I decided to start over again. I moved the CG back to 5- 1/6" and > the tow hook has been moved back as well. The tow hook, being 1/4" to 3/8" > in front of the CG is probably further ahead than it should be but I would > expect that to flatten the launch. If anything, the launching has gotten > worse. > > I use a 'launch mode' but do not any elevator adjustment in that mode. I > have tried my launch mode with... > > -flaps only, more flaps, more flaps > -flaps with a touch of aileron camber > -flaps and ailerons cambered together, more, more > -flaps with a little less aileron than flap. > > No matter what I do, the plane seems to launch with the nose too high and > almost always pops off at some point (usually at a lower height but sometime > when it starts to arc over). The only elevator I add during the launch, if > any, is a little down in some sort of vain effort to prevent the nearly > inevitable pop off. > > I even get a popoff some of the time with a full pedal launch. > > HELP! > Dave > > > > > RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
