cgroves
10-19-2005, 11:12 AM
Well, it can happen to anyone. I was out flying yesterday and got lazy pre-flighting the Predator.
Powered it up and did the range check, everything on the head and tail wiggled the right way, the throttle servo made the right noises. Battery checked out okay and nothing was chattering.
Fueled it up and started the engine, ran a little hotter (faster) than expected but I had yet to adjust the mixture so I figured that was the problem. Carried it out to the pad and put it down. Almost immediately the head started to aggresively spin up in idle. Went to lift off, I could hear the pitch change but the engine just started to bog. I decided something was not right and went to shut the engine down. But my kill switch was not working. In fact, not matter what I did I could not move the throttle control at all. I was stuck with a idling heli running the head at around 800rpm slowly wiggling its way into the mud and no way to stop it. The head was too fast to stop by friction. It takes a long time to empty a full fuel tank at just above idle trying to keep the heli upright.
It turns out the new idle screw lock bolt I had installed was incorrectly placed and had jammed the throttle barrel just above idle. The servo still moved enough to make the right noises but couldn't move the throttle very far. Lesson learned, don't get lazy, check EVERYTHING and LOOK AT THE PART you are checking to make sure it moves the right way.
Powered it up and did the range check, everything on the head and tail wiggled the right way, the throttle servo made the right noises. Battery checked out okay and nothing was chattering.
Fueled it up and started the engine, ran a little hotter (faster) than expected but I had yet to adjust the mixture so I figured that was the problem. Carried it out to the pad and put it down. Almost immediately the head started to aggresively spin up in idle. Went to lift off, I could hear the pitch change but the engine just started to bog. I decided something was not right and went to shut the engine down. But my kill switch was not working. In fact, not matter what I did I could not move the throttle control at all. I was stuck with a idling heli running the head at around 800rpm slowly wiggling its way into the mud and no way to stop it. The head was too fast to stop by friction. It takes a long time to empty a full fuel tank at just above idle trying to keep the heli upright.
It turns out the new idle screw lock bolt I had installed was incorrectly placed and had jammed the throttle barrel just above idle. The servo still moved enough to make the right noises but couldn't move the throttle very far. Lesson learned, don't get lazy, check EVERYTHING and LOOK AT THE PART you are checking to make sure it moves the right way.