bluestratos

Had (operative word) an CG chipmunk that had flown for 2 years. I loved the plane, great all around. Last time out (literally) I noticed a wierd twich, or hits so I brought her in, checked the battery, controls , range check all fine. Some one at the field said it was just the wind gusts ( it was a bit windy) I knew better but put it back in the air. Two circuits later the radio response died and I had the pleasure of watching her dive straight down at full power. lol...

The confetti..er wreckage was in a dirt field freashly plowed which absorbed the impact a bit. She hit at well over a hundred and was a total loss. The engine had minor damage and is reusable, most of the servos were destroy, as was the switch and battery pack so I cannot determin the cuase of the failure but it is a good guess that it was a switch failure or a battery problem.

I have lots of planes so no biggee but next time I will follow my instincts.. I should have known better as I know the difference between a hit and a wind gust.. lol

Randy

alan0899

G'day Randy,
Sorry about your loss.
Our Club President lost his Chippy a few months ago, just no control, it shredded itself through some trees, & when we got the wreckage back to the pits, we found corrosion on his RX pins, he lives near the sea, & the plane had been setup with the same gear for 3 years or so, so everyone should check their RX's from time to time, especially if the radio gear has not moved in a while.
It was just a coincidence that his was a Chipmunk too.

jetmech05

do you ever deep cycle your batteries? asssuming you're using NiCAD.
Was the battery 2 years old? It could have been anything but if your answers are 1 no and 2 yes I'd suspect the batttery.
Get your self an expanded scale voltmeter and leads and check your older batteries.
Sorry for your loss....

jollycub

My Feedback: (5)

I know this sounds goofy, but airplanes talk to you and let you know when they do not want to fly. Almost everytime I have crashed an airplane, the airplane would be hard to start, or would die on the runway or some other subtle behavior that indicates something is not right. And these are airplanes that I have had spent considerable time setting up before flying.
Rod Serling is not looking over my shoulder giving me second hand smoke, nor have I escaped the rubber room. Listen to your airplanes I tell ya, listen to your airplanes.

rollo

When you range checked was it with the motor running? Many times glitches show up because of engine vibration which may only be present when the plane is in flight or running. This was a tip that was passed on by a friend of mine.

bluestratos

I have, and use high end cyclers and just a few days before had cycled the chipmunk battery...a 1650 NMH.. had 1629 recharge millamps, well within tolerances.

I also recharged between flights and was fully charged on the last flight.

The plane started and ran beautifully on the ground, taxi etc... and the range check was done with engine running.

When I found the wreckage I found the battery in pieces but the red wire was partially melted right near the point it attached to the battery. This may have happened on impact or maybe vibration caused a dead short.. will never know for sure. I have a gut feeling the battery shorted out because the 5th cell had torn away on impact so there was no circuit that could have caused the melted wire. I only use good manufactures batteries but it looks as if the wire may have rubbed against the solder tab.

Best regards,
Randy