All,
Been a while since I posted due to holidays.
Just wanted to report on the demise of the clubs YT Fledgling electric trainer.
I had a training flight on the Fledgling on the Sunday morning with no problems.
On the next training flight (two other pilots) the aircraft appeared to ignore its RX and flew off in level flight toward the left of the field.
Fortunately (?!) it lost height and hit the ground (hard) just beyond our show strip but before the Activity Centre.
I was first to reach the aircraft and here's what I found:
- The plane had gone in pretty well dead straight nose first.
- The LiPo battery had passed through it's firewall, hit the back of the motor and bent / split badly. It didn't however explode / catch fire etc!
- The front half of the fuz was completely destroyed.
- The RX and servos were all mainly connected. Only the aileron servo had disconnected.
- The ESC was stone cold.
- The motor had separated from the plane completely and was half buried. When I touched it it was very hot. The mounting plate and front section were badly bent / mangled so I couldn't easily check that it was running free.
We collected up all the bits and they went into the back of Regs car.
I would like to offer my
opinion on
possible causes.
Cause 1) Classic loss of radio comms. This cause is supported by the fact that John lost his Sbach in a similar way about 5 minutes later. Something nasty transmitting on 2.4GHz...?!
Cause 2) Motor Failure: If (big if) the motor bearing failed or seized suddenly, it would take out (destroy) the ESC almost instantly but without heating the ESC up much. No ESC = no RX = no control. RX / Servo power is supplied by the ESC. This is supported by the findings of a hot motor but cold ESC and sudden loss of power and control.
Just my two-penny worth....
On a more positive note, I've been told that two new trainers have been built and test flown, so I can't wait to get on those at the weekend....
Cheers!
Jim
