My giant scale Cessna 182. It sure was a beautiful aircraft. Now it's in a bag, and I'm pretty sure I can thank Spektrum. This is the second plane I've lost on Spektrum.
I have a DX6i, and when I first got it, I loved it. I was a really big Spektrum fan for a long time. Now I'm losing my confidence.
The first was a small L-39. Pulling out of a shallow dive there was no reponse. I could hear the edf unit still running at my commanded power setting, but there was simply no response to stick inputs. Flew itself at high speed into a bush ripping it to pieces, but the fusealage was still intact except for the nose wich was ripped out due the battery continuing flight after the aircraft had stopped. After retrieval, the radio system worked fine. Totally unexplainable loss of control. Rx was a 6110e (before DSMX). Since I was one of only two people airborne, and the other guy was on 72mHz, I doubt DSMX would have made any difference. This happened right in front of me at only 100ft seperation between me and the aircraft. It was not a transmitter antenna orientation issue. I learned that lesson long ago. I always fly with my transmitter antenna pointed straight up overhead.
My giant 182 was purpose built for reliability. I invested a huge amount of money and took every precaution I could afford. I used an AR6210-X with satellite. (I understand that using an X receiver with a non-X transmitter means you are still flying regular old DSM2.) Antennas were oriented in 90 degree offset planes and were placed against the fuse side and bottom so only a 1/16 sheet of balsa and the monokote separated the antennas from the signal.. I used a 6V 2200mAh Nimh receiver battery to not rely on the BEC of the ESC in case the ESC fried. The receiver battery was charged up the night before the flight and showed 7.02V after a 6 hour .2mAh trickle. (I had done a 16 hr on it the previous week and only flew the plane twice after that charge.) The receiver was 2 feet away from the ESC and 1 foot away from the closest battery wire. Every extension wire coupling was tested with an ohmmeter after using CA to make sure no separation could possibly occur. The servos were not high current draw. Hitec HS-485HB. (It was, after all, only a Cessna and not a 3D monster so it didn't need anything more). The on/off/charge switch was tested before installation for any voltage drop across the contacts and only extremely minimal amounts could be detected, when I could detect any at all. Wire guage was ample to carry the current. Receiver was checked before and after each flight (all 5 I got to make) for blinkies with no indications of a problem.
Until last weekend. Airborne for 2 minutes and turning base for a touch and go, stick inputs became meaningless. The aircraft was flying itself, and as we all know, that is a bad thing. I prayed to regain control but could only watch as it rolled over and augered in. Hard. There was nothing left of the receiver battery to test, but I know it was in very good shape and could have easily supported 2 or 3 flights that day if not 10 were I a reckless builder and pilot. The receiver, however, in the rear cargo area, survived completely with all its connections perfectly intact including the one to the shredded end which used to be soldered onto the receiver battery. Bench testing today showed the receiver to be working perfectly. All servos tested fine as well eliminating a stuck or shorted servo that would draw huge current. Again, a totally unexplainable loss of control.
(BTW, I'm impressed with the Hitec HS-485HB. After a total loss high speed impact crash, not one of them even popped a tooth much less needed rebuilding with a new gearset.)
So I'm losing my confidence in Spektrum. Your pre-flight check should NOT have to contain a step wherein you remind yourself that even though you do everything right, there's still a 1/2% chance that you'll simply be disconnected from your aircraft and have to watch it be destroyed.
