Unknown Loss of Control

Over the past week I have been at the field where 3 aircraft have had loss of control, The interesting point is that they all came down at aproximately the same point aprox 100mts south of the trench and 50 mts east of the hedge at the end of the runway. The pilots of the first two thought the incidents were due to pilot error but happened with in 30 minutes of each other. In two cases the aircraft seemed to be flying normally and suddenly went into spins. The incident this morning was with a factory fitted stabalized small model and went into a spin. There have been several cases of loss of control of models recently includeing Colin Arnolds

Last week a small edf model that I was flying became almost uncontrollable whilst flying over the south field. Somehow I managed to turn it back towards the runway and drop it down just off the runway without incurring much damage. This week I flew the same model again without making any changes to the model and it behaved as it should. It's a mystery.

Thanks for sharing this information. Hopefully we can identify if there is a common cause of these crashes but we can only do it if we collect real time data to back up anecdotal evidence. It would be very useful if all those capable of datalogging setup their radios to record every flight and analyse any suspect incidents

The common feature could be that the models are almost directly opposite the pilot at the point of loss of control. If the Tx is directly facing the model and the antenna is pointing towards the model this could coincide with the hole in the RF doughnut (see attached picture). Also have you tested what happens to the control surface when a 'failsafe' situation occurrs on your models - this typically should be set to 'hold' for all controls except the throttle (which should go to idle).
Also consider the recent weather conditions, there has been a common theme of North and Westerlies which bring turbulance from the hedge and the big tree at the hut end - this could affect foamies quite dramatically.

The models that I have had affected by this issue are all electric so controls were set to neutral and motor shut down in failsafe mode. The Pulse 60 crash was directly opposite the Pilot box ( in the 4 years I have been flying it I never had an issue with control loss that couldn't be explained). The Wot 4 crashed out of bounds near the jet area having come across from the south side of the runway. I had absolutely no control and I could hear that the motor was under power when it hit which resulted in almost nothing being salvageable. The edf flight I previously mentioned seemed to very intermittently take control away from me.
All 3 incidents commenced opposite the pilot boxes. Unfortunately my tx doesn't have a facility to record flights so can't offer any more information.

My two pennies worth. As John has said earlier that it may the possibility of the antenna pointing directly at the model where there is minimal radiation as the model passes by in front of the pilots. Spektrum have gone for the built in aerial in their TXs and as most pilots generally hold the TX at a 45 deg angle the inbuilt antenna is again pointing directly at the model. So have other makers of TXs. :huh: After seeing this post and some concerns, I have had a look through my log files on various recent dates for a a number of models and followed the RSSI levels and there were never any signs of a drop out. We have had phases of these type of issues over the years but nothing was ever found.

Excluding Simon who is on Futaba were all the others all on Spektrum?

Or is it down to turbulence?