Super Sabre - Abingdon

Classic Jet at Abingdon. Super Sabre crashes after making the first turn. Did it stall due to a too tight a turn or suggestions are maybe a flap stayed deployed. The video is not helpful as the aircraft was to far away to view flap position on the wing furthest away. Review the clip Peter Willis......

Is that not a super sabre? A shame none the less

I stand corrected. I think it maybe the sight of some nice Hunters that has been embedded in my mind.:lol:

A take off flap setting is the norm, but it seems the cause was due to a flap retraction problem causing the wing to stall. Great shame as it was an awesome model!!

Word was one flap servo burnt out so didn't retract after take off, real shame, lovely model

Phil,

Thanks for putting the video up.

You are right, too far away and contrasty to check the flap positions. Having looked at the video I think this was a failsafe activation,as the roll rate was not excessive (as it would been with asymmetric flap) and the engine appeared to have throttle down by the time it hit the ground or it would have been far more comprehensively destroyed and probably have burned as well if the engine was still on high thrust. I think the tightening of the turn just before impact was probably when the engine shut down under failsafe and the aircraft properly stalled. The engine failsafe usually takes a second or two to kick in after signal loss, where as the radio gear on control surfaces goes into whatever failsafe mode has been set almost instantly and I think it was set to Hold last position rather than return to neutral. I would be looking at Tx battery or Rx positioning/orientation in this sort of event, might even be old DSM2 gear which can struggle when a lot of other Txs are switched on, as can happen at an event such as this.

Can't prove any of this theory of course but if I was doing a formal investigation into such an incident that is where I would start the search for evidence.
I would be interested in other (turbine experienced) members opinions, as I said to Phil yesterday I would rather learn lessons from other peoples misfortunes than my own!

Peter

Peter - So sorry to read of your mishap, you must feel really gutted to have lost such a beautiful model.
Hopefully you will be able to determine the cause, is there a case for limiting the number of models that
can be airborne at the same time to reduce possible radio interference ?
Colin.

It wasn't Pete's model Colin!!

Colin,

Yes, as Pete has already said it was not my model, thank goodness.

However, having not seen the crash in real time (just the immediate after effects) I was keen to see if there were any lessons to be learnt. I did have a chat with the pilot afterwards and he couldn't understand what had happened and explained that he had previously had 30 uneventful flights with it. However, another person who had seen the crash chipped in and said he thought that one of the flaps might not have retracted properly but any video of the event would show this, hence my request for Phil to post the video to review it.

The flying is limited to four models in the air at any one time at most Jet meets (sometime only three at any one time) but this is not the issue. It is all the other Txs switched on in the pits etc as turbine models take a lot of setting up and trouble shooting if something is not quite working correctly and with probably 50+ models there was a fair chance quite a few Txs were switched on at any one time. My limited understanding is that as most of the more modern Txs will be frequency hopping they tend to take up quite a bit of the allocated spectrum and as DSM2 does not frequency hop it can (in extreme circumstances) momentarily suffer from loss of uncorrupted signal causing a failsafe.