B52

[CARBON_ROD]

 Just out of interest I was quite taken with this model ,What do you all think i expect some of you have already seen it but there will be so,me who haven't  here it is then enjoy!http://www.youtube.com/watch?v=fbITzCI2AU0   regards TD

 

Edited By David Ashby - RCME Administrator on 30/12/2010 16:38:15

[Jonathan Lewzey]

very impressive. have seen that or something like it before. unfortunatley a similar model got wrecked by some clever guy trying to fly aerobatics with it

[flytilbroke]

Jonathan, The clever guy was not trying to fly aerobatics with it, although it was involved in an unfortunate arrival.

 

A very beautiful model .

[Jonathan Lewzey]

oh  i heard he tried a half roll and then half loop and stuffed it in, but maybe not entirely accurate.

[Pete B]

Is this the one you're referring to, Jonathan?

 

 

I suppose it could be suggested that the manoeuvre started with a half-roll and ended with the second half of a loop..........but they weren't intended by the pilot......

 

I don't know the cause but looks like a radio failure to me.

 

Pete

[Ian Jones]

Re the B52 crash. I remember the official report in which the pilot held his hand up to this awful crash. Unfortunately I can't seem to find it on the CAA web site at the moment.

[Erfolg]

Watching both videos, as a modeller I cannot be but impressed, that is until the crash.

 

My most frequentlyflown  model is some +20 years old. I also fly a small foam model. The contrast is that my old model only is alive because of its inherent flying qualities. When things go wrong, to-date it sorts itself out. My newer model is for me very impressive, yet not as tolerant of misuse when flying or landing. It expects you to do your part at least half adequately. I have had arrivals with this model a number of times now. Both are small enough and light enough on a probabilistic assessment basis to present little potential for damage.

 

Which brings me to the B52, the sheer size and everything about it, requires a high degree of thought and constraint in its operation. Because a crash is not just a question of time and money, but a number of other issues. The minimum will be bureaucracy, where someone will require informing, the second and equally important is damage to persons and or property. Both of these elements could have far reaching consequences to all of us modellers.

 

Thankfully in the last video, all seems well. In that the model was being flown in an apparently responsible manner, so as to control as far as possible the risks. The damage hopefully was just confined to the modellers wallet.

 

As most modellers I enjoy seeing these models. But thankfully mainly confined to large airfields with shows etc.

 

I do not want to see even a 1/4 scale F104 at my local patch as a regular flying model.

[Biggles' Elder Brother - Moderator]

Compare the take off's the second guy is clearly unhappy with the lateral control (ailerons) right from the off.

 

BEB

[Erfolg]

I did note the take off, in the latter video. I then watched the first video again. Both models seem to rock, the latter by a larger amount. I put this down to the narrow main undercarriage and additionally the apparently stronger wind in the second video, this apparent from the bulging ground sheet, that can be seen.

 

I do not know the cause of the crash.

 

It did make me think that in this era, where model avionics are viable and available, that a flight engineer with access to real time data and the logging of data is perhaps essential.

 

I would guess that airspeed and other data to assess how far from the stall the model is in say a turn would be essential, rather than visual judgement only.

 

[Jonathan Lewzey]

yes that must be it, but i hadn't actually seen the video before, just heard about it. if the pilot says he's responsible then he must be, whether by pilot error or insufficient radio backup. i would think it extremely unlikely that a model like this would have all the batteries and receivers fail within the first circuit. there doesn't seem to be any problem until the roll to the left which must be down to the pilot. if he was unhappy with the ailerons he is even more to blame as that looks like a public event. basically; great model, extremely poor everything else

[Ian Jones]

My recollection is that the pilot (Gordon Nichols) became disorientated and as a result ended up with the aircraft in a downwind low speed turn with more roll than the B52 could recover from, it stalled and could not be recovered.

[Ian Jones]

Still can't find any official report but this is the next best thing from someone that was stood next to Gordon at the time:

 

http://www.rctalk.co.uk/forum/topic.asp?TOPIC_ID=1683&whichpage=2

 

 

[Erfolg]

It did look like a stall, then again, what you think you saw is not always correct. I guess that is why football referees get so much wrong on TV replays.

 

Having stalled successfully, many of my models, whilst flying, sometimes at speed, it does seem an ever present problem.

 

Perhaps this is an area where more feed back to an RC Modeller could be really useful. Being honest I do not know how you would describe what is required. As a high speed turn, can result in a stall, as the AOA and velocity and rate of change all have a bearing if the wing will stall. A sounder telling me I have stalled would be to late. Yet the approach of the stall may be milliseconds for a model. So i do not know the answer.

 

With respect to the incident, I do not think there is anything  to say other than the model crashed safely. As long as it was due to the "what if" planning, the job is a good one. The flight plan and execution are to be applauded, as the contingency ensured a safe outcome.

[Jonathan Lewzey]

Posted by Ian Jones on 01/01/2011 15:05:19:

My recollection is that the pilot (Gordon Nichols) became disorientated and as a result ended up with the aircraft in a downwind low speed turn with more roll than the B52 could recover from, it stalled and could not be recovered.

 

 

A pilot flying that large and expensive a model in a straight line should never become disorientated  all forms of disorientation should be sorted at the learning stage of flying. the other forum link says he's competant, but clearly he's not competant enough. 

[James40]

Certainly looks like a low speed stall to me, exaggerated by the high angle of bank.

 

Such a shame on lovely model. 

[Pete B]

I see that this incident has been exhaustively analysed and discussed elsewhere and those involved know most about it.

 

Looking at the video again, halfway through the take-off run, the windsock is almost horizontal, which suggests to me that the airspeed may have been decaying towards the end of the downwind leg to a point where any control input might just have been sufficient to tip it into a stall. Perhaps this might make a case for telemetry with ASI readout on such models?

 

Great pity......

Pete

[flytilbroke]

The link provided by Ian Jones says it all really. It is factual in more than one way. The event WAS exhaustively analized by very knowledgable people.

[CARBON_ROD]

 Thanks for all the interest in my thread,All the info on the demise of the model in the second vid,which i found very interesting ,pleas feel free to carry on any discussion ,about these models .I'll keep watching with interest . TD

[Keiran Arnold]

Having read up on both this event and a full sized crash ( 1994 Fairchild Air Force Base)  it would appear that the aircraft entered an accelerated stall, a stall that occurs while the aircraft is experiencing a load factor higher than 1 (1g), for example while turning or pulling up from a dive. In these conditions, the aircraft stalls at higher speeds than the normal stall speed. Compounded by the fact the aircraft like the full sized used spoilers rather ailerons the aircraft exceeded a bank angle which would sustain flight.  I believe a US C17 suffered a similar fate (your area of SMS James)

Edited By Keiran Arnold on 02/01/2011 16:02:14