AAIB report on R/C Harvard published - attached as .pdf

[Don Fry]

In fairness Martin, a realistic risk assessment;

It is a median sized model. It hit a trailer on an industrial park.

Yes, it could be different. But it wasn’t.

Cause unknown. No reliable scene examination. Scene cleared up.

Not lip service, but not worth an after the fact examination.

[Chris Walby]

Its utter rubbish, does no one any credit and generates more questions than it does answers.

 

Best leave this to the professionals and its a far better read. 

 

For example this runs to 61 pages

Hawker_Sea_Fury_T_Mk.20_G-INVN_10-21 (publishing.service.gov.uk)

 

[Simon Chaddock]

I am not sure why the FS was did not work or was not set is not the real problem but simply the fact that a relatively large model flew away under power.

This was reported a serious incident  by the AAIB. No safety recommendations were made but if this sort of thing happens even a few times the AAIB probably will react and the CAA usually back them up. The model fraternity operate under CAA concessions.    

[EarlyBird]

11 hours ago, Martin Harris - Moderator said:

Back strictly on topic, this really does illustrate that the CAA are apparently paying lip service to investigation of reported incidents. As others have pointed out, nothing of any use has come from this and it just leaves many times as many questions as answers.

This is an undisputable fly away which as we all know should never happen with modern radios as the RX will go into FS settings within a few seconds of communication failure with the TX. This has emphasised the importance of setting and testing the FS, a lesson to us all. Assuming the FS was set and tested is there anyway for this fly away to happen, a dead RX battery for example? 

[PeterF]

There is talk of jammers being used, surely if there was jamming or a high power microwave transmission the RX would go into failsafe not fly away because it was no longer receiving a valid signal.

[PeterF]

2 hours ago, EarlyBird said:

Assuming the FS was set and tested is there anyway for this fly away to happen, a dead RX battery for example? 

As has been said above anything like a discharged or broken RX battery, black wire corrosion, dodgy power connector(s) or failed power switch. There was a fly away at our club many years ago, when the wreckage was checked the flier had soldered up their own RX pack to save a few pennies.

[EarlyBird]

3 minutes ago, PeterF said:

As has been said above anything like a discharged or broken RX battery, black wire corrosion, dodgy power connector(s) or failed power switch. There was a fly away at our club many years ago, when the wreckage was checked the flier had soldered up their own RX pack to save a few pennies.

? pushing the RX battery below minimum voltage will cause the RX to switch off and the model will continue to fly? Then when tested later the battery voltage will have recovered above the minimum and work as normal. That means the FS is not fail safe.? 

[Cuban8]

4 minutes ago, PeterF said:

As has been said above anything like a discharged or broken RX battery, black wire corrosion, dodgy power connector(s) or failed power switch. There was a fly away at our club many years ago, when the wreckage was checked the flier had soldered up their own RX pack to save a few pennies.

The trouble is one can imagine where all this might lead to given the widening of  officialdom and over-reaching doubtful bureaucracy as many of us believe we have been subjected to recently.....but we are where we are.

Given the huge number of R/C model flights that are carried out in a safe and orderly fashion annually in the UK, the few that do result in a problem even then go on to merely being classed as a local  incident with no other parties involved and hence no further action required except to fetch a bin liner and replace one's divot.

Certainly, there is a very slim chance that a model might cause property damage, or in ultra rare circumstances, personal injury to an uninvolved person - however regrettable this will be, let's not get carried away, but remain on our guard for those who might see an opportunity to add even more in the way of hoops for us to jump through.

 

[kc]

It seems to me that aeromodellers need to pre empt any official action by finding out what could cause a failsafe to fail to function and find out what one can do to ensure it always works.   Then we can say to the CAA it shouldn't happen again, so you don't need new regulations.   It's up to the BMFA etc  to find out whether anything on this particular model  ( such as  fancy battery backer, non standard Rx with different failsafe action, 'hack' Tx module, poor quality switch, too small a Rx battery or black wire corrosion etc etc   ) caused an unusual and unexpected problem that can be prevented in future.   That's what I expect my BMFA subs to be used for...........

 

Of course we may be over reacting to the report about this incident as the facts don't add up to us - maybe as nobody was hurt  the report will hopefully be just filed away and forgotten.  

 

 

 

  

 

 

 

Edited November 20, 2021 by kc

[Robin Colbourne]

It sounds to me as though the AAIB and BMFA should run some courses on post-accident data gathering, so at least one member of every club understands how to produce a detailed, accurate report.  You only need to read a few AAIB reports of full-size accidents to realise that first impressions and assumptions are often wrong (The Emilio Sala crash being a prime example.  The weather and the pilot's lack of an instrument rating being the initial focus, whereas carbon monoxide poisoning was later found to be the most significant factor).   In addition, witnesses are often completely wrong about what they saw and sequences of events.

 

In one of my contracts I worked as a validation & verification engineer, running environmental tests on electro-mechanical assemblies for armoured vehicles.   Root cause analysis of failures was a significant part of the job, and it was immediately apparent how essential a planned approach to investigation and lots of note-taking yielded information that would be easily lost if not done in a methodical manner.  In addition, I was forever trying to press home to my colleagues that there is no such thing as too many photographs, each one should include a caption board if possible, or failing that, zoomed out shots enclosing a caption board, either side of a closeup.  Very often photos taken to capture the general test area and equipment proved as vital as the close in ones of the assumed problem.

 

 

 

[Martin_K]

50 minutes ago, Robin Colbourne said:

....   In addition, witnesses are often completely wrong about what they saw and sequences of events....
 

Indeed. Eye witness evidence must be questioned. We 'see' what we expect to see. That is not a criticism of anybody. We can't help it, it is how the mind works. Fit the observations to an existing scenario. This is the basis for illusion.

 

Meaningful investigation requires serious effort.

[Cuban8]

Unless an incident involves personal injury, which would involve the authorities anyway, then I'd steer well clear of getting involved with full size style accident reporting. The thin end of a steeply widening wedge if you ask me.

[Robin Colbourne]

1 hour ago, Cuban8 said:

Unless an incident involves personal injury, which would involve the authorities anyway, then I'd steer well clear of getting involved with full size style accident reporting. The thin end of a steeply widening wedge if you ask me.

Its still a good idea to be able to find the root cause of a model crashing, otherwise you're just asking for a repeat.

 

[Cuban8]

50 minutes ago, Robin Colbourne said:

Its still a good idea to be able to find the root cause of a model crashing, otherwise you're just asking for a repeat.

 

Yes of course, but not within the full glare of a full sized accident report.