Crash near Bude, Cornwall: 24th July 2011

[AnFI]

1st draft - (not yet in English...)

Not showing people how to fly visually is like not showing people what dynamic roll over is and just telling them to stay away from sloping ground

I am becoming more surprised that the ability /understanding of how to guard visual cues is not that widespread – maybe worse than 80% !

Fundamentals of Visual Reference Flying – VRF - (1st Draft)

1st principle:
Guard your Visual References – never lose your VR – (you are in a machine who’s position and velocity can be controlled quickly and very accurately – for example you never have to take your machine 1 foot further than you can guarantee. If you can see to guarantee 20feet ahead then planning on flying 10 feet further should not be dangerous – but obviously you can’t be flying at 60knots because that would then commit you to occupying a position further than you can guarantee.)

A. know what visual references you are using – normally this is easy – you have Billions of visual cues – if that falls to a million visual cues then you probably wouldn’t give that much thought – even a thousand Visual Cues can look pretty good … 100 not too bad … 10 getting pretty serious … how many more can you afford to loose? At 3 then loss of one would be very serious (unacceptable), know what your reliable cues are and guard them.
B. The End of The World
In VRF the Limit of what you can see (and interpret) is the ‘End Of your World’… do not fly beyond the End of your World! The furthest Visual Reference in the direction of travel is the Critical Reference (CR) – it is the most important VR…
B.i The End of the World should always advance as you advance – if the EoW ceases to advance (or worse is ‘consumed’) then this must a) be detected immediately b) be responded to immediately – it cannot be allowed to persist for ‘any’ time at all…
B.ii The line from your eye to the CR is the demarkation between guaranteed VR and probability … (probability is unacceptable) the A/C must be actively controlled so that it is always able to stay in the ‘Guaranteed Sector’. (so : if you are too energetic (speed/height) you almost certainly are committed to a trajectory which forces you into the Probable Sector… (unacceptable)
B.iii Angle to the CR: at about 2degrees or less in the cruise the cyclic is often sufficient to stay in the Guaranteed Sector. 3 degrees is about the limit. ( and equates to 600ft at 2nm(4kvis) or 4nm (7kvis) at 1200ft) at Cruise speed at say 3kvis and 1200feet it is not plausible to guarantee staying in the Guaranteed Sector – you are ‘at DANGER’ because the speed loss will force your angle of descent to be shallower than required… You need to be at sufficiently ‘low energy’ to be able to stay only in the Guaranteed Sector…

So to simplify:
You must fly at a height and speed which enables you to stay in the Gauranteed Sector. With a speed which enables you to stop by (before) the End of the World.

You must be (totally) alert to the disappearance of the furthest cue (ideally not only on the direction of flight but in all possible directions).

Often people avoid clouds by ‘seeing’ them … this is obviously* not good enough. Clouds may not be visible (discernable/detectable) by day (as can be the case at night). So if you depend on seeing them to avoid them you will fail… sometimes (ie … not good enough)
… this applies not just to clouds but many types of obstacles, coal slag heaps at night, snow banks, white mountains in a field of white, trees at night from over-illuminated cockpits in badly lit landing sites … etc.

So there are some principles which need to be stood on their head.
One is you must assure the definite absence of cloud – this principle is often used at night – where an invisible object is revealing background – you cannot see the object but you can see where it certainly is not. (most people would do that instinctively – for others once this principle is shown/used it can become instinctive). This happens in daylight with clouds sometimes – where a cloud is above the ‘demarkation line’ but has no contrast with the poor visibility … the vis may be 8k but the (undetectable) cloud is at 1k… It becomes detectable by what it obscures rather than actually being visible (directly discernable).

Parralax – used often in mountain flying – is no more than using a normal visual cue although during ‘normal life’ is seldom relied upon – once the ‘victims’ attention has been drawn to this aspect of the visual field then the information from it becomes more relevant/obvious/natural.

Sliding doors:
I am sure you intend to fly your pax safely – obtaining the weather forecast is all very commendable – it enables you to cancel when you don’t like what it says. BUT holding a (worthless) piece of paper in your hand which claims the wx is good (enough) gets no prizes from St Peter when the wx turns out not to be what they said. IE a WX forecast (or sparse actuals) are not sufficiently certain to avoid IMC … they enable you to not go – but they don’t help when you meet circumstances requiring total guaranteed ablity to maintain your Visual References in light of the actual conditions encountered – I suspect that the casual way you refer to IMC and re-gaining visual cues infers that you are (or have been) an IRF pilot…



Sliding Doors - the example of the Gazelle pilot is a great one - weather (basically) ok but Visual Referance Flight methodology missing... result dead.


One clue (I often hear) to someone getting the wrong picture from outside is when people say the vis is getting worse – when infact they have climbed into a position where the forward view has reduced – the conditions were the same but their positioning of the aircraft has changed (they think it is something happening to them – rather than something they are causing) (some others: “the cloud has come down” – when in fact they have gone up! “That plane looks very low” – when infact it is at 2000ft and you are at 3000ft etc)

(TorqueTalk: pedantic (true) point about instinct – sure, nature/nurture etc blah blah.. but if you are taught then know then understand then implement subconsciously … then I think it’s fair to call it ‘instictive’ . But more importantly I think your point about pressing on into a place where the screen goes white points to a belief that there are a set of conditions where suddenly there is risk when previously there was not – only a ‘no risk’ approach is good enough and that should not depend on the conditions actually encountered…. )

IMHO early exposure to IRF diminishes the importance a pilot attaches to staying VMC and undermines VRF. It also can make him think that “life is like a box of chocolates” and becoming IMC is just something that can just happen to you if you fly in poor conditions… no you must keep VR in a VMC machine full stop. You need to want to AND you need to know HOW to (VRF) - both!


Being assaulted by a drunken Russian just now (who’s telling me (in Russian) that he killed 5 in Afganistan … etc) no time for finishing/editing … please make allowance for that…