In Australia we have a dismal record from which to draw, I fear - far
too many CFIT accidents attributable to illusions, mostly at night. The
principal generic cause is that pilots learn to fly at night in a
light-rich environment, the training aerodromes being mostly in or near
big cities. They thus learn a bad habit - over-use of external
reference. That typically catches them out when they fly in darkness to
a coutry town, let down on the aid, then continue towards the airfield
by visual reference to the small group of light that is the town, some
miles distant. The light source is essentially a single point. You
cannot make an angular relationship with a point. Our Bureau of Air
Safety Investigation (BASI) has written an excellent booklet on
illusions. I'll check out a source for you. In the meantime, some of
BASI's accident reports can be downloaded. In the report on tha accident
involving Piper PA-31 Chieftain VH-NDU near Young in NSW, you will find,
at pages 43 and 44, a good treatment of the 'focal plane trap' (or
'Mandelbaum effect') - wherein the pilot will 'see' a different picture
of the runway when flying a right circuit - as well as some thoughts on
height estimation at night (as in, don't rely on it). Start at:
http://www.dot.gov.au/programs/basi/pdf/ndusynop.htm
then select the above accident details. (It's a large report, but well
worth it, as it also uses Professor Reason's theories on 'defences' to
analyses the accident.)
Another manifestation of the problem of going from a light-rich
environment to near-total darkness is the 'Somatogravic' effect. Not so
much an illusion, an acceleration-induced 'false vertical' sensation
that causes fly-into-the-ground after take-off, when the pilot is using
visual reference when there really aren't enough cues available. Same
solution - fly the clocks - but of course there's much more to it than
that.
The avid trainers in the group will have spotted a connection here. The
Law of Exercise. If you want people to be able to cope with an illusion,
they must have experienced it.
Cheers
Doug