Sub-gravity sensation

I need to give a season opening briefing to all the pilots in our club next
week and naturally want to highlight safety issues. During preparation for
this meeting I've come across an accident report that attributed the cause
of the fatal accident to "Sub-gravity Sensation". There appears to be a book
available on the subject by Derek Piggott, but I cannot get ahold of this
book by Wednesday.

Anyone every heard of sub-gravity sensation? What is it?

Thanks,
Rod

I have not read Piggots book but the term Sub- Gravity refers to either =
reduced "G" or Negative "G" loading.

Some people are badly affected by such sensations and may act =
irrationally if subjected to them. A common cause of approach/landing =
accidents is due to such sensations being encountered by pilots in =
gusty/rough conditions and believing that they are stalled. When they =
take stall recovery action close to the ground when, in fact, the =
aircraft is not stalled, you can guess at the outcome

Rod,

Take a look at this:
http://www.glidingcaboolture.org.au/ReducedG.doc

I think it might be the paper that you're after.

Alastair


At 19:48 06 March 2004, Rod wrote:
I need to give a season opening briefing to all the
pilots in our club next
week and naturally want to highlight safety issues.
During preparation for
this meeting I've come across an accident report that
attributed the cause
of the fatal accident to 'Sub-gravity Sensation'. There
appears to be a book
available on the subject by Derek Piggott, but I cannot
get ahold of this
book by Wednesday.

Anyone every heard of sub-gravity sensation? What is
it?

Thanks,
Rod

Thanks for the helpful feedback on the subject. I can certainly use some of
this information for my briefing.

Regards,
Rod

Rod,

I did some research on this many years ago. I've since stored my notes
(read lost them in a known location). However, I can recall a few
important items you might want to include in your briefing.

Some people are more affected by reduced g sensations than others.
That said, all of us are affected by the feeling of falling. Without
training (the sort you would get in gymnastics or martial arts) when a
person falls, he will naturally throw his arms forward and tilt his
head back. It was believed that this response might have caused
several accidents in which pilots dove their aircraft into the ground,
the increasing sensation of reduced or negative g strengthening the
forward movement of the arms.

On the other side of the coin, those with increased sensitivity will
tend to avoid strong forward motions of the stick. It doesn't take
long to establish that a forward motion of the stick will lead to
discomfort while a rearward motion of the stick glues you safely in
the seat. Instructors need to watch for this tendency carefully.

Detecting over sensitivity is relatively simple. During stall
training, observe the student's head. At stall break, if the head
tilts back, this is an indication that you might want to check for
other warning signs -- anxiousness about performing stalls or flying
in turbulence. The shoulders are also a good barometer of tension.

Remedies... a snug, even tight harness helps. Smaller stature pilots
who use lots of cushions seem particularly affected since their belts
loosen up regularly. Tightening the belts should be added to the
pre-landing checklist. Also, in some cases I've found it helpful to
address the symptoms. A gentle hand on a shoulder will often help
relieve the tension. If a student is having trouble with performing
stalls and recoveries, have him nod, touching his chin to his chest as
he makes his stall recovery. Give him verbal reinforcement. "OK,
there's the stall. Nod yes. That's a stall and I'll recover by easing
the stick foward. Nod yes. I am in control." It seems to work for
those with a pronounced head tilt during reduced g.

OC

"Rod" wrote in message ...
Thanks for the helpful feedback on the subject. I can certainly use some of
this information for my briefing.

Regards,
Rod