"Cecil Chapman" wrote in message
...
Question:

As part of the Private Pilot training there is a minimum of 3 hours of
hood/instrument training required.

One of the things which seems to be always taught (it was the way I was
taught and the way I am instructing) is the one minute standard rate turn
which is to be used by a Private Pilot if he/she gets theirselves into
some
IMC, inadvertently.

No matter who I ask, I get the same technique (which is the way I was
trained during my PPL training); standard rate turn, one minute (3 degrees
per second times 60 equals 180 degrees). Aside from the scenario where
there is a vacuum system failure (where you lose the DG, for example),
what
is so wrong with teaching them to look at the bottom of the heading
indicator and standard rate turn to that value? The answers I get when I
ask this question, vary from, 'I was just taught to use time', 'the pilot
is
likely to forget the 180 degree heading they were supposed to roll out
on',
etc...

I teach, by timing, just as I was taught, but still haven't got a
compelling
answer as to why not have them look at the 'bottom' of the DG and turn to
that heading (standard rate)? For those I've spoken to that have said,
"they are more likely to forget the heading than mess up the time", I can
see that they could just as easily lose track of the time as they could
the
clock.

Anyone have any 'whys' on this one?

It's probably a carry-over from the old style of directional gyro, which
looked a lot like a larger wet compass with a caging knob mounted in the
panel. What is now thought of as the bottom of the display was out of view
on the far side (back) of the instrument.

I don't know when those ceased to be installed in new aircraft, but there
were a lot of them still in service in the 1980's--and they had a couple of
interesting quirks. They could be easily tumbled by an excessive bank angle
and the caging knob could also be left engaged--supposedly to prevent damage
when practicing spins in VMC. I was taught to ALWAYS pull the knob back AND
twist it sharply after resetting the direction to make SURE that it was not
still engaged.

IIRC, there was also a related quirk to the old "gull wing" artificial
horizons--in addition to being devilishly difficult to use. I believe that
they tumbled at just over 60 degrees of bank, and were very slow to recover.

The overall result was that, in the bad old days, the turn indicator was the
only gyro based instrument that you could always trust--even when taken by
surprise.

Peter