At 09:59 28 September 2016, Don Johnstone wrote:
At 06:46 19 February 2016, wrote:
Have you tried rebuilding the drum brake? My club used to have
a
Twin
Astir=
retractable and the drum - tiny though it looked - always did a
fair
job
o=
f stopping the ship. It was strong enough to make rubbing the
underside of
=
the nose on the runway a concern.

Very true, the original Grob 103 Twin Astir had no nosewheel so a
super efficient brake is not a good idea, unless of course you want
to
grind off the gel coat, or even worse the underlying structure
under
the nose. The Grob103 Acro did have a nosewheel and therefore
the
more efficient disc brake was not a problem.
I always wonder if people actually think through the implications
of
making something "better". Perhaps there was a reason why the
original design did not have a super efficient brake.
Duct tape can't fix stupid, it can muffle the noise.

The Twin Astir Trainer (fixed gear version) came with a standard
hydraulic disc brake from the factory. The ones which people are
retrofitting are the more numerous retractable gear versions. There
was a problem with that disc being too thin and deforming, but
TOST put out a retrofit kit to fix that issue last year.

I view the extra stopping power of the disc brake as another tool in
my toolbox of flight controls. I don't use all of its capabilities under
normal conditions, but if a situation occurs where I need that power, I
want to be able to access it NOW. For example, if I have a
low altitude rope break and am forced into a situation where there is
not much room to stop, I (personally) would rather get on the brake
hard (even if it means scraping the nose) in order to avoid being
forced to make an intentional ground loop (and breaking the tail
boom +) to avoid a looming obstacle.

I flew professionally for 42 years, and it always grated on me when
someone took a useful tool out of my toolbox "for my own good".

Whether one is a pilot, cabinet maker, electrician or whatever, one
has tools to ply one's trade. Some of those tools will have the
capability to kill or maim. It is the responsibility of the OPERATOR to
use those provided tools with skill, accuracy and judgement. Don't
blame the tool, when the problem is in reality an inept operator....

RO