Finish Gate Accident no. 2

M B wrote:
It occurs to me that if someone is on final glide at
the end of a competition, they may pick a speed (like
85 knots) which their computer says is optimal for
points, but which is both:

1) too fast for a rolling finish/landing
and
2) too slow for a pull up, turn around, and landing.

Is that an accurate assessment? Would a competition
pilot be put in a situation where he must decide between
points and safety of the landing?

This is exactly right. The mathematically optimal point score comes
when you cross the finish (50 feet, middle of the airport) at the
regular inter-thermal glide speed, 70-80 kts rather than 130. This is
of course about the worst place from which to start a sensible pattern,
especially when 50 other guys are doing the same thing at the same
time. You see fast finishes because most of us are a bit chicken and
hold some reserve, losing a few points in the process.

Everyone in these threads has been advocating "just do a rolling finish
if it seems touchy" but that's a hard decision too. The finish gate is
typically downwind, so the following pattern is only a 180 to land into
the wind. Thus, a rolling finish is a downwind landing, often in a
substantial wind, with a huge fleet landing in the opposite direction.


Furthermore the pilot in the typical marginal situation, with enough
energy to cross the gate at 50-100 feet with 70-80 kts, has to
dissipate a lot of energy to roll a finish at the far end of the
runway. If not, this pilot would cross the runway threshold at say
100-200 feet and 80 kts. At this point it's really too late to roll
(remember all those guys landing into the wind at the other end of the
runway!) and you don't have enough energy to do a proper flying finish.
Coffin corner.

So the decision to roll - accept a downwind landing into the face of
traffic - has to be made at least a mile or two out, while there is
still substantial energy left and a good chance of picking up 50-100
feet of energy, or misjudging your total energy by 50-100 feet. I think
I can start to sympathize with people who get in this mess.

John Cochrane
BB