Undershoot Vs. Overshoot airport landing accidents
At 21:14 18 April 2019, Paul Agnew wrote:
Lots of great insight to digest...Dive and Drag is an interesting
solution,=
if you have enough runway to scrub off the excess speed
and/or your
spoile=
rs are effective. My ASW19 stock spoilers are just not effective
enough
for=
me to try the Dive and Drag method.=20
Reverse Base Method =3D 180=C2=B0 turn to reverse +
90=C2=B0 turn to final
=
=3D 270=C2=B0 (two turns & wind corrections).
Why not just make a stable, descending 270=C2=B0 turn when
crossing the
fin=
al? In powered, fixed-wing aircraft, it's not unusual to get
assigned a
ri=
ght or left 270 to final by tower to improve spacing on departing
aircraft.=
It's a basic ground reference maneuver that could be adapted
for gliders
s=
o you roll out aligned with the runway.
We're supposed to be able to turn back to land above 200ft with
a rope
brea=
k, which is based on our collective understanding that we can
safely
execut=
e a turn, maintain speed, and align with the runway from that
minimum
altit=
ude. That requires 180=C2=B0 of turn, if the towplane drifted
downwind and
=
you turn into the wind (ideal, but our guys don't). Or, 210-
270=C2=B0
total=
if you have to reverse course, angle for the runway, then turn
back to
ali=
gn with the runway. The second scenario requires multiple, low-
altitude
tur=
ns. Is that ideal?=20
Performing a stable, 270=C2=B0 or 360=C2=B0 turn for
altitude correction
sh=
ould be within out skillset, but only if the excessive altitude is
above a
=
certain threshold for your ship. 100-200ft high? Maybe not the
best
option.=
Clear knowledge of your ship's descent rate in a turn is critical
for
deci=
sion making. =20
That said, I've always been successful with a little slip to correct
for
an=
y excess altitude. Starting the correction on the base leg and
performing
a=
slipping turn to final burns off a lot of excess altitude. (I
learned to
d=
o this with Phil Beale on my CFI-A checkride back in 1986.)=20
Paul A.
Jupiter, FL
When we flew K7 and K13 you could dive against the brakes,
provided you open the air brakes about 50kn then lowered the
nose the speed gain was not too high.If you put on 70Kn then
opened the airbrakes the speed would not reduce much.
However if you try that in a Mk 1 Duo discus you will be zooming
down the runway at 120+kn waiting for the boundary fence.
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