Email this Article
Printer-Friendly
Reader Comments
[Editorial]
WHAT’S ALL THIS CANYON TURN STUFF, ANYHOW?
Bob Pease
ED Online ID #17877
October 25, 2007
Let’s say you’re flying a
light plane, and you fly
up into a canyon at
8000 feet. At 8000 feet,
your turning radius is perhaps
600 feet. The canyon is 1000
feet wide. You’d like to turn and
get out of the canyon, but
there’s no room to turn. And the
canyon floor is rising too fast for
you to be able to climb out. Are
you dead?
Maybe not. I have been studying
this for several years. Our
good friends lost their daughter
in a flying accident in a box
canyon, just like that, about 10
years ago. She and another student
pilot died in the crash,
along with the certified flight
instructor. I still cry about that. A lot. Especially today. How
can you get out of this trap?
(a) Put down your flaps to 10°
or 15° (or maybe 20°) to
increase lift and drag. Apply
full throttle. Do not let speed
build up. Do not let your altitude
above the
canyon floor
get small.
Turning radius may be
600 feet at full speed,
but it may be smaller under
those conditions. You can turn
a lot better. Flaps and power
help you maintain control and
avoid stalling. Maintaining
some altitude above the
ground can be extremely
important in view of (c).
(b) Get way over to the right of
the canyon, maybe 40 feet
from the wall. I say to the
right, because the flight
instructor (or pilot in charge) on the left should be in
charge of these fairly dangerous
maneuvers. He has to
use his best judgement. His
feel for what the plane is
doing is very important.
When he cocks the
ailerons and pulls back on the
yoke, it may be very close to
a stall. You gotta have a feel
for that. It’s also true that the
engine’s torque may help you
turn left better than right. (If
the canyon is deepest on the
right, get over to the left. Or if
you know there’s a crosswind
from the right, turn toward it.)
(c) Make your turn early, make a
hard turn, and let the plane
descend. Use the plane’s lift
to pull you around in the
tightest possible safe turn that
you can do without stalling. If
you tried to hold altitude, you
will probably stall and crash.
But if you let the plane
descend to the left, you have
a better chance. That’s
assuming you are somewhat
above the canyon floor.
(d) Do not fly up into canyons.
Never. If you want to check out a canyon, always come
in from above and descend
—assuming the canyon does
not have excessive sharp
turns or narrows (of which
there may be many).
(e) Under conditions of full
power but lowered flaps, you
may be flying at 55 or 45
mph depending on the headwinds.
So even if planes
aren’t exactly as bust-proof as
cars, you have some chances
of surviving a 50-mph crash.
Not so at 85 mph.
The flaps may get you
around the corner. There’s no
guarantee, but that’s what I
would bet on. Better odds—
and a better chance for a
good pilot’s skill to help. Of
course, a really good pilot
would never get you in that
bind in the first place. A cat
will not crawl into a hole
where his whiskers scratch
the walls.
(f) If you live in flat country, you
may never have to worry
about this. But if you live
near mountains, you would
definitely want to practice
this at a safe altitude, out in
the open, so if you stall, you
have a lot of air under you to
recover. You may not be able
to judge how much space
this maneuver takes, but you
can get a feel for how the
plane feels and handles.
(g) If you were in a very narrow
canyon, maybe 200 feet
wide, you could zoom up,
cut speed, apply some flaps,
do a half-roll, cut power way
back, and finish your halfloop.
However, this is not
legal for most light planes,
and it might cause excessive
G’s or speed. It still might
save your life—if you were
600 feet or more above the
canyon floor.
MOUNTAIN PASSES
Do not fly directly toward a
high mountain pass trying to get
across. If you have a large altitude
margin, you might do that.
But if you aren’t sure, don’t try
to fly toward the pass.
Circle around on the right. If
your altitude is okay, then you
could fly up to the pass and go
ahead and veer right across the
pass. But if you are kind of skeptical,
and you think there may
be downdrafts, or if you aren’t
sure there will be enough
updraft, veer left and go around
again. Try to get a little higher
and burn off a couple gallons.
You may have much better luck
on the next try.
Too many pilots have failed
and crashed because they were
confident they could get over a
pass. But downdrafts can be
very nasty and can be the
downfall of “confident” pilots.
The Alaskan bush pilots who are
alive today have learned from
such advice.
See associated figure.
|