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Ed
McCauley wrote:
One other thought which I hope will spawn
further input, I've been told by many that, given the altitude, one should
consider pulling up and stopping the prop. Again, I've been told that the
flat plate drag drops dramatically. Anyone have any hard info on
this?
Ed, I lost the engine in my Cherokee 235 (constant
speed prop) while at 12,000' MSL near Winslow, AZ way back in '74. (Cause
was a broken camshaft idler gear but we didn't know that at the time) We
were flying eastbound on the way home to Clovis, NM from the Reno Air Races, and
paralleling I-40 on a hot and bumpy late summer afternoon.
The engine quit with a pretty big bang, fully waking those drowsing in
the back seat, then continued to windmill. I noted almost no traffic on the
highway below us and told my wife and friends (4 aboard) that we'd land
there. Mike Verzola, in the right front seat, asked if we could make it
to the airport off our right wing--mark me down significantly for lack
of situational awareness. A quick dip to the right revealed the Winslow airport
about 6-7 miles away--within gliding distance based on my previous "engine
out" practice, so I turned toward the center of the field.
I then tried the mixture, fuel pump, switch
tanks, carb heat--everything I could think of to restart--without result, so I
raised the nose to stop the prop. I was hoping to minimize damage to the
engine--it was shaking quite a bit and still making some grinding noises.
We were well below best glide speed, and very close to stall when the prop
finally stopped; then I lowered the nose to resume best glide. The result was
that we arrived overhead the Winslow airport at about 1300' AGL, well higher
than I expected to be. This allowed me to make a gentle 270 overhead
circle to a normal landing about 1/3 down the
runway.
I had lots of time to reflect on this while the engine
was being repaired, and was particularly interested in why we experienced the
better-than-expected glide. When the plane was flying again, I did a number of
glide tests with the engine turned off (mixture full lean) but with the
prop turning in coarse and fine pitch, and also with the engine stopped (same
procedure I used at Winslow). My results were that the Cherokee 235 would glide
at least twice as far with the prop stopped as with it turning in coarse pitch,
and almost three times as far as with it turning in fine pitch. I'm sure the
prop settings, type engine, load, and many other factors make the actual numbers
for every aircraft different, but it was an important lesson that's stuck with
me.
My other observations about this: Although I used to
really love to buzz around NM at treetop level, this incident almost
completely broke me of the habit; I have never done so since when I had anyone
else aboard. Altitude was life for us that day. We had time to react after the
engine quit--to talk about what happened and what we were going to do, to call
to Flight Service to declare an emergency, switch to 7700 on the transponder,
several steps to try a restart and a chance to select a suitable landing site
and then change for a better one. I also give a lot of credit for a
successful landing that day to my flight training. Training taught me to:
1) Always fly the airplane first; do anything else if/as you can; and 2)
know your airplane and it's capabilities/limitations--it won't do anything
during an emergency that it won't do during normal operations--except
bend.
I intend to evaluate and record the glide performance
of my Lancair during the test phase. I'll decide about stopping the prop as part
of this evaluation after I see how confident I am about landing in that
configuration--based idle-descent-to-landing practice. Given the potential
engine-out range of these planes and the neat navigation aids that can
graphically overlay how far you can go on a moving map display, it seems useful
information to have, and to have it right.
One man's experience and
opinion.
Bob Pastusek
N437RP in the paint shop
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