panamared5(at)brier.net Guest
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Posted: Tue Jan 23, 2007 6:53 am Post subject: Aerobatics, Power Management |
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Alan Cassidy wrote a good book called "Better Aerobatics". He discusses
power management in great detail. Basically he states maintain max power
at all times (I think he is talking mainly about competition aerobatics
where energy management is much more critical than in fun aerobatics where
if you run out of energy, take a break and get it back, not suppose to do
that in competition). In an purpose designed aerobatic machine this makes
sense. But I find in the RV during a downline, if I use full power it is a
very short downline, hard to get one vertical roll, let alone more on the
vertical downline. That RV can really accelerate going downhill. To make
the RV a better aerobatic machine, it needs more drag built in.
If you have a constant speed prop it is not too much of a problem as the
prop will act somewhat as a brake, but with a fixed pitch prop, I reduce
power whenever in a vertical downline. As for loops, on the backside I
sometimes reduce power, or will maintain max power if the next maneuver
requires a lot of energy, i.e. a hammerhead. For a Split S enter at
or below entry speed (I use 100 KTS), if you use full power, then use more
G to keep the speed below Vne, if you retard the power, then use less G to
complete the maneuver. Alan Cassidy discusses this strategy in his book.
As far as shock cooling and all that stuff. My TBO is 2000 hours non
aerobatic, or 1200 hours aerobatic. Aerobatics are hard on the
engine. Dick Rihn (father of: Dan Rihn, designer of the Aerobatic One
Design) told me once that snap rolls and tailslides are real hard on the
crankshaft. I believe him, and I do not routinely do either. I don't mean
to start a controversy about this, but he is a much more experience
aerobatic pilot that I and I would be foolish not to heed his comments.
People sometimes tell me that there is no such thing as light IFR. I do
not do IFR, but I sometimes think there is no such thing as light
aerobatics (gentleman aerobatics). They tell me they will never do a 6G
maneuver and I answer, would you do a 6G pullout to avoid going Vne, or
impacting the earth?
A well planned and executed aerobatic maneuver is so easy to do if done
right, if done wrong it is the most gut wrenching difficult thing you can
imagine. An example, for a slow roll (used in many aerobatic maneuvers,
cuban, immelman etc.) you use top rudder when in a 90 degree roll
attitude. But, if you get confused on what will be the top rudder (like in
a cuban and you use bottom rudder by mistake, then this gentleman
maneuver becomes aishow exciting.
Of course Charlie in your case, I am preaching to the choir. BTW, my
sister was a former T-37 instructor pilot.
Bob
Quote: | I'm an old fighter pilot and former spin instructor in the T-37.
Consequently, I have little fear of aerobatics and/or spins, erect or
inverted. I do realize the RV is not a hard acro bird, and don't plan
anything other than gentlemen's aerobatics. However, all my
experience is (was) in jets and I've done very limited acro in a
conventional powered airplane.
My questions pertain to power management doing acro in an RV (or any
conventionally powered airplane for that matter.) What does one do
with engine power in a loop or split S? Any difference between fixed
and constant speed props? Should I be concerned about shock cooling
while doing acro? I'm really talking about planned power changes and
not emergency power reduction because the nose is buried and the
speed is approaching Vne.
Can anyone recommend a book regarding conventional aerobatics?
Charlie Brame
RV-6A N11CB
San Antonio
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