Giving this some more thought, perhaps the problem isn't as much the wake generated by a coupe, but the limited control authority of a coupe for dealing with any wake. Since we don't have either any rudder pedals, or very limited rudder authority, that may be part of the answer. In a conventional 3 control airplane, you naturally use all, or nearly all of the rudder pedal travel along with full aileron deflection to either roll very fast, or to recover from an unintended roll or upset. Since the coupe suffers in the rudder control and authority areas, I bet the real problem is not the wake generated by the leading airplane, but is the inability of the coupe to deal with it. This may be a warning to all coupe pilots to be especially careful of the wake of any other airplane. What do you think?
Jerry Eichenberger
Columbus, Ohio
N2906H
>>> Jerry Eichenberger <[EMAIL PROTECTED]> 03/24/98 05:24PM >>>
Dave - As one who has done considerable formation flying, albeit in
airplanes much faster and heavier than the coupe, I don't think anyone
should try any kind of formation work, icluding but not limited to
landings, without a very current and competent instructor and lead pilot,
both of whom are very experienced formation flyers. Self teaching will
lead to disaster.
Secondly, when you talk about "propwash", do you mean wake turbulence?
I've never flown behind a coupe, so I haven't experienced what you talk
about. Generally, the violence of an airplane's wake is directly related
to weight and the lift being produced by the wings, and washing up from
the lower surface to the upper, at the wing tips. Since the coupe is so
light, and the total lift is therefore not very great, I wonder why the
turbulence is more than other airplanes?
Being a glider pilot, we train students to box the wake of the tow plane.
Often, the tow ships are Pawnees, L-19s, and other airplanes significantly
heavier and faster than is the coupe. While the glider pilot surely feels
the wake as he descends thru it, the glider, being of course, very light
itself, is in total control at all times during this maneuver. The
towplane's wake is encountered at least once every time that this training
is done. Of course, since tow lines are usually 200 feet long, the glider
is 200 feet behind the towplane, so the wake has dissipated some, but not
much.
I'm mystified why the coupe has such a great amount of wake turbulence.
As one who has studied both the physics and effect of wake turbulence
quite extensively, I wonder why that is. If anyone can help educate me,
please do.
Jerry Eichenberger
Columbus, Ohio
N2906H
>>> Mi Vida Loca <[EMAIL PROTECTED]> 03/24/98 04:26PM >>>
As someone who has flown a lot of formation and group flight I would like
to pass along a tip on group landings at a strip where there is only a
runway and no taxiway. You have 3 options.
1 each plane lands, turns around and back taxis as quickly as possible
2 each plane lands goes to the end and pulls off on the grass and all
taxi
back together
3 land go to the end pull over to one side of the runway and then turn
at a
right angle to the runway pointed at the opposite side of the runway.
Doing
this allows you good vision (either at your 3 o'clock or 9 o'clock
position) of the next aircraft coming in behind you and positions you so
the shortest distance off the runway is straight ahead in case his brakes
fail in which case you just add power and you are gone. The pilot will
have
no question where you will be going to get out of his way so no confusion.
The next plane down does the same but facing the opposite direction, each
subsequent aircraft alternates until everyone is down.
The lead should land as far down the runway as practical with each plane
following touching down progressively shorter. In this way you can get the
whole group down in far less time. Since the coupe has a really nasty prop
wash I also suggest either keeping good spacing between each aircraft or
each following aircraft flying a slightly steeper approach. (remember a
prop wash sinks.) If the runway is wide enough stager, one landing on one
side and the next the other side and so on. With practice, landing in
trail
with spacing as little as 100-150 feet is no problem. And with practice
you can have 3-4 aircraft all touching down at the same instant, _very_
impressive to the locals. As a courtesy though you should quickly test
your
brakes to insure that are working and announce they are working so the guy
ahead of you knows he is ok and can continue braking. This is best done by
simply announcing over the radio your position. When landing in formation
I
always call out my position number as soon as I touchdown and establish
braking. I simply call out one word "two" this lets Bill know I'm down and
under control, he is now free to brake hard, if need be cross over in
front
of me. Don't clutter the airway with needless chatter. Keep the radio
traffic short but concise.
One word of caution do not get into a coupe's propwash at low airspeed. It
can be extremely dangerous. A coupe has one of the nastiest prop washes
around, this is the voice of experience. I've seen it turn a trailing
aircraft 90 degrees up on a wing tip. On one occasion taking off in
formation from a very narrow runway which necessitated over lapping
wingtips I got sucked (fell back too far) and got into Bill's propwash on
climbout. I found myself flying sideways with the controls full over and
NO
CONTROL. It probably only lasted 2-3 seconds but at 25-50 feet it was a
lifetime.
Go up to altitude and start working around behind another coupe to get the
feel of where the propwash is and what it does to you, as you get the feel
do it at progressively slower airspeeds, gets worse the slower you get.
When you know the beast and where it lives you will have no problems in
the
future.
If there is interest in formation flying I will be more than happy to
discuss this, otherwise I'll try to remain mum on the subject. It is the
best flying there is though and is far safer than the traditional same
way,
same day group flight.
Tailwinds to all,
Dave
41 Charlie
Dave's Ercoupe Page
http://www.flash.net/~dmprosvc/dave
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