A lot
of "eyeball engineering" will work just fine up to about 150, perhaps
200 mph.
When you start looking 300 mph in the face, the rules are changing and
the laws
of physics are extremely nasty.
Remember the famous saying of one of the 20th century's great
philosophers -
Harry Callahan: "A man has GOT to know his limitations."
My saying is "The laws of physics will be strictly enforced"
. . . .and they'll kill you in a heartbeat without remorse.
Ya'll be careful out there in the "experimental" part of the flight
envelope.
Bill Freeman
Long EZ builder & pilot
BSME, MSME
EAA Technical Counselor
Geeze Bill,
You're worse than my mother! :-) I can assure you that I have no desire to
become hair teeth and eyeballs all over the ground somewhere, nor am I
looking for a smoking crater to crawl out of. I really don't want to try for
300 mph in a long EZ. Certainly not unmodified. Unfortunately, the Berkut is
out of my current price range. And the engineering required to design and
test a proper airframe would put the price of said airframe up past the
Berkut!! So absent a proper airframe, I'm very comfortable just trying to
make an extremely efficient aircraft. 200 is fast enough for me. It will get
you from point A to point B in a hurry. Plus the faster the plane, the
greater the pain (in an off field landing) Something that I definitely have
in mind, since this IS an EXPERIMENTAL engine. I was being somewhat tongue
in cheek with Paul when discussing trying to go 300 mph.
One of my friends used to be a factory test pilot. He would take the new
planes off the assembly line, fly them to altitude, put it in a dive,
accelerate to VNE and bump the stick in all directions to try and induce
flutter. Talk about pucker factor!!
My real goal with the design I posted was drag reduction, and reduced weight
= better efficiency and performance without sacrificing slow speed handling
or fuel burn. The power of the one rotor engine is somewhere in neighborhood
of 100 hp, which is the same as the original aircraft. I seriously doubt
that the drag reduction would be enough to allow a speed over 220 mph. There
just is not enough HP. But the fuel burn would be reduced and the power
required to cruise would be much less. In a long EZ same story with two
rotors. In fact a single rotor would be enough for the Long, especially with
a CS prop. I believe that Burt's original Long had an 0-200 in it and
actually outperformed Dick's 160 hp aircraft initially. What I would really
like to do is make a single-rotor turbo-compound aluminum engine with a CS
prop. THAT would really sip the fuel.
Light, slick, and efficient is much better than heavy, dirty, and wasteful.
Monty
The Long EZ prototype has (and has always had) a low compression
Lyc O-235 C2C. It never outperformed Dick's 160 hp bird except in
range. ("Pass everything but a gas station"). Actually, if they go high
enough, the big motor birds to OK on range,too.
The LE Vne is 190 kts, IIRC, and some folks are exceeding that. If you
stay in the 220 mph range you'll be about at Vne. Gotta let you know it gets
REALLY stable yet REALLY responsive to the controls at that speed.
Bump the stick to check for flutter and you rattle your eyeballs. Vne
testing was about the hairiest part of the flight test program.
Note my initial comment - "A lot of "eyeball engineering" will work just
fine up
to about 150, perhaps 200 mph. When you start looking 300 mph in the face,
the rules are changing and the laws of physics are extremely nasty."
I do try to be a voice of reason without putting too much of a damper on the
fun people are having experimenting. We need to make sure we have
T/Os and landings in a 1:1 ratio while developing interesting new things.
Ya'll be careful out there!
Bill Freeman
Long EZ builder & pilot
BSME, MSME
EAA Technical Counselor
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