REFLECTOR: MODIFICATIONS

Mon Jan 3 11:09:18 CST 2005

Scott;

And number 5. according to Duane - keep full power applied.  He says that in
about the same time that it takes to rotate when taking off, the engine
should get the plane flying again.

OH, and number 0, don't get into the situation where a flat stall can occur.
I see too many people fly too close to limits, just above stall speed when
in the pattern, and just practicing stalls.  Sort of practicing walking on a
high wire.  You can learn how to do it but WHY????

I have a good friend who loved to fly aerobatics, including inverted flat
spins.  But the last time he tried it (and he is a VERY experienced pilot
with lots of Aerobatic hours), he was not able to recover (well actually he
did - but he was just above the ground), and smacked into a hanger.  Luckily
he survived - folks were near by to pull him out - but his nice new
aerobatic plane and the hanger were destroyed in the fire.

I have a 1000 hours flying, but I see no sense in pushing the limits.  I fly
nice wide patterns with plenty of margin above stall, and I don't make steep
turns in the pattern.  But let me shut up before I have to eat my words!!!

HAPPY NEW YEAR EVERYBODY!!!
Ronnie

----- Original Message ----- 
From: "Scott Derrick" <scott at tnstaafl.net>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Monday, January 03, 2005 11:35 AM
Subject: Re: REFLECTOR: MODIFICATIONS

> To really test AFT CG all you need to do is:
>
> 1.)  Install a weight shifting mechanism like Danny did in Big
> Orange.  This allows the pilot to change the CG in flight.  If a stall is
> experienced  he just cranks the weight forward until the airplane flies
out
> of it, hopefully! :-)
>
> 2.) Wear a parachute and be prepared to use it.  Practice the procedure
you
> would use to exit the aircraft so you can do it under pressure.
>
> 3.) Do all flight testing at a high attitude,  I'd be at least 6,000 ft
AGL.
>
> 4.)  Be prepared for the possible loss of your airplane.
>
>
> As far as Danny's admonition to not use a bigger engine, he's probably
> right and wrong.  Remember Rutan telling Danny a safe side by side canard
> could not be built!  Once Danny proved it was possible Rutan licensed the
> Cozy to NAT.  All these designers do not want their designs changed.
First
> and foremost is because people do some really bonehead and deadly things
to
> them.  Second they are liable, depending on how a court will interpret
> things.  Third the design is their baby and they have considerable ego
> involved...
>
> Scott
>
>
> At 10:25 PM 1/2/2005, you wrote:
> >I wish there was a way to determine by testing where the aft c.g. limit
is
> >on a Velocity, the c.g. at which a deep stall occurs.  My wing is one of
the
> >original short chord wings, and I haven't installed the wing cuffs yet.
I'm
> >hoping that the vortex generators will help more than the wing cuffs
would.
> >
> >In the June 5, 1990 newsletter, Dan Maher was pretty adamant that a heavy
> >engine, even though the c.g. was correct, could increase the risk of a
deep
> >stall situation. He writes:
> >
> >"In our flight testing, we have been experimenting with the pitching
moment
> >of the aircraft by adding weight in the aft of the airframe, aft of the
CG,
> >and adding ballast in the nose to compensate for it.  We have found that
> >even though the aircraft is in the proper CG for safe flight, the
distance
> >of the major mass centers from the center of gravity has a tremendous
effect
> >on the pitch stability, which is manditory [sic] for safe operation. The
> >further from the CG, or closer to the nose and tail the center of masses
> >are, the more dangerous the aircraft becomes when the aircraft is pitched
in
> >flight by either the pilot or the flight environment. This pitching
motion
> >is only overcome by the flying and control surfaces of the aircraft. If
the
> >inertia is too great, the aircraft can be pitched into a dangerous
> >situation, like a deep stall or a PIO which is extremely dangerous in
> >landing situations. As a result of this information, we are requesting
that
> >you do not install constant speed propellers or heavier engines to the
> >Velocity. The 200 HP Lycoming, with all accessories, wet, and with a
wooden
> >propeller, weighs approximately 375 lbs (baffling & mount included). It
has
> >an arm of 163.5". This is ABSOLUTELY THE AFT LIMIT. A heavier engine
> >installation, or one with a longer arm will make the Velocity very
> >dangerous. So check the weight of your installation. If it exceeds 380
lbs,
> >and/or its CG is more than 18.5" aft of the firewall, DO NOT INSTALL IT.
The
> >total moment of the installation must not exceed 61,500 in-lbs."
> >
> >The caps are his.
> >
> >On the other hand, Alan Shaw told me that the deep stall incidents
wouldn't
> >have occured if the planes that stalled had been built and loaded
correctly
> >to begin with, and that the big engines are no problem. And I think he
knows
> >a lot about Velocities.
> >
> >In Velocity Views #37 there was mention of another deep stall incident,
but
> >not much was known about the airplane's configuration. Does anybody have
any
> >more information about that situation?
> >
> >Anyway, I wish there was a way we could test for deep stall without
risking
> >the airplane.
> >
> >Douglas Holub
> >DMO-055, Standard FG with a retractable nose gear, 50% done after 18
years
> >
> >
> >----- Original Message -----
> >From: "Dave Black" <dvblack at comcast.net>
> >To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> >Sent: Sunday, January 02, 2005 2:18 PM
> >Subject: Re: REFLECTOR: MODIFICATIONS
> >
> >
> > > > Tom,
> > >
> > >
> > > > I am suspecting my safe
> > > > envelope would be similar to other Elite RGs ... but the extra
> > > > weight in the back would no doubt have an effect.
> > >
> > > Your safe CG range should be IDENTICAL to all other LongWing Elites.
Your
> > > engine will not change that. The addition of your heavier engine
farther
> >aft
> > > simply means your particular plane will be more tail heavy.
> > >
> > > On my shortwing RG (not yet flying) the CG will be at aft limits with
a
> >single
> > > pilot, and at forward limits with two up front. That's just how big
the CG
> >box
> > > is. The rear seat has nearly no effect on CG. With your additional aft
> >weight
> > > and CG, you will need to load equipment or ballast forward in order to
> >keep
> > > the CG safe while flying alone. You might want to move the battery
farther
> > > forward.
> > >
> > > As far as finding out for certain what your specific CG and weight
range
> >is,
> > > that should be done during flight testing. Load the plane toward
different
> > > corners of the CG box and see how it performs at various speeds and
> > > configurations. Gradually expand the range in all directions. Have a
way
> >of
> > > changing CG during flight in the event you reach an uncontrollable
> > > configuration.
> > >
> > > As I understand it, of the two CG limits the aft limit is the more
> >dangerous.
> > > While forward CG will reduce elevator authority, exceeding aft CG
makes a
> >deep
> > > stall possible. Just a gut feeling: Your plane is unlikely to exceed
> >forward
> > > CG in any normal loading situation. But you need to be very careful
with
> >your
> > > aft CG. If CG is out of the aft limits the plane will fly beautifully
> >right up
> > > until it goes into a deep stall.
> > >
> > >
> > >
> > > We once owned a Cardinal RG. Before purchase I noticed at least half
of
> >these
> > > had nose gear damage history. Turns out it was not a defect in the
nose
> >gear,
> > > but in the CG. The plane is right at forward CG with a single pilot,
and
> >can
> > > exceed forward CG with two up front. After doing some W&B
calculations, I
> > > found that a single 100 pound pilot flying with 20 gallons of fuel
could
> >load
> > > the entire remaining legal weight flush against the aft cargo bulkhead
and
> > > still be within aft CG limits. There was simply NO way to load this
plane
> >out
> > > of aft CG without also loading it beyond weight limits.
> > >
> > > When we bought our V35-B Bonanza, I found the exact opposite. In that
> >plane
> > > you could load virtually the entire useful load under the pilot's feet
and
> > > never exceed forward CG. Aft CG was very easy to exceed, however --
> >especially
> > > with that huge cargo area.
> > >
> > >
> > > Dave Black
> > > Shortwing RG
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>
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>
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