REFLECTOR:Stall Characteristics

Scott Baker reflector@tvbf.org
Tue, 11 Nov 2003 20:12:58 -0500


Scott,
All I'm saying is that:
1) The aircraft is not designed to perform aerobatic flight and especially
slow speed aerobatic flight such as hammerhead stalls
2) I wasn't born yesterday, and while I don't at all pretend to be an expert
at aerodynamics - as a CFI with close to 1,000 hours of flight experience in
Velocity aircraft - I am would be quite worried about inviting a deep stall.
Opinions do matter.  What makes you take one CFI's opinion as gospel and
discount another's as garbage?
3) The purpose of my message was to get people thinking about the
consequences of a deep stall and to act responsibly.  I really don't know
how the aircraft will behave following a hammerhead type maneuver.  If
someone has been there - done that, I would love to hear about their
experiences.  I don't think that anyone has - I know the current flight crew
at Velocity have not - and so the subject is open to speculation.
4) Unless you have personal experience - or know of someone who has personal
experience who can testify as to the aircraft's behavior following a deep
stall - I think it is dangerous to offer an opinion that the aircraft is
(deep) stall proof.  I think the aircraft can be deep stalled - I think the
aircraft can recover from a deep stall - but I think it will take several
thousand feet of altitude and an engine/propeller combination that offers
thrust to help the aircraft out of the stall.
5) If we were to judge which opinion should prevail - caution vs.. "go
ahead, nothing bad can happen" ... guess which opinion I'm going to listen
to.
I don't understand why you are so defensive regarding an issue that if you
were wrong, could cost someone serious injury or death.
SB

----- Original Message ----- 
From: "Scott" <scott@tnstaafl.net>
To: <reflector@tvbf.org>
Sent: Tuesday, November 11, 2003 6:58 PM
Subject: Re: REFLECTOR:Stall Characteristics


> At 11:19 AM 11/11/2003, you wrote:
> >I think that those who are debating the stall characteristics of the
> >Velocity are making associations to the aircraft's behavior when it is
put
> >into a normal "pitch-buck" kind of stall.  Yes, the front wing looses
lift.
> >Yes, the nose drops when the canard stalls - but does the nose fall
> >(primarily) because of the CG of the aircraft - or is the nose drop
"helped"
> >by the fact that the main wings are continuing to develop lift?
>
> Scott,
>
> It would be prudent to get ahold of somebody who knows the aerodynamics of
> a canard to speak about this matter.  You have or had 3 CFI's that work
and
> fly these things every day.   I have talked to two of your paid  A&P/CFI
> types and they told me in no uncertain terms you cannot deep stall the
> Velocity if it is within gross weight and CG.  Now maybe they were
> referring to everyday kind of flying, I don't think so.  I was pretty
clear
> about my question.
>
> >What do you suppose might happen if a Velocity were lifted by a balloon
and
> >then released?  With no airflow over any of the control surfaces the
pilot
> >can "pump" the controls like mad ...and even with the propeller running,
> >nothing would happen until sufficient air flow is traveling over the
control
> >surfaces.
>
> PURELY HYPOTHETICAL , that's what that is.   Scott you are associating the
> aft cg deep stall flying characteristics and making the leap that that
> scenario apply's to a properly weighted aircraft.  With no basis in
> engineering analysis or practical experience.
>
> >We all know how light the nose weight is in our aircraft.
>
> Oh yeah, have somebody sit in the front seat and try to lift the
> thing!  Ever done that?  Its plenty heavy.
>
> >   If the
> >aircraft were dropped in a level attitude, would the gravitational weight
of
> >the nose overcome the upward force of the air on the canard - in other
> >words, without forward motion over the elevators, and without the main
wings
> >lifting the rear end of the aircraft, is the nose going to drop ... or
will
> >the forces of the air under the canard keep the nose from dropping while
the
> >aircraft is falling?
>
> You don't know do you?
>
> >I've never tried to initiate a deep stall (I don't think I'll ever have
the
> >tempted)!  Recovery (in my opinion) is linked to forward air speed.
>
> Ah, we finally get to the meat of your argument,  this is "your
> opinion"....  Well we all got those....
>
> Scott
>
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