showing an angle number. But that wasn't my point.
I didn't describe my point well. My comment referenced the AUS report:
various speed ranges and included the stall speed of the aircraft. The stall
aircraft. The displayed stall speed was known as the G-corrected stall speed.
stall speed. The 1G stall speed had to be manually entered into the EFIS. The
stall speed' ... not a stall angle, AOA.
relative wind. -- : that increment. An instrument should present these two
wing's AOA. The pilot's mind instantly knows what's happening.
the relative wind ... and not see some number that refers to the AOA. Pilots
they need to see that too, to see how much ... so they can quickly and
accurately move their wing to a sub-stall angle.
less confusing to leave 'speed' numbers out of it
altogether.
confused about the most basic thing about flying an airplane... the
from the stratosphere to the ocean. All those people died, and all of us
suffered because of it.
Thanks for giving me a chance to correct and clarify my comment.
[Not a problem... it's
always an interesting discussion. In reality both the vane-type and pressure-port sensors display the same information, albeit a bit
differently. Both work, the user just needs to understand what it is that s/he's looking at. Too many people forget that you can stall an
airplane at just about any airspeed, but a particular wing will stall at only one angle of attack. Since most training aircraft don't include an
AOA indicator the training focus is shifted to the airspeed because it's the only thing available. Forgetting that the stall speed increases
with wing loading (weight, angle of bank, control inputs, etc) is what comes up and bites even the seasoned pilot who doesn't keep the AOA vs airspeed
reality separate. <marv> ]
On Jan 8, 2013, at 4:07 PM, <marv@lancair.net>
<marv@lancair.net> wrote:
> Posted for Terrence O'Neill <troneill@charter.net>:
>
> Jeff,
>
>
Interesting Australian TSB report. I might offer one observation:
> Here an aircraft included an AOA of a type which showed stall, in
terms of
> speed being calibrated for 1G. The report refers to stall in terms of
>speeds.
> I note that this was a
pressure-differential-type AOA, which I think does not
> offer the pilot any information as to how many degrees the wing is at above
>
the wing's stall angle to the relative wind ... so that the report's
>reference
> to a deck or horizon angle is
meaningless. A vane-type AOA instrument
>reading
> out in degrees which would give the pilot an idea of how much he had to
pitch
> down to unstall the wing, would be informative to pilots ... for example, as
> in the unfortunate AirBus airliner crash where
the three high-time pilots
>held
> the wing at a stalled angle all the way down to the ocean, complaining on the
> recording in
the black box that they 'did not undertstand what was
>happening'.
> What does that tell us?
> Terrence
>
> [Not
true... the AOA Pro has a digital readout at the bottom of the display
>that shows angle of attack to the 10th of a degree. While
the Sport model is
>just a series of lights, its operation is the same. While it doesn't have an
>angular readout the display
goes from the AOA when the wing is making zero
>lift (pressures equal top & bottom of wing, determined with zero-G maneuver
>during
calibration... there would be no lights illuminated on the display at
>this point) to the AOA at which the wing stalls (all the lights on &
bitchin'
>Betty going nuts). Transition from top yellow light to bottom red light
>happens at the airspeed 15% above the
stall speed, regardless of CG, temp,
>gross weight, angle of bank, time of day, etc. SInce the wing will always
>stall at the
same AOA (somewhere around 16-17 degrees) that means that the red
>light comes on around 12 degrees. I would imagine someone with a
PRO could
>give the exact number, as the relationship is the same on it, with transition
>from yellow to red at 15% above stall speed,
again, which always happens at
>the same AOA. I hope this clears up that misunderstanding.
>
> <marv> ]
>
>
>
> On Jan 8, 2013, at
10:25 AM, vtailjeff@aol.com wrote:
>
> > For a good read see the following accident report from the Australian
> >Transport
Safety Board on a LIVP turbine accident. Be sure to read the
> >analysis.
> >
> >
> >
> >
Jeff
> >
> > -----Original Message-----
> > From: Ron Galbraith <cfi@instructor.net>
> > To: lml
<lml@lancaironline.net>
> > Sent: Tue, Jan 8, 2013 8:32 am
> > Subject: [LML] Re: Stalls & Spins
> >
>
> There is an ES video that shows what happens when you stall an ES at full
>aft
> >CG. Spins immediately, takes 2.5
turns and 3000' to recover. Test Pilot
>was
> >one turn from bailing out. Install an AOA system, install stall
strips,
> >practice flying at low speeds and learn what impending stalls feel like. The
> >airframe gives you many indications
that you are too slow. Learn them. Fly
> >safe.
> >
> > Ron
> >
> >
Sent from my iPhone
> >
> > On Jan 8, 2013, at 8:34 AM, George Wehrung <gw5@me.com> wrote:
> >
> >>
John,
> >>
> >> I would be interested in watching some of the videos on the ES in
>particular
> >>if not
the other airframes. Are they posted on the Internet by chance,
> >>doubtful but I thought I'd ask.
> >>
> >>
> >>
> >>
> >> Sent from my iPhone
> >>
> >> On Jan 8, 2013, at 15:50, John Smith
<john@jjts.net.au> wrote:
> >>
> >>> From my perspective, the key phrase is spin resistance.
> >>>
> >>> Having researched the NASA material and having also seen the Lancair
>videos
> >>>of actual flight
testing, rightly or wrongly, I installed the wing cuffs
>to
> >>>the Legacy on the basis that they seemed to offer the
opportunity to make
>it
> >>>harder to get into trouble, but accepting that if pushed too far into a
>spin,
>
>>>then the aircraft may or may not be recoverable. So, if one accepts the
>view
> >>>of many which is that "as was",
the aircraft was not spin recoverable,
>there
> >>>would only appear to be upside from installing the cuffs. The flaw is, of
> >>>course, that if indeed the Legacy is spin recoverable without wing cuffs,
>then
> >>>the addition of the
wing cuffs may preclude spin recovery!
> >>>
> >>> Unless someone goes to the trouble of spin testing the Legacy, or
any
>other
> >>>type fitted with cuffs, one will never know whether spin recoveries are
> >>>possible under
what flight and loading circumstances and, of course, with
>or
> >>>without wing cuffs.
> >>>
>
>>> Meanwhile, per my prior post on this, all I can say is that the albeit
>very
> >>>limited flight testing (straight
and level, and continuous 30deg AoB
>turns) in
> >>>my Legacy fitted with the cuffs shows that there is plenty of warning of
>the
> >>>impending stall – stall strips give the first "gentle" warning", followed
>by
> >>>the more
severe intermittent "shuddering" as the centre section drops in
>and
> >>>out of the stall (whilst the outboard sections are
still flying).
> >>>
> >>> I'm happy to talk to anyone if they are interested to talk about this
>more….
> >>>numbers below, but please note time is UTC + 8!!
> >>>
> >>>
> >>>
Regards,
> >>>
> >>> John
> >>>
> >>>
> >>> John N G Smith
>
>>> Tel / fax: +61-8-9385-8891
> >>> Mobile: +61-409-372-975
>
>>> Email: john@jjts.net.au
> >>>
> >>>
> >>>
From: <marv@lancair.net>
> >>> Reply-To: Lancair Mailing List <lml@lancaironline.net>
> >>> Date: Tuesday, 8
January 2013 2:25 AM
> >>> To: <lml>
> >>> Subject: [LML] Re: Stalls & Spins
> >>>
>
>>>
> >>>
> >>> Posted for "Peter Field" <pfield.avn@gmail.com>:
> >>>
>
>>> Dear Lancair Drivers:
> >>>
> >>>
> >>>
> >>> I've been following the
discussion on stalls and spins and I want to add
> >>> some additional factual information purely for your personal consumption
>and
> >>> reflection. Attached are excerpts from 10 different 1980-90 NASA flight
> >>> test final
reports on a series of GA airplanes in which NASA evaluated
>the
> >>> use of cuffs on leading edges to improve the behavior of
the test
>airplane
> >>> approaching the stall. For various reasons the cuffs improved lateral
> >>>
control entering the stall, but had the adverse effect of destabilizing
>the
> >>> aircraft once a fully developed spin was
achieved. Essentially, stall
> >>> behavior was improved at the sacrifice of spin recovery. Cuffs on wing
>
>>> leading edges are an add on design fix, the more elegant solution is
> >>> "washout," where the wing is twisted so the
outer portions of the wing
> >>> always operate at a lower angle of attack.
> >>>
> >>>
>
>>>
> >>> To my knowledge, Lancair has never subjected any of their aircraft to a
> >>> fully developed spin
matrix complete with appropriate instrumentation and
>a
> >>> spin recovery chute. There is no FAA requirement for
them to do so -
>it's
> >>> an Experimental Category airplane. Early on they may have lightly
>touched
>
>>> on such testing; but I have never seen any documentation on a fully
> >>> completed spin matrix, which would involve at
least 160 spins at various
> >>> cg's and lateral loadings. In my opinion, it would be highly risky to
>fool
>
>>> around much beyond the stall in any Lancair - there is no documentation
>that
> >>> indicates any of these
airplanes can always be recovered from a one turn
> >>> incipient phase spin or any fully developed spin. Being good at
spin
> >>> recovery isn't so much a matter of how skillful a pilot you are, it's a
> >>> matter of how many spins you've
experienced in airplanes known to be
> >>> recoverable. Being familiar with the stall characteristics of your own
>
>>> airplane should be a matter of personal preference.
> >>>
> >>>
> >>>
>
>>> Best regards,
> >>>
> >>> Pete Field (LNC2)
> >>>
> >>> USNTPS graduate
& spin recovery instructor
> >>>
> >>>
> >>>
> >>> -- For archives and unsub
> >>>http://mail.lancaironline.net:81/lists/lml/List.html
>
>
> --
>
> For archives and unsub
http://mail.lancaironline.net:81/lists/lml/List.html