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Lancair crash at SnF



 
 
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  #81  
Old April 25th 08, 01:12 PM posted to rec.aviation.piloting,rec.aviation.student
Stefan
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Default Lancair crash at SnF

WingFlaps schrieb:

I see the problem. You don't know what velocity is. It's a VECTOR. It
changes when you turn. If you don't understand this there's not much
point talking about anything that involves physics....


Actually, I know an awful lot about physics.

In everyday's language, the word velocity stands for the _magnitude_ of
the vector. Now if you want me to realise outside some technical or
scientific environment that you use the word velocity in the vector
sense, you better say so explicitely. Still easier would be to say
"direction".
  #82  
Old April 25th 08, 01:18 PM posted to rec.aviation.piloting,rec.aviation.student
Stefan
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Default Lancair crash at SnF

B A R R Y schrieb:

I'd rather hit a bus shelter or light poles @ 40-50 MPH than go in
inverted after a stall/spin @ 200-300 AGL.


But I hope that you rather risk a stall/spin than to hit a crowd of
pedestrians with that meat chopper turning.
  #83  
Old April 25th 08, 01:26 PM posted to rec.aviation.piloting,rec.aviation.student
WingFlaps
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Default Lancair crash at SnF

On Apr 25, 11:23*pm, Stefan wrote:
WingFlaps schrieb:

A direction change in a
plane is always due to acceleration (and that means more drag). That's
Newtonian physics.


Right.

You go from up wind direction (takeoff is usually
up wind) to turn in the wind direction to land down wind. There's an
acceleration, it is a change in _velocity_


Wrong.

it creates drag, it costs
height and that's the important bit. Now do you understand -TURNS are
not free,


Right.

Your're mixing up two completely different things. Of course, turns are
never "free". They cost energy due to higher drag, resulting from higher
speed, higher wingload and control deflection.


I'm not mixed up, You wanted to read something into what I wrote that
was not there and try to score some point I think Well you were wrong
and you still are. I never said airspeed did I?

One last time, as succinctly as I can: to change direction requires
more energy as extra drag = k.m.dV/dt. dV/dt is acceleration and that
is precisely the term I used. The aircraft does _accelerate_ into the
downwind direction. Airspeed may not change but _velocity_ sure as
hell does -'cos IT'S A VECTOR. Now, the energy needed for the change
in _velocity_ comes from the loss of height during the turn and that's
easy to calculate. It is much harder to estimate the extra drag loss
as this will depend on pilot skill and aircraft design. I hope you
finally understand, cos I'm really starting to find it tiresome trying
to explain to you some basic physics which you seem intent on mis-
interpreting.

I'll give you this last post, any continuance along your previous
lines of putting erroneous words into my mouth I will take as your
being a troll...

Cheers

  #84  
Old April 25th 08, 01:31 PM posted to rec.aviation.piloting,rec.aviation.student
Maxwell[_2_]
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Posts: 2,043
Default Lancair crash at SnF


"Bertie the Bunyip" wrote in message
...
Larry Dighera wrote in
:

On Fri, 25 Apr 2008 01:27:52 +0000 (UTC), Bertie the Bunyip
wrote in :

The best way to do it is with a steep bank. Very steep.



The bank angle may be quantified:



Good grief Larry, you really are an idiot.
Of course it can be quatified, but the numbers only tell a minute part
of the story. I can categorically state that I can do a 180 with 70 deg
bank at VSO 1.2 deadstick and come out the other end in one piece. Can
you? Try it using those figures and send my the answer via my Ouiji
board.


Bertie


There ya go, take a lesson from Dudley. If you can't dazzle'm with
brilliance, baffle'm with bull****.



  #85  
Old April 25th 08, 01:32 PM posted to rec.aviation.piloting,rec.aviation.student
Maxwell[_2_]
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Default Lancair crash at SnF


"Bertie the Bunyip" wrote in message
...
WingFlaps wrote in
:

On Apr 25, 8:50 pm, Bertie the Bunyip wrote:
Larry Dighera wrote
innews:3ui2149cg0sac5dsdsi4f05v8t42

:

On Fri, 25 Apr 2008 01:27:52 +0000 (UTC), Bertie the Bunyip


wrote in :

The best way to do it is with a steep bank. Very steep.

The bank angle may be quantified:

Good grief Larry, you really are an idiot.
Of course it can be quatified, but the numbers only tell a minute
part of the story. I can categorically state that I can do a 180 with
70 deg bank at VSO 1.2 deadstick and come out the other end in one
piece. Can you? Try it using those figures and send my the answer via
my Ouiji board.


Well I cannot understand you you can load the plane up like that and
not raise stall speed beyond 1.2Vs so you must be using a wing drop to
acclerate the turn? Do you could just stall out of the turn -but how
much height do you loose in the stall and it's recovery?


No, you have to lower the nose continuously to offload as you go around
the bend. You will end up fairy nose low at the end of the turn alright
but you can recover that as you level the wings. The turn is pretty
rapid at that speed so you won't be in it too long. It's as about "on
the edge" as you can get. It's the only way it can be done unles you
have an airplane with an outrageous climb. If you're proficient in spins
try it at a bit of altitude and a reduced bank angle. You can increase
the bank in subsequent attempts as you become more comfortable. just
don't get the idea that this will make you good enough to try it in
anger on it's own!


Bertie


Did you and MX work that out on the sim last night???


  #86  
Old April 25th 08, 01:32 PM posted to rec.aviation.piloting,rec.aviation.student
Maxwell[_2_]
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Posts: 2,043
Default Lancair crash at SnF


"Bertie the Bunyip" wrote in message
...
B A R R Y wrote in news:Z%iQj.22374$%41.15539
@nlpi064.nbdc.sbc.com:

Shirl wrote:
WingFlaps wrote:
I've also heard a lot of BS in this thread about not having good
palces to put the plane. There is nearly always somewhere flat to

put
the plane within 90 degrees of the runway centerline -even a road.
Malls have big parking lots!

I don't know about where you live, but malls here have lots of light
poles, concrete islands, park-and-rest benches and ... and ...

vehicles
everywhere. And having gone through it once, I'm no longer fooled by
what *looks* "flat" at 500, or even 50 feet.


I'd rather hit a bus shelter or light poles @ 40-50 MPH than go in
inverted after a stall/spin @ 200-300 AGL.


Exactly.

Bertie


One doesn't equal the other moron.



  #87  
Old April 25th 08, 01:33 PM posted to rec.aviation.piloting,rec.aviation.student
Maxwell[_2_]
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Posts: 2,043
Default Lancair crash at SnF


"Bertie the Bunyip" wrote in message
...
WingFlaps wrote in news:ac05ca83-bbc8-4c3b-9469-
:

On Apr 25, 8:31 pm, Stefan wrote:
WingFlaps schrieb:

Try reading the statement again, here it is:
"Now we add in the energy losses from having to accelerate with

the
wind and to glide speed."
To summarise your missed point, the pilot control inputs cost

energy
that is not factored into simple glide/time analysis.

This is absolutely correct. But then, I dont understand the

connection
to your first statement regarding the wind. Additioinal drag by

control
input is completely unrelated to the presence or non-presence of

wind.


Itls a turn upwind to downwind. That involves 2 direction changes, one
to reverse course and the the other to line up the runway. If there's
wind there will be an effect on line up. Try thinking about more
factors that cost altitude OK?


It's not so much the loss of altitude that will get you in this
manuever. it's the probable loss of control trying to manuever around
back towards the field.
Firstly, in any emergency that hasnt been drilled, you will have a
moment where you will be sitting there with your mouth open in utter
disbelief of what has just happened. in fact, even if you have drilled
for it you will still have this moment, but if it's been practiced the
moment you begine to do something about it will be sooner coming.
While you're sitting there wondering what's going on, the speed will be
bleeding off. Not good. Then, you will have to manuever the airplane
around using rapid manuevering at a relatively high bank angle if you're
going to make it (I'm assuiming you're still pretty low) and if you
aren't 100% au fait with this sort of flying you're going to be very
lucky to be able to maintain control of the airplane before the ground
reaches up and smites you. This is less about the maths than the
pilot;'s proficiency. The pilot who is proficient enough to do this will
have determined an altitude above which he knows it is possible to do it
and so the question will not be one of whether it's within the
performance capabilities of the airplane, but one of whether the pilot
can accurately control the airplane through the required manuever.
Here is what you'll have to do the instant the engine gives up:
Smooothly lower the nose as you roll just as smoothly, but as quickly as
possible, towards the crosswind, if any. You will have to continue to
lower the nose as the turn, which should ideally have at least 60 deg of
bank, is completed. you should be just nibbling the stall during this,
and , needless to say, perfectly co-ordinated. Pitch control is now
critical as what you're trying to do is cheat physics by offloading the
wing as you turn. a 60 degree bank in level flight will give you a stall
speed of 1.4 VSO and you should be below that so you're right on the
edge. This is all about having very good seat of the pants capability
based on experience. As you approach the desired heading to your landing
spot, you have to smoothly roll out and get the nose up and back to a
good glide attitude. You'll have sacrificed some altitude doing the
sharp turn, but far less than you would have making a wider turn with a
gentle bank. As you level the wings, you should be on, or close to, your
desired glide speed. This is a difficult manuever to pull off. Even
practicing at a bit of altitude has some risks. you're going to pull a
bit of G and it's easy to lose the plot and either spin out of it or
overstress the airframe praciticing it unless you know what you're
doing. It's not really something that most pilots should even consider.
Someone flying 25 hours a year s unlikely ever to become sharp enough to
do this reliably. I certainly wouldn't try it now unless there was no
choice.
There's a lot of crap talked about turning back and most of the
accidents occuring as a result of this are because the pilot has heard
it's possible and decides to learn how to do it when it actually
happens. Most modern flight manuals tell you it isn't possible but this
advice is ignored by guys who reckon they're a cut above because they
did the math or tried it once or twice at altitude or because they read
about it here.



Bertie


Now come on, Dudley wrote this for you, didn't he?


  #88  
Old April 25th 08, 01:34 PM posted to rec.aviation.piloting,rec.aviation.student
Maxwell[_2_]
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Posts: 2,043
Default Lancair crash at SnF


"Bertie the Bunyip" wrote in message
...
Dylan Smith wrote in
:

On 2008-04-25, WingFlaps wrote:
On Apr 25, 9:31 pm, Dylan Smith wrote:
IIRC, Vy is for a C172 is in the region of 65 knots - or best glide,
and


I can see you missed the point entirely. By the way, Vy is never at
best glide (it is above that ~69knots in a 172) -perhaps you would


I never said it was best glide. I said Vy for a C172 is *in the region
of 65 knots* (I don't actually remember what it is off the top of my
head, it's been 5 years since I flew a C172, but I do remember Vy
being close to 65 knots). I do, however, remember that for an 'N'
model C172, 65 knots was best glide and Vy was close to that number.
(In fact a brief internet search shows it to be 70 knots, so if the
pilot recognises an engine failure promptly, should not have to dive
to regain airspeed as your scenario stated. In reality, your 'concrete
numbers' are just as much handwaving: how many pilots seriously climb
out to 600 feet at Vx? How many pilots would seriously spend 10
seconds doing nothing but talking on the radio when the engine has
quit cold - instead of looking for a suitable landing site and
navigating towards said site?)

Good luck on your first engine failure during climb out, if you turn
back I hope you make it. but you'll have a better chance going
straight ahead...


Actually, I did go straight ahead but with 4000 feet of runway
remaining and a slow aircraft (C140), it wasn't exactly the hardest
aviation decision I've had to make.

If it happens again, I'll do what I think is prudent at the time. That
might be straight ahead, it might be turn to some amount, and it might
even be return to the airfield. I can't say at this point, and I won't
be able to say unless it actually happens - just like one of our
glider pilots did when the rope really did break at 200 feet: owing to
the strong tailwind that he would have had on a downwind landing, he
elected to land in a field instead, even though the turn itself was
eminently possible and he could have made it to the runway.

My friend who did have his engine lunch itself had the choice of a
built up area, a busy beach full of people, or the airfield. He was at
about 600 feet in a C150. If I had been in the same situation as him,
I'd have done the same - try to get back on airfield property because
it was the only thing flat not covered in people that was within
range. I can not fault his decision. (He did better than airfield
property, he did get it onto the runway).

What I'm trying to say in a long winded way is that there are no
prescriptive solutions. "Always land straight ahead" isn't always the
right decision, nor is the decision to turn back even if you really
can make the runway safely (in the glider example, the prospect of
groundlooping into a barbed wire fence when the glider got below wind
speed on the ground was a deciding factor to land in a field rather
than on the runway). It depends on conditions at the time, how much
altitude and airspeed you have, and what the terrain is like.


Actually, if you're light or have a tailwind, best glide will come at a
lower airspeed. in a manuever this tight you need every trick in the
book at your disposal.

Bertie


Only if you fly as lame a you do.



  #89  
Old April 25th 08, 01:48 PM posted to rec.aviation.piloting,rec.aviation.student
WingFlaps
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Posts: 621
Default Lancair crash at SnF

On Apr 26, 12:12*am, Stefan wrote:
WingFlaps schrieb:

I see the problem. You don't know what velocity is. It's a VECTOR. It
changes when you turn. *If you don't understand this there's not much
point talking about anything that involves physics....


Actually, I know an awful lot about physics.


So much that you mix up speed and velocity? LOL!

In everyday's language, the word velocity stands for the _magnitude_ of
the vector.


Nope. Not even at high school. The magnitude is "speed".

Now if you want me to realise outside some technical or
scientific environment that you use the word velocity in the vector
sense, you better say so explicitely.


Gosh, this isn't a technical forum? Was my post not including
"technical" terms like acceleration?

Still easier would be to say
"direction".


What does "flying with the wind" imply to you, a direction or a speed?
I'd say the former but I'm only a native English speaker.

Cheers

  #90  
Old April 25th 08, 01:49 PM posted to rec.aviation.piloting,rec.aviation.student
WingFlaps
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Posts: 621
Default Lancair crash at SnF

On Apr 26, 12:18*am, Stefan wrote:
B A R R Y schrieb:

I'd rather hit a bus shelter or light poles @ 40-50 MPH than go in
inverted after a stall/spin @ 200-300 AGL.


But I hope that you rather risk a stall/spin than to hit a crowd of
pedestrians with that meat chopper turning.


I thought the engine had stopped?

Cheers
 




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