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News Flash: You don't need elevator control !



 
 
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  #21  
Old November 1st 03, 04:25 AM
Andy Blackburn
external usenet poster
 
Posts: n/a
Default

Doug overstates the case a bit. Even without elevator
control it is possible to damp out the phugoid mode.
I tried this on a BFR recently and I encourage the
rest of you to give it a try as well. Since the phugoid
is a function of airspeed/pitching moment coupling,
you can damp it out by applying speedbrakes at the
bottom of the cycle. This take a bit of thinking ahead,
but it can be managed with practice.

The United 232 crew was able to control pitch through
pitch/thrust coupling. They applied collective thrust
to adjust pitch and differential thrust for directional
control. It was crude put effective enough to get to
the runway threshold. Unfortunately, the dug s wing
in on landing. It was not directly a result of the
phugoid mode, though I suspect all the different modes
conspired a bit.

At 00:48 01 November 2003, Doug Haluza wrote:
(nowhere) wrote in message
news:...
Yes, according to Peter Garrison's 'Aftermath' column
in the November
issue of 'Flying' you don't need to connect your elevator
control! I
quote: 'the NTSB report does not comment on the fact
that a
disconnected elevator does not make an ASW-20, or
for that matter any
other airplane, unflyable. The situation is aerodynamically
no
different from what occurs when the pilot removes
his hand from the
stick.'

I think I'll start leaving the elevators off my ASW-15
now. Imagine
how the reduction in drag will improve the performance!
Not having to
worry about pitch control will certainly cut down
on the cockpit
workload as well. The benefits are endless!


Well, it may be flyable, but not landable! The stick
free phugoid can
get pretty dramatic, even with the mass and friction
of the stick
attached to provide some damping . If you have not
tried this, you
should. Keep hands completely off and keep the wings
level with
rudder. Let the phugoid fully develop--it's a real
roller coaster
ride. Close to the ground, it's a crap shoot whether
you would land or
crash.

There was an accident a few years back in a DG-800
that had a loose
nut on the elevator control. The pilot hit on the down
part of the
phugoid and crashed wings level. He lived, but never
flew again.

The same thing happened to United Flight 232, the DC-10-10,
that
crashed while attempting an emergency landing at the
Sioux City
Gateway Airport, Iowa, in 1989. After losing all hydraulics,
they had
no movable flight controls. They were able to fly the
aircraft with
differential thrust on the two wing engines, but they
could not
control pitch on final approach.

I have not seen the article, but I'm surprised that
a knowledgable
person would suggest that elevator control is optional.




  #22  
Old November 1st 03, 03:23 PM
Andreas Maurer
external usenet poster
 
Posts: n/a
Default

On 1 Nov 2003 04:25:38 GMT, Andy Blackburn
wrote:


The United 232 crew was able to control pitch through
pitch/thrust coupling. They applied collective thrust
to adjust pitch and differential thrust for directional
control. It was crude put effective enough to get to
the runway threshold. Unfortunately, the dug s wing
in on landing. It was not directly a result of the
phugoid mode, though I suspect all the different modes
conspired a bit.


One might mention that NASA tried to recreate this 232'2 landing
using a simulator (as well as an F-15).
No aircrew *ever* was able to touch down their aircraft soft enough to
make the crash survivable.



Bye
Andreas
  #23  
Old November 1st 03, 05:02 PM
Doug Haluza
external usenet poster
 
Posts: n/a
Default

I think it would be difficult to overstate the severity of a total
loss of elevator control. It is possible to damp out the phugoid with
spoiler (and/or flap) but this won't help much close to the ground.
Deploying spoiler on the down part of the phugoid will reduce your
forward speed, but it will increase your vertical speed. The rate of
descent at impact is the real problem. It may be theoretically
possible to do something that could later be classified as a landing,
rather than a crash. But you only have one chance to do this, and the
probability of doing it exactly right on your first try is not very
high.

United 232 did not dig in a wing and cartwheel. The aircraft hit the
ground with a high descent rate (1850 fpm) slightly right wing low.
The right main gear broke through 12" of concrete, and the wing broke
off along with the tail section on impact. The rate of descent, and
loss of the wing, was a direct result of the phugoid mode.

P.S. For a very interesting first hand account of Flight 232 from Capt
Haynes see: http://www.panix.com/~jac/aviation/haynes.html

Andy Blackburn wrote in message ...
Doug overstates the case a bit. Even without elevator
control it is possible to damp out the phugoid mode.
I tried this on a BFR recently and I encourage the
rest of you to give it a try as well. Since the phugoid
is a function of airspeed/pitching moment coupling,
you can damp it out by applying speedbrakes at the
bottom of the cycle. This take a bit of thinking ahead,
but it can be managed with practice.

The United 232 crew was able to control pitch through
pitch/thrust coupling. They applied collective thrust
to adjust pitch and differential thrust for directional
control. It was crude put effective enough to get to
the runway threshold. Unfortunately, the dug s wing
in on landing. It was not directly a result of the
phugoid mode, though I suspect all the different modes
conspired a bit.

At 00:48 01 November 2003, Doug Haluza wrote:
(nowhere) wrote in message
news:...
Yes, according to Peter Garrison's 'Aftermath' column
in the November
issue of 'Flying' you don't need to connect your elevator
control! I
quote: 'the NTSB report does not comment on the fact
that a
disconnected elevator does not make an ASW-20, or
for that matter any
other airplane, unflyable. The situation is aerodynamically
no
different from what occurs when the pilot removes
his hand from the
stick.'

I think I'll start leaving the elevators off my ASW-15
now. Imagine
how the reduction in drag will improve the performance!
Not having to
worry about pitch control will certainly cut down
on the cockpit
workload as well. The benefits are endless!


Well, it may be flyable, but not landable! The stick
free phugoid can
get pretty dramatic, even with the mass and friction
of the stick
attached to provide some damping . If you have not
tried this, you
should. Keep hands completely off and keep the wings
level with
rudder. Let the phugoid fully develop--it's a real
roller coaster
ride. Close to the ground, it's a crap shoot whether
you would land or
crash.

There was an accident a few years back in a DG-800
that had a loose
nut on the elevator control. The pilot hit on the down
part of the
phugoid and crashed wings level. He lived, but never
flew again.

The same thing happened to United Flight 232, the DC-10-10,
that
crashed while attempting an emergency landing at the
Sioux City
Gateway Airport, Iowa, in 1989. After losing all hydraulics,
they had
no movable flight controls. They were able to fly the
aircraft with
differential thrust on the two wing engines, but they
could not
control pitch on final approach.

I have not seen the article, but I'm surprised that
a knowledgable
person would suggest that elevator control is optional.

  #24  
Old November 1st 03, 09:12 PM
Andy Blackburn
external usenet poster
 
Posts: n/a
Default

I would not suggest that loss of elevator is anything
but the most serious of mechanical incidents. However,
if it should ever happen, instead of throwing your
hands into the air and resigning yourself to a certain
fate, there are controls that you might be able to
use to maintain some measure of control - namely speedbrakes
and flaps (if you have 'em). Will it be a pretty
landing? Unlikely. Nevertheless, it beats the alternative.


I recommend practicing this rather than trying to figure
it out in real time in an emergency. I have practiced
flying without the use of each of the controls for
this reason.

Doug's right on UA 232 - the gear hit before the right
wing. The earlier comment was that the crew were unable
to control pitch with thrust. More precisely, they
were not able to adequately control pitch or heading
to make a good landing. If they had totally lost pitch
authority there would have been no survivors - which
I think was the main point. Use whatever control you
have.

9B

At 17:12 01 November 2003, Doug Haluza wrote:
I think it would be difficult to overstate the severity
of a total
loss of elevator control. It is possible to damp out
the phugoid with
spoiler (and/or flap) but this won't help much close
to the ground.
Deploying spoiler on the down part of the phugoid will
reduce your
forward speed, but it will increase your vertical speed.
The rate of
descent at impact is the real problem. It may be theoretically
possible to do something that could later be classified
as a landing,
rather than a crash. But you only have one chance to
do this, and the
probability of doing it exactly right on your first
try is not very
high.

United 232 did not dig in a wing and cartwheel. The
aircraft hit the
ground with a high descent rate (1850 fpm) slightly
right wing low.
The right main gear broke through 12' of concrete,
and the wing broke
off along with the tail section on impact. The rate
of descent, and
loss of the wing, was a direct result of the phugoid
mode.

P.S. For a very interesting first hand account of Flight
232 from Capt
Haynes see: http://www.panix.com/~jac/aviation/haynes.html

Andy Blackburn wrote in message news:...
Doug overstates the case a bit. Even without elevator
control it is possible to damp out the phugoid mode.
I tried this on a BFR recently and I encourage the
rest of you to give it a try as well. Since the phugoid
is a function of airspeed/pitching moment coupling,
you can damp it out by applying speedbrakes at the
bottom of the cycle. This take a bit of thinking ahead,
but it can be managed with practice.

The United 232 crew was able to control pitch through
pitch/thrust coupling. They applied collective thrust
to adjust pitch and differential thrust for directional
control. It was crude put effective enough to get
to
the runway threshold. Unfortunately, the dug s wing
in on landing. It was not directly a result of the
phugoid mode, though I suspect all the different modes
conspired a bit.

At 00:48 01 November 2003, Doug Haluza wrote:
(nowhere) wrote in message
news:...
Yes, according to Peter Garrison's 'Aftermath' column
in the November
issue of 'Flying' you don't need to connect your
elevator
control! I
quote: 'the NTSB report does not comment on the fact
that a
disconnected elevator does not make an ASW-20, or
for that matter any
other airplane, unflyable. The situation is aerodynamically
no
different from what occurs when the pilot removes
his hand from the
stick.'

I think I'll start leaving the elevators off my
ASW-15
now. Imagine
how the reduction in drag will improve the performance!
Not having to
worry about pitch control will certainly cut down
on the cockpit
workload as well. The benefits are endless!

Well, it may be flyable, but not landable! The stick
free phugoid can
get pretty dramatic, even with the mass and friction
of the stick
attached to provide some damping . If you have not
tried this, you
should. Keep hands completely off and keep the wings
level with
rudder. Let the phugoid fully develop--it's a real
roller coaster
ride. Close to the ground, it's a crap shoot whether
you would land or
crash.

There was an accident a few years back in a DG-800
that had a loose
nut on the elevator control. The pilot hit on the
down
part of the
phugoid and crashed wings level. He lived, but never
flew again.

The same thing happened to United Flight 232, the
DC-10-10,
that
crashed while attempting an emergency landing at the
Sioux City
Gateway Airport, Iowa, in 1989. After losing all hydraulics,
they had
no movable flight controls. They were able to fly
the
aircraft with
differential thrust on the two wing engines, but they
could not
control pitch on final approach.

I have not seen the article, but I'm surprised that
a knowledgable
person would suggest that elevator control is optional.





  #25  
Old November 2nd 03, 01:21 PM
Chris OCallaghan
external usenet poster
 
Posts: n/a
Default

Agreed. The problem with thinking through the possibilities for
control is that the pilot's assembly error will put the tow pilot at
risk immediately. Do you have a right to relearn how to fly your
semi-controllable aircraft by putting his or her life in danger? I've
seen several no elevator launches, and in each case, the pilot
discovered his error when he pitched high behind the towplane.

This is a good mental exercise, thinking about how other control
surfaces can be used to manage the aircraft, but I wonder just how
ethical it is to try to apply them at the cost of someone else's life.
I don't have an answer for this one. Just thought I'd throw another
variable into the discussion.
  #26  
Old November 2nd 03, 11:59 PM
Karl Striedieck
external usenet poster
 
Posts: n/a
Default

An article appeared in Soaring Magazine a few years ago titled "Attitude
Problems" dealing with ways of dealing with an unconnected elevator control.
Pilots of flapped ships can use flaps, spoilers and bank angle to adjust
pitch, standard ships the last two.

Gliders using a tow release in the nose will be more easily controlled on
air tow than those using a cg release, but, if an initial zoom up after take
off can be controlled, the latter can be controlled sufficiently to allow a
high tow and possible bailout as well.

As pointed out in an earlier contribution to this discussion, trying to
simulate a disconnected elevator by allowing the stick to move freely in
pitch won't create the same degree of instability, but it is still a useful
exercise.

Varying the bank angle to arrest phugoid zoomies is very easy to accomplish
(steepen bank to lower nose and vice versa). When a bailout is not an
option, use of this mode alone will result in the glider coming to back to
earth tangentially at a reasonable speed.

Anyone interested in a copy of the mentioned article can contact me.

Karl Striedieck








"Andy Blackburn" wrote in message
...
I would not suggest that loss of elevator is anything
but the most serious of mechanical incidents. However,
if it should ever happen, instead of throwing your
hands into the air and resigning yourself to a certain
fate, there are controls that you might be able to
use to maintain some measure of control - namely speedbrakes
and flaps (if you have 'em). Will it be a pretty
landing? Unlikely. Nevertheless, it beats the alternative.


I recommend practicing this rather than trying to figure
it out in real time in an emergency. I have practiced
flying without the use of each of the controls for
this reason.

Doug's right on UA 232 - the gear hit before the right
wing. The earlier comment was that the crew were unable
to control pitch with thrust. More precisely, they
were not able to adequately control pitch or heading
to make a good landing. If they had totally lost pitch
authority there would have been no survivors - which
I think was the main point. Use whatever control you
have.

9B

At 17:12 01 November 2003, Doug Haluza wrote:
I think it would be difficult to overstate the severity
of a total
loss of elevator control. It is possible to damp out
the phugoid with
spoiler (and/or flap) but this won't help much close
to the ground.
Deploying spoiler on the down part of the phugoid will
reduce your
forward speed, but it will increase your vertical speed.
The rate of
descent at impact is the real problem. It may be theoretically
possible to do something that could later be classified
as a landing,
rather than a crash. But you only have one chance to
do this, and the
probability of doing it exactly right on your first
try is not very
high.

United 232 did not dig in a wing and cartwheel. The
aircraft hit the
ground with a high descent rate (1850 fpm) slightly
right wing low.
The right main gear broke through 12' of concrete,
and the wing broke
off along with the tail section on impact. The rate
of descent, and
loss of the wing, was a direct result of the phugoid
mode.

P.S. For a very interesting first hand account of Flight
232 from Capt
Haynes see: http://www.panix.com/~jac/aviation/haynes.html

Andy Blackburn wrote in message news:...
Doug overstates the case a bit. Even without elevator
control it is possible to damp out the phugoid mode.
I tried this on a BFR recently and I encourage the
rest of you to give it a try as well. Since the phugoid
is a function of airspeed/pitching moment coupling,
you can damp it out by applying speedbrakes at the
bottom of the cycle. This take a bit of thinking ahead,
but it can be managed with practice.

The United 232 crew was able to control pitch through
pitch/thrust coupling. They applied collective thrust
to adjust pitch and differential thrust for directional
control. It was crude put effective enough to get
to
the runway threshold. Unfortunately, the dug s wing
in on landing. It was not directly a result of the
phugoid mode, though I suspect all the different modes
conspired a bit.

At 00:48 01 November 2003, Doug Haluza wrote:
(nowhere) wrote in message
news:...
Yes, according to Peter Garrison's 'Aftermath' column
in the November
issue of 'Flying' you don't need to connect your
elevator
control! I
quote: 'the NTSB report does not comment on the fact
that a
disconnected elevator does not make an ASW-20, or
for that matter any
other airplane, unflyable. The situation is aerodynamically
no
different from what occurs when the pilot removes
his hand from the
stick.'

I think I'll start leaving the elevators off my
ASW-15
now. Imagine
how the reduction in drag will improve the performance!
Not having to
worry about pitch control will certainly cut down
on the cockpit
workload as well. The benefits are endless!

Well, it may be flyable, but not landable! The stick
free phugoid can
get pretty dramatic, even with the mass and friction
of the stick
attached to provide some damping . If you have not
tried this, you
should. Keep hands completely off and keep the wings
level with
rudder. Let the phugoid fully develop--it's a real
roller coaster
ride. Close to the ground, it's a crap shoot whether
you would land or
crash.

There was an accident a few years back in a DG-800
that had a loose
nut on the elevator control. The pilot hit on the
down
part of the
phugoid and crashed wings level. He lived, but never
flew again.

The same thing happened to United Flight 232, the
DC-10-10,
that
crashed while attempting an emergency landing at the
Sioux City
Gateway Airport, Iowa, in 1989. After losing all hydraulics,
they had
no movable flight controls. They were able to fly
the
aircraft with
differential thrust on the two wing engines, but they
could not
control pitch on final approach.

I have not seen the article, but I'm surprised that
a knowledgable
person would suggest that elevator control is optional.







  #27  
Old November 3rd 03, 06:43 AM
F.L. Whiteley
external usenet poster
 
Posts: n/a
Default


"JJ Sinclair" wrote in message
...
I know of a Kestrel 19 that's done the same, twice. The wing attach

design
is very much the same. The pin is not load bearing, but only locks the
wings together. As long a 0 to negative G is avoided, they won't come

off.


Come on guys, this story is getting out of hand. Your asking us to believe

that
a Kestrel driver used his neat little wing assembly tool to force his

wings
together and then FORGOT to put the main pin in? And you say he did it

twice?
That pin is not load bearing, but any turbulance (like what we do to make

the
wing come out, on didassembly) will allow the wings to slide out and then

our
fictitious Kestrel driver would find himself wingless.
JJ Sinclair


Nevertheless, the owner admitted to doing this twice.

Frank


  #28  
Old November 3rd 03, 06:48 AM
F.L. Whiteley
external usenet poster
 
Posts: n/a
Default


"F.L. Whiteley" wrote in message
...

"JJ Sinclair" wrote in message
...
I know of a Kestrel 19 that's done the same, twice. The wing attach

design
is very much the same. The pin is not load bearing, but only locks the
wings together. As long a 0 to negative G is avoided, they won't come

off.


Come on guys, this story is getting out of hand. Your asking us to

believe
that
a Kestrel driver used his neat little wing assembly tool to force his

wings
together and then FORGOT to put the main pin in? And you say he did it

twice?
That pin is not load bearing, but any turbulance (like what we do to

make
the
wing come out, on didassembly) will allow the wings to slide out and

then
our
fictitious Kestrel driver would find himself wingless.
JJ Sinclair


Nevertheless, the owner admitted to doing this twice.

Frank

Maybe the tape and control linkages are _just_ enough........

One of our club members also landed his Std Jantar 2 following a winch
launch. A young lady that walked out to look at the glider picked up the
horizontal tail attach pin and handed it to him, as it had fallen out on
landing. He painted it in such a way that if it wasn't properly seated, a
color would show. He then booked a flight to Majorca to 'enjoy life' and
the fact that he was still living it.

Frank


  #29  
Old November 3rd 03, 09:14 AM
John Giddy
external usenet poster
 
Posts: n/a
Default


"F.L. Whiteley" wrote in message
...
| Maybe the tape and control linkages are _just_
enough........

The control linkages on the Glasfluegel ships are automatic,
so won't hold anything in. The tape may have been his
salvation...
Cheers, John G.

  #30  
Old November 3rd 03, 02:57 PM
Shaber CJ
external usenet poster
 
Posts: n/a
Default

One of our club members also landed his Std Jantar 2 following a winch
launch. A young lady that walked out to look at the glider picked up the
horizontal tail attach pin and handed it to him, as it had fallen out on
landing.


Where I used to fly, we had a pilot landing his Jantar when I saw the elevator
lift off the vertical tail plane by about a foot and start rotating. The glider
pitched up and banked, a wing dug in the ground and I think I saw that wing
bend about 45 degrees. I took off running as the glider was heading for me. I
had learned to keep an eye out when this pilot landed as twice before I had to
run to avoid ground loops (no offense to the pilot is meant, he is a good pilot
who flies every weekend). After the glider came to a rest I ran up to him and
he was sitting in the glider with a stunned look on his face and the cockpit
was half filled with dirt, the tops of the pilots knees where sticking up out
of the dirt.

Craig
 




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