Spoilers, no spoilers?

On Feb 11, 1:54 am, Bertie the Bunyip wrote:

Nothing goes down like the 727! First time I flew it I ended up level at
2,000' 30 miles form the airport. and that was without the spoilers!
With them it was like a brick!


If I understood correctly the last sentence, you did use spoilers in
midair?

Amine wrote in news:e921c55d-67f0-4b42-8b9b-
:

On Feb 11, 1:54 am, Bertie the Bunyip wrote:

Nothing goes down like the 727! First time I flew it I ended up level at
2,000' 30 miles form the airport. and that was without the spoilers!
With them it was like a brick!


If I understood correctly the last sentence, you did use spoilers in
midair?


Oh sure. All the time!

The 707 was restricted against it in latter years because of a stab spar
problem, but everything else uses them. There are a couple of them that are
only used on the groun on most airplanes, though. That function is fully
automatic, though.


Bertie

James Robinson wrote in
:

Bertie the Bunyip wrote:

Amine wrote:

Bertie the Bunyip wrote:

Nothing goes down like the 727! First time I flew it I ended up
level at 2,000' 30 miles form the airport. and that was without the
spoilers! With them it was like a brick!

If I understood correctly the last sentence, you did use spoilers in
midair?

Oh sure. All the time!

The 707 was restricted against it in latter years because of a stab
spar problem, but everything else uses them. There are a couple of
them that are only used on the groun on most airplanes, though. That
function is fully automatic, though.

I have a recollection of reading about an incident years ago on a DC-8
where a crew purposely deployed the ground spoilers at FL350 or
thereabouts. It did not go well.

The pilot had previous experience on B-727s, and had been recently
qualified on DC-8s. As they were cruising along, they got to
wondering (always dangerous) if the spoilers on the DC-8 could be used
as speed brakes, like on the '27s.

As I recall, the FE had to override an interlock by holding a
hydraulic pump switch, and the pilot slowly moved the spoiler handle,
expecting the spoilers to gradually rise with handle movement, like
the other aircraft he was used to. Instead, when he reached a certain
point with the handle, the spoilers instantly popped up to full
height, as they were designed to do.

In the excitement, the FE let go of the switch, dropping power to the
pump, and they couldn't retract the spoilers. Down they went.

They eventually recovered things at something like FL150, and learned
why they are called ground spoilers and not speed brakes.

OK. Never flew the DC 8. Would liked to have, though! you couldn't
deploy the ground spoilers on the 727 in he air unless you somehow
fooled the air/ground switch into thinking you were on the ground. Same
goes for most airplanes. ( spoilers and speedbrakes are pretty much the
same thing for the purposes of this discussion) I can't imagine why
anyone would try and deploy the ground spoilers in flight, though..
People do stupid things!


Bertie

James Robinson wrote in
:

Bertie the Bunyip wrote:

James Robinson wrote:

I have a recollection of reading about an incident years ago on a
DC-8 where a crew purposely deployed the ground spoilers at FL350 or
thereabouts. It did not go well.

The pilot had previous experience on B-727s, and had been recently
qualified on DC-8s. As they were cruising along, they got to
wondering (always dangerous) if the spoilers on the DC-8 could be
used as speed brakes, like on the '27s.

As I recall, the FE had to override an interlock by holding a
hydraulic pump switch, and the pilot slowly moved the spoiler
handle, expecting the spoilers to gradually rise with handle
movement, like the other aircraft he was used to. Instead, when he
reached a certain point with the handle, the spoilers instantly
popped up to full height, as they were designed to do.

In the excitement, the FE let go of the switch, dropping power to
the pump, and they couldn't retract the spoilers. Down they went.

They eventually recovered things at something like FL150, and
learned why they are called ground spoilers and not speed brakes.

OK. Never flew the DC 8. Would liked to have, though! you couldn't
deploy the ground spoilers on the 727 in he air unless you somehow
fooled the air/ground switch into thinking you were on the ground.
Same goes for most airplanes. ( spoilers and speedbrakes are pretty
much the same thing for the purposes of this discussion) I can't
imagine why anyone would try and deploy the ground spoilers in
flight, though.. People do stupid things!

I wonder whether the accusation by Boeing and the NTSB of the pilot
playing with the leading edge slats on the TWA 727 was influenced by
this earlier DC-8 episode? Since one pilot did something that would
normally be considered dumb, just maybe another one did something dumb
also. Since they couldn't (or some say wouldn't) point their fingers
on what actually did happen, blame the pilot by default.

My understanding is that the NTSB guy had done this in Phantoms and had
come up with the theory based on that. Boeing eventually admitted that
it was possible for the slats to have deployed after several other
airplanes had the same problem ( at lower altitudes) I wouldn't be
surprised if the DC 8 incident didn't play some role in that reprt,
however.
The crew were never sanctioned for this. Not by the FAA or their
company, but none were happy with the report, obviously.
I was just discussing this with someone who does know al the facts and
who also posts here. he might pipe up at this point.



Bertie

On 11 Feb, 15:33, Bertie the Bunyip wrote:
Amine wrote in news:e921c55d-67f0-4b42-8b9b-

If I understood correctly the last sentence, you did use spoilers in
midair?

Oh sure. All the time!

The 707 was restricted against it in latter years because of a stab spar
problem, but everything else uses them. There are a couple of them that are
only used on the groun on most airplanes, though. That function is fully
automatic, though.

Bertie

Now I'm confused. It's like we're back to square one with the issue
raised in the original post. I thought spoilers were never to be used
in midair, either because of structural limitations or because of
other safety reasons I am still trying to figure out... But now you're
saying you used them all the time on the 727.

Conclusion: it is OK to use spoilers to kill altitude/momentum.
Therefore, a too high/fast approach can be dealt with via spoilers
(when a go around isn't an option).

Or...?

On Feb 11, 11:29*am, Amine wrote:

Now I'm confused. It's like we're back to square one with the issue
raised in the original post. I thought spoilers were never to be used
in midair, either because of structural limitations or because of
other safety reasons I am still trying to figure out... But now you're
saying you used them all the time on the 727.

Heres the deal, it is OK to use spoilers in the air. They are used as
speedbrakes and for roll control. Older jets had restrictions against
using them with flaps deployed (Newer jets allow some flaps, usually
up to 10 degrees or so, depending on the jet). Also, there is a
resticion against using spoilers within a certain proximity to the
ground (Usually 800 to 1000 ft RA). So you CANNOT use spoilers when
you are in the landing configuration. I am not to familiar with the
crash mentioned in the OP but this is what I understand happened. It
is normal to have the autospoilers armed (by moving the spoiler handle
out of the detent) at 1000 AGL as part of the before landing
checklist. When you touch down all of the flight spoilers and all of
the ground spoilers will fully deploy automatically. This is sensed by
a Z bar on some of the older jets, or a squat switch, or wheel speed
sensors that requier the power levers to be closed (Idle).

Conclusion: it is OK to use spoilers to kill altitude/momentum.
Therefore, a too high/fast approach can be dealt with via spoilers
(when a go around isn't an option).

Or...?

Once again, cant use em in the landing config.
Frank

Here are some spoilers for the type of aircraft we fly
http://www.powerpacspoilers.com/

--

*H. Allen Smith*
WACO - We are all here, because we are not all there.


"Amine" wrote in message
...
On 11 Feb, 15:33, Bertie the Bunyip wrote:
Amine wrote in news:e921c55d-67f0-4b42-8b9b-

If I understood correctly the last sentence, you did use spoilers in
midair?

Oh sure. All the time!

The 707 was restricted against it in latter years because of a stab spar
problem, but everything else uses them. There are a couple of them that
are
only used on the groun on most airplanes, though. That function is fully
automatic, though.

Bertie

Now I'm confused. It's like we're back to square one with the issue
raised in the original post. I thought spoilers were never to be used
in midair, either because of structural limitations or because of
other safety reasons I am still trying to figure out... But now you're
saying you used them all the time on the 727.

Conclusion: it is OK to use spoilers to kill altitude/momentum.
Therefore, a too high/fast approach can be dealt with via spoilers
(when a go around isn't an option).

Or...?

Amine wrote in
:

On 11 Feb, 15:33, Bertie the Bunyip wrote:
Amine wrote in news:e921c55d-67f0-4b42-8b9b-

If I understood correctly the last sentence, you did use spoilers
in midair?

Oh sure. All the time!

The 707 was restricted against it in latter years because of a stab
spar problem, but everything else uses them. There are a couple of
them that are only used on the groun on most airplanes, though. That
function is fully automatic, though.

Bertie

Now I'm confused. It's like we're back to square one with the issue
raised in the original post. I thought spoilers were never to be used
in midair, either because of structural limitations or because of
other safety reasons I am still trying to figure out... But now you're
saying you used them all the time on the 727.

Use them all the time on al jets I've flown.

Conclusion: it is OK to use spoilers to kill altitude/momentum.
Therefore, a too high/fast approach can be dealt with via spoilers
(when a go around isn't an option).

Well, there is usualy a restriction on their use regarding altitude.
depends on the type, but we're not alowed to use them below 1,000' ( you
shoud be stable there anyway) and Boeing restrict their use on the 757
to 20 degrees of flap or less ( most all jets have a similar
restriction)

Or...?


Well, you might mean ground spoilers, also called lift dump. The
inflight spoilers have two functions. One is as a speedbrake and the
other is roll control. When aileron deflection exceeds x amount the
spoilers on one side start to come up to augment roll control. It varies
from airplane to airplane, but usually the outermost two or three
spoilers are used for roll control as well as speedbrake through a mixer
of one form or another ( obviously computerised in 'busses, for
instance) and there are one or two inboard of those used on the ground
only. We don't get to decide. the aileron ones work all by themselves.
The speedbrake is just a single handle next to the thrust levers, and
the ground spoilers are on the ground.
The Lockheed Tristar had a unique use for them in that they controlled
glidepath on the approach. I've only had it described to me, but
basically the airplane maintatined a stwady pitch angle and workng the
stick back and forth brought the speedbrake up and down to control
glide. Don't quote me on that, though.


Bertie

"F. Baum" wrote in news:ef16d6a2-5341-4090-b4d7-
:

On Feb 11, 11:29*am, Amine wrote:

Now I'm confused. It's like we're back to square one with the issue
raised in the original post. I thought spoilers were never to be used
in midair, either because of structural limitations or because of
other safety reasons I am still trying to figure out... But now you're
saying you used them all the time on the 727.

Heres the deal, it is OK to use spoilers in the air. They are used as
speedbrakes and for roll control. Older jets had restrictions against
using them with flaps deployed (Newer jets allow some flaps, usually
up to 10 degrees or so, depending on the jet). Also, there is a
resticion against using spoilers within a certain proximity to the
ground (Usually 800 to 1000 ft RA). So you CANNOT use spoilers when
you are in the landing configuration. I am not to familiar with the
crash mentioned in the OP but this is what I understand happened. It
is normal to have the autospoilers armed (by moving the spoiler handle
out of the detent) at 1000 AGL as part of the before landing
checklist. When you touch down all of the flight spoilers and all of
the ground spoilers will fully deploy automatically. This is sensed by
a Z bar on some of the older jets, or a squat switch, or wheel speed
sensors that requier the power levers to be closed (Idle).

My understanding with that DC8 accident was that they were doing something
a bit non-standard. Don't know what since I never flew one.




Bertie

James Robinson wrote in
:

Bertie the Bunyip wrote:

The Lockheed Tristar had a unique use for them in that they
controlled glidepath on the approach. I've only had it described to
me, but basically the airplane maintatined a stwady pitch angle and
workng the stick back and forth brought the speedbrake up and down to
control glide. Don't quote me on that, though.

Yep. They called it Direct Lift Control. It made for very accurate
autolands. It was set up when the flaps were extended for final
approach.

I remember flying in a couple of Tristars where the engine RPMs would
drop at the beginning of descent, and there would be no power changes
until the flare. The DLC system would control things on the glide
slope without the need for any power changes. I remember asking myself
how the pilot was so accurate with the power setting the first time it
happened, before I knew about the system.


That's it. I thought it sounded awful, but everyone i knew who flew them
thought it was fanatastic.


Bertie