A question on reversers

[[email protected]]

If you float in above the threshold a fair bit higher than Vref, is it
acceptable technique to chance the reverser to preclude landing too far
down the runway?

Thanks in advance,

Ramapriya

[Jim Macklin]

No

Vref is 1.3 Vso and even at higher speed float is not a real
problem, you fly the pitch attitude to a firm landing and
deploy the spoilers. Most jet aircraft have a nose down,
negative wing angle when the nose wheel is on the surface.
You can "plant" a jet and keep it on the ground without the
problem of ballooning off the ground that most light
aircraft encounter.

If you are out of the proper position, the proper procedure
is a go-around.

BTW, it seems you are trying to learn about paining aircraft
(decoy) and how to "speak" pilot, is there any ulterior
motive such as passing a security check with a stolen
airplane painted away from a professional shop and flown by
a crew that isn't qualified?


> wrote in message
oups.com...
| If you float in above the threshold a fair bit higher than
Vref, is it
| acceptable technique to chance the reverser to preclude
landing too far
| down the runway?
|
| Thanks in advance,
|
| Ramapriya
|

[Dave Stadt]

> wrote in message
oups.com...
> If you float in above the threshold a fair bit higher than Vref, is it
> acceptable technique to chance the reverser to preclude landing too far
> down the runway?
>
> Thanks in advance,
>
> Ramapriya

I just open the door and throw out the anchor. Works best on soft grass
runways.

[Matt Whiting]

Dave Stadt wrote:

> > wrote in message
> oups.com...
>
>>If you float in above the threshold a fair bit higher than Vref, is it
>>acceptable technique to chance the reverser to preclude landing too far
>>down the runway?
>>
>>Thanks in advance,
>>
>>Ramapriya
>
>
> I just open the door and throw out the anchor. Works best on soft grass
> runways.

That is called a soft-field landing, right? You should use it on all
grass strips, not just the soft ones. Because you never know when one
may be soft, so just assume that and always use the anchor. Worst case
is that the grass runway is hard and it just bounces along behind you.
No hard as long as it doesn't wrap around the tail. :-)

[[email protected]]

On 24 Jun 2006 03:48:13 -0700, wrote:

>If you float in above the threshold a fair bit higher than Vref, is it
>acceptable technique to chance the reverser to preclude landing too far
>down the runway?

I've only allegedly worked on couple of different types of buckets,
all on biz-jets and they have had one thing in common.

The aircraft must have a weight-on-wheels signal present somewhere in
the logic circuit before the reversers will unlock or deploy.

Inflight, if a not-locked condition is detected, the reversers are
hydraulically driven to the stowed position and pressure is maintained
holding them there until the not-locked condition goes away.

Unless you are learning to fly the space shuttle:

http://www.nasa.gov/vision/space/preparingtravel/rtf_week5_sta.html

http://www.nasaexplores.com/show2_articlea.php?id=04-067

http://www.aopa.org/pilot/features/9703feat.html

having the buckets out while flying is a RBT (really bad thing), but
I'm sure there are some exceptions out there.

http://www.globalsecurity.org/military/systems/aircraft/c-17.htm

TC

[John Gaquin]

> wrote in message

> If you float in above the threshold a fair bit higher than Vref, is it
> acceptable technique to chance the reverser to preclude landing too far
> down the runway?

It is bad technique to "chance" anything. Jim is right in that if you're
out of position for landing a miss should be your first consideration.

I can't speak for all transports, but I seem to recall on the 727 and 747
there are lockouts that prevent reverse actuation in flight. Not 100% sure
of the physical lockout on the 727, and too lazy right now to look it up.
:-) I do recall that inflight reverser use was possible on at least some
models of the DC8.

In any event, I wouldn't consider use of reverse immediately before landing
a good idea.

[Jim Macklin]

I don't know what color your skin is and don't really care
about your skin. But I was raising the issue since you have
asked questions about many subjects and topics that could
fit a profile of a person wanting to bad things. The
answers to those questions can be harmless as can the
questions. Yes, 9/11 has changed the way pilots are seen
and the way pilots look at others. We used to be a sort of
"band of brothers" and now we have to wear a name badge,
neckstraps with ID cards, and have the color of the day on
the lapel.

I'm pretty sure that the newsgroups are monitored and I was
just pointing out that the pattern of your questions could
come to the attention of some agency.

No offense was intended.

Jim
> wrote in message
oups.com...
| Jim Macklin wrote:
| >
| >
| > BTW, it seems you are trying to learn about paining
aircraft (decoy) and how to "speak"
| > pilot, is there any ulterior motive such as passing a
security check with a stolen
| > airplane painted away from a professional shop and flown
by a crew that isn't qualified?
|
|
| No way!
|
| It seems like post 9/11, to even want to know about
aviation isn't the
| done thing, and certainly not if you've dark skin.
Unfortunate... but I
| don't hold out against you, Jim. I've had worse
insinuations here on
| RAP in the past for no reason at all.
|
| Ramapriya
|

[.Blueskies.]

> wrote in message ...
> On 24 Jun 2006 03:48:13 -0700, wrote:
>
>
> having the buckets out while flying is a RBT (really bad thing), but
> I'm sure there are some exceptions out there.
>
> http://www.globalsecurity.org/military/systems/aircraft/c-17.htm
>
> TC

Yup, you found it. The C-17 thrust reversers are certified as flight controls.

[Jim Macklin]

The props on the King Air will reverse in-flight as can the
Pilatus bushplane. There can be some interesting
aerodynamic effects. But very few recreational airplanes
have any sort of reverse. But I agree, jets require the
squat switch (unless there is a malfunction) to deploy
reverse.




--
James H. Macklin
ATP,CFI,A&P

> wrote in message
...
| On 24 Jun 2006 03:48:13 -0700,
wrote:
|
| >If you float in above the threshold a fair bit higher
than Vref, is it
| >acceptable technique to chance the reverser to preclude
landing too far
| >down the runway?
|
| I've only allegedly worked on couple of different types of
buckets,
| all on biz-jets and they have had one thing in common.
|
| The aircraft must have a weight-on-wheels signal present
somewhere in
| the logic circuit before the reversers will unlock or
deploy.
|
| Inflight, if a not-locked condition is detected, the
reversers are
| hydraulically driven to the stowed position and pressure
is maintained
| holding them there until the not-locked condition goes
away.
|
| Unless you are learning to fly the space shuttle:
|
|
http://www.nasa.gov/vision/space/preparingtravel/rtf_week5_sta.html
|
| http://www.nasaexplores.com/show2_articlea.php?id=04-067
|
| http://www.aopa.org/pilot/features/9703feat.html
|
| having the buckets out while flying is a RBT (really bad
thing), but
| I'm sure there are some exceptions out there.
|
|
http://www.globalsecurity.org/military/systems/aircraft/c-17.htm
|
| TC

[[email protected]]

John Gaquin wrote:
>
> I can't speak for all transports, but I seem to recall on the 727 and 747
> there are lockouts that prevent reverse actuation in flight. Not 100% sure
> of the physical lockout on the 727, and too lazy right now to look it up.
> :-) I do recall that inflight reverser use was possible on at least some
> models of the DC8.


John, I'm sure the Thailand Air Lauda A320 crash of about 10 years ago
has escaped your attention :)

The pilots somehow accidentally deployed the reversers on finals and
couldn't recover the craft :(

Ramapriya

[.Blueskies.]

"John Gaquin" > wrote in message . ..
>
> > wrote in message
>
>> If you float in above the threshold a fair bit higher than Vref, is it
>> acceptable technique to chance the reverser to preclude landing too far
>> down the runway?
>
> It is bad technique to "chance" anything. Jim is right in that if you're out of position for landing a miss should be
> your first consideration.
>
> I can't speak for all transports, but I seem to recall on the 727 and 747 there are lockouts that prevent reverse
> actuation in flight. Not 100% sure of the physical lockout on the 727, and too lazy right now to look it up. :-) I
> do recall that inflight reverser use was possible on at least some models of the DC8.
>

http://en.wikipedia.org/wiki/Lauda_Air_Flight_004

[John Gaquin]

> wrote in message >
>
> John, I'm sure the Thailand Air Lauda A320 crash of about 10 years ago
> has escaped your attention :)
>
> The pilots somehow accidentally deployed the reversers on finals and
> couldn't recover the craft :(

The Lauda aircraft was a B767, and the accident occurred as a result of a
system failure some 20 minutes or so after T.O., not during a landing
approach. In normal operation, inflight reverse should be prevented in the
767.

In my post I was speaking in general terms, that as a matter of design,
operation of reversers in flight is usually prevented. However, there are
some exceptions, and in the event of a system failure or malfunction, all
sorts of unanticipated things can occur.

[John Gaquin]

".Blueskies." > wrote in message
>
> http://en.wikipedia.org/wiki/Lauda_Air_Flight_004

I'm sorry, but I don't see how that relates to my post. Lauda crashed due
to a malfunction.

[[email protected]]

John Gaquin wrote:
> > http://en.wikipedia.org/wiki/Lauda_Air_Flight_004
>
> I'm sorry, but I don't see how that relates to my post. Lauda crashed due to a malfunction.


Oops, thanks. I was thinking all along that a pilot deployed it
accidentally. Or was that the EgyptAir crash off Massachussetts?...

Ramapriya

[Jim Macklin]

It seems that was an act of terrorism, the co-pilot for what
ever reason seemed to be crashing the aircraft, but that was
just some news reports, don't know if there ever was a final
and official determination made.



> wrote in message
oups.com...
| John Gaquin wrote:
| > > http://en.wikipedia.org/wiki/Lauda_Air_Flight_004
| >
| > I'm sorry, but I don't see how that relates to my post.
Lauda crashed due to a malfunction.
|
|
| Oops, thanks. I was thinking all along that a pilot
deployed it
| accidentally. Or was that the EgyptAir crash off
Massachussetts?...
|
| Ramapriya
|

[tom418]

On the B727, the throttles must be in idle position in order to activate the
reversers. In the limitations section of the AFM, one is advised that
operation of reversers is not permitted in flight. I'm not aware of other
interlocks (Z-bar, etc)
"John Gaquin" > wrote in message
. ..
>
> > wrote in message
>
> > If you float in above the threshold a fair bit higher than Vref, is it
> > acceptable technique to chance the reverser to preclude landing too far
> > down the runway?
>
> It is bad technique to "chance" anything. Jim is right in that if you're
> out of position for landing a miss should be your first consideration.
>
> I can't speak for all transports, but I seem to recall on the 727 and 747
> there are lockouts that prevent reverse actuation in flight. Not 100%
sure
> of the physical lockout on the 727, and too lazy right now to look it up.
> :-) I do recall that inflight reverser use was possible on at least some
> models of the DC8.
>
> In any event, I wouldn't consider use of reverse immediately before
landing
> a good idea.
>
>
>

[Kingfish]

Jim Macklin wrote:
But I agree, jets require the
> squat switch (unless there is a malfunction) to deploy
> reverse.
>
I read recently the C-5 that crashed at Dover, DE had a #2 engine
reverser unstow right after takeoff. The crew attempted the approach
with full flaps instead of partial flaps per the POH and the sink rate
was too high to overcome.

[Ron Natalie]

wrote:
> If you float in above the threshold a fair bit higher than Vref, is it
> acceptable technique to chance the reverser to preclude landing too far
> down the runway?
>
> Thanks in advance,
>
> Ramapriya
>
Depends on the aircraft. The DC-8 used to allow two of the
engines to be flown in reverse on approach.

[Capt.Doug]

> wrote in message
> If you float in above the threshold a fair bit higher than Vref, is it
> acceptable technique to chance the reverser to preclude landing too far
> down the runway?

The acceptable technique is to discontinue the approach and go around for
another try. Unstabilized approaches account for a large number of airline
landing incidents.

As for the use of reverse, most airplanes prohibit using thrust reversers in
air because of unacceptably high sink-rates, assymetric thrust when one
deploys and one does not, or flight control surfaces losing effectiveness
due to disrupted airflow.

D.

[Jim Macklin]

You can go-around even after touchdown. A missed approach
begun at 100 feet on a CATII ILS may result in the aircraft
touching down, which is why you don't retract the landing
gear until a positive rate of climb is established.


--
James H. Macklin
ATP,CFI,A&P

> wrote in message
oups.com...
| Capt.Doug wrote:
| > > wrote in message
| > > If you float in above the threshold a fair bit higher
than Vref, is it
| > > acceptable technique to chance the reverser to
preclude landing too far
| > > down the runway?
| >
| > The acceptable technique is to discontinue the approach
and go around for
| > another try. Unstabilized approaches account for a large
number of airline
| > landing incidents.
| >
| > As for the use of reverse, most airplanes prohibit using
thrust reversers in
| > air because of unacceptably high sink-rates, assymetric
thrust when one
| > deploys and one does not, or flight control surfaces
losing effectiveness
| > due to disrupted airflow.
| >
| > D.
|
|
| Thanks, Capn; nice to hear from you again :)
|
| Cn you decide to go-around as late as when you're already
above the
| runway (unless the "above the threshold" bit of my msg got
buried
| somehow)?
|
| Ever since I first read about it, the asynchronous
possibility of
| reversers has struck me as worrisome, and that's the
reason I
| hesitantly mentioned it on the grass-landing thread.
Hadn't however
| reckoned for the howlers it elicited :)
|
| Ramapriya
|

[Walt]

Okay, I mainly just lurk here but thought I'd throw my two cents on
this.

When I was flying KC-135's in the '70's we'd air refuel a C-5 every now
and then.

It was very interesting just getting the C-5 into contact position, but
what was more interesting was when we'd practice a break-away. The C-5
would employ their thrust reversers and pretty much disappear.

Anyway, it's the only time I've known that thrust reversers were
employed in flight.

Today I'm retired and am flying my Warrior around Montana, and don't
plan on refueling a C-5 any time soon.

--Walt
Bozeman, Montana





John Gaquin wrote:
> > wrote in message
>
> > If you float in above the threshold a fair bit higher than Vref, is it
> > acceptable technique to chance the reverser to preclude landing too far
> > down the runway?
>
> It is bad technique to "chance" anything. Jim is right in that if you're
> out of position for landing a miss should be your first consideration.
>
> I can't speak for all transports, but I seem to recall on the 727 and 747
> there are lockouts that prevent reverse actuation in flight. Not 100% sure
> of the physical lockout on the 727, and too lazy right now to look it up.
> :-) I do recall that inflight reverser use was possible on at least some
> models of the DC8.
>
> In any event, I wouldn't consider use of reverse immediately before landing
> a good idea.

[[email protected]]

Walt wrote:
>
> It was very interesting just getting the C-5 into contact position, but
> what was more interesting was when we'd practice a break-away. The C-5
> would employ their thrust reversers and pretty much disappear.


Wow. And there evidently doesn't appear to be a maximum thrust limit
for deployment of the reversers either :)

Ramapriya

[John]

wrote:
> Walt wrote:
> >
> > It was very interesting just getting the C-5 into contact position, but
> > what was more interesting was when we'd practice a break-away. The C-5
> > would employ their thrust reversers and pretty much disappear.
>
>
> Wow. And there evidently doesn't appear to be a maximum thrust limit
> for deployment of the reversers either :)
>
> Ramapriya

This from the ancient memory area of my brain, so all appropriate
cautions should be exercised . . .

I seem to remember that years ago (perhaps a few decades) that I was
reading a Pilot Report in Flying magazine. The author was on final
approach in a Turboprop Commander (690?) and placed his hands on the
throttles with his fingers in position to pull the unlocks that would
have permitted him to pull the throttles back through into reverse.
The manufacturer's rep in the right seat immediately rebuked the author
and cautioned him not to touch the unlocks while airborne. I guess the
manufacturer thought that this would be a really BAD thing.

I miss the days when Flying's pilot reports were many pages long. It
seemed they were written more by test pilots and less by the folks in
marketing. I guess one reason maybe how long the magazines can have
access to the planes. One the editors commented last month, that in
the old days they would have the plane for a week and they would fly
them long distances. I recall some months back, a pilot report on the
Flight Design CT2K, where it seemed that the author declined landing
the plane because of bad crosswinds. A safe decision that I agree
with, but I remember thinking: "Sheesh, didn't they have enough time to
fly to another field or wait for better weather the next day?" Telling
us how a plane behaves in the pattern and during landing strikes me as
a matter of prime interest.

Blue skies to all . . .

John

[150flivver]

Walt wrote:
> When I was flying KC-135's in the '70's we'd air refuel a C-5 every now
> and then.
>
> It was very interesting just getting the C-5 into contact position, but
> what was more interesting was when we'd practice a break-away. The C-5
> would employ their thrust reversers and pretty much disappear.
> --Walt
> Bozeman, Montana

I find this hard to believe especially given the problem a C-5 recently
had with a thrust reverser becoming unlocked after take-off. Where
would a C-5 be if the bucket were to fail in the deployed position
airborne? Any current C-5 pilots care to confirm or deny the approved
use of thrust reversers airborne?

[Dave S]

Kingfish wrote:
> Jim Macklin wrote:
> But I agree, jets require the
>
>>squat switch (unless there is a malfunction) to deploy
>>reverse.
>>
>
> I read recently the C-5 that crashed at Dover, DE had a #2 engine
> reverser unstow right after takeoff. The crew attempted the approach
> with full flaps instead of partial flaps per the POH and the sink rate
> was too high to overcome.
>

It was an "unlock" indication which is one step before an "unstow". They
shut down the engine in question to prevent an aysmetric deployment.. I
THINK i saw that they had pulled the opposite side engine (#3) back to
idle for some reason (directional control presumably... but I would have
thought the rudder would have enough authority for that..)..

I heard the full flap thing too.. but my version has them retracting
from full to some partial setting, and that the airplane was flying
below the stall speed for that weight and flap setting, and then simple
physics took over.

Dave

[Walt]

150flivver wrote:
> Walt wrote:
> > When I was flying KC-135's in the '70's we'd air refuel a C-5 every now
> > and then.
> >
> > It was very interesting just getting the C-5 into contact position, but
> > what was more interesting was when we'd practice a break-away. The C-5
> > would employ their thrust reversers and pretty much disappear.
> > --Walt
> > Bozeman, Montana
>
> I find this hard to believe especially given the problem a C-5 recently
> had with a thrust reverser becoming unlocked after take-off. Where
> would a C-5 be if the bucket were to fail in the deployed position
> airborne? Any current C-5 pilots care to confirm or deny the approved
> use of thrust reversers airborne?

Well, being on the KC-135 side of the refueling I can't verify what the
C-5 did on the break-away.

I'd like to hear from a C-5 pilot too. It was supposed to be standard
break-away procedure for a C-5. I'll be more than happy to be corrected
on this.

--Walt

[Al]

"Dave S" > wrote in message
ink.net...
> Kingfish wrote:
>> Jim Macklin wrote:
>> But I agree, jets require the
>>
>>>squat switch (unless there is a malfunction) to deploy
>>>reverse.
>>>
>>
>> I read recently the C-5 that crashed at Dover, DE had a #2 engine
>> reverser unstow right after takeoff. The crew attempted the approach
>> with full flaps instead of partial flaps per the POH and the sink rate
>> was too high to overcome.
>>
>
> It was an "unlock" indication which is one step before an "unstow". They
> shut down the engine in question to prevent an aysmetric deployment.. I
> THINK i saw that they had pulled the opposite side engine (#3) back to
> idle for some reason (directional control presumably... but I would have
> thought the rudder would have enough authority for that..)..
>
> I heard the full flap thing too.. but my version has them retracting from
> full to some partial setting, and that the airplane was flying below the
> stall speed for that weight and flap setting, and then simple physics took
> over.
>
> Dave

The report also said that after securing the #2, they continued to
operate the #2 thrust lever instead of the #3 which was still operating.
Dead foot, Dead engine.

Al G.