Reverse thrust at STN / EGSS

[miss_heard]

With regard to landing at Stansted, do operators generally apply reverse thrust for a set period of time (e.g. 20 secs no matter what the conditions) or is it generally only applied until normal taxi speed is reached? In either case, what would be a 'typical' duration for the use of reverse on your type of a/c when landing at STN?

Thanks in advance

:)

[NigelOnDraft]

Well ther's a journo / NIMBY query if ever there was one :D

Selecting Reverse for a certain number of seconds :ooh:

[World of Tweed]

My companies SOP is to use reverse Idle. Until 60kts at all airfields unless otherwise briefied. Capt has right to use more if he/she wants.

We all try and abide by the noise police rules but falling the off the end of the runway is alot noisier usually.

[BOAC]

Until 60kts at all airfields unless otherwise briefied - Boeing recommend you should cancel reverse idle at 'normal taxy speed', not 60kts.

[Intruder]

Depends on the airplane and the operator...

Our 747 manuals tell us reverse as needed down to 80 KIAS, idle reverse by 60 KIAS, out of reverse by taxi speed. 60 KIAS is also our max for using a "high speed" exit taxiway, and 20 knots ground speed for normal taxi. So, out of reverse by 60 or 20 knots, depending on the situation...

[miss_heard]

Well ther's a journo / NIMBY query if ever there was one :D

LoL - I promise you I'm neither!


Selecting Reverse for a certain number of seconds :ooh:

Believe it or not, I heard a rumour that one airline's SOP was to select reverse for a fixed number of seconds, which was what prompted me to post the question to you guys and gals!


Thanks to the others for their answers though
:)

[electricdeathjet]

Most airfields we normally apply idle reverse thrust for about 22 seconds, but in STN we use maximum reverse thrust espically at night time for 45 seconds, so my wife can hear me and get the dinner on!:ok:

[sarah737]

Exactly the same as in your car: when you want to stop you push the brake for 17.5 seconds!

[I Just Drive]

I think you are all being a little bit too harsh. Its a tech question in a tech forum. Albeit from someone outside the industry (im guessing).

The answer is, unless your operator has a policy of using reverse idle (i.e. opening the reverser doors but not using any power, most airlines will promptly select reverse after touchdown, then continue to use it until reaching a certain speed. Usually from 100kts down to latest taxy speed.
At STN, RYR policy is to use idle reverse on the last flight of the day.

[lomapaseo]

Believe it or not, I heard a rumour that one airline's SOP was to select reverse for a fixed number of seconds, which was what prompted me to post the question to you guys and gals!


I suggest that statement aptly matches your name:}

Reverse thrust is also defined by the amount of thrust. If you use too much thrust below 60kts then the eflux will crawl forward of the engine inlet and lift stuff off the runway for the engine to run into.
Time is not a parameter in its use.

[barit1]

When I worked flt ops a few decades back, Boeing insisted on max reverse ASAP after t/d until safe stop was assured. This may have been a 747-unique practice for pilots unused to the eyeball altitude in a 747 at touchdown; Better safe than sorry.

Is this still the case? :8

[wiggy]

"Is this still the case"

No.

Rgds

[simfly]

I remember jumpseating on BA 757's into Aberdeen many times, and it was quite common for the captain to brief along the lines of "if I land near the TDZ we'll go idle reverse, land long and go full reverse!". I also recall on one occasion when a shower had just gone through, full reverse was planned anyway, and the pax told not to be alarmed about the increased noise or if they felt their necks coming apart! Obviously the length (or lack of) hard surface had a bearing in that... But wherever an aircraft is landing, I think the pilot can judge on touchdown how much or little reverse he / she requires to operate the aircraft safely and adjust as necessary on the roll out regardless of SOP's?

[Agaricus bisporus]

Is it not the case that use of reverse thrust is not factored into Landing Distance required? (Rhetorical question, it is not.)

Therefore that aircraft will stop as per the "book" regardless of reverse use, be it full, idle or none at all.

Boeing, at least, uses an autobrake logic to stop the aircraft using a fixed level of deceleration, and all reverse does is to relieve some of the load on the brakes. It has no effect whatsoever on landing distance.

It may be that other manufacturers use a different logic, but in a Boeing (probably 70% of traffic at STN) use of reverse will not affect landing distance - unless, of course, the tyre adhesion can't cope, as in contaminated conditions, when it could make a significant difference.

Why, then, use reverse at all, you may ask. Simple. $$$

Less work for the brakes means brakesets last longer, and brakesets cost big money. Idle reverse makes no more noise than no reverse which is why many airlines use idle only - saves dosh, saves wear and tear with no noise penalty, = win win for a change!

Ps. To all those who say in a pre-landing brief, "runway is short so I'll use 70% reverse" think again, just as "runway is wet/slippery so I'll use autobrake 3". Think about it. Just ain't logical!

[BOAC]

"runway is short so I'll use 70% reverse" think again, - unless t/r time is a factor for brake cooling?

[lomapaseo]

Why, then, use reverse at all, you may ask. Simple. $$$

Less work for the brakes means brakesets last longer, and brakesets cost big money. Idle reverse makes no more noise than no reverse which is why many airlines use idle only - saves dosh, saves wear and tear with no noise penalty, = win win for a change!


If you really want to save money then don't use reverse at all, just brakes.

It costs a lot more in maintenance to service reversers then it does brakes.

However I do agree that if you are going to be using the reverser at all it does save on brakes.

[Pugilistic Animus]

70% reverse:confused: ---all or {IDUL retardation thrust:}} --not 'nothing'---:oh:---for me:) [see edits]



what about full manual emergency braking?---you'd all be using full reverse in such a situation I guarantee:}

PA

[wobblyprop]

We use idle reverse as the norm on the 757/767. Saves fuel, we haven't been told to cost of brake wear etc.

The variation on that would be v.short runways or where the ambient temperature is high and the brake cooling schedule would affect the 1hour turnround time.

We are encouraged to single engine taxi in, SETI. Using idle reverse means that the engines require less cooling time before shutdown.

[easy1]

In answer to you're question,

"I'll use 'em for as long as i like, as hard as i like, and as much as i like, cos i'm the fu****g captain!!":}

Have a look at www.youtube (http://www.youtube) and search for yorkshire air, Bloody funny!!

[Forkandles]

Believe it or not, I heard a rumour that one airline's SOP was to select reverse for a fixed number of seconds, which was what prompted me to post the question to you guys and gals!
:)

Wasn't Ryanair, was it? ;):oh:

[OutOfRunWay]

I always thought that all boeing autobrakes used a fixed braking force for a given autobrake setting, not like the bus which will produce a fixed deceleraton, modulating the brake force if reverse is used.

Please correct me if Im wrong.

regards,
OORW

[BYALPHAINDIA]

We don't use RT much now at TOM.

[barit1]

I always thought that all boeing autobrakes used a fixed braking force for a given autobrake setting, not like the bus which will produce a fixed deceleraton, modulating the brake force if reverse is used.

Please correct me if Im wrong.


Putting the shoe on the other foot -

Wouldn't it be nice if power management for TO was always set to achieve a known acceleration rate, based on R/W length and Vr (or some other speed)? You'd never be in coffin corner for TOGW error, brakes dragging, etc.

[BYALPHAINDIA]

Yes see what you mean, The T/O rate depended on the RWY length available, it would have been a good idea.

[miss_heard]

Wasn't Ryanair, was it? ;):oh:

no, the other one

[CL300]

barit1

Join Date: Feb 2005
Location: flyover country USA
Age: 66
Posts: 2,138

Wouldn't it be nice if power management for TO was always set to achieve a known acceleration rate, based on R/W length and Vr (or some other speed)? You'd never be in coffin corner for TOGW error, brakes dragging, etc.


yep this is called flex take Off...and you have a stopwatch for acceleration at 100 Kts..

[POL.777]

OORW:
Boeing Autobrakes senses deceleration rate and modulates brake pressure accordingly. Application of reverse thrust will result in reduced braking pressure.
On the 737 NG the autobrake settings available are 1/2/3/max and RTO.
1 is equal to 1250 PSI and 4ft/sec scheduled deceleration
2: 1500 PSI 5 ft/sec
3: 2000 PSI 7.2 ft/sec
Max: 3000 PSI 14ft/sec above 80 kts. 12 ft/sec below 80 kts
RTO: 3000 PSI