Use of reverse thrust

[ghostie]

Hi all,

I've recently had the pleasure of taking a few flights on Continental 757's and 737's.

On both types I failed to hear the expected increase in engine noise after touchdown usually associated with the application of reverse thrust.

Is this a new trend, in an effort to reduce noise, or is it a fleet wide directive, in order to save a few pennies per flight? I know it all adds up, especially with the price of fuel these days.

Any information or comment would be very welcome. Apologise if this has already been covered in this or another forum.

Ghostie

[rog747]

my first flight on british eagle in 1964 on a bristol britannia the passengers got a little note passed around in-flight saying dont be alarmed by the propellers going into reverse on landing to assist braking...what a din!

it was fun !

[Bealzebub]

Yes it is a trade off between fuel use and brake wear. Obviously where the runway is long, then it is increasingly normal to only use reverse idle. Reverse thrust can still be selected for shorter runways, contaminated runways or any other time the crew deem it appropriate.

Some airports also request the use of reverse idle only, for noise reduction purposes.

[Crepello]

I've noticed this on CO recently, too. Assumed it was a change in SOPs, for the reasons Bealzebub mentions.

[gatbusdriver]

I always thought it was a trade off between engine wear and brake wear. We generally use idle reverse unless operationally required to use anything more.

[mutt]

More and more airlines are adopting this procedure as part of their Fuel Conservation programs, the savings per flight are small, but fleet wide they start to add up.

From a safety point of view, Thrust Reversers arent used in the calculation of your landing weight on dry runways, and they are actually pretty ineffective when compared to the other means of stopping.

You can expect to notice more airlines adopting this procedure, and some others that you probably didnt notice such as reduced landing flap.

Mutt

[Seat62K]

Is noise pollution ever a factor? For example, do those early arrivals into LHR from the Far East avoid using reverse thrust for this reason?

[FlightDetent]

Yes, quite often does the airport operator restrict the use of reverse above idle. For LHR my documentation reads:

NOISE ABATEMENT PROCEDURES
The following procedures may at any time be departed from to the extent necessary for avoiding immediate danger or for complying with ATC instructions.
...
REVERSE THRUST
Avoid use of reverse thrust between 2330-0600 LT except for safety reasons.

FD (the un-real)

[Kempus]

Its all a performence issue and I dont see an airline incorperating it into thier sops except under the heading of "recommends" as soon as an overrun happens it leaves the airline open to a whole lot.

If brake cooling times are not an issue a higher auto brake setting is prefered and use of ide reverse but as stated in all the manuals reverse thrust is more effective at higher speeds so altough no reverse thrust is taken into account for you will always apply some forum of reverse thrust may it be idle or max.

except for safety reasons

These words allow you to use reverse thrust at any setting at any time of day and the reasons can include wet/contaminated runway, crosswind and runway slope to name a few.

You'll find using a lower landing flap setting will use less fuel but again its all down performence!

cheers

[ghostie]

Thanks for the responses everyone. I fly about once a year and have always seen/heard reverse thrust being used in the past. I did notice the reduced landing flap as well, but thought no more of it. I did remark on one landing that the flap was deployed quite late in the approach as well.

Thanks again.

Ghostie