PPRuNe Forums - Reverse thrust

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SLF. I commute DUB-LHR weekly. I fly Aer Lingus or BMI. Both operate A321. Big difference however on landing. Aer Lingus always use reverse thrust aggressively both airports , and I mean aggressively. BMI rarely if ever do so and apply brakes gently on a longer but smoother and more comfortable landing roll. Why the difference in style?

Depends on what time the pubs open !!

JetBlue uses minimum reverse thrust, and claims it's for customer comfort (less noise). Dunno what the trade is between fuel usage and brake life...

EI aiming for minimum runway occupancy time?

2A

From my company SOPs (and I suspect that bmi's are similar)

Quote:

Select REV thrust immediately after the main wheels touch down. If runway performance is not limiting or where airport regulations restrict the use of reverse thrust, select and maintain REV IDLE until taxi speed is reached
(Benefits include increased passenger comfort, less brake wear, less environmental impact).

If the runway is short or contaminated or LVPs are in force REV MAX should be used.

Not withstanding the above, REV MAX may be used at any time the crew deem it necessary in the interests of safety.

The bit which takes some lateral thought to understand is the phrase "less brake wear". The reason this is so (we are told) is that carbon brakes work better and wear less when they are warm. Therefore it is advantageous to heat the brakes up during the landing roll and thus reduce wear!

Tried to insert the graph here but failed miserably!

What the graph shows is a steep increase in wear rate up to 100 deg and a steady decrease in wear rate above 100 deg. The proviso is that you prevent unacceptably high temperatures being reached.

EI have possibly taken a different view to bmi on this subject, because there are a number of factors to be considered. I believe that BA also have a REV Idle policy.

Hope that this helps
YS

This is an interesting topic. I have noticed that one particular operator (Monarch) always seem to use maximum reverse thrust and heavy breaking on the landing rollout at Manchester, whatever state the runway is in (Dry, Wet etc.).

BAe 146

BAe 146-100

Monarch SOP's on the bus are for max reverse (except at night due noise abatement) and medium autobrake. We used to use Idle reverse all the time with Medium brake in order to heat up the brakes for the reasons yellow sun mentioned. Trouble was that although wear on the brakes was reduced I believe the number of pad failures increased (due to disintegration).

As for the braking then yes you could use less braking with max reverse but the name of the game is runway occupancy!

Astraeus seem to use idle reverse thrust when landing in their 737's also.

T

Quote:

Monarch SOP's on the bus are for max reverse (except at night due noise abatement) and medium autobrake. We used to use Idle reverse all the time with Medium brake in order to heat up the brakes for the reasons yellow sun mentioned. Trouble was that although wear on the brakes was reduced I believe the number of pad failures increased (due to disintegration).

As for the braking then yes you could use less braking with max reverse but the name of the game is runway occupancy!

Cheers for that longarm. I thought I was kind of right. ;)

Regards
BAe 146