53 Minute turn around time

[BMM389EC]

Anyone have any info concerning the 53 min turn- around weight limit for landing on the 737? eg If landing at say at 25C with Flap 30 the limit may be 53000kg.
Is it correct that the 53 minutes starts from chocks on in the bay? What if the aircraft weighed 52500kg when it landed, surley then it would need close to 53 minutes before turning around? What if the turn around was 30 min?

[mainwheel]

A little confused! Are you asking about APU burn on turnaround?

[Zeus]

Brake cooling period?

[mainwheel]

Thats the other thing i considered.But have never heard of or experienced it.
Is there some sort of language translation problem here?

[Alex Whittingham]

There is a page in the CAA manual that is used in the JAR performance exam that I suspect BMM is referring to. I believe derives from the B737. It is headed 'Quick turnaround limit' and is composed of tables of weights for flap 15º, flap 30º and flap 40º at different pressure altitude/temperature combinations. The text header says 'After landing at weights exceeding those shown below adjusted for slope & wind wait at least 53 minutes and then check that wheel thermal plugs have not melted before excecuting a take-off.' There is a second detailed page allowing brake cooling times to be calculated parked, airborne gear down and airborne gear up. The second page allows taxy time to be taken into account, the first doesn't mention it.

I'm not B737 qualified so I can only guess how these tables should be used. Any 737 operators feel free to jump in.

Should the 53 minutes be on the ramp? I would guess yes, because brake temperatures generally rise while taxying. What if the a/c was near the limit on the first page? I would use the second, detailed, page to establish the cooling time.

Do these pages ever get used for real on the B737?

[eyeinthesky]

So how do the much-highlighted 20-min turnarounds of some UK LCAs square up with that? Especially if, as alleged recently, they are operating fast, maybe braking hard to make the first runway exit and then going again within 20 mins?

Not trying to stir up more 'trouble' for that particular airline, just interested.

[PPRuNe Towers]

Pilots with LCA's do not have the necessary manuals to work out the brake cooling periods. They generally only have the 53 minute table to hand. They have to accept purely verbal assurances that wise heads in offices have worked the figures for rapid turnarounds to be legal.

Legal advisors to these companies would not be terribly impressed if they were ever to conduct an investigation - hopefully prior to an abort/over-run. An adversarial lawyer would tear them to pieces.

There are many other waiting perf/fuel/technical type chickens looking to roost amongst the rapid growth companies.

[aztruck]

Brake cooling is all there in the Boeing Qrh, and it depends on all the usual variables as well as what Autobrake setting you use and whether or not you choose to use full reverse.
Our policy is Autobrake 1( or 2) and idle reverse only unless there is an obvious reason why. I flew into Taba the other day on a -700, temp 38c, Qnh 1007,2400 ft elevation and a full aircraft (148 plus 6 crew and return catering). No problem with the brakes at all. These are pretty equivalent figures to US operators in the Desert in Summer.