Question from a bus driver
 

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

We don't use RT much now at TOM.

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.

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

no, the other one

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

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