I have a question... during a reject on T/O would u rather use RTO Braking or take over manually (everytime) and use Max Manual? The question i am asking for is on the B 737 NG's. Comments on other aircrafts are also welcome.
Also which would provided a shorter stopping distance.
Can't speak for the 737NG, but the teaching (which originated from Boeing) for the B757/767 was to use RTO. Boeing claimed that max manual braking was less effective. I never experienced RTO braking in the aircraft, but one or two colleagues who did said it was like walking into a brick wall.
On the previous jet the procedure was to bury the brakes in the aluminum and allow the anti-skid system to stop the jet. In training, on the previous jet, I did that drill for about a dozen years. When I transitioned over to the NG it was a very hard habit to break; trying not to drive the brake pedals through the flooring and allow the RTO system to stop the jet. Iíve never had to do it for real yet in the airplane. All the guidance we get now tells us to use the RTO system rather than manual braking.
As BelArg says, where fitted, RTO every time and for the reason he gives in that in any crosswind it is very difficult if not impossible to achieve consistently high and even brake pressures through both feet and therefore the stopping performance will probably be less effective.
[Speaking for B737-200/300/400, B747-400 and A320]
Still agree that it is difficult to resist the temptation to stamp on the brakes, though
Location: In some hotel downroute or in some hotel doing union negotiations.
Training and advise from Boeing on the classic and NG is to use RTO. However in the SIM you see most step on the breaks and break RTO, often with pretty bad results as they do not realize how much you have to depress it for max manual. Allways a good lesson learnt when you leave the runway in the SIM, hope it helps for the rare case you have to use it in the real world.
The B777 achieves maximum possible braking with RTO in operation.
There is a "myth" in this airline that Maximum Manual Braking can achieve better results, but that results from slightly erroneous performance data fed into the Simulator data-base, and not an observation from the real aircraft.
Who knows? Maybe the simulator is correct, but so far nobody has voulenteered to do a comparative test in the real aircraft.
Having done a few RTOs for testing purposes on the 737NG, I can assure everybody that the sim does not prepare you for the event. If you're very fortunate, you may remember to check speedbrake up and deploy the reversers after you've stopped. RTO is an awesome function. Use the RTO function as your primary stopping aid.
In my previous jet, I taught that RTO braking would be exactly like holding the brakes for a static take-off-if you butt wasn't light or off in the seat cushion, you weren't pushing hard enough. It takes a huge push to get maximum anti-skid braking, something we don't do often, even in the sim.
As luck would have it, a student of mine had to do a max effort RTO at refusal speed. It did what I had taught and stopped with the NLG about 10 feet from the grass.