A couple of points re. the above posts.
Making a tight turn by locking up a brake would be generally considered inconsiderate treatment of the aircraft! obviously it scrubs the tyres, but also imposes a twisting force on the main gear leg. The leg will of course be built to withstand this, but long term wear will ensue. A pre-production Concorde once wrecked a main gear leg at Bahrain by turning too tightly, I'm led to believe.
On the 146 the nose gear breaks free of the steering mechanism and castors freely when turned beyond 70 degrees. It can be re-connected simply by forcing it back into the +- 70 degree range. So we would be wary of using differential thrust or brakes to assist the turn when turning tightly.
Happened to me once lining up on 28 at Zurich, it swung about 30 degress through centreline before I got it stopped (I couldn't just stamp on the brakes!) and I'm sure the other 146 crews waiting on the parallel taxiway knew exactly what was going on! I brought it back into submission with assymetric or differential thrust and brake, thats the only way, and is quite easy anyway. Won't make that mistake again. I now make a point of using the outside brake when turning, if needed. BAe/Avro don't recommend the use of differential thrust except when essential on slippery surfaces.
In general terms, on landing, aerodynamic braking is most useful at higher speeds, wheel braking at lower speeds. So for max stopping performance, reverse, spoilers and airbrakes just after touchdown, and minimal braking. (Holding the nose off the ground increases the frontal area and is very effective, but its also considered "hot-dogging" and would surely be the mark of a cowboy!)
As speed decreases, aero. braking diminishes in effectiveness, which is why most carriers procedures require reversers to be stowed by about 60 knots. Much lower than that and they risk ingesting debris blown up from the ground, but even at max reverse thrust, they're much less effective than wheel brakes at low speeds.
You sometimes see aircraft taxiing with a reverser deployed. This is not so much braking, its more a case of negating the idle thrust. Many aircraft, once rolling, will continue accelerating to the point where you have to use the brakes to slow to a safer taxiing speed. Remove some of the thrust and its not such an issue.
The correct braking technique for aircraft from Cessna 150s to 747s is to let the speed rise to the point where you think its fast enough, then slow to a walking pace, then let it accelerate again. A BA F/O once told me each brake application on the taxiways costs about £10 on a 777. The thing to avoid is riding the brakes, this wears them out faster, and heats them up short term.
Anti skid is usually an ON/OFF system, but Autobraking usually has several settings. I believe Boeings typically have a knob with OFF, and settings 1 to 4. There would not be an occasion in normal ops to switch the anti skid off. Like a car system, it will extract much more effort out of the brakes than a human can, and adjusts for the conditions. With anti skid off, there would be considerably more rubber left on runways than there already is.
Air brakes have a seperate lever, usually on the captain's side of the centre console, left of the thrust levers.
Reverse thrust is selected and modulated by levers protruding forward from the thrust levers. So when the thrust levers are back to idle, the reverse levers are in an easily accessible position. Engines have to be at idle to select reverse, then can be spooled up. Some types place a limit on RPM in reverse, some don't.
Brakes heat up at a rate which varies exponentially with speed, so its best to use them sparingly at high speed, increasingly as you slow down. Depending on whether they're carbon or steel, they lose effectiveness with temperature.
Air brakes of the fuselage mounted type (146 or F-28) are also more effective the faster you go. They're hardly noticeable at approach speeds. Wing mounted air brakes, however, certainly slow you down, but by virtue of their location, destroy large quantities of lift, so there is a much more dramatic effect.
Anyway, dinner's ready.
Regards - Musang