Originally Posted by
DaveReidUK
Braking may or may not have been possible (I don't know) but I suspect the A330 isn't among the few types that that have been certificated for reverser use while in the air (or while the aircraft thinks it's still airborne).
All conjecture at this stage, of course.
It's been a few years since I did any testing on a 320/330/340, but the brake system is under the manglement of the brake and steering control unit, (BSCU). The BSCU gets info from lotsa plaices. LGCIU 1/2, ADIRU 1/2, FCPC 1/2/3... (lé bus goes for FLA more than TLAs... ). The LGCIU's get the nose landing gear compressed signal, (NLG WOW for Bowing pukes) and the main landing gear L&R bogies in ground position, (MLG not tilted for Bowling dudes). The BSCU warning is actually inhibited IIRC from touchdown to 80kts on deceleration (phase 8?) which seems a little contrary. If Lé Plaine has broken the sensors for tilt on the MLG or reracked the BSCU, then switching off the Anti-skid & Nose wheel steering switch is expected to recover the brakes. you still lose TR and NWS, and as you have turned off anti-skid, then, that's fun. I just landed a jet w/o anti-skid and without normal braking system,in MNL last year, in the wet, took up all of the runway, barely touched the emergency brake system yet still had to replace all main tires, no ground spoilers and one thrust reverse cycle available... If the guys had a wet runway, no ground spoilers, no reveresers and no anti-skid, they duz got a a bit of a stopping issue.
all conjecture, but stuff happens. A crew deciding to do a G/A and then changing their mind has parked shiny bits in the weeds before too.
Never understood the warning inhibit rationale for lé Bus breaks, but then, golly, it is a wonderful advanced alerting system and everyone should have it as it is great and isnt it a shame that the dastardly B737 doesnt and well, golly, is that the grass coming up? But, I have the glorious advanced alerting system that B737 drivers can only dream about, and yet, there goes the approach lights, and, the LLZ antenna, and... whoops, lift your feet...
The auto brake function is triggered when selected, by the deployment of the ground spoilers... with MAX being modulated until the NLG WOW is made, assuming that the BSCU is working in the first place. Without the BSCU there isn't much B going along except for alternate W/O Anti-skid. The LDR for No ant skid, no spoilers, no TR is... a lot. No book handy, but it is usually at least 1.7 times the factored landing distance.