AF 447 Thread No. 12

[A33Zab]

OK465,
For the EFCS LAW:
The MEDIAN value is polled every second (T0) and compared to the MEDIAN at T0-1s, if the MEDIAN at T0 falls below 30kts of MEDIAN at T0-1s then at T0:

A// The EFCS goes to ALT LAW (ALT2B) and this is announced on ECAM: F/CTL ALTN LAW (PROT LOST)
B// A monitoring timeframe of 10sec is opened and if the MEDIAN value at T0+10s returns within 50kts of the MEDIAN at T0-1s then the EFCS returns to NORMAL LAW.

However if, like in AF447, the difference is more than 50kts then ALT LAW is latched for the remainder of the flight.

Resume: ALT LAW at T0 and LATCHED after T0+10sec.





(Source BEA report #1)