Vilas
A 320 has two independant braking systems. Normal on green and Alternate on yellow. Both are with antiskid. Accumutor is not alternate braking but a form of emergency back up. You only have seven applications and no antiskid. The landing distance required with only accumulator as brake would not be same as previous two. However in G+Y fail it would make sense to add alternate brake in inop system.
I Disagree with you on the above, the accumulator is a form of alternate braking as it is part of the alternate braking system.
2 Braking Systems:
- Normal Green Hyd System
- Alternate Yellow Hyd System and/or Accumulator.
4 Braking Modes:
- Normal Braking
- Alternate + Anti-Skid
- Alternate – Anti-Skid
- Alternate on Accumulator Only
It would make even more sense the other way round, if they removed it from the inop systems list in a B+Y hyd failure case, is a form of alternate braking.
Just look at the DSC 32-30-10 p1 and the diagram on p9; the ABCU is responsible for:
- Alternate Braking with A/SKID (BSCU controls the A/Skid)
- Alternate Braking without A/SKID
- Alternate Braking without A/Skid on accu only
so really they shouldn't even list it as an inop system at all!
This is really a trivial thing, however it does not make sense so it was worth discussing.