Airbus A32x FAC STD B0624

[Willie Nelson]

We have a new FAC standard on our aircraft which indicate that "alpha floor protection is inhibited when aircraft is above Mach 0.6" can anyone expand on why this was brought in?

It's B0624 apparently.

Cue Vilas?

[IFixPlanes]

AI said:
"In this domain of high Mach, the availability of the protection is not relevant because the aircraft is in a situation of high energy."

[FlyingStone]

Perhaps to eliminate the "Abnormal Valpha Prot" OEB, where the protections try to kill you?

[Willie Nelson]

I was thinking along the same lines but there are circumstances when wouldn't eliminate and perhaps that's why it's still there also.

[vilas]

May be to bring similarity with A330. In A330 alpha floor is inhibited beyond M.53. Valphaprot is different from alpha floor. Alpha floor is triggered at higher AOA than Valphaprot. This inhibition won't eliminate the OEB.

[Willie Nelson]

That's right because there are two other conditions that will trigger it also.

[PilotJames]

Originally Posted by IFixPlanes

AI said:
"In this domain of high Mach, the availability of the protection is not relevant because the aircraft is in a situation of high energy."

Yes. This is what Airbus says on the matter.

[vilas]

Alpha floor or even Valpha protection basically was designed to pilot induced loss of speed situation during approach. They themselves realised that beyond .5M at altitude it meant nothing so they never had it in A330. So they seem to have knocked it off even in A320.