Quote:
Originally Posted by
A33Zab
NAV ADR DISAGREE needs 10s monitoring to trigger.
ACARS msg was received @02:12:51; CMC has 60s maximum to correlate
to any failure message ~02:11:51 - 10s monitoring = ~02:11:41.
I'm not that sure of your interpretation of this timming.
NAV ADR DISAGREE was time-stamped at 0212 during the ACARS sequence. As I understand it, this is a cockpit effect (WRN) and not a fault (FLR), then, I do not think that it needed a correlation window to open before being displayed and an ACARS triggered.
Consequently, as it takes 5-6 seconds for ACARS protocole and 10 seconds to trigger, I would rather time it at 0212:51 less 15-16 seconds -> 0212:35.
I agree this WRN will be displayed (after 10s monitoring) in RT on the EWD.
If you are right about the transmitting time, my theory - silenced STALLSTALL while AOA >35° (AOAsw = 10.8°); THS ANU stops at 13°; NAV ADR DISAGREE all at the same time - won't hold.
The only escape, I can think of, is that NAV ADR DISAGREE (ATA34) warning is transmitted by FCDC (ATA27) as detected by FCPC, thus being external and therefore requires CMC to search for correlated failures.
But I have to study the books again, if mentioned somewhere.
Everybody seems to interpret ADR DISAGREE solely in relation with airspeed issues. So far, I don't know if it was only airspeed related as both AOA or pitot probes measuring values outside of their valid envelope could have basically the same effect.
ex pitot probes, FCPC gets Speed and AOA ARINC input from ADR, no raw data from pitot probes. Of course speed is directly related to pitot probe data. But indeed one can't exclude AOA.
Thx for you comment, gives me something to do.....