My question now to the Airbus gurus here is does the airplane allow you to exercise your piloting skills to maximimun advantage in an untrained and or unplanned situation? Remember, I am a Boeing/Douglas guy. Can you pull as hard as may be required? The difference between hitting the ground/ocean and recovery may well be pull hard on the horizion.
I will leave this open for discussion. Obviously the TWA aircraft under Capt. Gibson's command survived a 6 g recovery. The B-727 was never designed for this load factor, and the airframe in question was retired.
I do not want to hear BS about airframe certifiaction standards, comparrison in G loadings, etc. I will supply a link soon to the TWA incident, but I would hope that all professional aviators on this thread are aware.''
To answer your question:
Even in ALT LAW 2, Pitch Control is identical to ALT LAW 1 where flight law is a Load Factor demand law, similar to Normal Law, with limited pitch rate feedback and gains, depending on speed configuration.
Low Speed and High Speed Stability is available but with Pitch Attitude Protection Lost.
There is no Bank Angle Protection.
And,
In case of 2 ADR failure, there is No Low Speed Stability;
In case of 3 ADR failure, there is No High Speed Stability.
I therefore would tend to suggest that one could only pull 2,5 G's except if, due to other associated failures, the aircraft would change to Direct Law and Pitch Inputs would be then directly commanded by the pilots.
In other words, only in Direct Law, pilots are allowed to pull more than 2,5 G's...
To answer mine:
IMHO, this means also, that due to High and Low Speed Stabilization (where the aircraft gives inputs to the flight controls to prevent stalling it [and therefore, spin it]) and also to the fact that
AoA data is provided to BUSS - Back Up Speed Scale,
via the IR part of the ADIRU, in order to enter a stall the aircraft would have to have changed to Direct Law.
FCOM Abnormal Procedures tells us that even in a situation where two IR's or 3 ADR's are lost, Flight Controls Laws would still be ALT LAW 2.
This leads to me thinking that Human Factors may have played a role in the outcome of this accident. Pure speculation I must concede, as most of the argumentation I've seen in this thread.
Easy to accept that, in the middle of the stressing Unreliable Airspeed Indication troubleshooting, the (unprotected/unguarded) IR's were disconnected by mistake (in step of ADR's) in an attempt to display Backup Speed Tape...the rest one can guess. That's much easier, for me, to accept that, than a total failure of aircraft systems, tail fin or brake apart in several pieces.
Ready (and maybe deserving) to be flamed, now...
P.S.- Here's a partial transcript of Airbus Publication: SAFETY FIRST of Dec 2007 written by Joelle Barthe (Flight Operations Engineer, Airbus Industrie)
(my
bolding)
In order to decrease the crew workload in case of
unreliable speed, Airbus has developed the Back-
Up Speed Scale (BUSS) that replaces the pitch
and thrust tables. The BUSS is optional on
A320/A330/A340. It is basic on A380, being part
of the ADR Monitoring functions.
This indication is based on angle of attack (AOA)
sensor information, and is therefore not affected
by erroneous pressure measurements.
The BUSS comes with a new ADIRU standard
(among other new system standards), where the
AOA information is provided through the IRs and
not through the ADRs. This enables selecting all
ADRs off without loosing the Stall Warning
Protection.
The AOA information provides a guidance area in
place of the speed scale. When the crew selects
all ADRs OFF, then:
• The Back-Up Speed Scale replaces the PFD
speed scale on both PFDs,
• GPS Altitude replaces the Altitude Scale on both
PFDs.
The Back-Up Speed Scale then enables to fly at
a safe speed, i.e. above stall speed and below
maximum structural speeds, by adjusting thrust
and pitch.