But the T7 will not kidnap the control as the 330 does.

@CONF iture:
 

AoA protect is there for a reason, don't have to explain you that, unfortunally it was activated when not appropriate, fortunately there was and is a solution to overcome.

Question: what will be the instinctive reaction of the PF when stickshakers are suddenly activated?

Both JTSB as ASC did not initiated an investigation, although you say the control was 'kidnapped',
nobody - on this forum -seems to be concerned about that one.........shouldn't we?

@Kimon:

I admit the dual ADIRUs/SAARUs concept in B will be more robust against multiple failures compared to the 3 ADIRUs concept of A.
In single failure and in case of similar but - wrong data - it will not make any difference.

FWIW:

In A350 airbus will supply the ISIS (optionally a repeater for RH seat) with its dedicated pitot and static ports.
The triple ADIRUs concept will remain however with dedicated multifunctional probes (MFP) and slideslip sensors.
Only ADIRU#1 will be equipped with an additional normal AoA sensor.

Hopefully an initial push ... until, still hopefully, things point to the undue stickshaker activation and therefore the possibility to stabilize the situation, possibility refused to an Airbus crew before he shut a few computers down.

Some serious questions need to be asked why investigation bodies do not investigate a loss of control leading the EASA to publish an EMERGENCY AIRWORTHINESS DIRECTIVE and Airbus to modify its Flight Manual ...

That the event was "unfortunate" seems good enough for you to keep it quiet ... I just don't follow you on that path.

Just like the A330 did, but they have to overcome the increased force to stabilize and keep the continuing stickshackers.
most probably they will (ICW OCC!) continue in Direct and silence the shackers with CB. also dual - non procedural - action required.


On the contrary...I do agree! it is serious matter and should be investigated.
The only 'excuse' I can imagine is that the source of this INCIDENT was that obvious (mechanical blockage) they left it to EVA QA - as first in line - to investigate.
In the EAD it is not mandated to remove the conical plates or replace the AoA sensors in factory delivered airbii.

Yes, Kimon, the static ports have been known to freeze up.

No big deal until you climb or descend, and then altimeter doesn't change but the CAS/IAS does. With all the stuff we now have and a knowledge of power and pitch for various flight conditions you're usually in good shape.

Having the AoA sensors freeze at identical angles could be tricky, as you might lose some "protections" at higher true AoA.

Several here have experienced static system problems and are still here to contribute.

• 777 - It is possible to override the unjustified protection.
• 330 - It is NOT.

By focusing on the conical plates, you're missing the bigger picture : How a Flight Control System is giving FULL priority to an unjustified protection and how a crew is needed to save the aircraft that was supposed to save the crew ...

If people think the T7 won't behave strangely or contrary to pilot command if given duff data, have a look at this article (h/t Clandestino - my bold):

What happened on flight MH124 - Nation | The Star Online

EDIT - Clarification: Clandestino mentioned the incident, not the article itself.

• Strangely YES
• Contrary to pilot command NO

Show me the data of the elevator down when the pilot commands it up ... ?

Not sure what you're referencing here - but you know the T7 system doesn't work that way, instead it will gradually increase PFC resistance to the pilot's input via the backdrive system.

In the case of Airbus Alpha prot (as you well know), elevator down in response to a nose-up command is to maintain the aircraft at the alpha prot AoA, because to follow the pilot's command directly would result in an imminent stall.

IMO in A330 it is also 'overridable'.......manual pitch trim (to level off), I know....it's not in the procedures.

By T.S.
 

Are the following statements true on the B777 if it were an AF447?

1) Turning off the ADRs so as to force it in Secondary Mode à la A330 Alternate 1?


No. You can't turn the ADRs off in flight on a 777. The only way I know to force Secondary Mode is to open the pitot probe heat circuit breakers (which a normal flight crew should NEVER do).


2) B777 is w/o aural SW only yokeshakers so it is not subject to the 60KNS / 30 KNS cut-out set-up?


I *think* (but am not positive) that the shaker would cutout when the airspeed when too low, for the same reasons that the Airbus aural cuts out.


3) B777's equivalent of THS AutoTrim is that trims for speed only not pitch.


Not exactly. The 777 uses elevator for fast commands then trims the stabilizer to offload the elevator. 'Trim" on a 777 is really an aerodynamic state that's a combination of current elevator and stab positions, not an explicit state of either one individually.


4) Pitch authority is always driven via the elevators that command the stabs as opposed to the A330's separate - "divorced" - authority i.e. THS AutoTrim is separate entity that does not rely on elevator authority at all?



Both systems rely on both. AutoTrim and 777 stab trim are both composite systems that work together with the elevators to give the pilots what they ask for with minimum drag. The 777 has speed stability as part of the control law but, depending on the flight regime, the actual pitch command trying to return the airplane to trim speed might be elevator, stab, or both.

then time for a new PFD message :
MANUAL PITCH TRIM ONLY TO FIGHT ELEV

but I love your optimism ...

Thx..:hmm:

Normal USE MANUAL PITCH TRIM will do!

MAN PITCH TRIM ONLY + USE IT NOW !
In the wait for the single guarded switch ... I will also stick with the ADRs.