jcjeant at 22:40 feb 1
 

great article in link - BUT still unclear if pushing buttons either RESETS the FAC or totally kills it as in Circuit breaker . . :confused:

One of the big beefs with the Airbus design is that the opposite stick does not mirror the movement inputs that is being done with the stick of the PF and I agree this is perhaps a flaw in their design. If in doubt from what I understand there is a “Master” switch on the left side stick that disables the RH side stick.

As far as their “LAWS” are concern, I don’t think having some protection is a bad idea.

Even the Boeing C-17, another FBW aircraft as built in protection for stall via AOA sensors, perhaps not as extensive in some ways as the Airbus but also more permissive in other ways because of the theatre of operation it conducts its flights in. Even these protections did not stop a C-17 from stalling and crashing killing all 4 crew members while performing an over aggressive manoeuvre prior to an airshow.

Another interesting design philosophy the designers of the C-17 went for was a stick like on a vintage aircraft like the Piper Cub, not a side stick like on the Airbus nor a regular column like the B777 for their FBW aircraft and again unlike Airbus both sticks move in tandem.

In the end no manufacturer can make a “full proof” aircraft and it is up to the pilots to know each aircraft’s “quirks” and systems to fly it properly and safely.

@SAMPUBLIUS, with reference to post #2959 http://www.pprune.org/rumours-news/553569-air-asia-indonesia-lost-contact-surabaya-singapore-148.html#post8850384, "BUT still unclear if pushing buttons either RESETS the FAC or totally kills it as in Circuit breaker . ."

Recycling either FAC pb on the overhead panel disengages the FAC but retains flight envelope protections.

Pulling the CBs to reset the FACs, (the term "reset" is used in the FCOMs to describe the pulling-and-resetting of Circuit Breakers on the A320), kills the FAC and as has been stated by several posters, is prohibited when the aircraft is in flight.

With reference to the "GerryAirways" article, if true, one does have to loosen the seatbelt to reach the aft-overhead panel, but not to reach the FAC switches which are on the main overhead panel.

From the FCOM, ATA 22, Auto Flight:

Amen on the comment about the sidestick controller of each pilot being out of view of opposite pilot. Also, in the A320 series, when sidestick controller are active, the flight computers will ADD the inputs of BOTH pilot sidesticks together.

Some posts ago, mention was made of the artificial feel in "conventional" yokes of FBW jets, (a big help) especially when each "conventional" FBW yoke is just that, yoked together.

Not to mention a "quirk" in the A330 where the audio stall warning signal is removed below a certain IAS, then resumes blaring should the IAS begin accelerating. Haven't delved thru the A320 manuals, so don't know if 320 series has same low speed stall warning "quirk"

Enough already of low-time idiot new age FO's and their pitiful flying skills. The overwhelming majority of jet transport aircraft losses thru the decades were by and with old school experienced Captains and FO's

Yes I know that practically all actuators even with FBW are hydraulic, electric motors have characteristics which make them unsuitable for most control surfaces. The signalling is as you say electric but not "only". The BIG difference is that there is no need for hydraulic steering and computational elements like spoiler-mixers and ratio changers etc. Low level computers work out all that stuff - pooters like the FACs (and T7 ACEs) which are topic of conversation.

FA Computer. Think shut-down & reboot on the buttons. Unplugging it via the circuit breaker. If your computer is acting weird, reboot. if it has smoke coming from it pull the plug out.

I don't know the specifics of the A320 FAC reset button but even if it powers the processor down and back up again to do a full system restart it will have had time to shutdown properly. If you power off at the breaker - yes if it's smoking - you're taking a risk of corrupting data and never being able to get it back online at all.

catch21
 

"I don't know the specifics of the A320 FAC reset button"

Unless they've changed recently they're not "reset buttons" on the overhead but off/on switches. This matches with the FAC 1 + 2 fault procedure someone already posted here.

The switch is called "takeover priority" and there is one on both LH and RH sticks. If the switch is pressed this is enunciated with a red warning light plus a "priority left/right" voice warning.

The other stick is not permanently disabled. After either left or right side takes over, the other side can take it right back by pressing his own switch. This happened with AF447, repeatedly.

ELT found !
AirAsia emergency locator transmitter found in Mamuju | The Jakarta Post

All this chat about aerobatic and unusual recovery training is, very sad to say, pie in the sky. I've been there, done that and hope to do even more. That's what flying for fun is about. However, the modern thinking of airline flying - which is looked upon as a potentially vast profit making business - is to design trained monkey SOP's that keep the crew as far away from the need for basic piloting skills as possible. This is exacerbated by modern fail safe a/c design. Captains are being upgraded with half the experience of years ago. Some accidents are now contributed to bad decision making not always bad handling. That could come from lack of experience with the environment you find yourself in. We've all been in a new scenario, where SOP's and QRH's were not helpful, and used nouse, airmanship, tickly hairs on back of necks moments to help in decision making in dark moments. Hi-tech airports & ever more hi-tech high powered a/c, coupled with a diluted basic training syllabus and fast track command upgrades, creates an over dependancy on automatics & SOP's and an over relaxed approach to operating in a 'mother nature' environment where we are not supposed to be. When smart decision making is needed, to avoid the deadly combination of mother nature & gravity, some are found lacking - as a crew.
It has been said, earlier, that the Swiss cheese model is all about hazards and the layers are the defences. The holes are the weaknesses. I like that analogy. In some cases the holes are created when a hazard is encountered and the experience is not there to handle the scenario you are confronted with. Then a hole appears. I'm saying this in general conversation, not specific to this case. How to reverse this trend? There have been smoking holes, but the public reaction by the authorities and airlines has not been what we might have expected. Some years ago people on here said that smoking holes would create a reaction, but it hasn't happened. Some mishaps have been tried to be cured by redesign or extra technology. There has not been a reversal in training/checking philosophy demanded by the so-called safety agencies. Hm? Has there even been any discussion and a review process. Are a few smoking holes an acceptable risk & consequence in this vast profit making business? Is a technology based solution cheaper? Humans have always been, and perhaps always will be the major contributor to accidents, no matter what. To solve that would cost massive energy and funds. I suspect the temptation to use technology as a smart solution is too great. The days of stick & rudder airline flying may been a dodo. Very sad. But how do we improve the decision making process?

There is no need of high altitude sensitivity to start a PIO. Stopping the FAC is just so efficient :E
And the failure mentioned eight times before the mishap flight is enough too. And more, resonance is enough to start a roll "PIO" ...or divergent oscillation leading to break the plane like the Kirgiz KC-135 in a dutch roll which is not stabilized by the yaw damper, which can no more be stabilized by the rudder control .
Too much confidence in plane stability -in fact only static stability without consideration to the transient part of the flight leads to design failures. You may accept them on toys, but not on real airliners.
The F-16 did not seem to have such lettal simplification.

"(2/1/2015) A spokesperson for the Ministry of Transportation, Adravida Barata, told Tempo.co that Indonesian airlines are now required to have “at least” one medical personnel on standby to monitor the health of pilots and co-pilots before take-off.

This new safety requirement being imposed on Indonesian air carriers is outlined in a regulation issued by Transportation Minister Ignasius Jonan on January 15, 2015 of Health Standards and Certification of Flight Crew (Peraturan Menteri Perhubungan Nomor 8 Tahun 2015 tentang Standar Kesehatan dan Sertifikasi Personel Penerbangan).

Barata was speaking in Jakarta on Monday, January 26, 2015 at the National Anti-Narcotics Agency (BNN). He went on to explain that the medical staff would be expected to test the blood pressure of flight crew and determine if they are under the influence of alcohol. Emphasizing that specialist doctors are not required for such health screenings, the Ministry spokesman said such tests are needed to prevent pilots and co-pilots in an unfit condition from taking commands of a commercial aircraft.

The President Director of Indonesia AirAsia Sunu Widyatmoko asserted that his airline has always routinely reviewed the health of its cockpit crews. Commercial pilots must undergo a complete physical twice yearly, plus a separate additional drug screening by BNN also conducted twice a year. There are also unscheduled surprise checks conducted by the Aviation Medical team of the Directorate General of Aviation done at a minimum of once a year."

On reset of FAC versus Circuit Breakers
 

drphillips and others have stated the difference between reset and CB. MY point was/is that IF the FAC(s) are fubar due to ?? ( sensors, bad connections, etc ) then pilots wind up in a infinite loop of on-off, partial protection, full protection, etc.

Whereas pulling Circuit breakers at least stops that loop, but still prevents from bending the airplane.

The article seemed seemed to describe that pushing the reset button(s) would have fixed things or from my view seemed to treat the reset as a circuit breaker ( which it is not )


On other control issues suggest looking up ' phugoid ' in wiki re getting behind the curve or pilot induced oscillations or out of sync feedback..

Enough with the captain-out-of-seat rumor!
 

It did not happen according to the NTSC!

Even Reuters who started the whole thing had to walk back their original report:

Investigators say no evidence AirAsia captain left his seat | Reuters

Now back to you pros discussing relevant facts/rumors.

Just about the only sensible thing reported by Reuters so far

"Although more is becoming known about the chain of events, people familiar with the investigation warned against making assumptions on the accident's cause, which needed more analysis".

Boomtown the FAC flight envelope functions are not the same as the fbw protections. I would argue that selecting the two FAC off will put the aircraft into alternate law in the same way that selecting two functioning ADR off will achieve the same result.
I may have missed it in this now huge thread but what were the symptoms the aircraft was displaying that the crew were trying to correct? Was it directly connected to a FAC or did the previous history of the FAC predispose them to think that was the cause?

Forget about pilot procedures, loss of control and the accident for the moment.

Can experienced airbus FBW pilots suggest other reasons why management, maintenance and multiple crews allowed this aircraft to continue to fly with a history of unresolved FAC problems?

With the limited information available, what percentage of the responsibility for flight with a dodgy FAC would be reasonably attributed to each of these 3 groups?

Alternatively, suggest who else may be responsible?

Suggested response examples:
1 Nobody is responsible for flight with FAC problems. It was just an insignificant ongoing issue. Since everybody knew about it, it was no big deal and not affecting the safety of flight.
2 Engineers 0% were seeking to repair this difficult problem. They were doing their best. Flights were 100% captain responsibility.
3 Airbus 50% and regulatory authorities 50% should know about these problems and should have grounded the aircraft for repair.
4 The airline was under financial stress, and it is OK to cut a few corners.
5 Management unwritten financial stress information filters down through the system. Anyone who makes FAC an issue will suffer, so it is 100% management responsibility. Untimately the captain has no responsibility.
6 Engineers 100% should have grounded the aircraft after a few ongoing FAC reports. Pilots 0% should be able to trust engineers.
7 Management 100%, maintenance 100%, captains who continued to fly this aircraft 100%, Experienced first officers who continued to fly this aircraft 50%, 200 hour first officers who continued to fly this aircraft 0%
8 Management 30%, maintenance 30% captains 30% experienced first officers 10%.

Autoflight the engineering write up will be -Ground test satis , no fault found, please report further.
It has not yet been leaked ,what problems the FAC or FACs had been exhibiting on previous sectors. Standard practice would have been to swap their positions to try and troubleshoot the problem.

You have a small fleet of A320 aircraft. How do you troubleshoot an intermittent FAC?

Swap it with a FAC from another aircraft or your spare from stores.