Sidestick failure

[anti-ice98]

Hi everybody

Recently during simulator sessions, we had sidestick failures during takeoff corresponding to sidestick working in pitch, but stuck in roll and moreover sometimes stuck in full deflection on one side (for example rolling to the left or right), with absolutely no ECAM alert.
My personal research would tell me that this failure is not inhibited (sidestick fault not inhibited during takeoff, Ref FCOM FCTM), so that it should be associated with an ECAM alert.

My question is, is it realistic during simulator not to have any ECAM showing up during this ?

Thanks :)

[Winnerhofer]

http://www.aviationtoday.com/am/repairstations/Special-Safety-Report-The-Saga-of-Papa-Whiskey_200.html#.VAtoEksYmQs

[Field In Sight]

If it is possible to happen then it is probably worth training for.

Sims have these as a potential failures, so I would assume that it could happen.

The Lufthansa example is a perfect one. One in which the true value of CRM has been shown.

[No Fly Zone]

@Winnerhofer: :D:DThanks for including this somewhat older report. I had not previously read about this incident. A valuable learning experience for all and IMP LH-Teknik did one heck of a job in identifying and FIXING their procedural problems. From the top down, they GET IT. Let's hope that those changes remain in place and have been improved upon. I agree with your assessment that anyone interested in the subject should read the cited article. Thanks! ;)

[Winnerhofer]

Different problem and LH is Airbus's preferred tech partner.
FATAL LOGIC (tv-documentary about Airbus by Tim van Beveren/WDR, 1995) - YouTube (http://www.youtube.com/watch?v=FZ5Ht_mhdrI&feature=player_detailpage#t=533)

[tom775257]

There are two types of sidestick fault; one type that can be detected and one that can't by ECAM.

It seems simple though, if the aircraft is being handled in an incorrect fashion and not improving rapidly on vocalised concern, PNF push and hold the take over PB. Doesn't matter whether incap, side stick fault, loss of SA etc. it will solve the problem.

[OldLurker]

The Lufthansa story reflects great credit on LH but raises a question that I'd like to ask the big-iron drivers.

When we little people check our aircraft before taxi, the "full and free" check includes looking out of the window to see if the control surfaces are going up and down. With a large swept-wing aircraft, I imagine you can't see the control surfaces from the flight deck? During pre-flight check do you, as the LH techs did after maintenance on the incident aircraft, just move the sidestick and assume that the control surfaces are working, or do you have someone outside looking to see?

[Metro man]

On the FBW Airbus the lower ECAM screen displays a diagram of the control surfaces showing the movements as the controls are tested. The flight control page is called up automatically when we do the "full and free check".

[OldLurker]

Metro: Aha, that's neat. Thanks

[Winnerhofer]

http://webcache.googleusercontent.com/search?q=cache:7tj-3-vGJngJ:publications.polymtl.ca/872/1/2012_MarieEveCote.pdf+&cd=2&hl=en&ct=clnk


This is a cached version as the original just wouldn't appear.
Maybe something wrong with my ISP.

[Winnerhofer]

Sidestick Controllers
A320 The first officer indicated that he was in no doubt that the captain was taking control of the aircraft. He relaxed his grip on the right sidestick, but did not remove his hand. He stated that he was not aware of making any subsequent intentional control inputs through his sidestick. However, the DFDR readout indicated that neutral and nose-down inputs were made for some 12 s. The inputs from the first officer's side stick did not detract from the captain being able to achieve the desired aircraft attitude.

The two sidesticks of the A320 are essentially independent insofar as the pilots are concerned, in contrast to the 'traditional' system in which the two control colimns in the cockpit are mechanically interconnected. In other words, while the A320's computer systems co-ordinate the inputs from both sidesticks and base the control response on the algebraic sum of the inputs, there is no linkage between the two with regard to control feel. As a result, the inputs being made by each pilot on his sidestick cannot be sensed through his sidestick by the other. Had there been such a sense of movement between the two sidestick controllers, the co-pilot could have sensed the captain's input as he initiated the go-around, and released any pressure on his sidestick.
The A320 design makes provision for either pilot to take full control with his sidestick, e.g. in the event that one pilot should become incapacitated. To assume priority for his sidestick, i.e. to direct the computers to ignore inputs from the other sidestick, the pilot who wishes to assume priority must activate the 'instinctive autopilot disconnect button', more commonly referred to as the 'take-over button'. As soon as this button is activated, control authority is immediately transferred to that sidestick. However, the button has to be held down continuously for 30 s before control priority is permanently reallocated to that sidestick. Activation of the take-over button on a go-around was not part of Ansett Australia's standard operational procedures. Ansett Australia's procedures for activation of the take-over button (viz. to do so when it is believed that the response from the side stick is not normal), follow the recommendations and standard operating procedures laid down in the aircraft manufacturer's manual. As the aircraft was achieving the attitude required by the captain, he saw no requirement to activate the button.
A320 Crew As part of Ansett Australia Airlines' procedures for one pilot to take control of an aircraft from the other pilot, the pilot taking control is required to say 'taking over' or 'I've got it'. This procedure is designed to ensure that the pilot relinquishing control of the aircraft does so in a timely and positive manner. In this incident the captain of the A320 said 'Going around' and not 'Taking over', or 'I've got it'.

While the first officer reported that he was not aware of any delay or confusion in the hand-over/take-over process resulting from the captain's use of non-standard terminology, it is possible that the sequence was imperceptibly delayed for a short period of time.

Although the A320 successfully avoided the DC-10, under different circumstances the cross controlling between the two pilots (see para. 1.18.2) could have jeopardised a safe go-around.

The DFDR readout indicated that as the A320 commenced its go-around, both crew members were manipulating their sidestick controllers. Approximately 12 s of dual control inputs were recorded. The captain was making pitch-up inputs while the FO was alternating between neutral and pitch-down inputs. However, the FO stated that he was not consciously aware of having made any control inputs following the captain's call of `Going Around'. As described earlier, the aircraft's computer systems based the control response on the algebraic sum of the two sidestick inputs, as neither had priority.
It is evident that crew co-ordination broke down somewhat as the go-around was initiated, because the company standard hand-over/tak-over procedure was not employed. This may have contributed to the short period of control inputs from both pilots. This simultaneous input situation would almost certainly have been immediately apparent, and corrected rapidly had there been a sense of movement between the two sidesticks.
Whilst the engines were accelerating, the captain applied sufficient back stick to keep the aircraft in the air. He was concerned about the aircraft's performance, particularly during the time required for the engines to accelerate as he judiciously managed the aircraft energy balance, gaining altitude whilst minimising the reduction in aircraft performance. As engine pwer increased, the aircraft nose attitude was adjusted to ensure that the A320 tail would not strike the ground and to ensure that the two aircraft would not collide. The characteristics of the A320 and the crew behaviour described in the preceding paragraphs highlight the need to address cockpit resource management procedures, communication and design issues in the operation of such advanced technology aircraft. US studies, for example, have suggested that the 'traditional' CRM training may not be appropriate to the demands of the new generation of highly computerised and automated 'glass cockpit' aircraft.
August 1991 A320/DC-10 Incident at Sydney (http://www.rvs.uni-bielefeld.de/publications/Incidents/DOCS/ComAndRep/SydneyA320DC10/SydneyA320DC10.html)

[Winnerhofer]

https://app.box.com/s/pziwb76wrnkr0l7l98b2

[Meikleour]

Winnerhofer:

The report can be summed up by two points:

1) Incorrect Duplicate Inspection carried out by maintenance after work on the flying controls.

2) The failure of the pilots to check on the ECAM the CORRECT SENSE of the control movements during their controls check.

Incidentally, my last company required the PF to silently choose his own order of inputs for the control check - this required the PNF to actually read and correctly announce the appropriate control deflection. As opposed to having a set order which can lead to people announcing "what they think they see".

[john_tullamarine]

my last company required the PF to silently choose his own order of inputs for the control check - this required the PNF to actually read and correctly announce the appropriate control deflection

A simple, but elegant, solution to a known perceptual failing.

[FLEXPWR]

Meikleour, same here with my previous airline.

Random sidestick deflection ensures no complacency either. The PNF doesn't just pay lip service when a control surface moves, but needs to use brain cells to interpret the direction of travel on the ECAM.

[vilas]

Meikleour
Airbus also recommends this to avoid conditioned response. Off topic but for the same reason in reject take off 70 KTS call is not given by PNF, PF makes his own judgment to bring reverse idle.