If so, is there any way that Airbus' software could deduce which of these options a crew intends to take by analysing the combination of crew control selections in operation (TL positions, autothrust, reverse thrust, autobrakes, manual braking, flap/slats, etc) at this point in the landing? Alternatively, if just after touchdown, the aircraft software detects a combination of control selections which would preclude a safe 'go around', would it be safer, in this case, if the software made the decision for the crew and executed a full stop landing procedure (automatic selection of both engines to Max Reverse, deployment of GS, autobrake operation and activation of any other devices available for slowing the aircraft down)?
The thing is, if one engine is not in idle or reverse, the computer needs to decide whether it is a landing or a go-around. If one wants to do a single engine go-around then the aircraft must enable it to do so. If one (for some absurd reason) determines that after a reverser has been selected, a single (or all) engine go-around is safer, then it must be able to do so. Once on the ground, it is the crew who decides to continue the landing or go-around, or veer off and find a ditch to stop the plane... not the computer. If both reversers have been selected, spoilers would deploy anyways as it is obvious one wants to stop.
I suppose the main problem would be in determining the precise combination of control settings the software should use when deciding to execute a full stop landing procedure. Would the combination of 'Main Gear Compression' AND 'Max Reverse on at least one engine' AND 'Manual brake application by crew' AND 'Aircraft speed above 72kts' be a sufficiently strong indicator of the crew's intention to perform a full stop landing?
1 engine in reverse and 1 engine in forward above idle is no-man's land and neither airbus nor boeing wants to systematically decide / automate a decision on that grey area. I guess the reason is that it is impossible to determine what the crew wants to do in such a situation, and it only takes a car/cow to intrude on a runway as the aircraft is touching down at 500m away from the touchdown to determine in court whether such a system is prudent or not. Hands can slip on a panic, but shouldn't when performing a normal procedure (such as, selecting idle on flaring).
It might help tired and stressed crews when time is of the essence and they are unable to figure out quickly enough why their aircraft is failing to decelerate.
If they're tired enough to not bring both engines to idle, they're probably too tired to find the button in time!
3Ten,
- Has it been established wether the eng 2 throttle was actually (phisically) in the Climb position? By wreckage evidence or any other mean? At the date of the Airbus telex, Agust 2nd, the wording "recorded" is relevant enough for me, it states the recorded data.
I think the physical evidence melted in the fire...
However from the FDR data, the previous landing in CGH by the same crew (presumably performed by the same PF) showed the #2 thrust lever being left in idle and the #1 in reverse. Then, the following landing in Porto Alegre (presumably with the other guy as PF) shows that both thrust levers were recorded in reverse during the landing. In the fateful and final landing into CGH from Porto Alegre, the #2 lever was left in climb.
My vote goes with the #2 physically in the CLB position... sadly...
PK-KAR