A340 of Iberia skids off runway in Quito

[Chris Scott]

Aircraft on the ground?

Quote from atakacs:
I am still believing that a "panic stop" button (or more to the point some sort of procedure to get maximal breaking performance from the automation systems regardless of what they "think" of the pilot intentions or actual plane condition) could be a welcome enhancement.
Granted such a system would generate it's own problems (such as possible unwanted activation)…
[Unquote]

CONF iture is right to point out that, on touchdown − having belatedly recognised that the “numbers” are not right and knowing LDA to be marginal − a crew should give serious consideration to a go-around. We are speaking in general terms, of course. The pilots may be so shocked by the severity of the impact that they delay the decision. Alternatively, they may rightly decide that the aeroplane is crippled.

So the issue of whether the crew should have the ability to override the automatics with a “panic-stop” button, as atakacs proposes, is a legitimate one. His own misgivings about inappropriate (or even unintentional) deployment are evident, however. The nearest example that comes to mind is that of a VC10 in 1972, in which the (handling) captain’s attempt to perform a go-around was thwarted by the copilot’s selection of spoilers and reverse.

There might be a better solution to the Quito-type gear-damage scenario. On Airbuses, the FACs (Flight Augmentation Computers) already seem to have a good understanding of how the thing flies. [They are capable, for example, of calculating current gross weight in the air.] No conventional aeroplane, I suggest, can maintain 1-G flight at a low airspeed with low alpha (angle of attack).

The combination of the above 3 conditions for more than a moment can only mean one thing: aircraft on the ground.