So the preliminary findings of the investigation
into the Boeing 777 that crashed on landing in Dubai in August are that the
pilots touched down ‘long’ and elected to initiate a ‘baulked landing’
manoeuvre, presumably to reduce the risk of an overrun. Baulked landing is very
similar to a go-around – press the TOGA (take-off/go-around) switches to
automatically increase thrust (the 777 has two levels of thrust response
depending on the number of presses), partly retract the flap and once climb is
established raise the gear. However, with wheels on the ground the
TOGA switch thrust response is inhibited so for a baulked landing the pilots
must advance the throttles manually. A subtle but crucial difference, which if not
practiced regularly, may be overlooked in the heat of the moment.
Automation has all sorts of benefits in modern
aircraft but due to the very wide range of operating environments and
manoeuvres, it has different regimes of logic for different phases of flight.
If these regimes are not fully understood, together with the conditions that
bring about the transition from one to another, then the automation and hence
the aircraft, may not respond as expected. This is not unique to Boeing and
Airbus aircraft have suffered accidents for similar reasons. Today’s pilots
must learn to ‘think like their aeroplane thinks’…
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