Qantas, Air NZ jets in near miss

[Three Bars]

Otto:

Verbatim, the note in the FCOM says, "If positive visual verification is made that no obstacle or terrain hazard exists when flying under daylight VMC conditions prior to an obstacle or terrain warning, the alert may be regarded as cautionary and the approach may be continued."

Therefore the relevant points are:

1) It is not necessary to "brief" the possibility of a GPWS warning to continue the approach - the pilot only needs to have assessed (in day VMC conditions) that there is no threatening terrain in the vicinity of the approach path.

2) In all other scenarios (night and/or IMC), any GPWS warning must be followed - even if familiar with the local area.

WRT the level-off altitude following a GPWS warning, the recovery actions state:

"Monitor radio altimeter for sustained or increasing terrain separation."
"When clear of terrain, slowly (my bolding) decrease pitch attitude and accelerate."

Remember that when the GPWS warning profile is flown, the aircraft will be at a very high pitch attitude with maximum thrust set. Even if initiated very early, a level-off that would not cause a very uncomfortable bunt would use a considerable ammount of airspace.

There is no "upper limit" to a GPWS recovery manoeuvre. While the highest MSA at Auckland is 3400 feet, even if the pilot initiated the recovery at this altitude it is likely that a much higher altitude would have resulted following the level-off (for the reasons already given). Our Limitations manual tells us that: "Pilots are authorised to deviate from their current ATC clearance to the extent necessary to comply with an EGPWS warning." Therefore, if a GPWS warning was received, it would supercede any previous ATC altitude instruction.

Further guidance from the manuals is that GPWS warnings take precedence over TCAS advisories.