A320 incident Queenstown ATSB report

[sheppey]

Interesting ATSB report on an A320 flight below min safe altitude for procedure into Queenstown. See link.

Investigation: AO-2012-103 - Descent below segment minimum safe altitudes involving Airbus A320-232, VH-VQA near Queenstown, New Zealand on 16 July 2012 (http://www.atsb.gov.au/publications/investigation_reports/2012/aair/ao-2012-103.aspx).

One sentence in the report raised the eyebrows and maybe an Airbus pilot could clarify the procedure.

The report stated the aircraft got within 1097 feet from terrain due to the (mismanaged) descent profile on autopilot. It didn't say if the aircraft was IMC or VMC. If IMC, it could lead to a close shave due terrain. According to the ATSB report, on realising the aircraft was below minimum safe altitude for correct profile, the captain "commenced climb using auto-flight vertical speed mode". He then regained the correct safe altitude.

Getting that close to terrain in IMC for example, would it not have been quicker to immediately disconnect the autopilot and autothrottle and manually pitch up to the desired pitch attitude similar to a go-around - rather than remain on automatics and select an appropriate rate of climb on the auto-flight vertical speed mode with its inherent delay as the aircraft changes from a descent through level flight and into whatever climb rate was selected?

What selected rate of climb would the average pilot select in order to rectify the situation described in the report? If the aircraft is in VMC then the climb to the correct safe altitude is not so urgent on autopilot -but in IMC well that's a different story.

In other words, is it safer under the circumstances described in the ATSB report to get back to the correct safe altitude asap - which means manually such as would happen given a GPWS pull-up - or more leisurely by staying on autopilot and gradually return to safe height? Research papers on automation dependency have frequently referred to the reluctance by pilots to disengage the automatics even if circumstances dictated it was appropriate at the time.

[HEALY]

The bit about Open Descent being used as a vertical mode conducting an RNP approach in a place with such terrain and not adhering to sterile cockpit procedures says a lot to be honest. And we can be so quick to judge the level of incompetence displayed by other Asian carriers and appropriate mode awareness and understanding.

[scavenger]

Unless I'm reading the report wrongly, it was VMC. I wouldn't have thought using the automatics to climb back to the required altitude would therefore be a problem in this case.

Although descent continued beneath the two segment minimum safe altitudes for just over 2 minutes, a collision with terrain was highly unlikely given the fine and clear in-flight conditions and other risk controls such as the aircraft’s Enhanced Ground Proximity Warning System (EGPWS).

[Wally Mk2]

This scenario could be a good piece of info tied into the thread about hand flying airliners.
Take out the fact that it was VMC which by all accounts could have led the crew to vary slightly what they might have ordinarily done in solid IMC as has been mentioned the open descent & an ATC instruction to descend to a particular Alt are the key factors here I'd say.
The sterile cockpit part of it is very hard to stick to 100% of the time simply 'cause humans are not machines & are easily distracted especially when there is an enhanced visual aspect about all this, the view outside would have been very enticing with the appropriate comments of same.

Always makes good reading this stuff as we are ALL fallible.



Wmk2