The terminal at Auckland International Airport flooded on 27 January. Photo: Facebook / Sher Singh
Pilots landing at Auckland Airport during last month's floods had no idea how deep the water was on the runway, and at one stage levels were measured with a worker's boot, the Air Line Pilots Association says.
The association (ALPA), representing New Zealand pilots and air traffic controllers, wants a Transport Accident and Investigation Commission (TAIC) inquiry to look at the airport company's decision to remain open during the torrential rain on 27 January which flooded terminals and surrounding roads, and left the airfield awash.
TAIC has begun investigating an incident on the day of the flood where Air New Zealand flight NZ124 arriving from Melbourne hit six landing lights and deflated a tyre, forcing temporary closure of the runway.
ALPA president Andrew Ridling said pressure came on from airport management to get the runway reopened as soon as sufficient lights had been fixed, even though the experienced air traffic controllers who called him for advice on the Friday night felt conditions were so bad, it should remain closed.
"They were furious... Commercial expediency overrode safety. There was significant pressure from the airport company to remain open until the terminal flooded, and they were unable to process passengers."
With climate change bringing more frequent severe weather, Ridling questions whether airport managers lacking direct aviation experience have the expertise to make a call on opening or closing airports in extreme conditions.
A TAIC spokesperson said the investigation of the NZ124 landing would look at all the circumstances around the incident, including decisions crucial to it occurring.
If warranted, an interim report of matters requiring urgent attention could be issued before the final report, expected to take about 18 months, is completed.
Auckland Airport said safety was its top priority, and damage to the runway lights took place before the deluge occurred.
When asked to comment on Ridling's claims about management pressure to reopen the runway, the airport provided a written statement saying its post-incident review will consider all aspects of its response on 27 January, including the operation of the airfield, and it did not want to pre-empt this process by discussing it further.
"Auckland Airport rejects any suggestion that safety was not our primary focus."
The escalator being fixed at Auckland International Airport after the flooding on 27 January. Photo: RNZ / Lucy Xiu
The Civil Aviation Authority (CAA) said the NZ124 incident happened during heavy rain and gusting winds, and details of runway and weather conditions relayed to pilots would be established during the safety investigation.
CAA said extreme weather was a challenge for airports and airlines, but the travelling public could be confident that all aviation safety risks were being managed appropriately.
Who makes the call on airport closure?
At major New Zealand airports, physical runway inspections are done by airport staff, and that information is then relayed to pilots via air traffic controllers employed by Airways NZ.
Controllers also gather data from other sources such as MetService, and report what they can see from the control tower, so pilots can determine whether it is safe to land or take off.
But the ultimate decision on whether to close the airport lies with the operator, in this case the Auckland Airport company.
When water on the runway is more than 3mm deep, Ridling said aircraft could continue flying, but takeoff weights and various other restrictions came into play.
He said a pilot told him that when he asked for a report about water on the Auckland runway during the flooding, a car was sent out to check.
"The guy got out and said, 'oh yeah, it's about halfway up my boot.' That was the weather report, so they [the pilot] taxied back to the terminal and said, we're giving this away.
"I was told [the water was] 80mm to 100mm, but nobody could actually tell because nobody knew how big the boot was."
Ridling said the instrument landing system (ILS) on the airfield, used to guide pilots onto the runway, was fading in and out due to the weather.
"You don't need it to land, but it's there for the weather conditions we were experiencing that night."
Qantas confirmed that prior to the airport's closure, one of its flights to Sydney taxied out for takeoff, but returned to the terminal due to runway conditions.
Air New Zealand says it is working with TAIC on its investigation into the NZ124 incident. Photo: Unsplash / Douglas Bagg
Air New Zealand said it was working with TAIC, and as was standard practice while an investigation was underway, it could not comment on specific elements relating to the NZ124 incident.
The airline did not respond to questions about movements of its aircraft in and out of Auckland Airport during the severe weather event, but said customer safety was paramount.
"Air New Zealand would not fly if it was not safe to do so and alluding to anything different would be irresponsible."
Monitoring our runways
Ridling said the recent situation at Auckland highlights the importance of New Zealand using a new reporting system that gave pilots more detailed information about water, snow and ice on runways.
Three years ago, a Turkish budget airline skidded off a wet runway and broke apart while landing in bad weather in Turkey's capital Istanbul, killing three people and injuring 179.
Disasters like that, and the frequency of aircraft veering off slippery runways, prompted the International Civil Aviation Organisation (ICAO) to come up with a global reporting format (GRF) for runway contamination.
Each third of the runway is assigned a code for surface conditions ranging from 0 (very slippery) to 6 (dry), and the resulting runway condition code gives pilots guidance on braking and stopping distances.
During the pandemic, ICAO delayed the deadline for introducing GRF until November 2021, and an ICAO report on progress shows that as of late last year, New Zealand was only 14 percent of the way through the process, against an average of 65 percent for the Pacific region as a whole.
CAA said the GRF would be operating by November 2024 at the latest, and Airways NZ, which had been tasked with delivering runway reporting system, expected it would be ready before the end of this year.
Wellington Airport was the first in the southern hemisphere to comply with GRF after installing nine runway sensors, developed in conjunction with the MetService and similar to those in use on highways,
The sensors monitor runway conditions and transmit data to the control tower, and Wellington's runway inspection vehicles also have lasers that can measure depths of water up to 15mm.
Other airports, including Queenstown are looking at the technology.
Christchurch Airport decided against installing the sensors, and is keeping an eye on other technical options.
A spokeswoman said the airport regularly inspected its runways in line with GRF regulations, including driving out onto the runway and measuring significant amounts of water.
- This story originally appeared on Stuff.