Inside Air New Zealand’s nerve centre: How the airline gets its New York flight home

Air New Zealand uses Boeing 787-9 Dreamliners on its New York route. Photo / Supplied.

Air New Zealand always said getting back non-stop from New York to Auckland was going to be the hard part. Here’s a look inside the airline’s jet operations nerve centre in Auckland, where up to 24 staff work on getting NZ1 home. The flight is at the edge of the Dreamliner’s range and every kilogram is crucial in the countdown to take-off. The mission starts with getting the right plane.

Pre-flight – about one week out

On top of years of planning and allowing for disruption reported in June, preparation for each flight begins by picking the optimal plane, which can vary from week to week. Air New Zealand has five Boeing 787-9 planes with a premium heavy cabin configuration dedicated to the New York route. Their performance varies slightly from week to week and that means picking the right one is crucial. David Morgan, Air NZ chief flight operations and safety officer, says right now there’s a 540kg weight difference between the Dreamliners as they’re absorbing moisture at around 1kg a day, so the difference depends on their age and when insulation was replaced.

Then the airline assesses in real time the fuel consumption per kilometre of each of the aircraft, which varies, because the performance of the Rolls-Royce Trent 1000 engines varies during their lifetime.

“Either through engine performance or drag coefficient of the aircraft they will all vary,” Morgan who oversaw the introduction of a total of 14 Dreamliners to the fleet. While the performance is generally consistent, the airline is looking for any rapid change and that will dictate which aircraft is put on the route. The operations team bases the call on an assessment table provided by engineers.

“If the performance changes through 0.1 per cent a week that’s a pop-up for us and what we then do is call up engineering to have a look at the aircraft.”

During the years of buildup to launching the flight, weather trends, dominated by the constant west-to-east jetstream winds, were analysed to build the operational and commercial case for the 14,200km flight. And around a week out from each service, flight planners in the ‘‘nerve centre’' – the integrated operations centre at Air New Zealand’s Auckland Airport campus - look for specific weather events such as hurricanes, cyclones and, during the New York winter, snowstorm warnings that affect not only NZ1 but also the Auckland-New York NZ2 flight.

An Air New Zealand Dreamliner at JFK Airport following the inaugural flight. Photo / Supplied

The clock is running: 24 hours out

A full day out there’s another weather check using Met Service and offshore forecasters to assess whether NZ1 will have to fly around intensifying weather systems or strengthening jetstream winds.

But to add further complexity, these forecasts can also change in the hours before takeoff, let alone while the plane is airborne because it is such a long flight. For one flight this month there was a tonne of fuel difference between the expected requirement 24 hours out and when the flight departed because the winds had changed.

This is also when the load planners swing into action. They look at predicted baggage weight and they provide the load-control team with an all-up weight, in case passengers need to be rerouted on other flights or luggage needs to be offloaded, as happened on the first NZ1 flight.

The extra weight of the Jamaican netball team’s gear resulted in about 60 other bags being offloaded and sent on later.

Around two dozen operations centre staff are working on the New York flights at any one time (as well as others simultaneously) and since September they have built up a body of knowledge, says Suzanne Thimbleby, Air NZ’s head of airline operations.

They calculate to the “nth degree” the impact on fuel consumption of the number of adults and children and the number of bags that are carried. She says fewer children (who are lighter) have been carried than forecast and average Economy check-in luggage weights are around 21kg - 2kg lighter than allowed, although this may change around Christmas.

The airline surveys its passengers’ average weight every four years (the last domestic survey revealed a 1kg gain) and an international reweigh takes place next year which will help further sharpen forecasting.

Making the big call

At 24 hours out these load projections are handed to flight controllers and, with latest weather, the call is made on whether to activate the Pacific divert plan, as happened on October 29, after two false alarms.

The airline needs the 24-hour window to notify the plan and get a replacement staff to Nadi to step in for the four pilots and 10 cabin crew. Air NZ’s chief operating officer, Alex Marren, a veteran of operating airlines in the US eastern seaboard, says a quick pit stop can save days of recovery.

Alex Marren, Air NZ's chief operating officer, started with the airline earlier this year. Photo / Brett Phibbs

“It’s a pretty conservative, proactive plan just in case. We want to protect our customers to make as seamless an experience as possible.”

During the October 29 touchdown - just 63 minutes - about 20 tonnes of fuel was taken on and crew replaced.

Morgan says the business case for the flight included up to six diversions a year while Marren says even with as few as 180 passengers on NZ1 (not the maximum possible of 275), it remains commercially viable.

While the recovery plan needs to be activated 24 hours out, eight to six hours out from the scheduled time of departure further variables are being assessed; such as more baggage than expected and likely taxi or pushback delays, Thimbleby says.

Suzanne Thimbleby, Air NZ head of airline operations. Photo / Brett Phibbs

“If people are turning up with excess baggage – we know down to the kilogram, the crew get their plan, they assess it and do last-minute adjustments. Check-in closes one hour out and that’s when the final figures funnel up to the load planner and flight planner and the captain gets the final weights.”

At that point it’s the captain’s call – but they will always consult with flight operations.

The turnaround time is two hours on the ground at JFK Airport, when the aircraft is cleaned, restocked and crew rotated. That’s around 15 minutes longer than the average US flight.

Air NZ says both JFK and the Federal Aviation Administration are aware of the need for a quick getaway from Terminal One and it aims to park at the end of the pier rather than in “the alley”. While some passengers haven’t been impressed by the terminal or the Lufthansa lounge for premium travellers, Thimbleby says that operationally it’s worked well so far.

‘NZ1 - You’re clear to go’

Morgan says the plane takes on about 101 tonnes of fuel in New York. While the aircraft could take off with more on board, it can’t fit that additional volume into its fuel tanks, although there could be marginal improvements in winter. He explains that while a litre of water weighs 1kg, a litre of jet fuel weighs 780g.

“But the volume of the fuel will change depending on its specific gravity – as the fuel gets colder in New York you can put more volume into the tanks,” he says.

“The limiting factor on these flights is not take-off weight (all flights are taking off about 5 tonnes under maximum) - it’s the amount of fuel you can get in the tanks – payload is restricted.”

At the moment fuel can’t get beyond “volumetric cut-off” – similar to when motorists fill up a car at the petrol station.

Boeing has offered a software tweak that will allow airlines to reduce the air gap at the top of the tanks, something it has yet to activate.

During the 17.5-hour flight, the variables keep coming. Weather can change and mean the aircraft can burn a tonne less fuel than forecast while en route. Along the way, there’s “dynamic air replanning” available to respond to changing conditions and that’s how NZ1 avoided two planned “gas and goes” in Nadi.

Morgan says the work of load controllers who decide where baggage is stored becomes apparent during the ultra-long flights. Taking to a whiteboard in the operations centre, he explains principles of how the highly sensitive aircraft centre of gravity (COG) works. On the smaller A320, it has a range of just 45cm.

David Morgan, Air NZ chief flight operations and safety officer at Air New Zealand. Photo / Brett Phibbs

“Load control is crucial – the airplane has to operate in a centre of gravity envelope. If it doesn’t it becomes aerodynamically unstable.”

A Dreamliner’s efficiency improves as the COG moves towards the rear, but the tendency is to move forward as fuel is consumed during flight. The 787 stores fuel in the wings and a centre tank, using fuel from the centre one first.

“The load-control people plan to make the centre [of gravity] as aft as possible – if you move it towards the rear of the plane you end up with a plane with less drag and using less fuel.”

The flights have been running three times a week since mid-September and so far have landed with an average of around eight tonnes of fuel left in the tanks, says Morgan.

There’s a string of airports across the US and the Pacific flights can divert to in case of emergencies (or a refuelling “tech stop”) and in New Zealand if Auckland Airport is unavailable.

The aircraft have to carry sufficient fuel to make it to, in the first instance, Ohakea, then Wellington and then Christchurch. To complicate early operations, Covid-19 illness meant Ohakea’s firefighting capability wasn’t sufficient to handle widebody jets.

So the flight needed additional margin to make it further south, if needed. To get to Wellington requires 900kg more fuel and Christchurch an additional 1600kg.

One lever the airline hasn’t been able to use is sacrificing general cargo. It’s generally the first to go when loads are tight but from the start of operations it wasn’t an option on NZ1.

There has only been one flight where bags have been offloaded. For passengers who have been “proactively rerouted” through other North American ports, they have been thanked with a US$1500 ($2400) compensation payment and accommodation if required.

Cabin crew are at the front line of handling any disruption and say there have been challenges but the service has been a success.

Flight Attendants Association president Craig Featherby, who is also an inflight service manager, says passengers love the ease of point-to-point flying without having to transit and, on NZ1, there’s more room to spread out in Economy.

Cabin crew will also have three nights on the ground in New York, more than the minimum rest period of 46.5 hours in the contract. Time differences have made it particularly hard to get adequate rest.

“We appreciate that the Air NZ management team is exercising caution, mitigating fatigue and placing the wellbeing of its crew first, rather than schedule first, crew second,” says Featherby.

What’s the future?

NZ Airline Pilots Association president Andrew Ridling says flights have been managed well and conservatively and expects the risk of diversions easing as the airline gets more information and confidence around its longest route.

Featherby is also hopeful there’ll be more passengers on the Auckland-bound flights.

“The cabin crew hope to see those seats fill, as the more people who choose to fly on this route means an increase in demand, and makes the route more viable long term, more capacity which normally results in cheaper prices for the customers - which is a great win.”

Further out, new planes will help. The new 787-9s due to enter the fleet from 2024 are specifically designed for the route. There will be fewer seats as they will have a more premium skew in the new Layout of Passenger Accommodations (Lopa) and Morgan says the airline is talking to seat and cabin monument makers about reducing weight further.

The new planes will have up to 42 newly designed business class seats instead of the 27 in the outdated herringbone layout on existing ones. New engines will change the equation too. The twin GEnx engines have 10,000lb more thrust than the existing Rolls-Royce pair.

Air New Zealand's new cabins will have more premium seats. Photo / Supplied

“There’s more thrust so we can lift more payload off the runway and they’ve got more efficiency.”

Morgan says he speaks to his counterpart operators of ultra-long-haul flights into New York – Singapore Airlines and Cathay Pacific – on how they manage their flights.

Marren, who was director of customer planning at United Airlines the day two of its planes were used in the 9/11 terror attacks, is accustomed to pressure.

Following the NZ1 disruption, she’s apologised to customers affected but says for a fraction of a percentage of all flights around the world, this will happen.

The New York route will serve the airline well, she says.

“We’ve had a few teething issues coming online [but] it’s going to be a great market for us.”