Air New Zealand to weigh passengers departing Auckland International Airport. Video / Air New Zealand
It can be frustrating to see your plane on the tarmac and fellow passengers waiting by the gate at a small airport, despite being told you’ve missed check-in.
However, an Air New Zealand chief pilot has revealed a key reason even regional airports close their check-indesk 30 minutes before departure.
It may be surprising to some travellers, but it’s about passenger weight, according to Captain David Morgan.
Six hours ahead of departure, the airline’s operations team estimate how much fuel is needed for a flight, depending on the aircraft and route, Captain Morgan explained.
“At about that six-hour point, the system and the load planners will plan the load”, he said, describing this as a literal “balancing act” that involves dictating where luggage, cargo and passengers are placed in the aircraft.
Then, 90 minutes before departure, operations will calculate an estimated fuel quantity, depending on the known weight of the aircraft and how many passengers have checked in, Captain Morgan explained.
This could, for example, be 22 tonnes.
Captain David Morgan is a chief pilot and chief flight operations and safety officer at Air New Zealand.
Less than 30 minutes before departure, check-in will close and operations can calculate how many passengers will be on the flight and thus the final weight.
“Twenty-five minutes prior to departure, we give the final weight,” Captain Morgan said. With this information, operations can calculate whether they need, say, 21.8 or 22.2 tonnes of fuel.
“We get down to that level of granularity because fuel is expensive,” he said, adding planes can burn 20 per cent of the fuel simply by carrying the weight of it.
A 30-minute check-in cut-off can be annoying, especially at small airports where you can see passengers waiting at the gate or the plane on the tarmac.
However, this time is needed to allow operations to calculate the fuel needed and fill the plane, Captain Morgan explained.
“This is what frustrates some people, particularly in the regions, as they can see the plane, but what we’ve done is we’ve closed off the flight and we’re now working out how much fuel we want, based on the weight.”
How does Air New Zealand know the weight of each passenger?
The airline gained worldwide media attention earlier this year when it asked passengers to voluntarily step on an anonymous scale, with their carry-on bags, for data collection.
By weighing a statistically significant proportion of customers over a number of routes, Captain Morgan said the airline could then gauge the average weight of passengers.
That the survey is done across different routes is important because passengers travelling between certain destinations can tend to weigh more or less, Captain Morgan added.
“I’ve got to be careful how I phrase this but different routes have different weights because some people are smaller than others,” he said.
Having an accurate average weight allows an airline to better calculate how much fuel is necessary and avoid carrying excess fuel, which is both financially and environmentally costly.
