The growing threat of aircraft collisions on the ground

The burnt-out wreckage of a Japan Airlines plane at Tokyo’s Haneda airport was a sobering reminder that many of aviation’s worst accidents happen on the ground rather than in the air.

Safety investigators spent the week probing the sequence of events that led to a collision between the JAL Airbus A350 and a smaller coastguard turboprop aircraft as the former landed on the runway. All of the nearly 400 passengers and crew on board escaped the JAL plane, but five of the six-member coastguard team were killed.

Japan Transport Safety Board’s investigation is running in parallel with a police probe into possible professional negligence. State broadcaster NHK reported on Friday that airport camera footage showed the coastguard plane may have erroneously been on the runway for as much as 40 seconds before the collision.

Aviation safety experts cautioned against pre-empting the investigations’ findings, but they said the accident on Tuesday and a recent rise in near-misses highlighted the dangers passengers face while on the ground, and the need for improved alert systems to prevent deadly collisions.

“Traffic is coming back, things are getting busier and runway surface areas at airports are complicated and complex, with many moving parts and interactions,” said Hassan Shahidi, chief executive of the Flight Safety Foundation, a US-based non-profit which co-ordinated a December report calling for improvements to on-ground safety.

“This is an area of concern and there needs to be an international effort to prevent it.”

Collisions on the runway can be catastrophic. The deadliest commercial aviation accident occurred in 1977 when two Boeing 747 Jumbo jets collided on the runway at Tenerife airport amid confusion over clearances for take-off, killing 583 people.

The disaster led to major changes to safety protocol, including clearer and standardised communications between control tower and cockpit. With strict standards to keep aircraft apart on the ground and in the sky, the aviation industry can boast an increasingly stellar safety record.

But one former British Airways pilot said there remained a greater risk of problems on the ground than in the air. “It is a high workload environment, [where] you need to ramp up your attention to detail,” he said.

Planes operate collision avoidance systems while they are airborne, but there is no universal “last line of defence” at airports, according to the FSF report.

Modern aircraft are equipped with enhanced ground proximity warning systems that provide flight crews with timely and accurate information about potential conflicts with obstacles or terrain as they near the ground. But ground-based technology is “often cost-prohibitive and not scalable to deploy at thousands of airports”, it added.

Aviation safety experts said a dedicated ground-based alert system was more complicated to develop given the different types of aircraft and ground vehicles. It was important not to develop a system that provided false alerts to pilots, experts added.

Honeywell of the US already has several runway safety technologies in use by airlines but is working on a new “surface alert” system designed to prevent runway incursions by giving pilots visual and audio warnings about potential hazards.

The technology, which could be ready to deploy gradually over the next few years, “analyses aircraft position data through specialised algorithms to alert pilots if an aircraft or ground vehicle is on or near the runway”, said Jim Currier, chief executive of Honeywell Aerospace.

Tomoki Kuwano, a former JAL pilot who has been involved in multiple investigations of aircraft accidents, called for a broader inquiry into why there were not more sophisticated systems to prevent the kind of accident that occurred this week in Tokyo.

“It’s not like on the roads with traffic lights. The orders to stop and go [at airports] are all done by voice, and as long as that is the case, there is going to be a risk of human error and miscommunication,” said Kuwano.

Regulators and industry experts said there was no single factor behind the increase in near misses. But the problems have come as airports get busier after the lifting of coronavirus travel restrictions, leading to congested airfields and staff shortages in some control towers.

Some believe communication between pilots and control towers has deteriorated.

“Those disciplines are not as robust as they have been in the past. I think we are seeing a confluence of factors: Covid, a loss of expertise and loss of workforce,” said Shahidi.

There are 1,000 fewer controllers in the US than a decade ago, while in Europe trade unions have warned of the risks of short staffing and fatigue for pilots and air traffic controllers.

Runway safety is under particular scrutiny in the US, where there were nearly two dozen potentially serious incursions in 2023, according to the FSF, including a near-collision between a Southwest passenger plane and FedEx freighter in Texas in February.

A Federal Aviation Administration-commissioned report into air traffic safety, published in November, found that there had been a rise in the most serious type of runway incidents, and that air traffic control systems suffered from “inadequate funding” in staffing, equipment, technology and facilities.

The FAA said it was “pursuing a goal of zero close calls” and has taken action to reduce the amount of near misses amid an “erosion in the margin of safety in the national airspace system”, including $200mn of investment in runway lighting at airports.

With air travel for consumers forecast to soon exceed pre-pandemic levels, many capacity-constrained airports will be under pressure to squeeze as many flights in as their infrastructure can safely handle.

“Safety requires a lot of investment. You might not immediately perceive the benefits, but one day it will pay off,” said Frédéric Deleau, executive vice-president for Europe at the International Federation of Air Traffic Controllers’ Associations.

Still, flying remains extremely safe. In 2023 there were no fatal accidents involving large jet-engine passenger planes. There were two accidents involving smaller propeller aircraft that killed 86 people, but that figure is still a record low, according to To70, a Dutch aviation consultancy.

The figures represent the equivalent of less than one fatal accident every 15mn flights.

As the search continued for a voice recorder from the wreckage of the Airbus, experts said the lessons learned from the crash at Japan’s busiest airport would also shape policymaking to reduce the potential for near-misses and collisions.

“We can learn from the accident in order to improve the system, to make it safer and more resilient,” said Deleau.