A Japanese coast guard plane didn’t have permission to take off and was asked to hold short of the runway before colliding with a larger Japan Airlines Co. passenger jet, based on a transcript of Tuesday’s incident at Tokyo’s Haneda Airport. 

The readout of communications just prior to the crash was released Wednesday by Japanese officials in Tokyo. It appears to contradict the coast guard captain, who reportedly said he had “obtained permission to take off.” 

The De Havilland Canada Dash 8 acknowledged instructions to taxi to holding point C5 at 5:45 p.m., eight seconds after receiving the request from air traffic controllers, according to the transcript. 

“Taxi to holding point C5 JA722A No. 1, Thank you,” the flight crew responded, according to the transcript. It hasn’t been confirmed yet whether the captain or his co-pilot, who died in the crash, was speaking with the tower, officials said at a news conference. 

Adding to the intrigue is the fact that the so-called stop-bar lights on the intersections onto the runway, which provide a visual indication to pilots whether a runway is clear or not, have been out of service since Dec. 27. The lights on all intersections onto the runway in question are out, according to a so-called Notice to Air Missions, or NOTAM, that runs through Feb. 21

Given that the unserviceable lights had been widely circulated to pilots as part of the NOTAM process, the coast-guard pilots should be have been even more cautious about entering an active runway, according to several pilots, who asked not to be identified discussing procedures. 

At about 5:47 p.m., JAL Flight 516 touched down, striking the much smaller propeller airplane, which erupted in a ball of flames on the runway. Five of the six people aboard the coast guard plane were killed. The captain and all 379 aboard the airline’s Airbus SE A350 widebody managed to survive.

The transcript suggests the coast guard plane didn’t have permission to be on the runway prior to the crash, while the JAL passenger jet was cleared to land, as Bloomberg reported earlier.

At a news conference on Wednesday, coast guard officials avoided saying whether the captain could have misunderstood instructions from the tower, saying they would leave findings to the investigation under way. They said there could have been other interactions besides the recorded exchanges with the control tower.

While ground collisions are rare, they can be as deadly as ones that occur in the air. In the US, airlines have had a number of close calls in the aftermath of the Covid-19 pandemic, as a surge in travel coincides with a shortage of air traffic controllers. The Federal Aviation Administration last year ordered more training for controllers after a spike in near-collisions.

Previous fatal crashes that occurred on the ground include the 1991 collision between a US Air 737 jet and a Skywest Airlines turboprop that killed 35 people, and the deadliest disaster in aviation history: In 1977, two Boeing 747 jumbo jets collided in Tenerife, killing 583 people with just 61 survivors.

The transcript of the ATC interactions with multiple aircraft was submitted to investigators, Tetsuo Saito, minister of land, infrastructure, transport and tourism said at a press briefing. 

Investigators were seen around the crash sites at Runway C at Tokyo Haneda Airport on Wednesday. Footage showed the Airbus A350 as a burnt out carcass, with only the wings still somewhat intact. 

The coast-guard plane was destroyed beyond recognition, with investigators sifting through the mangled wreckage. The Dash 8 propeller plane was being used by the coast guard to delivery emergency aid to victims of the Jan. 1 quake in northwestern Japan.