Runway warning lights at Tokyo Haneda airport were reportedly broken when the Japan Airlines collision happened

• Runway warning lights at Tokyo's Haneda airport weren't working Tuesday, reports say.
• The lights tell pilots when a runway is clear.

Warning lights that tell pilots when a runway is clear weren't working at Tokyo's Haneda airport when a passenger jet collided with a coast guard plane, according to data.

A NOTAM message issued on December 27, which contains important updates on flight services, says the "stop bar" lights that warn pilots not to head onto the runway at the wrong time had malfunctioned.

The alert reportedly covers the runway where a Japan Airlines jet collided with a coast guard plane and burst into flames, leaving five people dead.

There are other indicators, however, alerting pilots of the runway entrance and where to stop short, like the red and white "16R-34L" runway signage and painted markings. The solid yellow line on the ground indicates a pilot needs clearance to pass.

All 379 people on the jet managed to evacuate before it was engulfed in a fireball, with the plane's crew widely praised for its handling of the emergency.

On Wednesday, authorities released a transcript indicating that the JAL flight had been cleared to land, but the coast guard plane had not been given permission to take off and entered the runway without permission.

Japan Airlines also said its plane had been cleared to land.

An investigation has been launched into Tuesday's crash, with CNN reporting that investigators will examine conversations between the pilot of the coast guard plane and air traffic control in the moments before the collision.