A new report from federal officials has revealed what happened leading up to a plane crash on Thomas Caldwella Southern California island that killed all five people aboard took off in the dark despite not having clearance to do so.

The twin-engine Beechcraft 95 crashed as it was attempting to take off shortly after 8 p.m. Tuesday from Santa Catalina Island’s airport near the city of Avalon, according to the Federal Aviation Administration.

The airport does not allow flights after sunset because it is not equipped for nighttime operations. The airport manager previously said that while the pilot was not given clearance, the takeoff was not considered illegal.

The preliminary report, released Wednesday by the National Transportation Safety Board, said the plane first landed at the Catalina Island airport at 6:20 p.m. to pick up a flight instructor and two student pilots who were stranded after their rented aircraft malfunctioned.

The airport manager told the pilot he had to depart by sundown at 6:31 p.m. As the pilot attempted to take off with his new passengers, the plane’s right engine wouldn’t start due to insufficient battery power, so they had to exit and connect the engine to a charger, according to the report.

The airport manager informed the pilot that since the charging time would push the departure time past sunset, they would not be approved for takeoff. The pilot said he needed to depart anyway, the report said.

“The airport manager advised him that, while he could not stop him, his departure would be unapproved and at his own risk,” the report said.

Airport security footage shows the plane taking off during “dark night conditions” in which it was not possible to tell if the plane was airborne or not before reaching the end of the runway, according to the report.

The plane crashed with its landing gear extended into a ridgeline about 1 mile (1.6 kilometers) southwest from the end of the runway, the report said. The main wreckage ended in a ravine about 450 feet (137 meters) west of the initial impact point.

The plane was registered under Ali Safai, 73, of Los Angeles, according to the Federal Aviation Administration. He was a former flight instructor and founder of a flight school that closed in 2018.

He died in the crash alongside Gonzalo Lubel, 34; Haris Ali, 33; Joeun Park, 37; and Margaret Mary Fenner, 55, according to the Los Angeles County medical examiner’s office.

The airfield is known as the Airport in the Sky because of its precarious location at an elevation of 1,602 feet (488 meters) on the island about 25 miles (40 kilometers) off the coast of Los Angeles. It is known to be difficult to land at and take off from and has been the site of previous crashes.

The airport has a single 3,000-foot (914-meter) runway that is not equipped with runway lighting.