The pilot flying Kobe Bryant and seven others Sunday was given clearance to fly in worse than normal weather conditions, without relying on instruments to guide him, according to recordings of his communications with air traffic controllers.

Shortly before the helicopter crashed, killing everyone on board, the pilot asked for and was approved for what's known as special visual flight rules, according to audio reviewed by The Washington Post.

In the recording, the pilot requests to fly under the special conditions.

The Burbank tower controller responds that it will be a few moments and asks the helicopter to hold. Seconds later, the controller tells the pilot that he can plan to transition to the north side of the Van Nuys Airport. He tells the pilot, several departures are coming off a runway and to "expect to follow the I-5 north and cross that way."

"No problem," the pilot responds, according to the audio, captured by the website LiveATC.

Ara Zobayan, the pilot, had held a commercial license since 2007 and was qualified to fly in bad weather conditions known as instrument flight rules, according to FAA records. He was also qualified to teach people to fly in those conditions, indicating that he had significant experience. Friends described him as experienced in social media posts after his death.

Nevertheless, Jeff Guzzetti, a former crash investigator for the Federal Aviation Administration, said the weather could have been a factor in the crash and pointed to numerous incidents where pilots have been caught off guard.

Guzzetti said it appears the weather worsened as the pilot tried to follow special visual flight rules, which meant he had to fly lower to keep clear of the clouds and be able to see the ground below.

Guzzetti said a question for investigators now will be, "Why did this flight occur when the weather was so poor?"

Ian Gregor, an FAA spokesman, said that a pilot remains responsible for determining whether it is safe to fly and for determining visibility.

Flight path data collected by flight-tracking service Flightradar24 shows the helicopter taking a circular route from John Wayne Airport toward Thousand Oaks. It cut across the broad coastal plain of central Los Angeles before going north around the basin of the San Fernando Valley and finally attempting to get across the rising terrain leading to Thousand Oaks.

The preliminary data suggests the aircraft, which crashed about 40 minutes after takeoff, briefly climbed to a top altitude of above 2,500 feet before it descended at a high rate before the crash.

After the pilot's request, the tower responds that he should head northwest and "follow the 5 Freeway. Maintain special VFR, special VFR conditions at or below 2500 [feet]."

The pilot repeats back the instructions: "Maintain special VFR at or below 2500 [feet], [follow] I-5 northbound."

Tower controller: "Number2EchoX roger, and you're cleared . . . "

The pilot responded: "Copy that. We'll maintain Special VFR, Copter 2Echox."

A National Transportation Safety Board team that flew to California on Sunday night to investigate the crash began its work early Monday morning.

NTSB spokesman Keith Holloway said the agency has a team of about 20 people in California and will be working with the FAA, the helicopter's manufacturer and the company that made its engine.

"One of the priorities is to collect as much perishable evidence as possible," he said. The FBI is helping the board's staff document the scene, which is standard procedure.

The investigation will examine weather data, radar information, air traffic control communications, maintenance logs and the pilot's record, Holloway said. The meeting early Monday will be used to assign roles and areas of focus for the investigation ahead.

The helicopter was a Sikorsky S-76B built in 1991, and experts say the model has a good safety record.

The first Sikorsky model to be designed for commercial use rather than military missions, the S-76 was first used to transport workers to and from offshore oil rigs and became a popular option for VIPs. The helicopter has been a choice of transportation for heads of state across the world and Fortune 500 companies.

The S-76B carrying Bryant on Sunday was owned by Island Express Holding Corp. The company registered the helicopter in 2015, according to the helicopter database helis.com. The records show the aircraft was previously owned by the state of Illinois, where it was likely used to transport the governor.

Experts believe the helicopter's age of 29 wouldn't raise safety concerns as long as the aircraft was properly maintained.