Kobe Bryant crash: Pilot may have been disoriented in fog, according to investigation documents

Ara Zobayan thought he was climbing rather than descending seconds before crash

The pilot flying the helicopter that killed Kobe Bryant may have been disoriented in thick fog when he reported the aircraft was climbing while it was heading towards the hills of California, according to documents released by federal investigators.

Group text messages showed weather conditions were a concern for pilot Ara Zobayan the day before the flight, but that conditions changed enough by the next morning that it "should be OK".

Moments before the crash that killed Mr Bryant, his daughter Gianna, and seven other people on 26 January – including the pilot – Mr Zobayan told air traffic control he was climbing to 4,000 feet before the aircraft descended into a hillside near Calabasas.

The new information was revealed in more than 1,700 pages of technical documents, emails, interviews and text messages compiled by the National Transportation Safety Board (NTSB) and released on Wednesday.

Federal investigators have not yet determined the cause of the crash, but after almost six months of investigation, the NTSB has not determined whether the 50-year-old favoured pilot of Mr Bryant received an adequate briefing on the weather before the flight.

"There was no information available to address whether the accident pilot availed himself of weather information from other sources prior to the accident flight," according to the NTSB.

Mr Zobayan ranked the flight as "low risk" before take-off after discussing the weather with the flight coordinator, who asked about the forecast.

"Just checked not the best day tomorrow but not as bad as it is today," Mr Zobayan responded.

The day of the flight, Mr Zobayan said: "Morning weather looking okay" before responding to how the weather is looking for a 9 am departure, to which he replied "Should be OK".

Mr Zobayan took off with the eight passengers from John Wayne Airport in Orange County at 9:06 am to a basketball tournament at Mr Bryant's Mamba Sports Academy in Thousand Oaks.

On his way from Orange County to Burbank, the helicopter was flying at an altitude of 1500 feet before the pilot told air traffic control he was going to "start our climb to go above the... layers."

When asked his intentions, Mr Zobayan said, "climbing to four thousand".

The report states that the helicopter was descending 17 seconds before the end of transmission data.

"Calculated apparent angles at this time show that the pilot could have misperceived both pitch and roll angles," the documents say.

Investigators interviewed current and former pilots for the company operating the flight, with some praising its standards and others saying there could have been a better culture of safety.

Island Express said it has previously cancelled flights for poor weather for celebrities including Kylie Jenner, NBA star Kawhi Leonard and rapper Lil Dicky.

"I believe that is a clear indication of the safety culture within the company," wrote Garret Dalton, Island Express director of operations.

A personal assistant to Mr Bryant, Cate Brady, told investigators that he never complained if there were changes to the flight schedule, and that the flight departure a day earlier had been delayed by 15 minutes due to weather.

According to the NTSC documents, Mr Zobayan was the favourite pilot of Mr Bryant and was one of the few that had undergone the special vetting needed for approval to fly the retired Lakers' legend.

Previously approved pilots were removed from the roster, one for needing to make an unscheduled stop for fuel and another for "being disliked by the customer".

The estate of Mr Zobayan, who was requested "almost exclusively", has been sued along with Island Express Helicopters Inc. by widow Vanessa Bryant, who filed a lawsuit filed in February that said the flight should have been aborted due to weather conditions.