Kobe Bryant death: Final moments before helicopter crash revealed by investigators

The final moments of the helicopter flight that killed Kobe Bryant and his daughter along with seven others have been revealed by investigators, with conformation that the aircraft plummeted for around 60 seconds before crashing into the Los Angeles hillside and bursting into flames.

Five-time NBA champion Bryant died on Sunday following a crash near Calabasas, 40 miles northwest of downtown Los Angeles, after travelling with his daughter and friends in heavy fog.

Authorities have so far been able to identify four of the nine bodies among the wreckage which includes 41-year-old Bryant through their fingerprints, though his 13-year-old daughter Gianna has not yet been able to be identified. Coroners were initially able to retrieve three of the nine bodies on Monday night, with the remaining six recovered the following day.

Investigators announced late on Tuesday night how they believe the helicopter crashed, detailing the final minutes of the flight that has caused an outpouring of emotional both within and outside of the sport due to the global reputation of the former LA Lakers basketball player.

The National Transportation Safety Board (NTSB) have estimated that the twin-engine Sikorsky S-76B attempted to climb out of a layer of cloud after requesting clearance to increase altitude from pilot Ara Zobayan, before making a sharp left descending turn.

From that point on, the NTSB believe that the helicopter plummeted at a speed of more than 2,000 feet-per-minute (approximately 26mph) and slammed into the hillside terrain 60 seconds later, bursting into flames on impact.

"This is a pretty steep descent at high speed," NTSB board member Jennifer Homendy told a briefing in Calabasas.

"The time from descent to impact was probably about a minute."

Homendy added that Zobayan’s sudden increase in altitude was him “trying to climb out of cloud” as the aircraft flew to 2,300 feet before its sudden turn, and added that the rate of descent "wouldn't be a normal landing speed."

"We know this was a higher-energy-impact crash," she said, adding that investigators had surmised that the helicopter was still in one piece before hitting the ground.

Homendy said that clouds, fog and limited visibility reported in the area on Sunday were a key focus of the investigation, which will take at least a year to complete.

The helicopter was not equipped with any kind of "terrain awareness and warning system," a device that might have alerted the pilot that the aircraft was dangerously close to the hillside, Homendy said. Nor did the helicopter carry a "black box" flight data recorder, which would make it easier to piece together the cause of the crash, she said.

NTSB recommendations that both devices be required equipment on helicopters like the one that crashed on Sunday have not been implemented by the Federal Aviation Administration, she said.

Homendy briefed reporters as authorities completed the on-scene phase of the investigation, clearing the tall, grassy slope of remaining wreckage and human remains. Among items recovered were an iPad that investigators hope may have belonged to the pilot for use in tracking flight and weather information, Homendy said.

The NTSB team carted a truckload of debris wrapped in large, white tarp bags while medical examiners positively identified remains of four victims, including Bryant and the pilot.

Bryant, who retired from the NBA in 2016 after 20 years with the Los Angeles Lakers, was on his way to a youth sports academy with his daughter Gianna. Her team that he coached was due to compete that day in a tournament.

NTSB officials privately briefed relatives of the dead by telephone on Tuesday, but Homendy declined to say anything about what was discussed or who took part in the call.

Speaking at the same news conference, Los Angeles County Sheriff Alex Villanueva said positive identifications had been made on four of the nine victims.

Besides Bryant and the pilot, a commercial aviator and certified flight instructor with more than 8,200 hours of flight experience, medical examiners confirmed the identities of John Altobelli, an Orange Coast College baseball coach.

A fourth positive identification was made for Sarah Chester, who died in the crash with her 13-year-old daughter, Payton, another basketball player involved in the tournament.

Altobelli's wife, Keri, and their 13-year-old daughter, Alyssa, a teammate of Gianna Bryant, were among the dead, along with an assistant coach, Christina Mauser.

Additional reporting by Reuters