A witness to the deadly crash of a helicopter carrying Kobe Bryant and eight others said it sounded normal just before slamming into a hillside and wreckage at the scene showed no sign of engine failure, federal investigators said in a report released Friday.
The 26 January crash occurred in cloudy conditions and experts said the "investigative update" from the National Transportation Safety Board reinforces the notion the pilot became disoriented and crashed while trying to get to clear skies around Calabasas, northwest of Los Angeles.
The veteran pilot, Ara Zobayan, came agonisingly close to finding his way out of the clouds.
He told air traffic control he was climbing to 1,219m.
He ascended to 701m, just 30m from what camera footage later reviewed by the NTSB showed was the top of the clouds.
But rather than continuing higher Mr Zobayan began a high-speed descent and left turn in rapidly rising terrain. He slammed into the hillside at more than 290 kph and was descending at 1,219m per minute.
"If you exit the bottom of the clouds at 1219.20m per minute at that high speed, you've certainly lost control of the aircraft," air safety consultant Kipp Lau said.
Kobe Bryant loved being a #GirlDad Source: Getty Images
He said Bryant's chopper could have emerged from the clouds in just 12 more seconds, assuming it was ascending at 152.40m per minute.
"Once you break out of the clouds it's clear. Everything lines up with the body," Mr Lau said.
"Now you have a real horizon."
Mike Sagely, a helicopter pilot in the Los Angeles area with 35 years of flying experience, said the aircraft's last moments suggest Mr Zobayan had started to execute a manoeuvre designed to pop above the clouds by flying up and forward.
"When he went into the clouds, he had a full-on emergency," Mr Sagely said.
When pilots try to turn instead of sticking with the pop-up manoeuvre, "probably in the neighbourhood of 80 to 90 per cent of the time, it's catastrophic," he said.
The crash occurred as the group was flying to a girls basketball tournament at Bryant's Mamba Sports Academy.
He coached his 13-year-old daughter Gianna's team. She and two teammates were among the nine people killed.
The deaths shook Los Angeles and the sporting world.
Within hours, thousands had gathered outside Staples Center, where Bryant starred for the Lakers and began a makeshift memorial that became a massive display of flowers, candles, personal notes, basketballs and other mementoes.
A public memorial for Bryant and the other victims is scheduled for 24 February at Staples.
Fans gather to pay their respects at a memorial for the late Kobe Bryant near the Staples Center in Los Angeles. Source: AP
The date 2/24 corresponds with the No. 24 jersey he wore and the No. 2 worn by Gianna.
The NTSB's report was a compilation of information and data about the flight, helicopter and pilot.
It's likely to take a year for the NTSB to issue a report about the cause.
Mr Zobayan was a regular pilot for Bryant and the chief pilot for Island Express Helicopters, with more than 8,200 hours of flight time.
He was certified to fly solely using instruments - a more difficult rating to attain that allows pilots to fly at night and through clouds when the ground isn't visible - and was a pilot to other celebrities including Los Angeles Clippers star Kawhi Leonard and Kylie Jenner.
During the flight with Bryant's group, Mr Zobayan did not report any equipment problems and sounded calm while communicating to air traffic controllers.
His final transmission said he was going to climb above the clouds.
Eight seconds after reaching peak altitude, he started the fateful descent.
A witness told the NTSB the hillside where the crash occurred was shrouded in mist when he heard the helicopter approaching.
It sounded normal and he then saw the blue-and-white aircraft emerge from the fog moving forward and down. Within two seconds it slammed into the hillside just below him.
Kobe Bryant's helicopter crash wreckage shows no evidence of engine failure. Source: The New York Times
The others killed included Orange Coast College baseball coach John Altobelli, his wife, Keri and daughter Alyssa; Bryant's friend and assistant coach, Christina Mauser; and Sarah Chester and her daughter Payton, 14.
A public memorial for the Altobelli family will be held Monday at Angel Stadium in Anaheim.
