Richard Branson's Virgin Galactic space flight under investigation after claims it should have been aborted

The US Federal Aviation Administration (FAA) has confirmed it is investigating the "deviation of the descent" of the July 11 flight of the Virgin Galactic rocket plane that carried British billionaire Richard Branson.

The investigation follows a report by The New Yorker magazine which claims the flight should have been totally aborted well before it reached the edge of space.

One minute into space flight carrying Richard Branson, warnings began to appear in the cockpit. The craft was about 30km in the air and travelling at twice the speed of sound above New Mexico.

It was at this point, the magazine claims, the craft was veering off course and the flight was at risk.

A yellow warning light had appeared in the cockpit relating to Virgin Galactic's rocket, which is designed to burn for one minute. With just seconds to go before the rocket was due to burn out, a red warning light appeared, indicating the craft was not flying at a steep enough angle to reach the edge of space.

During training scenarios and flight planning witnessed by The New Yorker, Dave Mackay, a former Virgin Atlantic pilot and Royal Air Force veteran, and retired Air Force pilot Mike Masucci were joined by former NASA astronaut CJ Sturckow to run through procedures for responding to this exact scenario and these warnings.

Sturckow said that a yellow light should "scare the shit out of you" because "when it turns red it's gonna be too late".

"According to multiple sources in the company, the safest way to respond to the warning would have been to abort," the magazine claims.

But, with Branson leading the race to space against Jeff Bezos who was due to attempt a flight into space less than a month later, the flight continued.

The article's author Nicholas Schmidle says it's unclear as to who made the final decision to continue the mission.

"Whether or not their decision was motivated by programmatic pressures and the hopes of their billionaire bankroller sitting in the back remains unclear. Virgin Galactic officials told me that the firm's top priority is the safety of its crew and passengers. Branson, however, is known for his flamboyance and showmanship," Schmidle said.

An FAA spokesman told Reuters the vehicle "deviated from its Air Traffic Control clearance as it returned to Spaceport America".

The FAA's investigation is ongoing.