"before his flight" is correct and usable in written English.
It is used to indicate that something happened before another event. For example, "The traveler finished packing his bags before his flight."
It was the night before his flight back to China.
Even before his flight to Britain questions were being asked.
Phillips made it to the airport, ready to join the Mets, before his flight was canceled.
Saleh told the Guardian that he was calling his mother before his flight from Heathrow on Wednesday morning.
Mr. Henry, who now instructs pilots on safety, thinks problems with his helmet seal kept him from breathing enough pure oxygen before his flight.
He spent the days before his flight attempt studying weather charts and making sure that the conditions were as near perfect as possible.
This is the last time Lukas Podolski will look up at the Billy Goat's stand as one of their own, before his flight to London.
He said he planned to lose some weight before his flight but had no trepidation about being so high above the planet.
True to form, he was still in the process of getting his passport two hours before his flight and left for Turkey without luggage.
"I don't believe the authorities will shoot down a 61-year-old mailman in a flying bicycle," he told the paper before his flight.
Settling into a divan backstage, he is dressed in T-shirt and black jeans, looking anxious before his flight back to New York later that evening.
