Investigators from the US National Transportation Safety Board (NTSB) are examining a near collision of a Southwest Airlines Boeing 737 and a news helicopter at Houston Hobby airport.

NTSB says at 12:25CDT on 28 April the 737 (N242WN) and the Bell helicopter (N6YJ), came within an estimated 125ft (38.1 meters) vertically and 100ft (30 meters) laterally from each other as both were departing the airport.

The Southwest aircraft, bound for Baltimore, was cleared to depart runway 12R. NTSB says at the same time the helicopter was cleared to depart from another part of the airport.

"The near collision occurred as the helicopter converged into the flight path of the 737 shortly after the jetliner lifted off from the runway," says NTSB. "Both crews took evasive manoeuvres to avoid colliding."

NTSB says this is the second runway safety incident it has investigated within the last two weeks after on 19 April a Southwest Boeing 737 and a small private aircraft came within 200ft (61 meters) of colliding over the airport in Burbank, California.

Source: Air Transport Intelligence news