Washington (CNN) -- A US Airways jetliner last week came within 100 feet of colliding with a small cargo plane near the Minneapolis-St. Paul Airport, according to the National Transportation Safety Board, which announced Thursday it is investigating the incident.
According to an NTSB account, on September 16, US Airways flight 1848, an Airbus 320, was cleared for takeoff about 6:49 a.m. CT (7:49 a.m. ET) on runway 30R airport at the same time the cargo plane, a Beech 99, was cleared for takeoff on a parallel runway, 30L.
Immediately after departure, air traffic controllers instructed the US Airways crew to turn left and head west "causing the flight to cross paths with the cargo plane about one-half mile past the end of the runway." Neither pilot saw the other aircraft, because they were in the clouds, although the US Airways pilot heard the Beech pass nearby.
Recorded radar data indicates the two aircraft had 50 to 100 feet of vertical separation as they passed each other about 1,500 feet above the ground.
A collision avoidance system aboard the US Airways jet issued climb instructions to the crew to avert collision. The Beech 99 was not equipped with a similar system and the pilot was unaware of the situation.
The US Airways flight, which was headed for Philadelphia, carried 90 passengers and a crew of five. The Beech 99 had only the pilot aboard. The cloud cover began at 900 feet and there was 10 miles of visibility below the clouds, the NTSB said.
NTSB and FAA investigators conducted a preliminary investigation at the Minneapolis airport traffic control tower on September 18 and 19 and are continuing to review the circumstances of the incident.