Sounds like they were IFR and in the soup.
Dave
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NTSB ADVISORY
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National Transportation Safety Board
Washington, DC 20594
September 23, 2010
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NTSB INVESTIGATING NEAR MIDAIR COLLISION OVER MINNEAPOLIS
INVOLVING COMMERCIAL JETLINER AND SMALL CARGO AIRCRAFT
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The National Transportation Safety Board is investigating a
near midair collision between a commercial jetliner and a
small cargo aircraft that came within an estimated 50 to 100
feet of colliding near the Minneapolis-St. Paul Airport
(MSP).
On September 16, 2010, about 6:49 a.m. CDT, US Airways
flight 1848 (AWE 1848), an Airbus 320, was cleared for
takeoff on runway 30R en route to Philadelphia,
Pennsylvania, carrying five crewmembers and 90 passengers.
At the same time, Bemidji Aviation Services flight 46
(BMJ46), a Beech 99 cargo flight with only the pilot aboard,
was cleared for takeoff on runway 30L en route to La Crosse,
Wisconsin. Weather conditions at the time were reported as a
900-foot ceiling and 10 miles visibility below the clouds.
Immediately after departure, the tower instructed the US
Airways crew to turn left and head west, causing the flight
to cross paths with the cargo aircraft approximately one-
half mile past the end of runway 30L. Neither pilot saw the
other aircraft because they were in the clouds, although the
captain of the US Airways flight reported hearing the Beech
99 pass nearby. Estimates based on recorded radar data
indicate that the two aircraft had 50 to 100 feet of
vertical separation as they passed each other approximately
1500 feet above the ground.
The US Airways aircraft was equipped with a Traffic Alert
and Collision Avoidance System (TCAS) that issued climb
instructions to the crew to avert collision. The Beech 99
was not equipped with TCAS and the pilot was unaware of the
proximity of the Airbus. There were no reports of damage or
injuries as a result of the incident.
NTSB and FAA investigators conducted a preliminary
investigation at the Minneapolis airport traffic control
tower on September 18th and 19th and are continuing to review
the circumstances of this incident.