Narrative:

While enroute at 8000 ft the flight crew spotted an aircraft at their 12 o'clock also on the airway. ATC advised of a cessna citation operating VFR; 500 feet above our altitude which was verified visually and via the TCAS. The crew advised the aircraft was in sight and would maintain visual separation. ATC then relayed the information to the citation who acknowledged the transmission. As the citation grew closer; it appeared to complete a turn to the north which would allow us to pass well behind the aircraft making it no factor.the flight crew maintained visual with the citation; and the citation abruptly began a 180 degree turn which put it on a direct collision course. In response; the TCAS issued an RA to 'monitor vertical speed.' the citation appeared to continue its turn thus maintaining a direct collision course and appeared to descend toward our aircraft. The pilot flying maintained visual separation by descending approximately 250 ft to avoid the incoming citation. Visual contact was lost as the citation passed overhead and when contact was reestablished the citation was uncomfortably close and slowly moving off to the left of the aircraft.following the incident; the flight crew advised ATC of the RA and asked the purpose of the citation's maneuver. The citation responded by stating they were performing steep turns for a check ride.

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Original NASA ASRS Text

Title: DHC-8 Captain reported an NMAC with a Cessna Citation that performed a 180-degree steep turn in front of the DHC-8.

Narrative: While enroute at 8000 ft the Flight Crew spotted an aircraft at their 12 o'clock also on the airway. ATC advised of a Cessna Citation operating VFR; 500 feet above our altitude which was verified visually and via the TCAS. The Crew advised the aircraft was in sight and would maintain visual separation. ATC then relayed the information to the Citation who acknowledged the transmission. As the Citation grew closer; it appeared to complete a turn to the north which would allow us to pass well behind the aircraft making it no factor.The Flight Crew maintained visual with the Citation; and the Citation abruptly began a 180 degree turn which put it on a direct collision course. In response; the TCAS issued an RA to 'Monitor Vertical Speed.' The Citation appeared to continue its turn thus maintaining a direct collision course and appeared to descend toward our aircraft. The Pilot Flying Maintained visual separation by descending approximately 250 ft to avoid the incoming citation. Visual contact was lost as the Citation passed overhead and when contact was reestablished the Citation was uncomfortably close and slowly moving off to the left of the aircraft.Following the incident; the Flight Crew advised ATC of the RA and asked the purpose of the Citation's maneuver. The Citation responded by stating they were performing steep turns for a check ride.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.