Narrative:

En route to jackson, tn (mkl), from muscle shoals, al (MSL), inbound to jks VOR on 150 degree radial (approximately 5-10 mi sse of jks), observed traffic on TCASII at 12 O'clock, 1500 ft above, closing at high rate. Tried to observe oncoming traffic ahead and above, as it closed from 20 NM to pass just off our right side and 1500 ft above. When TCASII traffic was crossing 1500 ft directly above us and just slightly right of our position, I saw motion out of the corner of my eye. A C152 crossed directly above our wing (right to left) no more than 50- 100 ft above our aircraft. Cessna was white with red trim, and appeared as though it may have been climbing. Captain queried center, who advised he had observed no traffic other than the aircraft approaching head-on and 1500 ft above. Center had no other traffic on radar, and the C152 never appeared on our TCASII.

Google
 

Original NASA ASRS Text

Title: FLC OF BAE3100 AT CRUISE HAS NMAC WITH C152 APPARENTLY CLBING. THE CESSNA NEVER SHOWS ON THE TCASII AND CTR INDICATES THEY HAVE NO OTHER TFC.

Narrative: ENRTE TO JACKSON, TN (MKL), FROM MUSCLE SHOALS, AL (MSL), INBOUND TO JKS VOR ON 150 DEG RADIAL (APPROX 5-10 MI SSE OF JKS), OBSERVED TFC ON TCASII AT 12 O'CLOCK, 1500 FT ABOVE, CLOSING AT HIGH RATE. TRIED TO OBSERVE ONCOMING TFC AHEAD AND ABOVE, AS IT CLOSED FROM 20 NM TO PASS JUST OFF OUR R SIDE AND 1500 FT ABOVE. WHEN TCASII TFC WAS XING 1500 FT DIRECTLY ABOVE US AND JUST SLIGHTLY R OF OUR POS, I SAW MOTION OUT OF THE CORNER OF MY EYE. A C152 CROSSED DIRECTLY ABOVE OUR WING (R TO L) NO MORE THAN 50- 100 FT ABOVE OUR ACFT. CESSNA WAS WHITE WITH RED TRIM, AND APPEARED AS THOUGH IT MAY HAVE BEEN CLBING. CAPT QUERIED CTR, WHO ADVISED HE HAD OBSERVED NO TFC OTHER THAN THE ACFT APCHING HEAD-ON AND 1500 FT ABOVE. CTR HAD NO OTHER TFC ON RADAR, AND THE C152 NEVER APPEARED ON OUR TCASII.

Data retrieved from NASA's ASRS site as of July 2007 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.