SF34 suffers near midair collision with small aircraft at 13000 ft MSL.

Attributes
ACN	799498
Time
Date	200808
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zfw.artcc
State Reference	TX
Altitude	msl single value : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	SF 340A
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Small Aircraft Low Wing 1 Eng Retractable Gear
Operating Under FAR Part	Part 91
Flight Phase	cruise : enroute altitude change
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	799498
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	conflict : nmac
Independent Detector	aircraft equipment : tcas other controllera other flight crewa
Resolutory Action	flight crew : took evasive action
Miss Distance	horizontal : 0 vertical : 300
Supplementary
Problem Areas	Airspace Structure Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

13000 ft; ATC notified us of approaching unidented VFR traffic. TCAS did not show anything at first. Captain and first officer scanned and found aircraft climbing; then descending about +500 ft and changing headings about +20 degrees right then left. We thought the aircraft was a light single piper and may have been doing flight training or maneuvering; but questioned why at such a high altitude. TCAS then came alive; commanded an immediate climb. At this same time; captain turned on all lights; flashed landing lights; disconnected autoplt and made a climbing turn; keeping the piper in sight at all times and climbing about 200 ft; then returning to assigned altitude of 13000 ft. ATC was kept in the loop; and we informed them of what happened. I believe if we had not taken immediate action; this could have been close. The piper pilot never saw us; turned and climbed right into us. I believe we missed him about 300-400 ft. We could see it was red on white and I kept eyes on the aircraft as it passed in front and under us. First officer said TCAS read 300 ft at that time.

Original NASA ASRS Text

Title: SF34 SUFFERS NMAC WITH SMA AT 13000 FT MSL.

Narrative: 13000 FT; ATC NOTIFIED US OF APCHING UNIDENTED VFR TFC. TCAS DID NOT SHOW ANYTHING AT FIRST. CAPT AND FO SCANNED AND FOUND ACFT CLBING; THEN DSNDING ABOUT +500 FT AND CHANGING HDGS ABOUT +20 DEGS R THEN L. WE THOUGHT THE ACFT WAS A LIGHT SINGLE PIPER AND MAY HAVE BEEN DOING FLT TRAINING OR MANEUVERING; BUT QUESTIONED WHY AT SUCH A HIGH ALT. TCAS THEN CAME ALIVE; COMMANDED AN IMMEDIATE CLB. AT THIS SAME TIME; CAPT TURNED ON ALL LIGHTS; FLASHED LNDG LIGHTS; DISCONNECTED AUTOPLT AND MADE A CLBING TURN; KEEPING THE PIPER IN SIGHT AT ALL TIMES AND CLBING ABOUT 200 FT; THEN RETURNING TO ASSIGNED ALT OF 13000 FT. ATC WAS KEPT IN THE LOOP; AND WE INFORMED THEM OF WHAT HAPPENED. I BELIEVE IF WE HAD NOT TAKEN IMMEDIATE ACTION; THIS COULD HAVE BEEN CLOSE. THE PIPER PLT NEVER SAW US; TURNED AND CLBED RIGHT INTO US. I BELIEVE WE MISSED HIM ABOUT 300-400 FT. WE COULD SEE IT WAS RED ON WHITE AND I KEPT EYES ON THE ACFT AS IT PASSED IN FRONT AND UNDER US. FO SAID TCAS READ 300 FT AT THAT TIME.

Data retrieved from NASA's ASRS site as of May 2009 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.