Narrative:

We were monitoring tower to runway 31 for takeoff. A VFR stinson called tower as we approached the departure end of runway 31. The stinson reported 5 mi out of the airport and said he would be passing 3 north of the airport at 2800 ft MSL. We arrived at the approach end of runway 31 and waited for about 1 min for the flight attendant to report ready. She did and we reported to tower 'ready for takeoff.' tower again asked the stinson for his position and the stinson reported '5 west.' tower cleared us for takeoff with a right (north) turn on course 3 and a climb to 4000 ft. On course heading was approximately 80 degrees. We were climbing through 2600-2700 ft, a heading of 0-20 degrees when the first officer, the PF, saw the stinson at approximately 11 O'clock and 2800 ft. The first officer increased our bank angle from approximately 10 degrees to 30 degrees and stopped the climb and leveled at 2700 ft. I looked up and saw the stinson at 9 O'clock, 200 ft distant at 2800 ft. When I looked up, both aircraft were on a diverging course, the stinson, evidently having seen us, was turning to port 20 degrees bank. The flight continued uneventfully after this. My primary mistake was taking the stinson pilot's position reports at face value. It was not possible for him to be 5 mi west of the airport 1 min after he called 5 mi west of the airport, even assuming he gave a correct report to begin with. I should have assumed he didn't know his exact position and planned on their being a non-transponder (he did not have a transponder) a couple of mi north of the field. The safest course of action then would have been to refuse the takeoff clearance. Failing that, I could have directed my attention outside rather than inside the aircraft. I could also have directed the first officer to climb fast or turn tight. In the future, I shall assume that position reports of this type are inaccurate and plan accordingly. Supplemental information from acn 316246: the aircraft either didn't have a transponder or it was turned off. We had no TCASII indication.

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Original NASA ASRS Text

Title: NMAC IN CLASS D AIRSPACE.

Narrative: WE WERE MONITORING TWR TO RWY 31 FOR TKOF. A VFR STINSON CALLED TWR AS WE APCHED THE DEP END OF RWY 31. THE STINSON RPTED 5 MI OUT OF THE ARPT AND SAID HE WOULD BE PASSING 3 N OF THE ARPT AT 2800 FT MSL. WE ARRIVED AT THE APCH END OF RWY 31 AND WAITED FOR ABOUT 1 MIN FOR THE FLT ATTENDANT TO RPT READY. SHE DID AND WE RPTED TO TWR 'READY FOR TKOF.' TWR AGAIN ASKED THE STINSON FOR HIS POS AND THE STINSON RPTED '5 W.' TWR CLRED US FOR TKOF WITH A R (N) TURN ON COURSE 3 AND A CLB TO 4000 FT. ON COURSE HDG WAS APPROX 80 DEGS. WE WERE CLBING THROUGH 2600-2700 FT, A HDG OF 0-20 DEGS WHEN THE FO, THE PF, SAW THE STINSON AT APPROX 11 O'CLOCK AND 2800 FT. THE FO INCREASED OUR BANK ANGLE FROM APPROX 10 DEGS TO 30 DEGS AND STOPPED THE CLB AND LEVELED AT 2700 FT. I LOOKED UP AND SAW THE STINSON AT 9 O'CLOCK, 200 FT DISTANT AT 2800 FT. WHEN I LOOKED UP, BOTH ACFT WERE ON A DIVERGING COURSE, THE STINSON, EVIDENTLY HAVING SEEN US, WAS TURNING TO PORT 20 DEGS BANK. THE FLT CONTINUED UNEVENTFULLY AFTER THIS. MY PRIMARY MISTAKE WAS TAKING THE STINSON PLT'S POS RPTS AT FACE VALUE. IT WAS NOT POSSIBLE FOR HIM TO BE 5 MI W OF THE ARPT 1 MIN AFTER HE CALLED 5 MI W OF THE ARPT, EVEN ASSUMING HE GAVE A CORRECT RPT TO BEGIN WITH. I SHOULD HAVE ASSUMED HE DIDN'T KNOW HIS EXACT POS AND PLANNED ON THEIR BEING A NON-XPONDER (HE DID NOT HAVE A XPONDER) A COUPLE OF MI N OF THE FIELD. THE SAFEST COURSE OF ACTION THEN WOULD HAVE BEEN TO REFUSE THE TKOF CLRNC. FAILING THAT, I COULD HAVE DIRECTED MY ATTN OUTSIDE RATHER THAN INSIDE THE ACFT. I COULD ALSO HAVE DIRECTED THE FO TO CLB FAST OR TURN TIGHT. IN THE FUTURE, I SHALL ASSUME THAT POS RPTS OF THIS TYPE ARE INACCURATE AND PLAN ACCORDINGLY. SUPPLEMENTAL INFO FROM ACN 316246: THE ACFT EITHER DIDN'T HAVE A XPONDER OR IT WAS TURNED OFF. WE HAD NO TCASII INDICATION.

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.