Narrative:

Our light transport was cruising at 7000', northbound, when the captain called to my attention an small aircraft at 11 O'clock, approximately 300' above our altitude (altimeter set to travis approach local value). I glanced to my left in time to see the small aircraft close on us. If we were both at the same altitude collision would have occurred. The small aircraft took 4 seconds maximum to cross our flight path. Evasive action, even if the captain had disconnected the autoplt and climbed within 1 second after contact, would probably not have been successful. I called travis approach as soon as he was through talking. This took approximately 30 seconds. I asked him if his scope showed traffic sebnd about 7500' MSL. He stated 'yes, I have one 6 1/2 mi from you, sebnd.' I responded 'that's him.' the controller then called the small aircraft and asked him his altitude. We heard the small aircraft pilot respond 7700'. He was supposed to be at 7500' and there was not 700' separating us vertical. I then ended my transmission to approach with 'thanks.' the controller never called this traffic to us, and he made no comment after my 'thanks.' the only logical variables creating this incident were our 2 altimeter settings, controller vigilance, our traffic scan, pilot's attention diverted, fatigue, etc. Enough has already been printed re: human performance. Inevitably, accidents will occur from incidents when all the variables arrive at the same point in time and space. However, a collision avoidance system would have prevented this. Finally, the small aircraft also did not see us as he took no evasive action.

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Original NASA ASRS Text

Title: CLOSE PROX COMMUTER-LTT GA-SMA.

Narrative: OUR LTT WAS CRUISING AT 7000', NBND, WHEN THE CAPT CALLED TO MY ATTN AN SMA AT 11 O'CLOCK, APPROX 300' ABOVE OUR ALT (ALTIMETER SET TO TRAVIS APCH LCL VALUE). I GLANCED TO MY LEFT IN TIME TO SEE THE SMA CLOSE ON US. IF WE WERE BOTH AT THE SAME ALT COLLISION WOULD HAVE OCCURRED. THE SMA TOOK 4 SECS MAX TO CROSS OUR FLT PATH. EVASIVE ACTION, EVEN IF THE CAPT HAD DISCONNECTED THE AUTOPLT AND CLBED WITHIN 1 SEC AFTER CONTACT, WOULD PROBABLY NOT HAVE BEEN SUCCESSFUL. I CALLED TRAVIS APCH AS SOON AS HE WAS THROUGH TALKING. THIS TOOK APPROX 30 SECS. I ASKED HIM IF HIS SCOPE SHOWED TFC SEBND ABOUT 7500' MSL. HE STATED 'YES, I HAVE ONE 6 1/2 MI FROM YOU, SEBND.' I RESPONDED 'THAT'S HIM.' THE CTLR THEN CALLED THE SMA AND ASKED HIM HIS ALT. WE HEARD THE SMA PLT RESPOND 7700'. HE WAS SUPPOSED TO BE AT 7500' AND THERE WAS NOT 700' SEPARATING US VERT. I THEN ENDED MY XMISSION TO APCH WITH 'THANKS.' THE CTLR NEVER CALLED THIS TFC TO US, AND HE MADE NO COMMENT AFTER MY 'THANKS.' THE ONLY LOGICAL VARIABLES CREATING THIS INCIDENT WERE OUR 2 ALTIMETER SETTINGS, CTLR VIGILANCE, OUR TFC SCAN, PLT'S ATTN DIVERTED, FATIGUE, ETC. ENOUGH HAS ALREADY BEEN PRINTED RE: HUMAN PERFORMANCE. INEVITABLY, ACCIDENTS WILL OCCUR FROM INCIDENTS WHEN ALL THE VARIABLES ARRIVE AT THE SAME POINT IN TIME AND SPACE. HOWEVER, A COLLISION AVOIDANCE SYS WOULD HAVE PREVENTED THIS. FINALLY, THE SMA ALSO DID NOT SEE US AS HE TOOK NO EVASIVE ACTION.

Data retrieved from NASA's ASRS site as of August 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.