Narrative:

Climbout on vectored 090 heading; passing approximately 5;800 ft; 250 KIAS with clearance to climb to 13;000 ft MSL. Departure control issued an amended clearance to 7;000 ft MSL. After the pilot flying changed the MCP to 7;000 ft and the pilot not flying verified; the jet leveled off at 7;000 ft MSL. ATC advised of a VFR king air approximately ten to twelve miles east; southbound; level at 7;500 ft MSL; and that he had the us in sight. The aircraft was observed; reported by pilot not flying to ATC; and then ATC issued clearance to maintain visual separation and cleared the flight to 13;000 ft. Both pilot flying and pilot not flying verified. MCP was changed to 13;000 ft and the pilot flying started an immediate climb at 250 KIAS. Within five seconds into the climb; with a rate of climb of approximately 2;500 FPM; the crew was alerted via TCAS with 'monitor vertical speed;' immediately followed by 'adjust vertical speed;' then 'descend;' followed by 'maintain vertical speed;' and then 'clear of conflict.' as the aural warnings were being given; the pilot flying was adjusting the flight path of the jet as expeditiously as possible; all the while maintaining visual separation with the sighted aircraft. The pilot flying estimated the distance of the aircraft to be five to seven miles; at the time of the initial aural alert; via both TCAS and eye sight. The end result was that our flight passed above and to the left of the king air approximately 200 ft vertically and 1/2 mile horizontally. There was no known traffic call made by the king air to ATC; or ATC to us during all this time. Upon landing and deplaning passengers; the pilot flying debriefed the crew (flight attendants and first officer) and discussed the situation. The a flight attendant commented that one passenger had asked during his deplaning if the flight had come close to another aircraft during climbout. No other passenger was known to have commented. The flight continued on uneventfully after the turn. The unexpected climb interruption by ATC might have contributed to 'closing the gap' between subject aircraft in this situation. Leveling off and then given clearance to continue the climb led to the TCAS alerting the crew. When the pilot flying and pilot not flying initially saw the other aircraft; the only aircraft in sight; and TCAS showed the ATC altitude mentioned; the pilot flying felt comfortable that visual separation could be maintained without expecting the resulting alerts and situation. Given the fact that any crew does not know what the TCAS sees; the only result is that the crew accomplish the appropriate reactions as expeditiously as possible. In this case; there were no other aircraft observed visually and; at one point; the pilot not flying observed our aircraft above the TCAS displayed aircraft approximately 300 to 400 ft. It was during this time the pilot not flying recalled hearing the 'monitor vertical speed' followed by 'descend' and was just a bit confused to what he saw on TCAS; heard aurally; and saw visually.

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Original NASA ASRS Text

Title: B737 flight crew experiences a TCAS RA with a VFR King air at 7;500 FT after being cleared to climb if visual separation can be maintained.

Narrative: Climbout on vectored 090 heading; passing approximately 5;800 FT; 250 KIAS with clearance to climb to 13;000 FT MSL. Departure Control issued an amended clearance to 7;000 FT MSL. After the pilot flying changed the MCP to 7;000 FT and the pilot not flying verified; the jet leveled off at 7;000 FT MSL. ATC advised of a VFR King Air approximately ten to twelve miles east; southbound; level at 7;500 FT MSL; and that he had the us in sight. The aircraft was observed; reported by pilot not flying to ATC; and then ATC issued clearance to maintain visual separation and cleared the flight to 13;000 FT. Both pilot flying and pilot not flying verified. MCP was changed to 13;000 FT and the pilot flying started an immediate climb at 250 KIAS. Within five seconds into the climb; with a rate of climb of approximately 2;500 FPM; the crew was alerted via TCAS with 'monitor vertical speed;' immediately followed by 'adjust vertical speed;' then 'descend;' followed by 'maintain vertical speed;' and then 'clear of conflict.' As the aural warnings were being given; the pilot flying was adjusting the flight path of the jet as expeditiously as possible; all the while maintaining visual separation with the sighted aircraft. The pilot flying estimated the distance of the aircraft to be five to seven miles; at the time of the initial aural alert; via both TCAS and eye sight. The end result was that our flight passed above and to the left of the King Air approximately 200 FT vertically and 1/2 mile horizontally. There was no known traffic call made by the King Air to ATC; or ATC to us during all this time. Upon landing and deplaning passengers; the pilot flying debriefed the crew (Flight Attendants and First Officer) and discussed the situation. The A Flight Attendant commented that one passenger had asked during his deplaning if the flight had come close to another aircraft during climbout. No other passenger was known to have commented. The flight continued on uneventfully after the turn. The unexpected climb interruption by ATC might have contributed to 'closing the gap' between subject aircraft in this situation. Leveling off and then given clearance to continue the climb led to the TCAS alerting the crew. When the pilot flying and pilot not flying initially saw the other aircraft; the only aircraft in sight; and TCAS showed the ATC altitude mentioned; the pilot flying felt comfortable that visual separation could be maintained without expecting the resulting alerts and situation. Given the fact that any crew does not know what the TCAS sees; the only result is that the crew accomplish the appropriate reactions as expeditiously as possible. In this case; there were no other aircraft observed visually and; at one point; the pilot not flying observed our aircraft above the TCAS displayed aircraft approximately 300 to 400 FT. It was during this time the pilot not flying recalled hearing the 'monitor vertical speed' followed by 'descend' and was just a bit confused to what he saw on TCAS; heard aurally; and saw visually.

Data retrieved from NASA's ASRS site as of April 2012 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.