Narrative:

We were cleared into position and hold on runway 27L. After we were cleared, the tower told an air carrier mdt Y to execute a missed approach on runway 36 due to spacing. The tower controller told the mdt Y flight to fly a left pattern for runway 36. Shortly thereafter, the tower cleared us for departure. It was my leg. I rotated the aircraft to 20 degrees pitch up. We were very light which made air takeoff roll very short and our rate of climb in excess of 4000 FPM. Right after the nose pitched to 20 degrees up, the captain called to 'put the nose down.' since I didn't understand that there was a traffic conflict, I only lowered the nose slightly. The captain then took over control and forced the nose down to a slight descent attitude. As I looked up, I saw the mdt Y flight approximately 400' above and in front of us. If the captain hadn't seen the mdt Y flight, our path would have most definitely crossed. Upon arrival at bos, the captain called the tower controller at phl. The tower controller told him that he (controller) thought the mdt Y flight would make a closer downwind leg and would not be in conflict with us. He also didn't know we were 'light' and would have a short ground roll. I believe this wouldn't have happened if the tower controller issued more specific instruction to the mdt Y flight as to distance from airport so as not to conflict with aircraft departing from runway 27. The captain should have also made the instructions clearer to me as to the traffic conflict such as, 'traffic 12 O'clock, get the nose down.'

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Original NASA ASRS Text

Title: MLG DEP OFF RWY 27L HAS NMAC WITH MDT ON DOWNWIND LEG FOR RWY 36.

Narrative: WE WERE CLRED INTO POS AND HOLD ON RWY 27L. AFTER WE WERE CLRED, THE TWR TOLD AN ACR MDT Y TO EXECUTE A MISSED APCH ON RWY 36 DUE TO SPACING. THE TWR CTLR TOLD THE MDT Y FLT TO FLY A LEFT PATTERN FOR RWY 36. SHORTLY THEREAFTER, THE TWR CLRED US FOR DEP. IT WAS MY LEG. I ROTATED THE ACFT TO 20 DEGS PITCH UP. WE WERE VERY LIGHT WHICH MADE AIR TKOF ROLL VERY SHORT AND OUR RATE OF CLB IN EXCESS OF 4000 FPM. RIGHT AFTER THE NOSE PITCHED TO 20 DEGS UP, THE CAPT CALLED TO 'PUT THE NOSE DOWN.' SINCE I DIDN'T UNDERSTAND THAT THERE WAS A TFC CONFLICT, I ONLY LOWERED THE NOSE SLIGHTLY. THE CAPT THEN TOOK OVER CTL AND FORCED THE NOSE DOWN TO A SLIGHT DSNT ATTITUDE. AS I LOOKED UP, I SAW THE MDT Y FLT APPROX 400' ABOVE AND IN FRONT OF US. IF THE CAPT HADN'T SEEN THE MDT Y FLT, OUR PATH WOULD HAVE MOST DEFINITELY CROSSED. UPON ARR AT BOS, THE CAPT CALLED THE TWR CTLR AT PHL. THE TWR CTLR TOLD HIM THAT HE (CTLR) THOUGHT THE MDT Y FLT WOULD MAKE A CLOSER DOWNWIND LEG AND WOULD NOT BE IN CONFLICT WITH US. HE ALSO DIDN'T KNOW WE WERE 'LIGHT' AND WOULD HAVE A SHORT GND ROLL. I BELIEVE THIS WOULDN'T HAVE HAPPENED IF THE TWR CTLR ISSUED MORE SPECIFIC INSTRUCTION TO THE MDT Y FLT AS TO DISTANCE FROM ARPT SO AS NOT TO CONFLICT WITH ACFT DEPARTING FROM RWY 27. THE CAPT SHOULD HAVE ALSO MADE THE INSTRUCTIONS CLEARER TO ME AS TO THE TFC CONFLICT SUCH AS, 'TFC 12 O'CLOCK, GET THE NOSE DOWN.'

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.