Narrative:

On the before takeoff checklist, prior to our departure from jfk, I inadvertently failed to turn on our aircraft's transponder. This was most likely the first link in a chain of events that led to a potential conflict. In our air carrier X takeoff from jfk's runway 31L, we were cleared the kennedy 6 departure canarsie climb up to 5000 ft. Tower switched us to the departure frequency. I was flying the aircraft and the captain was working the radios. The captain checked in with departure with current altitude and cleared altitude 'out of approximately 2000 ft for 5000 ft. Departure acknowledged our call. There was no mention of our transponder not being on. A short while later departure called us and cleared us up to 7000 ft. While passing approximately 6000 ft the captain saw an aircraft Y in front of us. He looked down at our TCASII display to find out his distance and altitude. It was at this point we realized that our transponder was not on and hence had no TCASII information. He then turned on our transponder/TCASII and the aircraft showed up on our display as being at 3 mi in front, 300 ft higher than us, and moving left to right. I stopped our climb at 6700 ft. We then got a TCASII TA alert 'traffic, traffic.' shortly after that we got an RA alert 'monitor vertical speed' with the TA vsi showing not to climb. Departure then called and gave us an immediate 90 degree left turn. He also gave the other aircraft a climb. Departure then cleared us to our flight plan route and thanked us for our help. We estimate our distance was 2 1/2 mi at the closest point. Our type of aircraft used to have a feature in which the transponder came on automatically at liftoff. This feature was taken out with the new TCASII modification. With the all too often call 'check transponder on,' I would like to have that feature back.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR X FAILED TO TURN XPONDER ON. HAD LTSS FROM Y AT SAME ALT ASSIGNED.

Narrative: ON THE BEFORE TKOF CHKLIST, PRIOR TO OUR DEP FROM JFK, I INADVERTENTLY FAILED TO TURN ON OUR ACFT'S XPONDER. THIS WAS MOST LIKELY THE FIRST LINK IN A CHAIN OF EVENTS THAT LED TO A POTENTIAL CONFLICT. IN OUR ACR X TKOF FROM JFK'S RWY 31L, WE WERE CLRED THE KENNEDY 6 DEP CANARSIE CLB UP TO 5000 FT. TWR SWITCHED US TO THE DEP FREQ. I WAS FLYING THE ACFT AND THE CAPT WAS WORKING THE RADIOS. THE CAPT CHKED IN WITH DEP WITH CURRENT ALT AND CLRED ALT 'OUT OF APPROX 2000 FT FOR 5000 FT. DEP ACKNOWLEDGED OUR CALL. THERE WAS NO MENTION OF OUR XPONDER NOT BEING ON. A SHORT WHILE LATER DEP CALLED US AND CLRED US UP TO 7000 FT. WHILE PASSING APPROX 6000 FT THE CAPT SAW AN ACFT Y IN FRONT OF US. HE LOOKED DOWN AT OUR TCASII DISPLAY TO FIND OUT HIS DISTANCE AND ALT. IT WAS AT THIS POINT WE REALIZED THAT OUR XPONDER WAS NOT ON AND HENCE HAD NO TCASII INFO. HE THEN TURNED ON OUR XPONDER/TCASII AND THE ACFT SHOWED UP ON OUR DISPLAY AS BEING AT 3 MI IN FRONT, 300 FT HIGHER THAN US, AND MOVING L TO R. I STOPPED OUR CLB AT 6700 FT. WE THEN GOT A TCASII TA ALERT 'TFC, TFC.' SHORTLY AFTER THAT WE GOT AN RA ALERT 'MONITOR VERT SPD' WITH THE TA VSI SHOWING NOT TO CLB. DEP THEN CALLED AND GAVE US AN IMMEDIATE 90 DEG L TURN. HE ALSO GAVE THE OTHER ACFT A CLB. DEP THEN CLRED US TO OUR FLT PLAN RTE AND THANKED US FOR OUR HELP. WE ESTIMATE OUR DISTANCE WAS 2 1/2 MI AT THE CLOSEST POINT. OUR TYPE OF ACFT USED TO HAVE A FEATURE IN WHICH THE XPONDER CAME ON AUTOMATICALLY AT LIFTOFF. THIS FEATURE WAS TAKEN OUT WITH THE NEW TCASII MODIFICATION. WITH THE ALL TOO OFTEN CALL 'CHK XPONDER ON,' I WOULD LIKE TO HAVE THAT FEATURE BACK.

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.