B737 FLC TAKE EVASIVE ACTION AFTER OBSERVING ANOTHER ACFT COMING TOWARD THEM DURING CLBOUT WHICH HAD BEEN GIVEN BY ATC AS A PRIMARY TARGET WITH UNKNOWN ALT READOUT OR CONTACT WITH APCH CTL IN CLASS C AIRSPACE.

Narrative

I WAS PROVIDING OJT TRAINING TO A RECENTLY XFERRED CTLR ON APCH/DEP CTL. THE TRAINEE ALSO HAD APPROX 18 YRS ATC EXPERIENCE. ACR X B727 DEPARTED RWY 29; RWY HDG; CLBING TO 3000 FT. ACR CHKED IN 'OUT OF 2000 FT FOR 3000 FT.' HE WAS ASSIGNED 8000 FT AND TURNED DIRECT MANCHESTER (MHT -- THE DEST -- A VERY SHORT FLT) APPROX 240 DEG HDG. I HAD BEEN WATCHING A PRIMARY TARGET (NO XPONDER) FOR A FEW MI THAT WAS NOW 6 NM DUE W OF PWM EBOUND. I INSTRUCTED THE TRAINEE TO 'ISSUE THE TFC.' THE TFC WAS ISSUED WITH ACR X INSTRUCTED TO 'STAY ON RWY HDG.' THE PLT RESPONDED THAT THEY WERE HDG 270 DEGS AND ASKED IF THAT WOULD BE OK. AT FIRST THE TRAINEE SAID 270 DEGS WOULD AVOID THE TFC; THEN REALIZED IT WOULD BE TOO CLOSE AND TURNED ACR BACK TO 290 DEGS; THEN RPTED THE TFC IN SIGHT LESS THAN 1/2 MI 'HDG RIGHT AT US AT OUR ALT (4000 FT).' THE PLT QUESTIONED HOW CLOSE THE TFC CAME TO THEM AND ASKED WHAT ALT WE SHOWED ON THE TFC. WE TOLD HIM THERE WAS NO XPONDER; NO ALT. WE TRACKED THE PRIMARY TARGET TO A SMALL ARPT IN NORTHERN MAINE. BEFORE LNDG; THE PLT ASKED BANGOR APCH FOR A XPONDER CHK (HIS FIRST CONTACT WITH ATC SINCE DEPARTING CONNECTICUT). THE PLT CALLED US ON THE PHONE AND ADVISED THAT HE PASSED OVER PWM AT 5500 FT (HE CHANGED HIS MIND WHEN TOLD THAT '3 AIRLINE PLTS WILL TESTIFY YOU WERE AT 4000 FT'). HE FURTHER SAID HE WAS MONITORING THE ATC FREQ AND 'THOUGHT YOU MIGHT BE TALKING ABOUT ME AFTER I SAW THE B727 GO BY.' WHY THE PLT MONITORED THE FREQ AND NEVER CALLED US IS BEYOND ME. WE COULD HAVE AVOIDED AN NMAC AND MAYBE WORSE. IF THE ATC SVC IS THERE; USE IT! IT'S LESS WORKLOAD ON ATC TO TRACK AN ACFT AND GIVE AN ALTIMETER THAN CONSTANTLY BE ISSUING TFC 'TYPE AND ALT UNKNOWN.' I SPOKE WITH THE ACR PLT ON THE PHONE AND TOLD HIM THE PRIMARY TARGET WAS IN AN AREA WHERE THE ONLY ALT HE COULD BE AT; AND BE LEGAL; WAS 1500 FT AND BELOW; BUT I HAD THE TRAINEE ISSUE THE TFC ANYWAY 'BECAUSE YOU NEVER KNOW.' MY TECHNIQUE; WHICH I RECOMMEND; IS TO ADD PHRASEOLOGY 'NO XPONDER' WHEN MAKING A CALL TO A TCASII EQUIPPED ACFT. THE PLT LIKED THE IDEA BECAUSE THEY (LIKE ME; WHEN I JUMP SEAT) INITIALLY LOOK AT THE TCASII TO BETTER CORRELATE THE TFC RELATIVE TO THE ACFT. ADDING 'NO XPONDER' GETS EVERYONE LOOKING OUT THE WINDOW INSTEAD OF LOOKING AT A BLANK TCASII BOX. LOTS OF LESSONS HERE: 1) ATC; 2) FLY AT APPROPRIATE ALTS; 3) DON'T ASSUME ACFT ARE FOLLOWING FARS; AND 4) ALWAYS LOOK OUT THE WINDOW.