NMAC BTWN A LEAR JET CLBING OUT AFTER TKOF TWR CTLED ARPT AND A MIL TYPE ACFT LEVEL ON A COLLISION COURSE.

Narrative

FO RAN THE CHKLIST TO INCLUDE TURNING THE XPONDER ON TA/RA MODE TO UTILIZE THE TCASII SYS ON THE GND GIVING US ADDITIONAL HELP TO IDENT ANY TFC IN THE AREA. WE (ACFT X) IDENTED A SLOW MOVING ACFT GOING NBOUND OFF THE LAKE SHORE WHEN THE TWR INFORMED US THAT A C172 (ACFT Z) WAS WHAT WE SAW ON OUR TCASII OVER MEIGS FIELD. WE WERE CLRED FOR TKOF WITH A CLRNC TO CLB TO 2000 FT WITH A TURN TO 140 DEG HDG. WE TAXIED SLOWLY INTO POS TO GIVE THE C172 ADDITIONAL SEPARATION TIME AND CAREFULLY RUN THE CHKLIST AND PREPARED FOR A SHORT FIELD TKOF. THE TKOF AT XA07Z WAS CONSIDERED NORMAL WITH A STANDARD CLBOUT TO FOLLOW OUR CLRNC. WHILE IN THE CLB THROUGH APPROX 1500 FT AND TURNING THROUGH A HDG OF 060 DEGS; WE HAD A TCASII ALERT OF 'REDUCE VERT SPD' OFF OF OUR L FRONT. OUR FIRST THOUGHTS WERE THAT IT COULD BE THE C172 NBOUND THAT WE MAY BE PASSING BEHIND IN OUR TURN TO A 140 DEG HDG. AS WE CONTINUED OUR CLB AND TURN THE TCASII GAVE A TFC RA ALERT TO 'DSND; DSND.' AT THAT TIME WE BECAME MORE CONCERNED AND CAPT BUNTED THE ACFT OVER TO FOLLOW THE TCASII ALERT. HE LEVELED OUR WINGS ON AN APPROX 070 DEG HDG AND STOPPING THE CLB AT APPROX 1800 FT INDICATED. LOOKING OFF TO OUR L WE SAW WHAT APPEARED TO BE A MIL ACFT Y SBOUND; 100 FT ABOVE US AND FLYING ON A COLLISION COURSE WITH OUR ACFT. WE WERE ALSO CHANGING FREQS FROM TWR TO DEP WHEN THIS EVENT TOOK PLACE. FO QUESTIONED THE DEP CTLR WHAT WAS GOING ON AND WHAT ALT THE MIL LOOKING ACFT WAS AT. THE CTLR SAID THE RPTED ALT WAS 2100 FT. I THEN WENT BACK TO THE TWR CTLR AND ASKED WHY THAT WAS ALLOWED TO HAPPEN. THE TWR CTLR SAID THAT ACFT Y CONTACTED MEIGS TWR TO GET PERMISSION TO GO THROUGH HIS AIRSPACE AT 2500 FT. THE TWR CTLR TOLD ACFT Y OF OUR DEP FROM MEIGS. THE PLT TOLD MEIGS TWR HE HAD US IN SIGHT WHICH PROBABLY GAVE THE TWR CTLR REASON TO BELIEVE THAT HE WOULD STAY AT 2500 FT TO GIVE US SAFE SEPARATION. THAT DID NOT HAPPEN. WE CONTINUED ON TO AMES; IA; WHERE WE CALLED MEIGS TWR AND CHICAGO DEP CTL ON THE TELEPHONE TO DISCUSS THE NEAR MISS EVENT. MEIGS TWR CTLR SAID HE WAS INFORMED OF THE TFC AFTER WE DEPARTED MEIGS. CTLR SHOWED CONCERN FOR THE EVENT; BUT ALSO SHOWED CONCERN THAT WE MIGHT VIOLATE HIS ACTIONS. WE ALSO TALKED TO THE SUPVR AT APCH CTL. APCH CTL SAID THAT ACFT Y WAS AT 2100 FT AND GAVE US SIMILAR INFO WE RECEIVED FROM THE TWR. CTLR SAID HE WOULD INSTRUCT THE QUALITY ASSURANCE DEPT TO REVIEW THE SERIES OF EVENTS AND THAT THEY WOULD HAVE THE RESULTS AVAILABLE TO US LATE AFTERNOON AUG/XA/99. WE BELIEVE THAT THE PERSON MOST RESPONSIBLE IN THIS IS THE PLT OF ACFT Y. IT MAY BE THAT THE CLOUDS N OF MEIGS FIELD WERE LOWER AND CAUSED ACFT Y TO DSND TO KEEP US IN SIGHT. THERE APPEARED TO BE MORE SCATTERED CLOUDS CLOSER TO THE SHORELINE; BUT AS WE HEADED EBOUND; THE LOWER SCATTERED CLOUDS DISSIPATED. WHATEVER THE CASE; IT BECAME A VERY UNSAFE SIT.