SMA HAS NMAC WITH HELI ON DEP TO ASSIGNED ALT.

Narrative

THIS NEAR-MISS INCIDENT OCCURRED DURING DEP PHASE OF FLT FROM TUCSON INTL ARPT (TUS) TO PAYSON; AZ; MUNICIPAL ARPT (E69) AND INVOLVED MY ACFT AND A HELI THAT WAS APPARENTLY INBOUND TO TUS. PRIOR TO OUR TKOF; TUCSON CLRNC DELIVERY WAS ADVISED THAT OUR PLANNED DEP HDG WAS 340 DIRECT PAYSON; WITH CLB TO CRUISE ALT OF 3800 FT MSL. OUR TKOF CLRNC FROM TUS INCLUDED A L DOWNWIND DEP FROM RWY 11L; BUT WAS AMENDED SHORTLY AFTER WE WERE AIRBORNE BY TWR REQUEST THAT WE PROCEED DIRECTLY TO 'A' MOUNTAIN (A VFR LANDMARK APPROX 9 NM NW OF TUS VOR ON RADIAL 325); AND RESUME OUR OWN NAV THEREAFTER. JUST PRIOR TO XING 'A' MOUNTAIN WE WERE HANDED OFF TO TUCSON DEP CTL AND RPTED THERETO CLBING THROUGH 5500 FT MSL. DEP CTL ISSUED US AN ALT RESTR TO REMAIN AT OR BELOW 5500 FT MSL AND EXPECT FURTHER CLB CLRNC IN ABOUT 4 MIN. NOTHING WAS SAID ABOUT RTE OF FLT; SO WE CONTINUED TO 'A' MOUNTAIN AS TWR HAD REQUESTED; TURNED NWARD FROM THERE; AND CAME LEVEL AT 5500 FT MSL. ABOUT 3 NM N OF 'A' MOUNTAIN; WHILE LEVEL AT 5500 FT MSL; WE OBSERVED A HELI COMING OPPOSITE DIRECTION AND PERFORMING AN ABRUPT DSNDING R TURN; APPARENTLY AS A DEV MANEUVER TO AVOID OUR FLT PATH. WE ESTIMATE THAT THE HELI CAME WITHIN 200 FT HORIZ AND WAS APPROX 100 FT BELOW AND TO OUR L WHEN WE PASSED. WE SEEM TO RECALL HEARING TUCSON APCH ADVISE THE HELI PLT OF OUR POS AND ALT; BUT DO NOT RECALL BEING ADVISED CONVERSELY THAT A HELI WAS A FACTOR IN OUR TFC SIT. AS TO PROBABLE CAUSE OF THIS INCIDENT; IT SEEMS UNCERTAIN WHETHER ATC DIDN'T PROVIDE ADEQUATE RTING/ALT INSTRUCTIONS TO AVOID CONFLICT OR THE HELI PLT DIDN'T UNDERSTAND THE SIGNIFICANCE OF ATC'S TFC RPT. WE ATTEMPTED TO MAINTAIN VIGILANCE FOR OTHER TFC (AS ALWAYS); BUT SIMPLY DIDN'T SEE THE HELI UNTIL IT WAS ALREADY IN THE DSNDING TURN. (1 POSSIBLE FACTOR MAY BE THAT THE HELI PLT DIDN'T EXPECT OUR CLOSURE RATE TO BE AS FAST AS IT WAS. OUR AIRSPD AT THE TIME WAS 120 KTS AND INCREASING; BUT WE WERE RPTED AS A 'GRUMMAN AT 5500 FT...' AND MANY PLTS OF HIGHER-PERFORMING ACFT EXPECT OR PERCEIVE SMALL PLANES TO BE RELATIVELY SLOW.)