FLC INTERP OF MEL POSES HAZARD TO JOB SECURITY.

Narrative

I ARRIVED AT ACFT FOR FLT ORD-PIA AND MAINT HAD AML AND MAINT WAS WORKING ON ACFT. CAPT ARRIVED; WE COMPLETED BEFORE START CHKS; PAX BOARDED. MAINT DEFERRED R LOW WIPER FUNCTION; HIGH SPD WIPER WAS OPERATIONAL OK. WE DEPARTED ORD TO PIA. WX AT PIA AT 40 DEG F VFR WITH LIGHT PRECIPITATION. AT PIA; CAPT LOOKED AT ACFT MEL AND NOTICED ACFT SHOULD NOT BE DISPATCHED TO OR FROM FIELD IF PRECIPITATION WITHIN 5 SM OF ARR OR DEST ARPT; BUT WAS FOOTNOTED 'OK TO DISPATCH IF BOTH HIGH SPD WIPERS (CA AND FO) WAS OPERATIONAL.' CAPT AND I WERE UNSURE OF FOOTNOTE MEANING. IT APPEARED THAT THE DEFERRAL REQUIRED NO PRECIPITATION AT DEP OR ARR ARPT. WE CALLED DISPATCH; CHIEF PLT ON DUTY AND MAINT OP CTL (MOC). EACH OF THE THREE STATED OK TO DISPATCH IN CURRENT PRECIPITATION. CAPT AND I DISAGREED AND CHIEF PLT ON DUTY DETERMINED THE ACFT OK TO GO. I OBJECTED BUT WAS THREATENED WITH LOSING MY JOB IF WE DID NOT DEPART PIA IN ACFT. CAPT AND I ASKED THAT ALL 3 WOULD SEND IN WRITING THEIR INTERP OF AML AND THEY READ IT AS OPERATIONALLY AIRWORTHY. THEY DID AS WE ASKED AND SENT INTERP IN WRITING. CAPT CONCURRED AND WE DEPARTED PIA TO ORD. ACFT WAS REPAIRED IN ORD.