SMA FLC HAS COM EQUIP PROBS; DSNDS BELOW ASSIGNED ALT.

Narrative

WE WERE TRYING TO CONTACT UNICOM WHILE MONITORING ZMP FREQ. THE #2 COM DOESN'T WORK AS WELL AS IT SHOULD AND I WAS TRYING TO TROUBLESHOOT IT WITH THE OTHER PLT IN THE COCKPIT. HE IS WITHOUT A MEDICAL BUT DOES MOST ALL OF THE FLYING AND COMS ACTIVITIES. BECAUSE OF HIS LIMITED KNOWLEDGE OF THE ACFT AVIONICS SYS; I HAD TO HELP HIM WITH THE COMS EQUIP PROBS. WE WERE CLRED DOWN TO 4000 FT MSL FROM 6000 FT MSL AND COMMENCED OUR DSCNT BY UTILIZING THE AUTOPLT. AFTER STARTING OUR DSCNT HE ATTEMPTED TO COMMUNICATE WITH UNICOM. AFTER SEEING HE WAS HAVING TROUBLE; I DECIDED TO HELP WITH THE AVIONICS. WE BOTH BECAME ENGROSSED IN THE PROB WHICH THEN LEFT NOBODY FLYING THE AIRPLANE. WHEN I GLANCED AT THE ALTIMETER; WE WERE AT 3800 FT MSL AND DSNDING ABOUT 500 FPM. I MADE NOTE OF THE DEV AND THE OTHER PLT MADE THE NECESSARY CORRECTION WITHOUT DISENGAGING THE AUTOPLT. WE LEVELED AT 4000 FT MSL AND NOTHING WAS SAID TO US BY ZMP. WE SUBSEQUENTLY RECEIVED CLRNC FOR THE VISUAL APCH AND LANDED WITHOUT INCIDENT. A PREVENTIVE MEASURE COULD BE TAKEN BY ALLOWING 1 PLT TO FLY WHILE THE OTHER COMMUNICATES OR HAVING THE PLT WITHOUT THE MEDICAL BECOME MORE KNOWLEDGEABLE ABOUT THE ACFT SYS. HOWEVER; THE ROOT OF THE PROB STEMS FROM THE OTHER PLT'S REFUSAL TO UPGRADE HIS SKILLS WHILE DENYING THE NEED TO SPLIT COCKPIT DUTIES. ALSO; HE SHOULD BE WILLING TO SPEND THE MONEY TO KEEP HIS AVIONICS EQUIP IN TOP SHAPE SO SMALL PROBS LIKE THIS DON'T CREATE BIGGER ONES.