ON THE DAY OF DEPARTURE THE PLT HAD RECEIVED A 30 MIN FAMILIARIZATION FLT UPON COMPLETION OF THE SUPERSTAR CONVERSION. EMPHASIS WAS DIRECTED TO ENG GAGES, FUEL FLOW & COUNTER, & POWER SETTINGS. THE FLT WAS FLOWN AT 5,500 FT. THE PLT THEN OBTAINED A WX BRIEFING & FILED A FLT PLAN. ABOUT 15 MIN AFTER DEPARTURE, WHILE CLIMBING THRU FL 170, THE PLT RADIOED THAT HE HAD LOST BOTH ENGS. THE ACFT WAS SUBSEQUENTLY OBSERVED DESCENDING UNCONTROLLED OUT OF THE OVERCAST. AT ABOUT 1,000 FT AGL THE RIGHT AILERON SEPARATED. THE FUEL BOOST PUMPS WERE FOUND IN THE 'OFF' POSITION. THE AFM STATES THAT THEBOOST PUMPS SHOULD BE ON DURING CLIMB ABOVE 10,000 FT. THE PLT HAD BEEN ENROLLED IN AN AEROSTAR TRANSITION SCHOOL THE PREVIOUS MONTH DURING WHICH A 2-HR COMBINED DEMONSTRATION/FLT EVALUATION FLT WAS CONDUCTED. THE INSTRUCTOR PLT RECOMMENDED FURTHER MULTI-ENG TRAINING.