FTW82AA299

7-Seat acft took off with 4 adults & 8 children aboard. Acft rotated at about 2000 ft down rwy & climbed in a flat nose high attitude before settling into 30 ft trees about 4223 ft from point of lift-off. Acft oscillated violently 2 or 3 times in the pitch axis during the 20-30 sec flt. Acft was about 445 lbs over max gross weight & CG was 4.26 inches aft of the aft limit. On 6/9/82 the plt took a checkride to have a "centerline thrust only" restriction removed from his multi-eng rating. 59 of his 62 hrs multi-eng were as copilot. He had no formal C-414 training & had recd only 2 hrs of instruction in conventional multi-eng acft. He had never been required to perform wt/bal computations in his military flying or any FAA exam or checkrides. Co management did not comply with insurance stipulations which required plt of theflt to attend a Cessna flt training school, nor did the plt satisfy the minimum hr requirements. FAA cert examiner lost cert on 7/10/82, history of incomplete or substandard checkrides. Occupants died of thermal burns & smoke inhalation.