Page:CAB Accident Report, United Airlines Flight 16.pdf/11

 At the time of the accident, aircraft NC 16086, equipped as above described, held a currently effective airworthiness certificates which authorized the transportation of 21 passengers and a crew of four and the operation of the airplane at a standard gross weight of 24,400 pounds and a provisional gross weight of 25,200 pounds.

It appears from the record that the airplane and its equipment had received the overhauls, inspections, and checks which are provided for in company practice and approved by the Civil Aeronautics Administration. The wings, fuselage, and center section are required to be overhauled at or before the completion of each 5,000 hours of flight time and an engine overhaul is required at or before the completion of each 625 hours. The empennage, landing gear, wheels, brakes, tail wheel assembly, nacelles, control system, hydraulic system, electrical system, aircraft accessories, engine accessories propellers, aircraft engines, engine instruments, fixed plane radio equipment fuel and oil system, and oil tanks and lines are all required to be overhauled at each engine overhaul (625 hours' flight time). Aircraft NC 16086 had accumulated about 2,299 hours since the last overhaul of the wings, fuselage and center section, and had accumulated about 520 hours since the last overhaul of the engines, propellers, and other parts and equipment.

In addition to the overhauls described above, the airplane and its equipment is, as a matter of practice, given other routine periodic inspections and checks. United requires three types of inspections. The number one inspection is merely a visual inspection of the airplane and its equipment given at service stations along the route as the trip progresses. The number two check is an inspection which is performed after each 25 to 40 hours of flight time. It consists of uncowling and inspecting the engine and inspecting the