A Cessna 650 Citation III corporate jet was destroyed in an accident near Trigorial, 11 km west-southwest of Roma-Ciampino Airport (CIA), Italy. Both crew members were killed. The airplane was chartered to carry out a medical flight to Cagliari to pick up a patient for transplant surgery at Bologna. But first the jet had to be flown from its home base at Roma-Ciampino Airport to Bologna Airport (BLQ) to pick up a medical team. At 05:54, shortly before departed, Ciampino Tower cleared flight 301 for a PEMAR 5 ALFA Standard Instrument Departure. Following a right hand turn after takeoff from runway 15, the jet was to fly towards the coastline at a heading of approx 240ø. The flight took off from runway 15 at 06:00. After contacting the Roma Radar controller, the crew were received clearance to “fly direct to Bolsena, climb level 240, no speed restriction.” This meant that the crew could continue the right hand turn after takeoff to a heading of 336ø for a direct course to Bolsena. About half way the turn was discontinued. The airplane climbed in a shallow left hand turn which progressively became steeper. Altitude was lost and the airplane struck terrain nose down. CAUSE (translated from Italian report): The cause of the accident was due to an impact with the ground resulting from the loss of control of the aircraft by the captain, who was also the PF. It appears very likely that during the initial phase inadequate attention was replaced by a phase of spatial disorientation, resulting in a loss of situational awareness, which prompted an inadquate intervention on the flight controls by the PF, resulting in total loss of control of the aircraft (having accentuated the tilt to the left wing, instead of leveling the aircraft). It is reasonable to assume that the PF, based on the conviction of being in a right turn for Bolsena in IMC night conditions, misinterpreted the unusual turn, using the controls in order to accentuate the bank angle to the left, drastically reducing the vertical component of lift. This turn has consequently caused the aircraft to assume an attitude of increasing bank, a condition that has been aggravated by the continued application on the controls of a positive load factor in order to stop the sudden loss of altitude, without first leveling the wings. Or the aircraft is stabilized in a pronounced downward spiral to the left. The first officer (PNF), engaged in the management of navigation equipment, has created the unusual turn of the aircraft in conjunction with the commander (PF). Nevertheless, the considerable gradient of experience on the airplane and hierarchy within the organization between the captain and the first officer has probably prevented him to intervene in a more directive or authoritative way in the recovery phase of the situation. Also contributing to the outcome of the event was the lack of detail in the definition of the duties of the crew procedures and inadequate adherence to the basic principles of CRM/MCC, with reference to the monitoring and statement of the navigation modes active, navigation procedures and in particular to the lack of requests for inclusion of turns and routes, the deficiency in the performance of controls and optimization of automation that can lighten the workload in a time unfavorable from the point of view of the circadian rhythm and IMC night. In this respect, it seems fitting to remember the problem of spatial disorientation, although known and studied for decades, is still relevant, and that the only way to counter it is the application of proper use of instruments in compliance with the basic principles of CRM/MCC, which should be part of the normal operating procedures of an operator. This is especially true when working outside of normal circadian rhythms, when it is most easily seen a slowing of cognitive processes.