Background
On 27 February 2011, a McKinnon G-21G, registration N221AG, was parked at a hangar at Al Ain International Airport. The aircraft was a modified Grumman Goose equipped with turbine engines. Preparations were underway for a test flight followed by a departure to Riyadh, Saudi Arabia, for an autopilot installation and annual inspection.
Sequence of Events
At approximately 12:12 UTC, a mechanic contacted the Al Ain tower and informed the aerodrome controller that the aircraft would depart that evening. The mechanic stated that the departure would not be before 14:00. The controller requested the estimated time of departure and asked if the crew planned a test flight. The mechanic confirmed they wanted to stay in the pattern to ensure everything was "okay" before departure. The controller advised a clearance to operate in the circuit.
At 14:10, the aircraft was pushed out of the hangar. The two mechanics loaded luggage and a bladder fuel tank into the cabin. At 14:17, the aircraft was fueled with 1,898 liters of Jet-A1, 563 liters less than the requested 2,461 liters. At around 15:00, the 28-year-old pilot in command (PIC) and a 61-year-old pilot boarded, occupying the left and right cockpit seats, respectively. The two mechanics sat in the first row of passenger seats.
At 15:44:48, the PIC checked aircraft radios with the ground movement controller (GMC). At 15:55:13, he requested a three-minute delay on the ramp. The aircraft taxied to the holding point of Runway 19. At 16:02:38, the PIC contacted the aerodrome controller for a closed circuit. At 16:05:37, the aircraft was cleared for takeoff. It lifted off and climbed normally. When reaching 300 to 400 feet AGL at approximately the midpoint of Runway 19, the aircraft turned left with a calibrated airspeed of about 130 knots. The turn continued with increasing rate and loss of height. At approximately 16:07:11, the aircraft impacted Taxiway F between Taxiways K and L, with a slight nose-down attitude and left roll. It came to rest about 32 meters from the initial impact point. No emergency was declared. The aircraft was destroyed by impact forces and subsequent fire. All four occupants sustained fatal injuries.
Probable Cause
The Air Accident Investigation Sector determined that the cause of the accident was the PIC's lapse in judgment and failure to exercise due diligence when he decided to enter into a steep left turn at inadequate height and speed. Contributing factors included the PIC's self-induced time pressure to rapidly complete the post-maintenance flight, his desire to rapidly accomplish the requested circuit, his lack of recent experience in the aircraft type, and the flight being SPIFR (Single Pilot IFR) requiring a high standard of airmanship.