What happened
The crew of G-AGZA was granted permission to depart for Glasgow following a period of restricted operations at Northolt. During the initial climb phase, the aircraft failed to gain altitude effectively and entered a sustained stall condition. The plane subsequently collided with a residential structure in Ruislip, located north of the airfield, coming to rest on its roof. The impact did not ignite a fire, and the cabin remained largely intact. All five occupants sustained injuries, with the captain suffering serious harm. A four-month-old infant inside the damaged house was found unharmed.
Findings
Investigations revealed that the crew failed to adequately prepare the aircraft for flight by neglecting to remove accumulated snow. The fuselage, wings, elevators, and tail surfaces were covered in snow during departure. This contamination significantly reduced aerodynamic performance, increased drag, and rendered the airspeed insufficient for safe takeoff under the prevailing weight conditions.