What happened
On 28 October 2003, a DHC-8-311 Dash 8, registration G-BRYW, was performing a passenger flight near Aberdeen, Scotland. While being radar vectored for an approach to Runway 34 at a controlled speed of 230 kt, the aircraft descended through 7,000 feet and entered a cloud layer. During this period, the crew had only intermittent visual contact with the ground, and the weather radar was not in use.
As the aircraft entered the cloud, it was subjected to a heavy jolt followed by further turbulence. This instability caused the aircraft's speed to exceed limits, triggering the overspeed warning horn. The pilot initially attempted to manage the situation by reducing engine power, but the warning persisted. The pilot then increased the propeller RPM to assist in slowing the aircraft. The aircraft exited the cloudbank approximately thirty seconds later and completed the landing without further complications.
The investigation
The investigation examined the flight conditions and the aircraft's response to the turbulence. It was noted that while the seat belt sign was active and the cabin crew had been notified of the approaching landing, the cabin had not yet been officially confirmed as secure. The investigation also reviewed the local meteorological conditions, noting that the low-level weather forecast for the region had previously indicated the potential for moderate turbulence within cloud formations.
Findings
- The aircraft encountered significant turbulence while descending through 7,000 feet.
- The turbulence led to an overspeed condition that required manual intervention via power and propeller RPM adjustments.
- Two members of the cabin crew sustained minor injuries due to the intensity of the turbulence and required hospital treatment.
- There were 24 passengers on board, none of whom were injured.