What happened
On 12 June 2023, a Boeing 737-8K5, registration G-FDZX, was performing a commercial passenger flight from Zakynthos to Manchester Airport. As the aircraft approached Runway 05R, a thunderstorm was moving across the airfield. Although the crew had noted the approaching weather, they continued the approach as they maintained visual contact with the runway.
Upon reaching the decision height of 390 ft, the aircraft entered heavy rain, causing the crew to lose all visual reference to the runway. The crew immediately initiated a manual go-around, disconnecting the autopilot and autothrottle and manually advancing the thrust levers. During the initial climb, the aircraft encountered a sudden 18-knot loss of headwind due to a shifting wind direction. This caused the airspeed to drop rapidly.
In response to the decreasing airspeed, the commander reduced the aircraft's pitch attitude. Because the thrust had not yet been increased to the level required for the new wind conditions, this pitch reduction led to a slight descent, triggering an EGPWS "don't sink" caution. The commander subsequently applied full thrust, allowing the aircraft to regain airspeed and climb away safely. The flight then diverted to Newcastle to avoid the deteriorating weather.
The investigation
The AAIB examined the flight data recorder, cockpit voice recorder, and the operator's flight management data. The investigation focused on the crew's reaction to the loss of visual reference and the subsequent aerodynamic changes. The investigators analyzed the wind conditions, noting a significant shift in wind direction during the go-around phase.
Technical analysis by the aircraft manufacturer highlighted that the pilot's decision to lower the nose was inconsistent with established windshear escape guidance, which recommends maintaining a specific pitch to maximize climb performance. The investigation also explored the psychological impact of the "startle response" caused by the sudden transition from visual to instrument conditions in heavy rain.