AAIB Report: Boeing 737-8200, EI-HET, 4 December 2023
Go-around followed by level bust and loss of control, London Stansted Airport, 4 December 2023
EI-HETs approach from radar data, showing path before TO/GA switch activation (yellow track), and subsequent track (orange track). 3° ILS G/S illustrated by purple line
After an unstable ILS approach, a manually flown go-around (GA) was initiated at 1,940 ft amsl and 3.6 nm from touchdown. During the approach the mode control panel altitude display was set to 100 ft, but not reset to the missed approach altitude (MAA), prior to the GA being commenced. In the GA the aircraft committed a level bust as it climbed through the MAA of 3,000 ft amsl. Upon recognising this the PF pitched the aircraft down and entered a descent, having reached a maximum altitude 4,030 ft amsl. During the descent the aircraft reached a nose-down attitude of 17.7° and 295 KIAS, with Flaps 5 extended before a recovery and climb was initiated, during which its lowest recorded height was 1,740 ft agl. After the recovery was commenced the EGPWS warning sounded. The entire event occurred with the aircraft in IMC.
Prior to the GA the MAA was not checked by either pilot and during the GA the PF was fixated on the flight directors and expected them to command the aircraft to level off.
There have been several serious incidents which occurred during go-arounds with similar factors to that found in this investigation involving EI-HET. Although EI-HET is a Boeing 737-8200 [MAX], the incident could have occurred in any variant of the Boeing 737, or any other type of aircraft with similar autopilot and flight director systems.
As a result of this serious incident the operator has taken three safety actions including informing its pilots about this event and introducing a Discontinued Approach procedure.