Neither pilot of a Ryanair Boeing 737 Max 8-200 noticed that the aircraft was descending from its assigned altitude during a go-around, after the captain wrongly assumed the autopilot and autothrottle were engaged.
The aircraft, inbound from Szczecin on 8 March last year, had conducted a go-around at 15ft during approach to London Stansted’s runway 04.
It levelled at 3,000ft ahead of a left turn which formed part of the missed-approach procedure.
The first officer, who was flying, agreed to set up the flight-management computer for the second approach and temporarily hand over control to the captain.
But the first officer, during the handover, did not mentioned that the autopilot and autothrottle had been disengaged just before the go-around.
“The [first officer] said that this was the first time he had handed over control during manual flight and that he did not know the precise call outs that were stated in the [flight manual],” says the UK Air Accidents Investigation Branch.
It states that the first officer “did not highlight” the fact that he was flying manually and “assumed” the captain realised this.
The inquiry adds that the full go-around procedure – including flap retraction and potential re-engagement of the autopilot and autothrottle – had not been completed before the handover.
After the captain took control, it says, the first officer was loading the flight-management computer, and the captain was monitoring this process.
As a result, neither noticed that the aircraft had started descending after entering the procedural left turn.
The 737 lost 600ft before the captain, having realised the situation, recovered control and climbed back to 3,000ft.
With the captain subsequently deciding to remain as the flying pilot, the jet (EI-HGG) landed without further incident and none of the 178 occupants was injured.
The inquiry says the flying pilot should prioritise monitoring the cockpit instruments, especially if the other pilot is “heads down”.
“Had [the captain] done so, he may have been better placed to notice the descent before the aircraft lost a significant amount of height,” it states, although it adds that the other pilot should also allow time for an instrument review.
“If the [first officer’s] actions needed to be checked or carried out on his behalf, control of the aircraft should have been handed back over.”
