The Boeing 737 jet – which was carrying 67 passengers and six crew – was flying into the Scottish airport from Majorca in September last year when air traffic controllers asked for a landing delay.
According to a report issued by The Air Accidents Investigation Branch (AAIB), the aircraft initially climbed and then descended for 57 seconds before action was taken.
The report said crew likely became "overloaded" by their high workload during the go-around. The AAIB said it was a "serious" incident and the crew’s lack of flying hours during the pandemic was one of a combination of factors that led to them not noticing the descent. The aircraft landed safely.
A spokesperson for Tui said: "We have worked closely with the AAIB throughout this investigation. We can confirm we have adopted all recommendations and learnings from the report alongside air traffic control and the aircraft manufacturer, which are now also binding for all other operators and partners.
"The health and safety of our customers and colleagues is always our number one priority and we would like to provide reassurance that the safety of the aircraft was assured throughout this flight.
"We have always provided training that exceeds all regulatory requirements, and this also includes the additional refresher and recency training completed by all pilots prior to flights being undertaken post-Covid."