The travel industry bids farewell to one of the best-known figures at the Civil Aviation Authority today when David Moesli, deputy director of the consumer protection and markets group, retires after four decades at the regulator.

Moesli has been a central figure in the oversight of the air tour organiser’s licence (Atol) regime and consumer financial protection since the 1980s and played a leading role in managing the biggest failures the UK travel industry has seen – International Leisure Group in 1991, XL Leisure in 2008 and Monarch in 2017.

He has worked at the CAA almost since its inception in 1972, joining the authority in the mid-1970s.

Moesli initially worked in the authority’s economic regulation group at a time when the CAA regulated UK air fares and issued route licences to UK carriers on both domestic and international routes.

The subsequent deregulation of EU aviation saw the CAA’s role modified.

Moesli moved into the consumer protection group in the 1980s, where he was initially responsible for Atol licensing and met all new Atol applicants.

By the end of the 1980s, he was also responsible for dealing with Atol failures.

In March 1991 Moesli was centrally involved in the CAA’s handling of the failure of International Leisure Group (ILG), triggered by the first Gulf War.

The group, comprising leisure carrier Air Europe and tour operator Intasun, was the UK’s second-largest holiday business at the time. Despite ILG going into administration well ahead of the summer when few customers were abroad, the CAA had to arrange large numbers of refunds to holidaymakers.

Through the 1990s, Moesli became increasingly involved in the development of the Atol regulations, publishing guidance to the industry on “What is a package holiday?” as new technology and trading methods fuelled the rise of ‘dynamic packaging’.

He worked on changes to the financing of Atol protection and introduction of the Atol Protection Contribution (APC) on holiday bookings in April 2008.

In September the same year, Moesli played a major role in managing the biggest travel group failure and repatriation up to that time when XL Leisure Group went into administration.

The XL failure, at the end of the summer season, involved the repatriation of 43,000 holidaymakers and led to a substantial revision of the Atol arrangements.

In its aftermath, Moesli led the CAA team which developed the Atol Certificate to provide consumers with evidence that their booking is financially protected and introduced Flight-Plus Atols to protect holidays provided outside the Package Travel Regulations.

Subsequent consumer research suggested the changes led to improved public awareness of Atol and the protection it offers.

Moesli was involved in managing yet another a major failure, the biggest to date, when Monarch ceased trading last October with 100,000 customers overseas and some 300,000 forward bookings.

Despite the scale of the operation, the CAA handled the repatriation arrangements entirely itself for the first time, commissioning a fleet of almost 60 aircraft deployed over a fortnight.

Richard Moriarty, deputy chief executive of the CAA and director of the consumers and markets group, paid tribute to Moesli, saying: “David has been a leading member of the CAA team, dedicating his career to protecting consumer rights.

“We thank him for his service, and we all wish him well for the future. He leaves behind a strong team passionate about working with the travel industry to the benefit of consumers.”

Moriarty is due to take over as CAA chief executive this summer.