New rules are to be introduced on the size of oil workers travelling to and from offshore installations by helicopter.
Passengers with a shoulder width of 22 inches or more will be classed as “extra broad” and will have to sit next to a similarly large helicopter window.
It follows a Civil Aviation Authority (CAA) review of helicopter safety.
Concerns were raised about larger passengers being able to escape from a crashed aircraft quickly.
The changes come after a study revealed the average oil worker had risen in weight by close to 20% over the past 30 years.
There were concerns that size had become a risk factor in helicopter accidents, with larger workers finding it harder to leave helicopters during emergencies due to the size of the exits.