A US fighter plane has become the first military aircraft crash site in the UK to receive protected status – 77 years after it came down during the Second World War.

The Lockheed P-38 Lightning – nicknamed the Maid of Harlech – and its pilot crash-landed in the sea off the North Wales coast in September 1942.

Cadw, the Welsh Government’s historic environment service, has designated the plane and its crash site as a scheduled monument for its historic and archaeological interest.

The aircraft’s preserved hull is two metres beneath the seabed and has only been visible three times since the crash – in the 1970s, 2007 and 2014 – when sea and sand conditions were favourable.

The pilot was Second Lieutenant Robert F Elliott, then 24, of Rich Square, North Carolina, who flew from Llanbedr in Gwynedd, North Wales, on a gunnery practice mission before getting into difficulties and crashing.

He walked away from the crash-landing, but was reported missing in action a few months later while serving in Tunisia.

His nephew Robert Elliott, himself a retired US Navy veteran and a member of the 49th Fighter Squadron Association, from Kingsport, Tennessee, said he was “honoured and delighted” by the recognition.

Mr Elliot, who visited the site in 2016, said: “My uncle was among those brave and expert fighter pilots who served with distinction during World War Two.

“My visit to the site with my wife Cathy in 2016 was very moving and emotional.

“The 49th Fighter Squadron, to which this aircraft was assigned, has a rich and storied history dating back to 1941 and is still active today as the 49th Fighter Training Squadron. I look forward to returning to Wales and offer my support of this historic designation.”

Matt Rimmer, a local aviation historian, said: “I feel it not only acknowledges the significance of this particular aircraft in a historical context, but also the important role played by Wales in the air war against Nazi Germany and the thousands of air crew from many countries who trained here, many of whom lost their lives either in accidents during training or subsequently in combat.”

Wales’s deputy minister for culture, sport and tourism, Lord Elis Thomas, said: “This site is of international significance and I’m delighted that this designation underlines its special qualities as well as protecting it for the benefit of future generations.

“As we have seen following Remembrance events over the weekend, sites such as this represent events which must not be forgotten. Wales will always remember and respect all those who contributed to securing the peace we are so fortunate to enjoy today.”