John Dockerty, father of Major Christopher Dockerty, died aged 96. His son was among 29 killed in the RAF Chinook ZD576 crash in 1994. The helicopter departed from RAF Aldergrove in Northern Ireland bound for Fort George near Inverness when fog caused the incident.

The crash was first attributed to pilot error. A 2011 review overturned that finding. John Dockerty campaigned for further answers until his death.

The Chinook Justice Campaign states John Dockerty was the last surviving parent of a crash victim. His daughter Nicola Rawcliffe, a campaign member from Diss in Norfolk, said her father questioned his son's death for 32 years and did not blame the pilots, as shown in his letters.

Rawcliffe added that her father campaigned persistently and expressed frustration at the lack of resolution from government and Ministry of Defence. She noted the added burden on parents seeking explanations from the state.

John Dockerty released videos backing the campaign. Ministers met campaigners in December. They have a scheduled meeting with victims minister Alex Davies-Jones this week.

A Ministry of Defence spokesman said the accident underwent six inquiries, including an independent judge-led review.