The Nimrod aircraft took off on an exercise Search and Rescue (SAR) sortie from its base at RAF St Mawgan. It was carrying in the bomb bay, as part of the SAR equipment, a normal load of 5 inch reconnaissance flares. In accordance with normal practice, the first navigator switched the flare’s release units to live shortly after takeoff. Some 30 seconds later a cockpit indicator warned the crew of a fire in the bomb bay. The captain immediately instructed the co-pilot to fly the aircraft back to base while he transmitted a MAYDAY call and informed the rest of the crew. During the return flight ground witnesses saw the Nimrod trailing smoke, with several burning flares, a parachute and other objects falling from the aircraft. The aircraft landed safely. Although the fire services quickly extinguished the intense fire, the aircraft was extensively damaged. CAUSE: “The accident was caused by a reconnaissance flare becoming detached from its carrier and subsequently igniting in the bomb bay . How it came to be released could not be positively determined.”