<sod >The US planes - two P3 Orion maritime patrol aircraft - were called in to fill what defence experts have described as a âgapping chasmâ in Britainâs anti-submarine capability following the scrapping of the Nimrod patrol aircraft fleet in 2010.< eod>< sod > Two American P3 Orion maritime patrol aeroplanes were called in to fill what defence experts described as a âgaping chasmâ in Britainâs anti-submarine capability following the scrapping of the RAFâs Â£4bn fleet of Nimrod surveillance aircraft in 2010.< eod>