The Ministry of Defence has again been forced to call for US military assistance to help track a suspected Russian submarine spotted off the Scottish coast.

Two US Navy aircraft were drafted in to conduct anti-submarine patrols along with a Royal Navy Frigate near the home of the UK’s Trident fleet at Faslane, Argyll.

Critics claimed the US deployment raised questions about the UK’s ability to protect its nuclear submarines following the scrapping of the RAF’s £4bn fleet of Nimrod surveillance aircraft in 2010….

The operation follows a deployment in November of two US Navy Orions, a Royal Canadian Air Force Aurora and a French Dassault Atlantique….

This week, US crews coordinated with the anti-submarine frigate HMS Somerset, which has been operating off Scotland for a month.

A source at RAF Lossiemouth is reported to have disclosed that the US aircraft, known as Skinny Dragons and usually based in Hawaii, have been flying up to two missions a day since New Year’s Eve.

Image: HMS Ambush, July 15, 2013 (photo: UK Ministry of Defense)