RAF planes grounded after technical fault Six Boeing Sentry E3D aircraft are temporarily out of service as a precautionary measure after the fault was discovered on a routine inspection at RAF Waddington in Lincolnshire. A Ministry of Defence spokeswoman said: "A routine inspection on an E3D aircraft at RAF Waddington has revealed a technical issue with one of the in-service aircraft. Routine E3D operations have been temporarily suspended pending further engineering investigation. There is no loss of operational capability. The spokeswoman stressed that the Sentry is one of a range of aircraft capable of conducting surveillance and other options, including five Sentinel R1 aircraft, are being utilised.