The RAF operates seven E-3D Sentry AEW1 aircraft (AWACS) in the airborne surveillance and command-and control role. The aircraft are based at RAF Waddington, where they are operated by Nos 8 and 23 Squadrons as the UK’s contribution to the NATO Airborne Early Warning and Control Force. The E-3D Sentry AWACS also forms one arm of the UK Intelligence, Surveillance, Target Acquisition and Reconnaissance (ISTAR) triad of Sentinel R1, E-3D Sentry AEW1 aircraft and Nimrod R1 aircraft.
Whilst primarily procured as an airborne early warning aircraft, the E-3D has been extensively employed in the Airborne Warning and Control System (AWACS) role. The E3-D Sentry, known to the RAF as the AEW Mk1, is based on the commercial Boeing 707-320B aircraft, which has been extensively modified and updated to accommodate modern mission systems. Mission endurance is approximately 10 hours (over 5000nmls), although this can be extended by air refuelling. The E3-D is the only aircraft in the RAF’s inventory capable of air refuelling by both the American ‘flying-boom’ system and the RAF’s ‘probe-and-drogue’ method.
The normal crew complement of 18 comprises four flight-deck crew, three technicians and an 11-man mission crew. The mission crew comprises a tactical director (mission crew commander), a fighter allocator, three weapons controllers, a surveillance controller, two surveillance operators, a data-link manager, a communications operator and an electronic-supportmeasures operator. The Sentry’s roles include air and sea surveillance, airborne command and control, weapons control and it can also operate as an extensive communications platform.
The aircraft cruises at 30,000ft and 400kts and its Northrop Grumman AN/APY-2 high-performance, multi-mode lookdown radar, housed in the black radome, is able to separate airborne and maritime targets from ground and sea clutter. One E-3D Sentry AEW1 flying at 30,000ft can scan over 312 kms, it can detect low-flying targets or maritime surface contacts within 215nmls and it can detect medium-level airborne targets at ranges in excess of 280nmls. The multi mode radar provides lookdown surveillance to the radar horizon and an electronic vertical scan of the radar beam provides target elevation and beyond-the-horizon operation for longrange surveillance of medium and high-altitude aircraft.
These attributes allow it to determine the location, altitude, course and speed of large numbers of airborne targets. The aircraft’s mission systems can separate, manage and display targets individually on situation displays within the aircraft, or it can transmit the information to ground-based and ship-based units using a wide variety of digital data links.
The communications systems provide the required internal and external communications to support the AWACS command-and-control mission. The aircraft has a multi UHF/VHF/HF radio fit to provide secure digital data links, secure-voice or clear-voice radio communications and secure satellite communications for extended-range operations. A planned upgrade programme will include new mission display-consoles, increased radio and satcom capacity and improvements to the AN/APY-2 radar.
E-3D Sentry AEW1 Specifications
Powerplant: Four CFM 56 2A-3 turbofans
Thrust: 24,0001bs each
Wingspan: 44.98m (147ft 7ins)
Length: 46.68m (153ft 3ins)
Height: 12.7m (41ft 7ins)
Max T/O weight: 151,136kg (332,500lbs)
Max endurance: 11 hours
Max speed: 460kts (530mph)
Max altitude: 35,000ft plus
• Operates in air and sea surveillance and airborne command-and-control roles.
• Crew of 18, including an 11-man missioncontrol crew.
• Flying at 30,000ft it can scan 312 kms at ranges up to 280nmls.
• Multi-mode lookdown radar separates targets from ground and sea clutter.
• Transmits information to ground units or ships using digital data links.