Boeing E-3 Sentry

Boeing E-3 Sentry
Name	E-3 Sentry
Caption	A United States Air Force E-3 Sentry in flight.
Type	Airborne early warning and control (AEW&C)
National origin	United States
Manufacturer	Boeing
First flight	25 October 1975
Introduction	March 1977
Status	In service
Primary user	United States Air Force
Number built	68
Developed from	Boeing 707

Boeing E-3 Sentry is an American airborne early warning and control (AEW&C) aircraft developed by Boeing as a modification of the Boeing 707 airliner. It is distinguished by its large rotating radar dome mounted above the fuselage, which provides all-weather surveillance, command, control, and communications. Entering service with the United States Air Force in 1977, the E-3 has been a cornerstone of NATO and allied air defense networks, with variants operated by several nations including the Royal Air Force, French Air and Space Force, and the Royal Saudi Air Force.

Development and design

The development of the E-3 Sentry was driven by the United States Air Force's need for a modern airborne warning and control system to replace the aging Lockheed EC-121 Warning Star. Following the cancellation of the Boeing 707-based Boeing 707-320B commercial airliner program, the airframe was selected for modification. The key mission system is the Westinghouse AN/APY-1/2 radar, housed within a 30-foot diameter rotating radome that provides a 360-degree view over land and water. The aircraft's IBM CC-1 computer system and extensive communications suite, including Have Quick secure radios and Link 16 datalinks, allow it to coordinate fighter aircraft and direct surface-to-air missile batteries. The design team integrated these systems to create a platform capable of tracking airborne and maritime targets at ranges exceeding 250 miles, a capability proven during the Cold War against the threat posed by the Soviet Air Forces.

Operational history

The E-3 Sentry achieved initial operational capability with the United States Air Force's 552d Air Control Wing at Tinker Air Force Base in 1977. Its first major combat deployment was during the Gulf War in 1991, where it played a pivotal role in the air campaign of Operation Desert Storm, controlling thousands of coalition sorties and contributing to the high success rate of USAF McDonnell Douglas F-15 Eagle fighters. NATO E-3A components, operating from Geilenkirchen Air Base in Germany, have been continuously deployed for missions over the Balkans during the Kosovo War, over Afghanistan for ISAF operations, and in Eastern Europe following the Russian annexation of Crimea. The aircraft has also seen extensive service in ongoing operations such as Operation Inherent Resolve against the Islamic State of Iraq and the Levant.

Variants

The primary variants are defined by their operational users and system upgrades. The E-3A was the initial production version for the United States Air Force. The E-3B denotes USAF aircraft upgraded with enhanced computer processing, JTIDS, and improved IFF systems. The E-3C featured additional secure communications. The E-3D is the designation for the aircraft operated by the Royal Air Force, which are based on the Boeing 707-320C airframe. The E-3F is the variant used by the French Air and Space Force. NATO operates a fleet of E-3A Component aircraft, which are collectively owned and maintained by the alliance. The Royal Saudi Air Force operates the E-3A variant, sometimes referred to as the KE-3A in its tanker configuration.

Operators

Current military operators include the United States Air Force, which maintains the largest fleet. The NATO Airborne Early Warning and Control Force operates a multinational fleet from its main operating base at Geilenkirchen Air Base. Other national operators are the Royal Air Force of the United Kingdom, the French Air and Space Force, and the Royal Saudi Air Force. Previous operators included the Chilean Air Force, which leased aircraft. The Japanese Air Self-Defense Force operates the Boeing E-767, a similar AEW&C platform based on the Boeing 767 airframe, rather than the E-3.

Specifications (E-3 Sentry)

* **Crew:** Flight crew of 4 (pilot, co-pilot, navigator, flight engineer) plus 13-19 mission specialists * **Length:** 152 ft 11 in (46.6 m) * **Wingspan:** 145 ft 9 in (44.4 m) * **Height:** 41 ft 9 in (12.7 m) * **Powerplant:** 4 × Pratt & Whitney TF33-PW-100A turbofan engines * **Maximum speed:** 530 mph (855 km/h) * **Range:** 4,000 mi (6,400 km) * **Service ceiling:** 41,000 ft (12,500 m) * **Radar:** Westinghouse AN/APY-1/2 pulse-Doppler radar

Aircraft on display

Several retired E-3 airframes are preserved in museums. A former United States Air Force E-3B (serial 77-0354) is on display at the Museum of Aviation near Robins Air Force Base in Georgia. Another early test aircraft, an EC-137D (the prototype designation, serial 71-1407), is part of the collection at the National Museum of the United States Air Force at Wright-Patterson Air Force Base in Ohio. NATO also maintains a retired E-3A for static display purposes at Geilenkirchen Air Base.

Category:Airborne early warning and control aircraft of the United States Category:Boeing aircraft Category:Cold War aircraft of the United States Category:Four-engined jet aircraft