EP-3 Aries II

EP-3 Aries II

The Lockheed EP-3 is a land-based, signals reconnaissance version of the P-3 Orion, operated by the United States Navy.


A total of 12 P-3C aircraft were converted to replace older versions of the aircraft, which had been converted in the late 1960s and early 1970s. The aircraft is known by the acronym ARIES, or “Airborne Reconnaissance Integrated Electronic System”. and has Signals intelligence (SIGINT) capabilities. SIGNIT is the interception of signals, whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication (electronic intelligence—abbreviated to ELINT). The EP-3E generally has a crew of 24, including linguists, cryptographers and technicians.

The squadrons that flew the EP-3E also flew the Lockheed EC-121 Warning Star from 1962 to 1974 and the Douglas EA-3B Skywarrior from 1960 to 1991. There are 11 EP-3Es in the Navy’s inventory, the last of which was delivered in 1997.


After the cancellation of the EP-X Program, the US Navy has planned to replace the EP-3E Aries II with the MQ-4C Broad Area Maritime Surveillance (BAMS) unmanned aircraft and the MQ-8B Fire Scout unmanned helicopter. All P-3 Orion aircraft assigned to special projects squadrons (VPU) and all EP-3E Aries II aircraft are expected to fully retire by 2025.


  • EP-3A: Seven modified for electronic reconnaissance testing.
  • EP-3B: Least known of all in the P-3 family. Three P-3As (BuNo 149669, BuNo 149673, and BuNo 149678) were obtained by the CIA from the US Navy under Project STSPIN in May 1963, as the replacement aircraft for CIA’s own covert operation fleet of RB-69A/P2V-7Us. Converted by Aerosystems Division of LTV at Greenville, Texas, the three P-3As were simply known as “black” P-3As under Project Axial. Officially transferred from US Navy to CIA in June/July 1964. LTV Aerosystems converted the three aircraft to be both ELINT and COMINT platforms. The first of the three “black” P-3As arrived in Taiwan and were officially transferred to ROCAF’s top secret “Black Bat” Squadron on June 22, 1966. Armed with 4 Sidewinder short range AAM missiles for self-defense, the three “black” P-3As flew peripheral missions along the China coast to collect SIGINT and air samples. When the project was terminated in January 1967, all three “black” P-3As were flown to NAS Alameda, California, for long term storage. Two of the three aircraft (BuNo 149669 and BuNo 149678) were converted into the only two EP-3Bs in existence by Lockheed at Burbank in September 1967, while the third aircraft (149673) was converted by Lockheed in 1969–1970 to serve as a development aircraft for various electronic programs. The two EP-3Bs, known as “Bat Rack”, owing to their period of service with Taiwan’s “Black Bat” Squadron, were issued to the US Navy’s VQ-1 Squadron in 1969 and deployed to Da Nang, Vietnam. In the 1980s these two planes were based at the Naval Air Facility, Atsugi, Japan with the Atsugi VQ-1 detachment. Later, the two EP-3Bs were converted to EP-3E ARIES, along with 10 EP-3As. The 12 EP-3Es retired in 1990s, when replaced by 12 EP-3E ARIES II.
  • EP-3: ELINT aircraft for the Japanese Maritime Self-Defense Force.
  • EP-3E ARIES: 10 P-3As and two EP-3Bs were converted into ELINT aircraft.
  • EP-3E ARIES II: 12 P-3Cs were converted into ELINT aircraft. Last delivered in 1997.
  • EP-3J: Two, modified from P-3As, for FEWSG were uses as simulated adversary EW platforms in exercises; later transferred to the former Tactical Electronic Warfare Squadron 33 (VAQ-33), then transferred to the former Fleet Air Reconnaissance Squadron 11 (VQ-11).


Crew 22
Length 116 ft 10 in (35.61 m)
Wingspan 99 ft 8 in (30.38 m)
Heigh 33 ft 8.5 in (10.274 m)
Wing area 1,300 sq ft (120 m2)
Empty weight 61,491 lb (27,892 kg)
Gross weight
135,000 lb (61,235 kg)
Max take off weight 135,000 lb (61,235 kg)
Power plant (Dry thrust)
4 × Allison T56-A-14 turboprop engines, 4,910 shp (3,660 kW)
Power plant (Thrust with afterburner) 
Maximum speed (Sea level)
Maximum speed (High altitude) 380 kn (440 mph, 700 km/h)
Combat radius
2,200 nmi (2,500 mi, 4,100 km)
Ferry range
4,830 nmi (5,560 mi, 8,950 km)
Service ceiling
28,000 ft (8,500 m)
Rate of climb 2,175 ft/min (11.05 m/s)
Wing loading 103.8 lb/sq ft (507 kg/m2)
Design load factor
a wide variety of ELINT, SIGINT and COMINT systems known as the ARIES Suite


Related Post

Leave a Reply

Your email address will not be published.