It shouldn't surprise us that countries routinely keep an eye on what other countries are doing. Normally, these surveillance activities go unnoticed by the general public -- by definition, reconnaissance missions are not highly publicized.


Photo courtesy U.S. Department of Defense
An EP-3E spy plane

In this edition of HowStuffWorks, we will take a look at the highly-sophisticated surveillance plane EP-3E ARIES II (Airborne Reconnaissance Integrated Electronic System II) and see how it collects information.

Listening In
Military officials have likened the EP-3E to a vacuum cleaner in the sky that uses state-of-the-art equipment to suck up electronic communications, including telephone calls, e-mail, ship-to-shore relays, faxes and satellite transmissions. Basically, the surveillance plane’s main task is to eavesdrop on targeted areas, process the findings and send the information to American military commanders.


Photo courtesy GlobalSecurity.org
The EP-3E spy plane is the ears of U.S. surveillance operations.

The EP-3E is equipped with some of the most advanced surveillance equipment in the world. Most of the plane’s systems are classified, but there is some information known about the surveillance equipment.


Photo courtesy U.S. Department of Defense
A radome is attached to the spy plane's underbelly.

The plane is equipped with sensors, receivers and dish antennas to capture electronic signals. There are two compartments, one on the top and one on the bottom of the plane, that house antennas. The EP-3E is also equipped with an AN/APX-134 radar antenna and a radome, which are located in a specially-modified cargo bay, according to GlobalSecurity.org. The radome is a dome-like shell underneath the plane. It houses the radar antenna and is transparent to radio-frequency radiation.

The Plane and Crew
In the 1990s, the Navy had 12 Lockheed-Martin P-3Cs converted into EP-3E ARIES II aircraft. These new planes were designed to replace the aging ARIES I aircraft, which were built in the late 1960s and early 1970s. Modifications to the EP-3E began in 1996, and the last aircraft was delivered in 1997. EP-3Es have been used for reconnaissance in support of several military operations, including support of NATO forces in Bosnia and joint forces in Korea.


Photo courtesy GlobalSecurity.org

The EP-3E has four Allison T56-A14 turboprop engines, each generating 4,900 shaft horsepower to propel the plane to an average cruising speed of about 345 mph (555 kph). The four propellers, four-bladed Hamilton-Standard 54H60-77s, convert the engine's shaft horsepower into thrust. The plane is built with five fuel tanks, four wing tanks and one auxiliary tank. The auxiliary tank is a bladder-type tank located in the lower fuselage.

EP-3E Aries II
Wingspan
99 feet 6 inches
(30.36 meters)
Height
34 feet 3 inches
(10.42 meters)
Length
105 feet 11 inches
(32.28 meters)
Engines
four Allison T56-A14 turboprop engines
Crew
24
Range
3,000 miles
(4828 km)
or 12 hours
Max. Speed
350 knots
(402 mph / 648 kph)

The unarmed plane is operated by a 24-person crew, which includes three pilots, one navigator, three tactical evaluators, one flight engineer, equipment operators, technicians and mechanics. The plane has 19 crew stations and a total seating capacity of 24.