[Llarry]

A look at Airborne Early Warning (AEW)...

The U.S. Navy found itself in trouble late in 1944. While dominating the naval war with Japan, the advent of the kamikaze threat, with Japanese pilots and planes using suicidal tactics to attack USN ships, created losses that could not be sustained, particularly as the Allies operated ever-nearer to Japan. Various tactics, such as the stationing of radar picket destroyers well away from high-value ships such as aircraft carriers helped, but then the destroyers became targets themselves for kamikaze attacks.

On a crash basis, the Navy began development of a radar system that could be installed in a carrier plane and flown out from the fleet, extending the radar horizon considerably. The result was a conversion of the TBM torpedo bomber, with a large radar installed where the torpedo/bomb bay had been and with a data link back to the fleet. The war ended before the resulting TBM-3W could make it to the fight, but the airplane entered fleet service in small numbers just after the war. At the same time, the Navy experimented with the same radar installed in B-17 bombers transferred from the Army Air Force (soon to be USAF.) But AEW was still in its infancy and not widely used in the fleet.

The next step was the installation of the same radar in the Douglas AD Skyraider (the A-1 of the Vietnam war era) and finally every carrier had an AEW capability.

At about the same time, a land-based barrier patrol force consisting of large radar-equipped Lockheed Constellations was formed and these flew (boring) barrier patrols off both coasts of the U.S. for years. (There were also radar picket ships in use at the same time and for roughly the same purpose: to guard against attacks on the continental United States by the Soviet Union.) By the 1970s, the whole barrier patrol scheme was abandoned. However, the Air Force also adopted the AEW EC-121 Constellation and these were vital to U.S. operations in the Vietnam war.

Carrier-based AEW took a major step forward in the late 1950s with the introduction of the Grumman E-1B Tracer, a twin-engine derivative of the S-2 Tracker ASW plane. The E-1B was replaced in turn by the turbine-powered, purpose-designed Grumman E-2 Hawkeye, which remains the Navy's carrier-based AEW aircraft today in improved form.

The USAF, having seen the value of the radar planes in Southeast Asia, replaced it's old EC-121 Constellations with a new Boeing 707-based Airborne Warning and Control System (AWACS) E-3 and these remain in service today and are critical to Air Force operations around the world. Several other countries bought the E-3 (the photo is of an RAF E-3D Nimrod.)

While this history has been U.S.-centric, there are other interesting AEW or AWCS aircraft in use around the world. Japan operates Boeing 767-based AWACS and I posted earlier about the Beriev AEW versions of the Russian Il-76.

All of the above radar planes use a rotating antenna. The innovative Israelis have come up with a different approach: fixed phased-array radars giving all-around coverage without rotating. They've fitted these to Boeing 707s as well as the more recent Gulfstream G550, which must take an award as one of the most odd-looking aircraft ever.