ALRI System Now Operational at Otis

ENT AFB, COLO. -- A newly devised airborne radar surveillance I system providing better and much faster advanced warning against sneak enemy aircraft attack upon the United States has been accepted and now is in full operation, Lt. Gen. Herbert B. Thatcher, commander of ADC, announced early this month.

The new airborne system, called ALRI (airborne long-range input), is carried aboard huge Lockheed EC-121H radar aircraft hundreds of miles out over the Atlantic Ocean.

The 551st AEW&C Wing at Otis AFB, Mass., a unit of the 26th Air Division, is the only Air Force organization to have this aircraft in operation. Commander of the 551st Is Col. Rudolph B. Walters. The organization also was the first to work with and modify the pilot project before ADC accepted it.

It was pointed out that the new systems are not in new aircraft. The ALRI modification has been made to RC-121D aircraft, which have been used at Otis since 1955. EC-121H is a new designation for the aircraft now filled with the modern electronic equipment but flying the same missions.

The new system made it possible for the Air Force to decide recently that Texas Tower radar stations off the coast of New England could be decommissioned without loss of adequate radar surveillance coverage.

This month's announcement by General Thatcher marked a milestone in the three-year program.

ALRI is an automated means whereby early warning capability of the airborne seaward extension forces of ADC are expeditiously processed and utilized by SAGE system direction centers.

An ADC spokesman said, "in operation the airborne search radar detects targets and feeds this information Into a computer In the aircraft. The computer constructs target messages for-transmission to the ground communications group, also a part of the system. This target information is then fed directly Into the central direction centers of the SAGE system in a matter of seconds." ADC offensive fighters and missiles also at Otis are immediately available to Intercept and destroy the target if necessary.

The Air Force Logistics Command at Wright-Patterson AFB, Ohio, played a major role in development of the ALRI system. The Burroughs Corporation, Paoli, Pa, produced ALRI, as a completed system.



New Otis AF Air Defense Takes Over


OTIS AIR FORCE BASE, Sept. 14 - A new airborne, automated' detection and communications system was announced today by Air Defense Command Lieutenant General Herbert B. Thatcher.

The entirely new concept in semi-automatic air defense extends early warning coverage over the horizon, beyond the range of offshore-based radar and line of sight communications. The new electronics system, known as ALRI - Airborne Long Range Input - attained full Air Force operational status this week following extensive air defense operational testing.

The ALRI system capability was a significant factor in the Air Force's decision earlier this year to discontinue the use of the controversial Texas Towers located off the New England coastline, without the loss of adequate defense radar surveillance.

ALRI aircraft, designated EC-121H is a modified version of the Lockheed Warning Star, RC-121D, which has flown the over- water air defense mission at Otis since 1955.

The 551st AEW and C Wing and its airborne squadrons commanded by Colonel Rudolph B. Walters, maintained continued coastal radar surveillance during the months required to change over to the ALRI EC-121H and to test the unique system tinder actual operational conditions.

The acceptance of ALRI, climaxes a four year Air Force development and testing program.


The aircraft commander briefs the first pilot on emergency procedures prior to taxiing out for takeoff. airborne radar operator at the no. 1 radar position adjusts the controls for the automatic transmission of radar information from the search antenna to the data processor. The radio operator taps out signals on the key to relay weather and aircraft clearance messages over long range radios. Precise calculations by the flight engineer allow the aircraft to remain on patrol for a maximum amount of time. _

 The navigator (r) logs the progress of the airplane during flight and advises the pilot of the course to be flown while a communications-navigation aids technician adjusts the settings on the equipment. Height finding operator relays target altitude information at the request of the SAGE center. THE 'NEW EC-121H -- The 551st AEW & C Wing at Otis AFB, Mass. has the only EC-121H aircraft In operation In the Air Force. The aircraft now carries the new ALRI system In a bubble located just in back of the cockpit. Pictured above Is the old RC-121D aircraft. (USAF Photo)OUR ARCTIC ASSIGNMENT--The Iines of communications for the 26th Air Division now stretch more than seven and one half million square miles. The division's new Goose Air Defense Sector has responsibility for the Arctic area.

 The radar crew chief maintains constant radio contact with the SAGE direction center to assure a continuous flow of radar data. An airborne data processor technician removes one of the many "black boxes" which he repairs in flight. A second radar man turns his set to standby as radar information begins automatic processing. Radar technicians tune the search radar sets to allow maximum radar surveillance while on patrol.

Air Defence Sectors   The navigator (r) logs the progress of the airplane during flight and advises the pilot of the course to be flown while a communications-navigation aids technician adjusts the settings on the equipment. 






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