Boeing NT-43A Radar Test Bed Sighted in Death Valley


On a trip to Death Valley a few years ago, I spotted a Northrop B-2 Stealth Bomber flying in formation with the highly modified Boeing NT-43A. It was a new one on me. The Air Force operates a modified NT-43A as a Radar Test Bed (RTB) with radar imaging gear on its nose and tail in radomes that are 9 feet long and over 6.5 feet in diameter.

The pair cruised around the valley in a racetrack pattern about 7,000 feet above the ground. I pulled out my 400mm telephoto to snap these shots as they made their closest pass.

NT-43A Radar Test Bed, 73-1155 making radar images of a Northrop-Grumman B-2 Spirit at an altitude of about 7,000 feet over Death Valley on January 24, 2003. Death Valley is utilized as a natural radar test facility. It is over a mile deep and a hundred miles long, shielded from all radar transmitters, providing an environment free from radar interference.

The RTB is used to make radar images of stealthy aircraft. The images are used to evaluate the effectiveness of their stealth characteristics, to reveal the rate of degradation of the radar deflecting and absorbing components as the aircraft age, and to determine the effectiveness of maintenance and repair methods.

NT-43A, 73-1155 carries Boeing construction number 20702. It first flew on July 2, 1974 and was delivered to the Air Force ten days later. It served initially as a navigation trainer. It was retired from that role and delivered to AMARC on September 25, 1997. Identified as TH002, it was sealed with spraylat and sat in the desert sun for over two years. 73-1155 was selected for modification as the Radar Test Bed. It was pulled out of storage at AMARC and delivered to the Ogden Air Logistics Center (OO-ALC) at Hill Air Force Base, Utah for refurbishment on November 19, 1999.

Joe Baugher's serial number web site

AMARC Experience web site

73-1155 was flown to an aircraft maintenance and modification facility at Goodyear, Arizona in March 2000 for the installation of the enormous radomes on its nose and tail. DENMAR, Inc. was the prime contractor for the modification of the NT-43A. It is run by Denys Overholser, who wrote the "Echo 1" software used to evaluate the stealth characteristics of the Have Blue and F-117A Stealth Fighter. Under contract to DENMAR, Inc., the Lockheed Skunk Works designed and fabricated the mounts for radar installations on the nose and tail of the RTB at Air Force Plant 42 on the grounds of the Palmdale Airport in California. The mounts are made primarily of carbon epoxy honeycomb sandwich with machined aluminum fittings. They are 16.5 feet long and 6.2 feet in diameter. After conversion, it was rolled out on February 22, 2001. Its first flight in its new configuration was flown on March 21, 2001.

GlobalSecurity.Org's Boeing T-43 page

Cactuswings web site

Visiting Phoenix web site

Over Death Valley on January 24, 2003.

Study in black and white.

The flight operations contractor for the NT-43A is EG&G, operator of the "Janet Airlines" 737s and former T-43As that are used to transport workers to and from secure facilities in the Nellis AFB ranges. The lack of public sightings of the RTB suggests that the NT-43A operates from one of those secure facilities. It was sighted inside a hangar at Goodyear in December 2004, but otherwise it is rarely seen.

Update: Joe Decker sighted the NT-43A in the company of a Northrop-Grumman B-2A Spirit over Mesquite Flat Dunes in Death Valley on Thursday March 23, 2006.

This photo shows the NT-43A at Goodyear, Arizona shortly after the completion of its modifications. Note the optical or infra-red sensor housings on the top of the nose and tail radomes.


The NT-43A RTB performs a function once performed by a modified Douglas A-3 Skywarrior. From 1991 to 1993, Douglas TA-3B Skywarrior, BuNo 144856 was equipped with the Metratek AIRSAR Synthetic Aperture Radar for making radar images of the Stealth Bomber in flight. It was registered as N160TB and operated by Thunderbird Aviation at Deer Valley, Arizona. The modified Skywarrior and Stealth Bomber were occasionally seen flying a similar racetrack pattern over Death Valley.

NTA-3B, BuNo 144856 is now registered N879RS and operated by Raytheon at Van Nuys. It is currently being used to test radar for future generations of stealthy combat aircraft.

Link to Metratek's AIRSAR system page.

Link to the A-3 Skywarrior Association web site's page with pictures of the A-3 with the AIRSAR installation.


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