The story of the D-21 Drone and project Senior Bowl, the Most Secret Program ever developed by the famed Lockheed Skunk Works

The Most Secret Program ever developed by famed Lockheed Skunk Works was not the SR-71 Blackbird, but the D-21 Drone and project Senior Bowl

By Linda Sheffield Miller
Jan 15 2023
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At Beale AFB, in California, you would think that the SR-71 Blackbird program would be the biggest blackest deepest secret. You would be wrong. The biggest secret was Project Tagboard/Senior Bowl.

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Project Tagboard/Senior Bowl is a relatively unknown project in the history of Area 51 reconnaissance A-12 aircraft. This project was Top Secret from its inception and during the Senior Bowl part of the project, there were less than 100 personnel cleared to work on it.

Actually, at Beale Air Force Base (AFB), in California, you would think that the SR-71 Blackbird program would be the biggest blackest deepest secret.

But you would be wrong.

The biggest secret was Project Tagboard/Senior Bowl.

According to Air Force Test Center History Office documents, all manned flights over the Soviet Union were discontinued by President Dwight Eisenhower after Francis Gary Powers’ U-2 spy plane was shot down May 1, 1960. However even if the US government was planning on using satellites for reconnaissance, the technology was still a few years away and the Central Intelligence Agency (CIA) determined unmanned drones could fill the gap until satellites became viable.

For this reason in the 1960s the famed Lockheed “Skunk Works” developed the D-21 a highly-advanced, remotely piloted aircraft (RPA) designed to carry out high-speed, high-altitude strategic reconnaissance missions over hostile territory.

The top secret D-21, the high-speed, high-altitude spy drone air launched from the the back of a Mach 3 A-12 aircraft
M-21 and D-21.

According to the document Project Tagboard/Senior Bowl Overview by Road Runners Internationale, Project Tagboard/Senior Bowl was the brain child of Lockheed’s Skunk Works’ Kelly Johnson. It consisted of a drone (D-21) mated to a modified A-12 aircraft (M-21), the combination known as MD-21 (mother/daughter).

The project was first conceived in 1962 when Lockheed’s Kelly Johnson got approval from the CIA to add two aircraft to the existing A-12 assembly line. Known as M-21’s, these aircraft were built with a second crew station for the Launch Control Officer (LCO) and structurally enhanced aft fuselage with a large dorsal pylon to carry the new drone atop the rear fuselage. When attached, the wingtips of the D-21 would have only six inches of clearance with the tops of the vertical stabilizers of the mother ship. This combination was known as the MD-21 (mother/daughter).

The D-21 would be launched from the back of the M-21. Ideally, after conducting its reconnaissance mission it would eject a hatch with photo equipment to be recovered either mid-air or after the hatch landed.

However, on the fourth flight test, the D-21 experienced an “asymmetric unstart” as it passed through the bow wake of the M-21 causing the mothership to pitch up and collide with the D-21 at Mach 3.25. Crewmembers Bill Park and Ray Torick ejected from the M-21, but Torick opened his helmet visor by mistake and his suit filled up with water causing him to drown.

The top secret D-21, the high-speed, high-altitude spy drone air launched from the the back of a Mach 3 A-12 aircraft
B-52 and D-21.

After the accident and after the death of Ray Torick, a test flight engineer, the M-21 launch program was cancelled but testers still believed the D-21 would make a valuable reconnaissance vehicle and decided to launch the drone from B-52Hs under a top secret test program named Tagboard. The new code name for the D-21 project became Senior Bowl.

It was Kelly Johnson, President of Skunk Works, who suggested to use the B-52. As a result of Johnson’s advice two B-52’s were modified: 61#0021 and 60#0036. Both B-52’s are still in the US Air Force (USAF) inventory. The ultra secret 4200 test squadron was formed at Beale.

Only a few of the men that flew the SR-71 had been read into the program: out of necessity one of the few included my father Richard “Butch” Sheffield, SR-71 RSO who had already been read into Oxcart in 1965. In his unpublished book he writes that on the flightline he was with Bob Spencer, SR-71 pilot. They were taxing out when they saw the B-52 with a drone underneath it. Spencer asked ‘What is that under that B-52?’ My Dad responded ‘I have no idea.’ He couldn’t tell Bob Spencer the truth.

These two B-52‘s were kept away at the end of the runway apart from any other operations.

D-21 drone.

The D-21s were used on four flights over communist China but none of these missions fully succeeded.

Two flights were successful, however the imagery could not be recovered from the D-21’s hatch. The other two operational flights ended with one being lost in a heavily defended area and the other D-21 simply disappeared after launch.

The main mission of the D-21 was to fly over China and take pictures of its nuclear weapons test facility in the remote west central of the country near Lop Nor.

The pictures were supposed to be dropped in the ocean and recovered by the Navy. During the Cold War this information was necessary for the defense of the US.

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The fourth and final mission of the D-21 drone took place on Mar. 20, 1971 and was undertaken by D-21 #527. Experts at the 4200th Support Squadron and at Skunk Works concluded that #527 must have malfunctioned. It was thought to have gone down near Lop Nor. This drone is on display in China at their national aviation museum. So we know that it got close to the target.

Senior Bowl lasted from January 1968 until Jul. 15, 1971. Interestingly, after the fall of the Soviet Union, Ben Rich (then retired president of Lockheed’s Skunk Works) finally had an opportunity to tour Russia himself. While in Moscow, the KGB presented Rich with a gift of what they thought were the remains of a stealth fighter that had crashed in their territory. As it turned out, the wreckage was actually pieces and parts of the lost D-21 Drone!

Be sure to check out Linda Sheffield Miller (Col Richard (Butch) Sheffield’s daughter, Col. Sheffield was an SR-71 Reconnaissance Systems Officer) Facebook Pages Habubrats and Born into the Wilde Blue Yonder for awesome Blackbird’s photos and stories.

Photo credit: U.S. Air Force

B-52 Model
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Linda Sheffield Miller

Linda Sheffield Miller

Grew up at Beale Air Force Base, California. I am a Habubrat. Graduated from North Dakota State University. Former Public School Substitute Teacher, (all subjects all grades). Member of the DAR (Daughters of the Revolutionary War). I am interested in History, especially the history of SR-71. Married, Mother of three wonderful daughters and four extremely handsome grandsons. I live near Washington, DC.

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  1. M. Allen Schultz says:

    Linda Sheffield Miller : Thank you for the wonderful article about my projects, written by someone who was closer to them. Creating them from here in ND and then stepping away so others could do their jobs seemed the best way. Sorry to hear the Drone portion did not work as they hoped for – perhaps it was too soon compared to the remote piloting and control systems we have today. One aspect you might not know, and might not be in the history you have access to; I also intended for the Drone to just stay there in it’s natural wind tunnel, and be a Hypersonic engine that would take over for the other two engines, and take the plane even faster. What a wonderful birthday gift you provided; that I could read about even more of my life’s results that I never knew about.

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