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Blackbird Mach 3 Duet − M-21 “Blackbird” + D-12B Tagboard rare pair, 1 of 2

21 April 2014

Blackbird Mach 3 Duet − M-21 “Blackbird” + D-12B Tagboard rare pair, 1 of 2


Lockheed M-21 and D-21B Tagboard − photo by Joseph May

Lockheed’s M-21/D-21B Tagboard in the Main Gallery of the Museum of Flight − photo by Joseph May

The Museum of Flight has a beautiful pairing of Mach 3+ aircraft created for high value Cold War reconnaissance missions, the Lockheed M-21 as well as D-21 drone — the M-21 (known by Lockheed as “Archangel” and by the USAF as  “Oxcart”, now known most often as “Blackbird”) was the mothership to the drone which has the codename Tagboard.  The M-21 design is modified from the A-12 (the direct ancestor to the SR-71 ) externally differentiated by a second cockpit, the Launch System Operator’s position — making it difficult indeed to determine if one is looking at an M-21 or an SR-71 unless the D-21 is mounted atop the fuselage. The D-21 Tagboard shares in the Blackbird lineage with its titanium construction and a design to live in the Mach 3+ extremely high altitude regime — not briefly visiting it. Unlike the M-21, it was powered by a ramjet engine (Marquardt  XRJ-43) and intended as a one shot vehicle — giving an idea how valuable recce information can be and the costs associated with the Cold War. The M-21, of course, would lift the D-21 to altitude and speed whereupon the D-21’s engine would be started and, with the three M-21/D-21 engines at full power the drone would release and ease upward, between the closely neighboring vertical fines of the M-21, through the mothership’s Mach 3 shockwave. Easy to envision but the aeronautical physics were daunting. After a few successful releases a catastrophic accident occurred during a release in which both aircraft were lost as well as one of the crew. This ended the M-21/D-21 program with a mothership change to a B-52H with modifications to the D-21. All remaining Tagboards were modified to the D-21B design by the addition of dorsal shackles (for mounting to the Stratofortress wing pylons), a 20% increase in the vertical fin area and ventral mounting points to attach a booster rocket (needed to propel the drone to ramjet operational speeds).


Lockheed M-21 and D-21B Tagboard − photo by Joseph May

A closer view of  the rare pairing of the Lockheed M-21/D-21B Tagboard exhibit − photo by Joseph May

Lockheed M-21 and D-21B Tagboard − photo by Joseph May

Lockheed M-21/D-21B Tagboard − photo by Joseph May

Lockheed M-21 and D-21B Tagboard − photo by Joseph May

The intelligent end of the M-21/D-21B Tagboard duo − photo by Joseph May

Lockheed M-21 and D-21B Tagboard − photo by Joseph May

Lockheed M-21 was a two seat version of the A-12 (the 2nd position is for the launch system operator) and made it externally very much alike the SR-71 − photo by Joseph May

Lockheed M-21 and D-21B Tagboard − photo by Joseph May

The business end of the Lockheed M-21/D-21B Tagboard strategic reconnaissance assembly − photo by Joseph May

Lockheed M-21 and D-21B Tagboard − photo by Joseph May

The Lockheed M-21/D-21B Tagboard pairing had three high tech engines (all three used JP-7 fuel) for continual operation at Mach 3 and higher − photo by Joseph May

John L. Little (Asst. Curator and Research Team Leader/Museum of Flight) was more than kind to clarify why M-21 has a D-21B mounted atop rather than a D-21 and it is simply that there are no D-21 Tagboards as all existing ones had been modified to the D-21B. Additionally, both aircraft are on loan from the National Museum of the U.S. Air Force. More from Mr. Little in the Wednesday post which emphasizes the D-21B Tagboard.

Next Wednesday, this two part photo essay addresses the D-21B.



7 Comments leave one →
  1. 21 April 2014 12:16

    WOW!!!! You weren’t kidding about a great lens!! WITHOUT QUESTION…THESE are FANTASTIC shots…incredible light positioning…dimension..contrast..and unique!

    • travelforaircraft permalink*
      21 April 2014 18:56

      Yes, I was lucky and owe so much thanks to the building’s design firm since there was so much quality light streaming through the more than generous windowed area. The images were taken both lenses, a 14mm wide angle and a 24-105mm zoom.

  2. 21 April 2014 12:19

    ALSO!!!…Shots 1-2-4 and ESPECIALLY FIV!! … forgot! …..add DYNAMIC to the latter! P:-)

  3. 21 April 2014 12:35

    OOPS!…Sorry_#1_….instead,meant 1-2-3-6 and _ESPECIALLY_ SEVEN!!! .SEVEN because it makes the the subject airplane as well as the airplanes in the background and foreground look like they’re REALLY flying!

    Sorry _#2_..because was so EXCITED about the image favs that I didn’t recheck before sending!

    • travelforaircraft permalink*
      21 April 2014 18:58

      No sweat, I’m happy you enjoy the photos. Luckily the M-21/D-21B sits on the sunken floor of the Main Gallery which gave me an unusual opportunity to shoot from just above the level of the cockpit from a set of stairs.

  4. Bruce Kay permalink
    22 April 2014 17:26

    Ah, one my favorites. I did a bit on engineering support on the J-58 which powered the YF-12A through the A-12, M-21 and SR-71. Incredible engine to see run at night on a P&WA test stand. How it shook your body! Ear muffs with ear plugs were not enough, keep you mouth closed!

    The F-12 was to be a air superioriority fighter and was configured with 20mm and internally nested AAMs. At high altitudes and speed it could take three western states to turn 180 degrees (an exaggeration stated often among Pratt engrs) killed off the fighter designation. The YF-12A had a sharply cut fuselage chine for the guns.

    Bruce Kay

    Date: Mon, 21 Apr 2014 05:07:53 +0000

    • travelforaircraft permalink*
      22 April 2014 20:21

      Cool. The Museum of Flight has a J-58 on display and I took images of it but what hit me was how small it is compared to how much power it delivered, of course it is on display without afterburner stages. I should post a photo once I go back and learn about the magical engineering done on the J-58, especially with the inlet cones. The engine for the D-21 drone was taken back from the museum since it had a radiation hazard associated with some of the metal alloys used in the engine. It would be nice to see that one in comparison, though needing to produce less thrust than the J-58, being a pure ramjet.

      I think the abbreviated chines on the YF-12A also had a bit to do with the nose radar installation, but am not sure. It’s challenging to think of the YF-12A and what could have been. I think one of the main challenges, aside the turn radius you noted, would have also been the overtake speed in consideration of entering the missile firing envelope and flying past the target not long after missile launch.

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