AP 118 · No. 10 Section II · Aircraft Plate 268 / 322

Plate 268 of 322 · Cold War · Drone launch aircraft and Mach 3 reconnaissance drone

Lockheed M-21 & D-21

M-21 60-6940 with D-21, painted as Lockheed M-21 60-6940 (Article 134), the only surviving M-21, carrying a D-21 reconnaissance drone on its back as displayed at The Museum of Flight, Seattle, Washington: a two-seat development of the A-12 Blackbird with a second cockpit for the launch control officer in place of the A-12’s camera bay, a long flat-sided forebody edged by sharp chines, a thin delta wing with two Pratt & Whitney J58 engines in nacelles at mid-span, each with a pointed inlet spike, two inward-canted fins on the nacelles and a pointed tail cone; the D-21 sits level on a tall narrow pylon on the spine, with its own spiked ramjet inlet, chined fuselage, thin swept wing and single fin: the M-21 in bare titanium with black on the whole nose, the chines, every wing edge, the tail cone and the inlet spikes, ‘U.S. AIR FORCE’ and the star-and-bar on both sides of the fuselage, ‘06940’ in black on a grey-blue panel on both fins, ‘134’ in white on the nose chines and red blanking plates in the exhausts; the D-21 overall black with small white stencils and a light grey nozzle, as photographed at Seattle (no M-21 or D-21 is in a UK museum; shape from A-12 and D-21 three-views and the SR-71 drawing, checked against photographs; the stencil wording is not legible in any photograph and is generic, and the museum’s jack stands are left out).

3D model

Turn it over

A procedural model built in Blender from published dimensions, drawings and photographs, painted as Lockheed M-21 60-6940 (Article 134), the only surviving M-21, carrying a D-21 reconnaissance drone on its back as displayed at The Museum of Flight, Seattle, Washington: a two-seat development of the A-12 Blackbird with a second cockpit for the launch control officer in place of the A-12’s camera bay, a long flat-sided forebody edged by sharp chines, a thin delta wing with two Pratt & Whitney J58 engines in nacelles at mid-span, each with a pointed inlet spike, two inward-canted fins on the nacelles and a pointed tail cone; the D-21 sits level on a tall narrow pylon on the spine, with its own spiked ramjet inlet, chined fuselage, thin swept wing and single fin: the M-21 in bare titanium with black on the whole nose, the chines, every wing edge, the tail cone and the inlet spikes, ‘U.S. AIR FORCE’ and the star-and-bar on both sides of the fuselage, ‘06940’ in black on a grey-blue panel on both fins, ‘134’ in white on the nose chines and red blanking plates in the exhausts; the D-21 overall black with small white stencils and a light grey nozzle, as photographed at Seattle (no M-21 or D-21 is in a UK museum; shape from A-12 and D-21 three-views and the SR-71 drawing, checked against photographs; the stencil wording is not legible in any photograph and is generic, and the museum’s jack stands are left out). Drag to orbit, scroll or pinch to zoom · download .glb (1.4 MB)

Data plate

Specification

First flight, number built and top speed are for the whole family (M-21 mothership & D-21 reconnaissance drone); engine, crew and dimensions are for the M-21 60-6940 with D-21 modelled here.

History

The M-21 & D-21

After Francis Gary Powers’s U-2 was shot down over the Soviet Union in May 1960, the United States promised to stop flying piloted aircraft over Soviet territory. The CIA’s Mach 3 A-12, then being built by Kelly Johnson’s Skunk Works at Lockheed, would still need a pilot, so in October 1962 Lockheed began work on an unmanned alternative: a reconnaissance drone that would be carried to speed and height on the back of an A-12 and released to fly a preset course over its target. The project was named Tagboard in late 1963. Two A-12 airframes were completed as launch aircraft, designated M-21: 60-6940 (Article 134) and 60-6941 (Article 135). In place of the A-12’s camera bay each had a second cockpit for a launch control officer, and a pylon on top of the fuselage carried the drone.

The drone, the D-21, was built largely of titanium, like its carrier, and was shaped like a small Blackbird, with chines, a thin swept wing and a single fin. A Marquardt ramjet drove it at more than Mach 3.3 at about 90,000 ft. It had no landing gear: at the end of its flight it was to drop its camera and film in a capsule for an aircraft to catch in mid-air, and then destroy itself. Captive flights on the M-21 began on 22 December 1964, and the first launch came on 5 March 1966. The drone had to separate in the disturbed air above the M-21 at more than three times the speed of sound, and on the fourth launch, on 30 July 1966, the D-21 hit the tail of 60-6941 and both broke up over the Pacific. The pilot, Bill Park, was rescued, but the launch control officer, Ray Torick, drowned.

Kelly Johnson cancelled launches from the M-21. The D-21s were modified as the D-21B, which was carried under the wings of a Boeing B-52H and boosted to speed by a solid-fuel rocket. Under the name Senior Bowl, four operational missions were flown over China between November 1969 and March 1971, but not one returned usable film, and the programme was cancelled on 23 July 1971. Thirty-eight D-21s were built. The remaining drones were stored at Davis-Monthan, Arizona, and only became public knowledge in the late 1970s. No M-21 or D-21 is in a UK museum.

This airframe

M-21 60-6940 (Article 134) with D-21

60-6940The airframe modelled

60-6940, Lockheed Article 134, is the only surviving M-21. It flew in the Tagboard trials, 80 flights and 123.9 hours in all, and after the programme ended it spent nearly twenty years in storage at Lockheed’s Palmdale plant with the surviving A-12s. It is now displayed at The Museum of Flight, Seattle, Washington, with a D-21 drone, D-21B number 510, mounted on its pylon. The model shows the pair as photographs of them at Seattle do: the M-21 in bare titanium, a patchwork of slightly brighter and duller sheets, with black on the whole nose, the chines, every wing edge, the tail cone and the inlet spikes; ‘U.S. AIR FORCE’ and the star-and-bar on both sides of the fuselage; ‘06940’ in black on a grey-blue panel on both fins; ‘134’ in white on the nose chines; and red blanking plates in the exhausts. The D-21 is overall black with small white stencils and a light grey nozzle. The shapes come from three-views of the A-12 and the D-21 and from the SR-71 drawing used for the SR-71 in this Hangar, checked against photographs. The stencil wording on the drone cannot be read in any photograph and is generic, and the aircraft stands on its wheels rather than on the museum’s jack stands.

Where to see one

Not on charge

The only surviving M-21, 60-6940, with a D-21 on its back, is at The Museum of Flight, Seattle. None is in a UK museum.

All 322 plates

Profiles and models are procedural interpretations built in Blender from published dimensions, three-view drawings and photographs of each airframe. Treat the museum aircraft as the reference.