Secrets of the Skunk Works

Though an order came down to clean house, an employee hid this A-3 concept model for 45 years. Kelly Johnson originally carried it to a 1958 meeting in a suitcase. Making the tail optional was a rudimentary attempt at stealth; without it, the aircraft would have appeared smaller on radar screens. Nine months later, the concept evolved into the A-12 Blackbird.

In a White House ceremony, President George W. Bush presented the National Medal of Technology and Innovation to the Skunk Works, citing its “record of developing cutting-edge aircraft, technologies, and systems for the U.S. Government.” Sculptor Mico Kaufman designed the three-inch bronze medal. This is the only time it has been awarded to an aerospace company.

Intended for classified briefings, this 1960s wood box holds 100 three- by four-inch glass slides showcasing everything from zero-speed (hover) attack helicopters to Mach 25 spaceplanes. The Aerospaceplane was a classified orbital bomber study, created as planners looked beyond the Mach 6 X-15 toward sustained hypersonic flight. The Skunk Works foresaw requirements for research aircraft to explore spaceplane technologies and define their operational systems.

For every design that makes it into the air, there are thousands that don’t. This one didn’t. The designation was for Variable Sweep, seventh configuration. A two-seat bomber proposed in 2006, it was engineered around a variable-cycle engine that flew efficiently at both subsonic and supersonic speeds. This bomber concept explored the advantages and tradeoffs of swinging versus fixed wings. “Stealth is a fundamental enabler for access to denied areas,” says company director Stephen Justice, “but future bombers will first need to fly very far, arrive very quickly, and then persist. That’s a very conflicting set of requirements, a design nightmare. But that’s where the fun is for us.

This late 1950s helmet belonged to Skunk Works test pilot Ross Cooper. It completed the partial pressure suit worn during the first U-2 flights, and was hand-painted with the company’s then-secret emblem. The helmet’s soft shell protected the cramped cockpit’s low canopy from scratches. For nearly four decades, the skunk was itself a very protected image, never seen outside classified areas.

A May 1975 Skunk Works report, “Progress Report No. 2, High Stealth Conceptual Studies,” includes this early drawing from a stealth aircraft study called Project Harvey (named after the invisible rabbit in the 1950 James Stewart movie); the program eventually led to the F-117. Based on results from D-21 drone flights, Kelly Johnson believed that Little Harvey’s smoothly blended shapes offered the best combination of speed and stealth. Ben Rich, Johnson’s protégé, argued for faceted angles. It was one of the rare times Johnson’s design did not prevail.

U-2 engineers borrowed off-the-shelf hardware whenever possible, like this circular slide rule modified for cockpit mounting. Pilots used it to calculate the airplane’s exact performance, which was critical information when overflying the Soviet Union in an aircraft whose speed needed to be maintained within a five-knot range. It was probably used only in early testing, since its density altitude maxes out at 60,000 feet—two miles below the U-2’s eventual operational ceiling.

In November 1958, Kelly Johnson took a Lockheed JetStar to a secret meeting organized by the CIA in Cambridge, Massachusetts. He carried this blue-print, carefully folded inside the same ordinary suitcase that held his A-3 concept model, to show a panel of experts determined to develop an airplane that would outpace Soviet missile advances.

Engineers used this 24-inch-long model, made from balsa wood and meticulously scribed with India ink, to show placement of the F-117’s internal structure and access doors. The model shop found it nearly impossible to make all the flat surfaces come to a single point on one corner. Engineers later encountered the same difficulty fabricating the prototype on the factory floor.

Project Harvey, an initiative to develop a radar-undetectable aircraft, was followed by a tailless rhomboid design, quickly renamed the Hopeless Diamond when Lockheed engineers discovered that while it was truly stealthy, it was uncontrollable in flight. This drawing shows the outboard wings and single tail that were tacked on to improve stability. The Harvey studies evolved into Lockheed’s Have Blue stealth demonstrator, the direct precursor to the F-117.

Intended as an operational follow-on to the X-33 suborbital spaceplane technology demonstrator, the single-stage-to-orbit VentureStar never left the drawing board. Skunk Works pitched a mission-ready version, carrying a payload of two Militarized Space Planes and 16 Common Aero Vehicles (warhead-equipped hypersonic gliders), to the Air Force with this 20-inch-long stereo lithograph model, made in 1999.

This faded glass slide illustrates a study for a NATO competition, which was seeking a vertical-takeoff-and-landing interceptor to replace the F-104 Starfighter. Power came from the supersonic variant of Rolls-Royce’s Pegasus engine; The notation “PCB” in the description of the propulsion system meant “plenum chamber burning,” an afterburner-like thrust booster for the front fan.

Dated March 1976, this 250-page document gave the Defense Advanced Research Projects Agency a technical summary of the XST, the design that evolved into the Have Blue flying prototype and eventually led to the F-117. It showed program personnel that every stealthy configuration choice involved tradeoffs, affecting radar signature, flight stability, cost, and performance. Crammed with engineering data, it was not declassified until 2012—and there are still pages off-limits to the public.