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Lockheed Have Blue

Lockheed Skunk Works · Stealth Technology Demonstrator / F-117 Predecessor · USA · Cold War (1970–1991)

The Lockheed Have Blue was a U.S. classified stealth-aircraft technology demonstrator built by Lockheed Skunk Works under DARPA's Experimental Survivability Testbed (XST) programme. Its first flight in December 1977 proved that a practical, combat-useful low-observable aircraft could be designed and flown. Have Blue led directly to the F-117 Nighthawk, the first frontline stealth strike aircraft, which entered service in 1983. Two Have Blue prototypes were built; both were lost in flight accidents during the 1978–1979 test campaign, but the programme had already established the feasibility of fielding low-observable combat aircraft.

Have Blue was a single-seat demonstrator roughly 38 ft (11.6 m) long with a 22.5-ft (6.9 m) wingspan. Empty weight was around 8,950 lb and maximum take-off weight 12,500 lb. Power came from two General Electric J85 turbojets of about 3,000 lbf each, giving a top speed near 600 mph (subsonic). The airframe's defining feature was its highly faceted exterior — flat polygonal panels in place of conventional curves, engineered to redirect radar returns into narrow, predictable lobes. Other distinctive elements included inward-canted twin vertical stabilisers, a blended wing-fuselage shape, an F-104 Starfighter cockpit canopy, and parts borrowed from existing aircraft to keep classified prototyping costs down. The resulting radar cross-section was orders of magnitude smaller than that of any contemporary aircraft.

For Kids — a shorter, friendlier version

Lockheed Have Blue was a secret American stealth-fighter test plane. It was built by Lockheed's Skunk Works in the late 1970s to test stealth ideas. Have Blue first flew in 1977 and led directly to the F-117 Nighthawk, the world's first operational stealth fighter.

Have Blue is small: 38 feet long with a 22-foot wingspan, smaller than a school bus. Two General Electric J85 jet engines pushed it to 600 mph, faster than most race cars. The plane has a strange faceted (flat-paneled) shape with angled surfaces that reflect radar beams away from the source.

Only two Have Blue test planes were built. Both crashed during testing in 1978 and 1979, but the stealth ideas were proven before the crashes. Test pilots ejected safely from both crashes. The crashes destroyed the only Have Blues, so no original Have Blue survives today.

Have Blue's success led to the F-117 Nighthawk, the first stealth fighter to fly combat missions. The F-117 entered service in 1983 and fought in Iraq and the Balkans. Have Blue's faceted shape inspired the F-117, B-2 bomber, and many other modern stealth aircraft. The Have Blue project was kept secret for years.

Fun Facts

Have Blue was kept secret for many years; the public didn't know it existed until 1990.
Only two Have Blue test planes were ever built.
Both Have Blues crashed during testing, but both test pilots ejected safely.
Top speed is 600 mph, faster than most race cars.
The plane has a strange faceted (flat-paneled) shape that scatters radar beams.
Have Blue led directly to the F-117 Nighthawk stealth fighter.
No original Have Blue survives; both crashed and were destroyed.

Kids’ Questions

What is stealth?

Stealth means hard to detect on radar. Most aircraft show up clearly on radar screens, letting enemies find and shoot them. A stealth plane is shaped to reflect radar beams away from where they came from, making it nearly invisible. Have Blue's flat-paneled shape was the first design to test this idea on a flying aircraft.

Why so secret?

If America showed off Have Blue, the Soviet Union would have copied the ideas and built their own stealth planes. By keeping it secret, America had a head start on stealth technology by 10+ years. The F-117 was also kept secret until 1988. Today most countries know how stealth works, but specifics about each plane's design are still secret.

Why did both crash?

The first Have Blue crashed in 1978 when its landing gear got bent on a hard landing. The pilot tried to fly back to base but the gear failed completely; he had to eject. The second Have Blue crashed in 1979 when a hydraulic line ruptured, causing engine failure. Both crashes were normal flight-test risks, not stealth-related problems.

Variants

Have Blue HB-1001 (first prototype, 1977): First prototype. Maiden flight 1 December 1977 from Groom Lake (Area 51), Nevada. Lost in a flight accident on 4 May 1978; the pilot ejected safely. Completed a classified flight-test campaign before the loss.
Have Blue HB-1002 (second prototype): Second prototype. Lost on 11 July 1979 during radar-cross-section flight testing. Pilot Lt. Col. Ken Dyson ejected safely. Both prototypes were lost in similar engine-failure circumstances.
F-117 Nighthawk (frontline successor): Frontline stealth strike aircraft derived directly from Have Blue. Service entry 1983, with combat use through the Cold War, Operation Desert Storm and beyond. See the separate F-117 entry.

Notable Operators

U.S. Air Force / DARPA (former classified): Sole programme sponsor. Two Have Blue prototypes were flown by the Lockheed Skunk Works flight-test team from Groom Lake (Area 51), Nevada, between 1977 and 1979, under a classified programme that included radar-cross-section evaluation in flight. Both prototypes were lost in accidents, but the programme still proved that fielding a radar-evading combat aircraft was feasible.
Preservation / museums: No surviving Have Blue prototypes — both were destroyed in flight accidents in 1978 and 1979. Programme documentation and a handful of components are held in U.S. aerospace heritage collections, though much of the record remains classified as of 2026.

Frequently Asked Questions

What was Have Blue's role in stealth development?

It was the breakthrough demonstration. Have Blue was the first practical proof that a combat-useful aircraft could be built with a sharply reduced radar cross-section. Three engineering advances stood out: (1) faceted-surface design grounded in Pyotr Ufimtsev's 1962 Soviet paper 'Method of Edge Waves in the Physical Theory of Diffraction', which Lockheed engineer Denys Overholser turned into a workable radar-cross-section prediction method; (2) integration of radar-absorbent materials (RAM); and (3) engine-exhaust shielding combined with other signature-reduction features. Have Blue's radar cross-section was orders of magnitude smaller than that of conventional aircraft, and the F-117 Nighthawk applied its lessons to a frontline strike platform.

Who was Pyotr Ufimtsev?

A Soviet electromagnetic engineer and mathematician. His 1962 paper 'Method of Edge Waves in the Physical Theory of Diffraction' supplied the mathematical foundation for calculating the radar cross-section of complex shapes. The Soviet government dismissed the work as having no military value, on the assumption that radar-evading aircraft were impossible, and the paper was published openly and translated into English. Lockheed engineer Denys Overholser found it and applied its methods to Have Blue and the F-117 Nighthawk. The irony is that openly published Soviet research enabled the U.S. stealth breakthrough that would erode Soviet air defences for decades. Ufimtsev later emigrated to the United States and worked on U.S. stealth-aircraft programmes.

Why were both Have Blue prototypes lost?

Engine and flight-control problems. HB-1001 was lost on 4 May 1978 after engine and flight-control issues during low-speed flight and landing; pilot Bill Park ejected safely. HB-1002 was lost on 11 July 1979 after an engine fire during high-altitude radar-cross-section testing; Lt. Col. Ken Dyson ejected safely. Neither loss was catastrophic for the programme — by the time of the second crash the classified test objectives had largely been met and F-117 development was already underway. Have Blue accepted high flight-test risk in exchange for the stealth breakthrough it produced.

Where was Have Blue tested?

At Groom Lake (Area 51), Nevada — the U.S. classified flight-test facility. Have Blue flew there to preserve secrecy, as did the F-117 Nighthawk and other Skunk Works programmes that followed. Area 51 has hosted U.S. classified aerospace testing for decades, including the U-2, A-12, SR-71, Have Blue, F-117, RQ-170 Sentinel and other classified types. Most Area 51 activity remains classified through 2026, and the base continues to shape both U.S. aerospace heritage and aviation-enthusiast culture around classified programmes.

What followed Have Blue?

The F-117 Nighthawk. After Have Blue's classified breakthrough, Lockheed Skunk Works developed the frontline F-117, which first flew in 1981 and entered service in 1983. F-117 combat use included 1989 Panama (Operation Just Cause), the 1991 Gulf War (Operation Desert Storm, with heavy strikes against Iraqi targets) and 1999 Yugoslavia (Operation Allied Force, where one F-117 was downed by a Yugoslav SA-3 Goa missile). The type retired in 2008 after 25 years of service. Later stealth platforms — the B-2 Spirit (Northrop), F-22 Raptor (Lockheed Martin), F-35 Lightning II (Lockheed Martin) and B-21 Raider (Northrop Grumman) — all build on the foundation Have Blue laid down.

Sources

National Museum of the U.S. Air Force — Have Blue
Wikipedia — Lockheed Have Blue — CC BY-SA.