Ben Rich was in the radar room with the technician when the technician turned to Rich and said that he wasn’t getting ANY return so the model must have fallen off the pole. Rich looked and it was still there!
In the early 1970s, a Defense Advanced Researched Projects Agency (DARPA) study brought to light the extent of vulnerabilities of U.S. aircraft and their on-board equipment to detection and attack by adversaries, who were deploying new advanced air-defense missile systems. These systems integrated radar-guided surface-to-air missiles (SAMs) and air-launched radar-guided missiles, all networked with early-warning, acquisition, and targeting radars, and coordinated within sophisticated command and control frameworks.
To mitigate these growing threats, DARPA embarked on a program to develop strategies and technologies for reducing radar detectability, including the reduction of radar cross section through a combination of shaping (to minimize the number of radar return spikes) and radar absorbent materials; infrared shielding, exhaust cooling and shaping, and enhanced heat dissipation; reduced visual signatures; active signature cancellation; inlet shielding; and windshield coatings.
In the mid-1970s, DARPA oversaw the development of HAVE Blue, the first practical combat stealth aircraft, which made its first test flight by the end of 1977. This led to the procurement by the U.S. Air Force of the F-117A stealth fighter.
As shown by the picture in this post, during the HAVE Blue development Lockheed placed a model of the aircraft on a pole outside on the Radar test range in Nevada to test its Radar Cross Section (RCS).

‘When the F-117 (aka Have Blue and eventually, “The Wobbly Goblin”) was still being designed, Ben Rich, at that time head of Lockheed’s Skunk Works, took a large-scale model of the aircraft to a radar test facility to determine how stealthy it really was. Rich tells this story in his Autobiography Skunk Works. (BTW, a great read),’ Joe Shelton, Author and Pilot, explains on Quora.
‘They placed the model on the “pole” to begin the test.
‘Rich was in the radar room with the technician when the technician turned to Rich and said that he wasn’t getting ANY return so the model must have fallen off the pole.
‘Rich looked and it was still there!
‘Rich knew then that they had something special with the Have Blue design.’
They were shocked at one point when they did get a return off the model. A bird was sitting on it.
Shelton concludes:
‘BTW, the Wobbly Goblin moniker came from the fact that is wasn’t the most stable aircraft to ever have flown. Maybe just the opposite.’
Eventually, the F-117 became operational in October 1983.

Photo credit: Lockheed Martin