In the early days of aviation, pilots learned to fly by instinct. But in low visibility, instinct was worse than useless—it was deadly. Finding a technical solution did not take long; overcoming the fliers’ seat-of-the-pants mystique did.
The idea seemed fantastic: Dig a tunnel a quarter mile long under enemy territory without being detected and listen in on secret communications. In the end it went off without a hitch. Almost.
