Skunk Works

Other Voices

Denys Overholser

In October 1975, Ben Rich informed me that we and Northrop had won the first phase of the competition and would now contest against each other’s designs in a high noon shoot-out at the Air Force’s radar test range in White Sands, New Mexico. The two companies were each given a million and a half dollars to refine the models and told to be ready to test in four months.

The government demanded competition on any project, but that Hopeless Diamond shape was tough to beat. We built the model out of wood, all flat panels, thirty-eight feet, painted black. And in March 1976 we hauled it by truck to New Mexico. The White Sands radar range was used to test unarmed nuclear warheads, and their radars were the most sensitive and powerful in the free world.

The tests lasted a month. I never did see the Northrop model because under the ground rules we tested separately, on different days. In the end we creamed them. Our diamond was ten times less visible than their model. We achieved the lowest radar cross sections ever measured. And the radar range test results precisely matched the predictions of our computer software. This meant we could now confidently predict radar cross section for any proposed shape, a unique capability at that point in time.

The range was as flat as a tabletop; the pole downrange was in a direct line with five different radar antenna dishes, each targeting a different series of frequencies. The model was mounted atop the pylon and then rotated in front of the radar beam. Well, two very funny things happened. The first day we placed our model on the pole, the pole registered many times brighter than the model. The technicians had a fit. They had thought their poles were invisible, but the trouble was nobody had ever built a model that was so low in radar signature to show them how wrong they really were. Their pole registered minus 20 decibels—okay as long as the model on top was greater than 20. But when the model was registering an unheard-of lower value, the pole intruded on the testing. An Air Force colonel confronted me in a fit of pique: “Well,” he snorted, “since you’re so damned clever, build us a new pole.” I thought, Oh, sure. Build a tower that’s ten decibels lower than the model. Lots of luck.

In the end we had to team up with Northrop to pay for the poles, because the Air Force wasn’t about to foot the bill. It cost around half a million dollars. And I designed a double-wedge pylon which they tested on a 50,000-watt megatron, state of the art in transmitters, that could pick up an object the size of an ant from a mile away. On that radar the pole was about the size of a bumblebee. John Cashen, who was Northrop’s stealth engineer, was in the control room when they fired up the radar. And I overheard their program manager whisper to John: “Jesus, if they can do that with a frigging pole, what can they do with their damned model?”

Ben called me every day for the latest results. The model was measuring approximately the equivalent of a golf ball. One morning we counted twelve birds sitting on the model on top of the pole. Their droppings increased the radar cross section by one and a half decibels. Three decibels is the equivalent of doubling its cross section. And as the day heated on the desert, inversion layers sometimes bent the radar off the target. One day, while using supersensitive radar, the inversion layer bent the beam off the target, making us four decibels better than we deserved. I saw that error, but the technician didn’t. What the hell, it wasn’t my job to tell him he had a false pattern. I figured Northrop probably benefited from a few of them too, and it would all come out in the wash.

But then Ben Rich called me and said, “Listen, take the best pattern we’ve got, calculate the cross section level, and tell me the size of the ball bearing that matches our model.” This was a Ben Rich kind of idea. The model was now shrunk down from a golf ball to a marble because of bad data. But it was official bad data, and no one knew it was bad except little me.

So Ben went out and bought ball bearings and flew to the Pentagon and visited with the generals and rolled ball bearings across their desktops and announced, “Here’s your airplane!” Those generals’ eyes bugged out of their heads. John Chasen was livid when he found out about it because he hadn’t thought of it first. “That goddam Ben Rich,” he fumed. And a few months later, Ben had to stop rolling them across the desk of anyone who wasn’t cleared.