Chapter 26: ►

_The Agricultural Approach_

“And that, gentlemen, is the story of the X-15 to date.” My assistant switched on the lights in the briefing room. The group I was addressing--the fifth that month--was part of an Air Force headquarters inspection team. In aviation circles word of the X-15 was beginning to spread. We were besieged by official delegations from NACA, the Pentagon, and Congress, who wanted to know what it was all about. Charlie Feltz abhorred briefings--they seriously interfered with his work, for one thing--and had dumped this “public relations” chore on me. Through growing experience I developed an hour-long “road show,” complete with slides of charts and artists’ conceptions of the ship, and I thought it was pretty good. I could spout the speech in my sleep and, I think, frequently did.

“Are there any questions?” I concluded.

“I have a question about the seat,” a captain spoke up. “As I understand it, the pilot may spend long hours in the cockpit on the ground before take-off and during flight to launch point. Have you given any thought to a seat cushion, an air-inflatable or foam-rubber base, to add to the pilot’s comfort? Seems to me it’s asking quite a lot for the pilot to sit on cold, hard steel for all that time.”

“Captain, as I believe I pointed out earlier, our overriding consideration in this airplane is saving weight. There are, of course, foam-rubber seat pads and inflatable air cushions under development. There is even an undulating air cushion which gently massages the behind during prolonged flight....”

“Yes,” the captain said. “I have read reports on these projects....”

“Well, any one of these seat pads could weigh as much as a pound, maybe two pounds. In the final analysis this is pure luxury payload. To take it into the air, we must add seven or maybe fourteen pounds to the overall weight of the airplane. Besides, these pads might slip around during ... ah ... shall we say ... the rough portions of the flight profile.

“Now, I’ll tell you what we did about this. We sat down and said to ourselves: ‘Who in this country has had the most experience in keeping someone in a seat under rough conditions over prolonged periods?’ The answer, we found soon enough, was the International Harvester Company, manufacturers of tractors and farm equipment. We learned they had investigated the natural frequency of a man’s spine and how long a spring you should sit him on, and what’s the best shape of the seat, so that he gets the best opportunity to stay on a piece of farm equipment bouncing over rough ground, bearing in mind that a farmer might ride that seat twelve to sixteen hours a day.”

“Is that a fact?” the captain asked in wonderment.

“That’s a fact,” I said. “So you will see that the seat in the X-15 is an exact duplicate of a tractor seat, with apologies to International Harvester. It’s of minimum weight and maximum comfort and will keep the pilot solidly in place in event of rough flight.

“Around here, we call this type of engineering the agricultural approach, getting right down to fundamentals, as basic as land and seed, and figuring the thing out. It’s typical of our thinking on this airplane.”