He blames the mistake on too many missions with too little sleep, and although he was able to maintain control of the aircraft, the error could have had disastrous consequences.
He's the right man to study the problem for the military. After several missions, he says, he was just "numb."
But that nagging question returns. What do you do about it?
Some jobs are so demanding it's hard to find time for lunch, let alone a nap. And few workplaces have a bed available for weary employees.
And there's that old cultural bugaboo.
"The social connotation of someone who naps is lazy, slothful," said Stanford's Howard. "Attitudes toward people who nap are hard to break."
But now there's a growing body of scientific evidence that should wake up a nation, and a world, to an increasingly dangerous situation.