Hey Pilot, open the doggone window!

Wednesday, September 26th, 2012

Science-fiction author Jerry Pournelle was an aeronautical engineer at the dawn of the Jet Age, when he was asked to study smoke at high altitudes:

The Internet is abuzz with stories of how stupid Romney must be because he said something about aircraft ventilation. The occasion was a heavy smoke incident on a flight that his wife took. The Huffington Post went insane with laughter about how Romney was so stupid he wondered why you can’t just open the windows on a jet plane. Clearly he is not qualified to be President, and in fact must be so incompetent as to need a keeper. Of course the first assumption is that the Huffington Post and other media must be joking; but apparently they were not.

Next comes the ‘news’ that Romney was joking. Probably graveyard humor on hearing that his wife had been in danger but was now safe. Whether or not Romney was joking, which should have been obvious — it’s not as if he has never been aboard a jet airplane. He may even have owned one — it’s not quite so trivial a question as you might at first think. As it happens I know something about this from a long time ago.

This was once a serious topic for discussion and study. As it happens I was in the Human Factors and Reliability Group at Boeing when the 707 went commercial. Boeing’s marketing methods for the 707 were simple: the Company brought the Chief Pilots of most of the major airlines to Seattle as guests to watch the Gold Cup 90-mile unlimited hydroplane boat races from the Boeing barge on Lake Washington. The Gold cup is run in heats, with a major break between heats for mechanical overhaul, and during one of the recesses, without prior announcement, the watching crowd (and the TV audience of course) was told to Look Up! Here comes the new Boeing 707 Stratocruiser! At which point Chief Test Pilot Tex Johnston brought the Dash 90 — the flying prototype of the 707 — down the length of Lake Washington, and at about 700 feet he barrel rolls just in front of the Boeing barge. The result was that within a week every senior pilot in America was in his President’s office panting “We gotta have one!” and Boeing had about a hundred orders within a month.

Boeing began building and selling the 707. Howard Hughes came up to Boeing Field in his private Constellation, and camped out at the end of the runway (with about 17 young lady starlets and stewardesses) while negotiating the design and purchase of a fleet of them. The commercial jet age began.

But within a month of the first commercial passenger jet flight — people paid a premium price for a jet ticket, since it cut hours off cross country flight times — they had a cabin pressure loss above 40,000 feet. The passenger oxygen masks deployed, but people didn’t know how to use them. The pilots did an emergency dive to 7500 feet, then a more gradual descent, so that there was enough oxygen content and cabin pressure for breathing without oxygen masks, but the FAA gave Boeing notice that within 30 days we had to give sufficient evidence that the passenger oxygen system was safe or the 707 fleet would be grounded. Dr. Don Stuhring, the Boeing Central Medical flight surgeon, and I as a human factors engineer were given the task: come up with evidence acceptable to the aviation medicine and human factors professional community, and do it fast.

We spent the next three weeks at the University of Washington altitude chamber. Of course Boeing had a good altitude chamber — in fact a better one than the UW — but we wanted the UW people involved in the experiments including data collection so there would be no question of the accuracy of the data. We took several rides to 40,000 feet a day — actually on most I took them, with Dr. Stuhring outside to preside if there was medical need, which there never was — and flew flight profiles of emergency cabin pressure losses, rapid descent to 10,000 feet and gradual descent to 5,000, with the subjects using the emergency oxygen system while we monitored blood oxygen content, heart rate, and other data. In those days collecting physiological data from non-restrained subjects was very difficult, and I had to use a bank of analog computers to filter out electronic noise. The subjects were paid volunteers from the UW student body, faculty, and staff, and included young and old, sick and healthy. It was a heck of a month, but we got the data, it was accepted by the relevant boards, and the 707 wasn’t grounded.

We (Don Stuhring and I) also participated in discussions about ventilation. What would happen if there were smoke incidents? Obviously you can’t open the cabin to external ventilation if you’re much above 10,000 feet, but rapid descent will fix that. Deployment of the passenger oxygen system will buy you some time, but if the smoke isn’t dissipated you got problems. There was serious discussion of building in external windows operable by the cabin crew. The alternative was a pilot controlled ventilation system, which raises the question of its reliability. We had considerable confidence in the competence of the flight attendants — generally known as stewardesses — despite the public  ‘coffee, tea, or milk?’ jokes about ‘stews’; and if we started looking into things that might fill the cabin with smoke most of those might also cripple a pilot compartment controlled ventilation system. I remember saying something to the effect that I had a lot more confidence that Miss Sparling here can open the window than I have in the hydraulics working after parts of it turn into blue smoke.

We’ve come a long way from those days in the 1950’s, but clearly there’s still the possibility of a smoke incident and ventilation problem. And some of us may remember that prior to jet aircraft there were manually operable windows on passenger airline craft. Didn’t George Kennedy open one of them and fire a flare in one of the sequels to “Airport”?

For those who don’t know: without a very efficient oxygen mask delivering pure oxygen, you won’t perform well, or even last long, above 30,000 feet. We learned a lot about that in World War II. With pure oxygen at positive pressure you can manage at about 43,000 feet (this is from memory, but it’s in the right range) but you’re already in need of a pressure suit.

Of course if you’re inhaling smoke at high altitudes you’re really in trouble. Efficient ventilation of aircraft at high altitudes has been the subject of considerable study, particularly for military aircraft — how do you get a Flying Fortress home if there’s smoke in the cabin and AA guns below? But I wouldn’t expect the Huffington Post columnists or editors to know much about that. Their “update” on the incident still doesn’t show much understanding, but that’s to be expected too. Which is fine; my point is that it’s a more complex subject than they think, and Mr. Romney is clearly aware of that. I doubt he knows as much about it as I do, but that’s another story. At one time Stuhring and I knew more about it than perhaps anyone did, not because I was so smart, but because I had reason to think about it. Mr. Romney has a tendency to answer questions asked of him, and to have confidence that if what he says is wrong, someone will correct him. That was true of Newt Gingrich, too, and it’s no bad trait for a President since it shows that he expects to have smart advisors who will say what they think.

The incident tells a lot about many people; perhaps more about the press than about Mr. Romney.

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