How High is Up?

by Michael Amrine

There is no ceiling in aviation. Every year altitude limits are pushed higher. Credit "Tommy" Tomlinson with most of it.

IF you look on the rolls of TWA you'll find the name of D W Tomlinson, vice president in charge of engineering. That's the man we went to see at Kansas City airport where, in one wing, they transact all the business of a coast-to-coast airline headquarters and, in another wing, they dismantle an engine into 6,000 parts and put it back together like new in four hours.

We were looking for Tomlinson, so we didn't notice a heavy-set fellow who walked past — an amiable man in tweed trousers and leather flying jacket. We were shown into a little cubicle, and there left with this introduction. "Tommy, here's that guy from Flying and Popular Aviation.

Immediately we knew why everybody from office boy to grease monkey calls him Tommy. He's seen the other side of 36,000 feet, but he's never gone "high hat." He pioneered the search that enabled TWA to put $1,750,000 into five Stratoliners and make them pay, but he's still as democratic and easy to meet as he was when his $175 Jenny played a part in the establishment of the first ground school at the US Naval Academy at Annapolis.

What he knows he knows for sure. If he doesn't know he doesn't spoof you. "How high is up? What's on the other side of the stratosphere? How do I know? I haven't been there!"

When it comes to the sub-stratosphere, though, Tommy is a man who has been there.

Both the British and German governments are just catching on to the fact that the key to the future of flying, including war flying, lies in the question, "How high is up?" Most bombers over London have been flying at 15,000 feet, or above, according to information Tommy has received. "But that's no excuse for their inaccuracy, except at night," Tommy said. "It's not the altitude; many of them have been going over without even bomb-sights; just unloading when they felt like it, knowing they will hit an area somewhere near their objective, even if not the exact target.

"Even at 30,000 feet they could be reasonably accurate — and immune to pursuit planes. Little pursuits can't have the pressurized cabins required for that height without paying too heavy a penalty in weight. Anti-aircraft guns will be useless. You can't see a plane at 30,000 feet.

"Pursuit planes at these altitudes are so near their ceiling that they cannot maneuver effectively," he said. "They have a small margin of speed over multi-engined bombers and, at that height, it would be virtually impossible for them to gain tactical advantage. The stratosphere, remember, is a height above which the temperature of about 50° below zero is constant. No matter how high you go, it is still only 50° below zero, or thereabouts. At 25,000 feet it is liable to be 30° below and cumbersome clothing is a handicap. Besides that, machine gun operation is slowed up due to congealing lubricants.

"The larger bombers," he said, "with sealed cabins and fine heating systems, provide their crews with normal level comfort. The men don't even have to wear oxygen masks." So he is looking for the appearance of bombers flying seven or eight miles above the earth, before the war is over.

Tomlinson's work in high-altitude flying dates back almost to 1917 (when he graduated from Annapolis). Five years later his designation as a Naval Aviator was revoked because of his daring in the air. "You won't live very long if we let you fly," his Commander said. Tommy, even then, preferred flying in bad weather to good weather.

In 1925 he won back his designation of Naval Aviator by herding a $175 Jenny across the continent. He had made a bet with a superior officer (the late Benny Holcombe), that he could fly his old crate from Batavia, NY, to San Diego, thus proving his flying skill.

Holcombe agreed, because no Jenny had flown over the continental divide. None has since. Tomlinson was in San Diego within a week, but he flew through the Rocky Mountains, not over them. For weather reports, he read newspapers along the way. For navigation, he followed railroads through the passes; sometimes only 50 feet above the ground, or 100 feet from a mountainside. "Half the time I landed in cow pastures and alongside filling stations," Tommy commented. "And I am one pilot who has looked down and seen a Model T Ford outdistance him. It happened on this same trip. I ran into a 45 mph gale over Oklahoma. My 60 mph was cut to 15 mph going against the wind, and the farmer was whooping it up. I looked as if I was standing still."

The day after he landed at San Diego, Tomlinson became Flight Officer of the Navy's "Fighting Six" squadron, a unit of the aircraft battle force of the Fleet. In 1928 he became commanding officer of the squadron.

During these years his old Jenny was always near him in a Navy hangar, often flying in bad weather when no one else dared leave the ground. He'd take off straight into the overcast, set a compass course and trust to his instruments, which were crude and not always dependable.

In the summer of 1928 he directed what was probably the first "on top" rendezvous in history. He and his two pals of the "Three Seahawks" acrobatic trio were planning a trip to San Francisco. That morning the ceiling was 100 feet; visibility not much more.

At 3,000 feet, Tomlinson cleared the overcast. At 4,000 feet he straightened out. His pals followed and went by dead reckoning for 150 miles before they saw ground beneath them. This with only a compass, a tachometer, and a ball bank indicator to help them!

But his pals were Lieuts A P Storrs and W V Davis, who both now command squadrons. At the 1928 air races in Los Angeles they performed probably the most hair-raising stunts ever seen. Starting with a trick in which Tommy flew his Boeing F2B upside down at 25 feet with his two other Seahawks half-inverted on either side of him, they went into a series of low-altitude formation loops. In the last one Tommy's wheels were spinning along the ground.

Tommy disbanded the trio after this show. "An aerial clown doesn't live long enough to enjoy his money," he said. "If he got any, which I didn't."

After he left the Navy, Tomlinson flew a Ford tri-motor for Maddux Airlines between Los Angeles and San Francisco. Here, again, he was known for always trying to persuade fellow-pilots to fly high: "Get above the weather."

"That means 8,000 or 10,000 feet to an average transport pilot," Tommy said. "On the Stratoliners, it's 18,000 to 20,000.

"At 20,000 feet you eliminate practically all weather. Oh, some storms have been known to reach to 40,000 — maybe 50,000. But mostly they don't amount to much above 20,000 feet."

He began scrawling a picture on a scratch pad on his desk. "Look, a thunderstorm is shaped like this; sort of like a diamond, with the base a small cone reaching to the earth. Then it fattens out like this. At the top it is a smaller cone, and that is usually just a pinpoint above 20,000 feet.

"Beside the weather, another advantage of going up is speed. Your actual speed increases one per cent per 1,000 feet above the ground — until you get up …."

Until you get up — to where? Where does the thinness of the air become too thin for flight — and what needs to be done to overcome that?

"The thinness of the air holds you back in two main ways," Tommy said. "Your engine power decreases due to the lower density of the mixture in your cylinders. But worse yet is the problem of your propeller. You can increase the pitch, but at some point it begins to cavitate. It whirls in a vacuum. What you need then is a larger propeller, greater diameter, more blade surface.

"This is a physical problem something like the one which faces those who go to the stratosphere in balloons. Stratosphere balloons have been inflated as high as six-story buildings. The propellers we need would be too unwieldy. If you want to figure out one that would change its length — doing thousands of rpms — well —"

Beside the propeller and the engine super-charging problem, there used to be a third stratosphere problem — oxygen for the pilot. Tommy remembers vividly a close call he had in his experimental single-motor Northrop Gamma. The flight began with two oxygen bottles of 39 cubic feet capacity, hooked up in parallel. One bottle was turned on at a time. A research engineer with Tommy was supposed to pass instructions to the pilot when the first bottle was nearly empty, so that final descent would be made before the oxygen in the second bottle was gone.

They were flying at 30,000 feet when the oxygen supply failed. Tommy nosed the plane down to 25,000 feet, where he felt he would be able to retain consciousness until an altitude was reached where oxygen would be available.

At about 22,000 feet the oxygen came back on, and he assumed the engineer had simply forgotten to check the first bottle and had failed to turn on the second one. Tommy went back to 32,000 and continued.

When he landed, he found that when the engineer had turned to check the oxygen in the first bottle, he had pulled the oxygen tube off the nipple to the oxygen line. A companion had been unable to revive him. It was pure luck that the other engineer knew how to connect the second bottle — he had been brought along just as an observer. Death would have been certain for the unconscious engineer, or perhaps for all, if he had not.

Such situations are unheard-of today because of Tomlinson's work in pressurized cabins which maintain an atmosphere in the plane steadier than exists outside.

That's why he is believed when he says, "Up is as high as we can make it. The sky has no limit. If it were not for the war, we would have ocean transports over the Atlantic in two years flying at 25,000 to 30,000 feet, cutting our present Clipper time in half.

"I heard the other day of a flying boat that's to be built that will be bigger than the B-19. That isn't cause for amazement. Engineering skill could build and fly a plane weighing 200 or 300 tons, as much as a streamline railroad engine and a whole load of passenger cars. A ship like that would require units of 4,000 hp — and don't ask me how many. You can get some idea of a 300-ton ship when you consider that the Stratoliner weighs 22½ tons.

"A 300-ton ship could carry a great many passengers, and fly around the globe as easily as you trot around the block. The difficulty isn't the engineering factors, but the matter of a payload. You wouldn't need such a ship for any airline in the world today.

"When I had my Jenny, the world didn't need a Stratoliner. When we adapt the things we've learned in this war to peacetime use, you'll see what I mean when I say, 'there's no ceiling to aviation'."

This article was originally published in the July, 1941, issue of Flying and Popular Aviation magazine, vol 28, no 7, pp 22-23, 100.