Part 4 (2/2)
All the parts are now working well together. Such wires as were before in undue tension have secured relief by slightly elongating their loops, and each one is now doing its bit, and all are sharing the burden of work together.
The Struts and the Spars, which felt so awkward at first, have bedded themselves in their sockets, and are taking the compression stresses uncomplainingly.
The Control Cables of twisted wire, a bit tight before, have slightly lengthened by perhaps the eighth of an inch, and, the Controls instantly responding to the delicate touch of the Pilot, the Aeroplane, at the will of its Master, darts this way and that way, dives, loops, spirals, and at last, in one long, magnificent glide, lands gently in front of its shed.
”Well, what result?” calls the Flight-Commander to the Pilot.
”A hundred miles an hour and a thousand feet a minute,” he briefly replies.
”And a very good result too,” says the Aeroplane, complacently, as he is carefully wheeled into his shed.
That is the way Aeroplanes speak to those who love them and understand them. Lots of Pilots know all about it, and can spin you wonderful yarns, much better than this one, if you catch them in a confidential mood--on leave, for instance, and after a good dinner.
[Footnote 8: A.M.'s: Air Mechanics.]
[Footnote 9: b.u.t.t means to thicken at the end. Screw means to machine a thread on the b.u.t.t-end of the wire, and in this way the wire can make connection with the desired place by being screwed into a metal fitting, thus eliminating the disadvantage of the unsatisfactory loop.]
[Footnote 10: Deviation Curve: A curved line indicating any errors in the compa.s.s.]
[Footnote 11: A propeller screws through the air, and the distance it advances during one revolution, supposing the air to be solid, is known as the pitch. The pitch, which depends upon the angle of the propeller blades, must be equal to the speed of the aeroplane, plus the slip, and if, on account of the rarity of the air, the speed of the aeroplane increases, then the angle and pitch should be correspondingly increased.
Propellers with a pitch capable of being varied by the pilot are the dream of propeller designers. For explanation of ”slip” see Chapter IV.
on propellers.]
[Footnote 12: Getting out of my depth? Invading the realms of fancy?
Well, perhaps so, but at any rate it is possible that extraordinary speed through s.p.a.ce may be secured if means are found to maintain the impulse of the engine and the thrust-drift efficiency of the propeller at great alt.i.tude.]
[Footnote 13: Box-kite. The first crude form of biplane.]
PART IV
'CROSS COUNTRY
The Aeroplane had been designed and built, and tested in the air, and now it stood on the Aerodrome ready for its first 'cross-country flight.
It had run the gauntlet of pseudo-designers, crank inventors, press ”experts,” and politicians; of manufacturers keen on cheap work and large profits; of poor pilots who had funked it, and good pilots who had expected too much of it. Thousands of pounds had been wasted on it, many had gone bankrupt over it, and others it had provided with safe fat jobs.
Somehow, and despite every conceivable obstacle, it had managed to muddle through, and now it was ready for its work. It was not perfect, for there were fifty different ways in which it might be improved, some of them shamefully obvious. But it was fairly sound mechanically, had a little inherent stability, was easily controlled, could climb a thousand feet a minute, and its speed was a hundred miles an hour. In short, quite a creditable machine, though of course the right man had not got the credit.
It is rough, unsettled weather with a thirty mile an hour wind on the ground, and that means fifty more or less aloft. Lots of clouds at different alt.i.tudes to bother the Pilot, and the air none too clear for the observation of landmarks.
As the Pilot and Observer approach the Aeroplane the former is clearly not in the best of tempers. ”It's rotten luck,” he is saying, ”a blank shame that I should have to take this blessed 'bus and join X Reserve Squadron, stationed a hundred and fifty miles from anywhere; and just as I have licked my Flight into shape. Now some slack blighter will, I suppose, command it and get the credit of all my work!”
”Shut up, you grouser,” said the Observer. ”Do you think you're the only one with troubles? Haven't I been through it too? Oh! I know all about it! You're from the Special Reserve and your C.O. doesn't like your style of beauty, and you won't lick his boots, and you were a bit of a technical knut in civil life, but now you've jolly well got to know less than those senior to you. Well! It's a very good experience for most of us. Perhaps conceit won't be at quite such a premium after this war. And what's the use of grousing? That never helped anyone. So buck up, old chap. Your day will come yet. Here's our machine, and I must say it looks a beauty!”
And, as the Pilot approaches the Aeroplane, his face brightens and he soon forgets his troubles as he critically inspects the craft which is to transport him and the Observer over the hills and far away. Turning to the Flight-Sergeant he inquires, ”Tanks full of petrol and oil?”
”Yes, sir,” he replies, ”and everything else all correct. Propeller, engine, and body covers on board, sir; tool kit checked over and in the locker; engine and Aeroplane logbooks written up, signed, and under your seat; engine revs. up to mark, and all the control cables in perfect condition and tension.”
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