In cranking an airplane, a certain formula is always gone through. The mechanician at the propeller calls out, “Close!” The aviator closes the switch and repeats the word. This short-circuits the ignition apparatus so that no spark occurs in the cylinders. The propeller is turned in order to introduce explosive mixtures into the cylinders. When ready to start the mechanician says “Open!” The aviator opens the switch and repeats the word. The charges in the cylinders then fire when the propeller is turned.
After the engine starts, the machine is “trimmed” by helpers and jockeyed for a favorable “take-off” into the air. (See Figs. [14], [15].) This model of airplane climbs on a gradient 1 to 7; its minimum speed is 41 miles per hour. In other words, if the speed is less than 41 miles per hour the machine will not fly horizontally.
The Ascent.—The tractor was headed into a 30-mile northwesterly wind so that the “take-off” was quick and easy; there were only a few seconds spent rolling over the field, when the airplane left the ground and I felt the never to be forgotten cushioning feeling of the air. For ten seconds there was experienced a decidedly weakening nervous chill, which occurred to me once before when making a high dive from a spring-board. It was the sort of physiological disturbance that can only be counteracted by immediately pulling one’s self together saying, “Well, here goes nothing!” The momentary depression was immediately followed by a corresponding elation of feeling which strange to say did not leave me during the trip and is always associated with thoughts of the journey. There was no dizziness, although I am peculiarly susceptible to the least change in balance. The earth did not recede as we progressed steadily upward; we seemed part of the earth, but not of it. Although the airplane reached an altitude of 3,000 feet in a comparatively few minutes, the barometer falling from 30.0 to 27.0 inches, the decreased bodily pressure was not at all noticeable.[H]
[H] Trans-American Climatic Association, 1915, 31:20, Hot Springs, Va.
Next to the supporting quality of the atmosphere I had noticed the 70-mile blast of air as the airplane pushed its way steadily onward and upward. Naturally, the exhaust of the motor in addition to the roar of the wind made conversation impossible. Some airplanes have telephone communication between observer and pilot. (See [Fig. 9].) During one flight in a machine not so equipped, the passenger noticed the breaking of some apparatus. Knowing that it was impossible to make himself heard he hastily scribbled the word “Accident!” on a bit of card, whereupon the pilot shut off his engine and glided to earth.
Two-thousand Feet above Point Loma.—Carrying out my suggestion as to investigating the “woolly,” the pilot drove the machine straight for Point Loma and those unseen aërial breakers. Suddenly there were two distinct “wallops” and I felt the fuselage beneath me respond as if struck by a stuffed club. There was evidently first a surge then a drop, and it was the descending current of air that deprived the airplane of the supporting medium, hence the shock. Point Loma itself, from this altitude, and seen directly from above, looked very like a barracuda’s backbone—long, low, and ugly. Although this peninsula (see [Fig. 21]) is less than 500 feet high it so effectively deflects the prevailing northwesterly wind that the upward surge has been noticed by aviators at an altitude of 4,000 feet. It is no wonder then that these descending winds, called “woollies” (from their churning the water into isolated masses which look like tufts of wool), are dreaded alike by yachtsmen and birdmen. They have been known to carry away topsails from too closely venturing schooners and student aviators always give the vicinity of Point Loma a wide berth.
No Winds Aloft.—We had not changed our direction since leaving the ground, but after passing over Point Loma the airplane was put sharply on a port course. I had been expecting this and must confess, somewhat dreaded it, innocently thinking that a 30-mile wind added to our 70-mile rate of speed would “heel” the craft to an uncomfortable angle when the course was changed from northwesterly to southerly. What was my astonishment to find that the putting about was unaccompanied by any of the nautical motions such as tilting or canting. Theoretically one may be ever so well grounded in physical laws but it seems to take actual experience to bring their truth home to us. Of course there can be no wind in the air; when we entered the air it was moving 30 miles an hour in relation to the earth but as soon as we were free from the earth the velocity of the wind had no effect on our flight. No matter how strong the gale, so far as it concerned the airplane, if the wind be steady no difficulty is experienced; the aviator is concerned only by wind-shifts.
The Velo Cloud Seen from Above.—In kindergarten days I remember that one of the first questions I asked was “Are clouds smoke?” And this early query was really first answered in the air. Fog on a mountain top may be cloud, but somehow cloud free from close proximity to the earth seems different.
The machine was put through the cloud blanket much as a horse takes a hurdle; it seemed unlike fog and more of a palpable substance. As we emerged, the sun was shining on it like a silvery sea with gently undulating surfaces and it looked for all the world as supportable as layers of cotton-wool. Many times have cloud-banks from mountain tops been observed, yet the upper side of the velo cloud from a flying-machine looked very different. The cloud was only four or five hundred feet thick and extended inland a few miles in irregular outline. The seaward edges of the velo cloud were not ragged, and apparently paralleled the coast for 10 or 15 miles.
Such was the exhilaration and confidence the air gave that I can understand how parachute jumpers confidently step off into space, for to them the air is a supporting medium no more terrible than a transparent sea to a good swimmer. I believe that the record parachute drop was made in 1916 by Colonel Maitland, of the English Royal Flying Corps, who descended in a parachute 10,000 feet from an airplane. Fifteen minutes was occupied in the descent.