Flying the Atlantic in Sixteen Hours

gation o

that sustained and sufficient concentration can give a man what he wants; and on this assumption I decided to learn whatever might be learned about navigation as applied to airc

position on the surface of the earth, and determines the exact direc

ut have not yet reached finality-witness the introduction within the last few years of the Gyroscopic C

navigator are light, so long as he can see the ground and check hi

ows much from the navigator of the sea. He makes modifications and additions, necessitated by the different conditions of keeping to a set course

planations of the science is that of Lieutenant Commander K. Mackenzie Grieve in "Our Atlantic Attempt," which he wrote in colla

avigation of aircraft and the navig

t, necessitating more frequent observat

flying, according to the direction and strength of the wind. In cloudy weather, or at night, a change in the wind can alter the

ation in a long journey is permissible. Another favorable point is that rocks, reefs and shoals need not be avoided. This pe

d Directional Wireless Telegraphy. None should be used alone; for although accuracy may be

, as well as an accurate and reliable chronometer. Suitable charts must be provided, showing all parts of the route to be covered. Whe

BY "DEAD

favorable conditions, it gives a high degree of accuracy. A minimu

ulated from its known speed and direction over the surface of the earth or o

p, as apart from the direction in which it is headed, an instrum

d in such a way that an observer can, by looking through the center of the disc, see the ground or ocean below him. The disc is then turned until objects on the ground-or white-caps, icebergs, ships, or other objects visible on the su

while a certain angular distance is described-this being found by suitable sights, attached to the Drift Bearing Plate. From the result, considered in conjunction with

ir speed meter, because of the effect of the wind. The difference is greater or less acco

as on a slide rule, the strength and direction of the wind. Should the actual track of aircraft over the earth's surface not coincide with the desired course, the Course and Distance Calculator, or a similar inst

R JOHN ALCOCK JUS

ST DIRECT TRANSA

e course, the air navigator, with the aid of a specially prepared set of "traverse tables" (as used by mariners), can easily plot on his chart the distance covered and

If aircraft are cut off by clouds or fog from all possibility of sighting the surface of the earth, grave errors ma

Y ASTRONOMIC

venly body, such as a star that is easy of recognition. The method depends upon the known fact that at any given instant the sun is vertically above some definite poin

on. The method of carrying out such calculations is too involved for the scope of this volume, and

rface of the earth may be described. From any point in any one circle the heavenly body will appear to have the same altitude or elevation above the horizon. A single observation of the altit

e a different circle, corresponding to the position of the second body. T

are visible and choice of suitable heavenly bodies may be made. During the day, however, the light of

e between them, would give the intersecting circles and fix the position. But the aircraft being in motion, it is necessary

s shown on the chart-so small that it may be regarded as a straight line.

e of the solar observation is indicated on it. The track should be intersected at this po

to be exact, it is necessary that not only should the sun or stars be viewed clearly, but

two corrections being given in the nautical almanac. There may be, also, an error inherent in the sextant itself. For extremely refined navigation, corrections are applied in a

e southern hemisphere, the altitude, corrected for declination of the body under observation, gives the aircraft's latitu

ut great care should be taken in making such observations, since a spirit level on an a?roplane or airship is not

a general rule this drawback does not hamper air navigation to any great extent, since aircraft should be able to climb above most of the

the craft at the intersection of the line of bearing with the position line. At the time of writing, however, there are no satisfactory means of making such a measurement with the requ

WIRELESS DIR

telegraphy is rapidly becoming a reliable and accurate means of a?rial navigation. Although complicated in desig

E WAS TAK

SED DISASTER AT THE ST

acon, station being known, the bearing of the aircraft from that station may be plotted on a suitable chart, in which small segments of great circles are represented by straight lines. Simultaneous bearings on two know

omatic means whereby directional signals can be sent out at intervals of one hour or less. Such signals will be coded, so that the crews of a

is possible for him to direct his course so that the craft is always

o counteract drift and proceed in a direct line towards his destination, the air navigator frequently has to direct his course so that the craft is not heade

y aircraft headed always

raft headed so as

surface of the ocean for drift, although desirable, is not absolutely necessary. The drift may be calculated with accurac

on to themselves. This is, perhaps, the most accurate method. Its disadvantage lies in the fact that whereas the heavier and more robust apparatus needed for it can easily be employed in the s

ther. Fogs and clouds do not make it inoperative, nor even less accurate. Another recommendation is that its u

tay, while using astronomical observation and the system of "Dead Reckoning" as checks upon the wireless bearin