New Britain herald., 1919-06-14
SEA RULES ID AIR PILOTING
limy Bomber Will Be Steered Just Like Marine Craft

4plytng methods of marine navigation to an air flight Lieut. Arthur Whit ten Brown expects to fly across the Atlantic in the Vimy bomber ma 1chine, piloted by Capt. Jack Alcock, 4and to mako d landfall' within 20 or 80 miles of his objective in Ireland or England.
 Lieut. Brown was an American elcc- l trlcal engineer before he joined the British flying service in 1914. He has described in a statement which he has prepared for the Associated Press an interosting description of the difficult ties encountered in a transatlantic l flight and the methods by which he hopes to overcome them.
 'In flying an airplane over large bodies of water such as the Atlantic ocean, where the pilot may be for hours out of sight of any landmarks by which he could judge his position, it Is to the methods of navigation which have been developed by the mariners that the pilot turns to learn where the location and the course to his destination is,' writes Lieut. Brown.
 t.Bnfortunately difficulties arise from the start in applying these meth ods with accuracy. This is true be- cause the airplane is at the mercy of the wind and appears to move in the direction in which the wind blows with the speed at which it is blown In the second place the speed of the airplane is from five to ten times that of the commercial vessel.
 ''The high speed of the airplane renders 1t necessary to make frequent observations for position, and this in turn makes it undesirable to use the slow, albeit accurate means of calcu- lation ordinarily employed. In con- sequence special charts have been de- vjsed for use with the sun or stars which enable the pilot to fix his posi- sion in a very short time, although not with the accuracy demanded in marine work. With the aid of these charts, together with @ seXtant for ob- serving the sun or stars, a chronome- ter and compass, the pilot should be able to make a landfall within 20 to 50 miles of the desired point.
 s'This, however, he will not be able to do unless he keeps careful watch on the direction and strength of the wind, which may alter between his observations and without his knowl- edge. In order to check this, an in strument known the drift lnd1ca- tor has been devised, by means of
 
 rection of the wind and the speed at which he is travelling over the ocean, so long as he can see the ocean and the flares or smoke bombs which he drops into it for the purpose of mak- ing his observations of drift.
 Should the pilot be flying in clouds so that he can see neither the ocean nor the sky, he can only de- pend upon his compass which gives direction only. Under these circum- stances he may drift many miles out of his course without being aware of it unless he employs a late develop ment of wireless telegraphy, by means of which he can measure his bearings from two or more land stations and fix his position at the point of inter- section: For short distances, this method has proved it's reliability, but it has yet to be proved that it Is suit able for such a journey as the trans atlantic flight until further improve ments have been made in the appar- atus employed.
 ''Let us take flight from St. Johns, steering the airplane along the short est route for Galway Bay, and starting sometime in the afternoon.
 Before leaving the ground, the drift indicator is set to the required course and an approximate compass course is worked out which will allow for the drift caused by the prevailing wind. After rising into the air and gaining sufficient height, the airplane Is set on the compass course and this course is then corrected until the de- sired course set on the indicator is made good. The time of passing over the coast is noted and the speed over Rhn errn ic Gon and speed of the wind at the height of the airplane are calculated and the drift indicator carefully watched so as to detect any alteration and to make the necessary corrections
 During the first hour the height of the sun above the horizon is meas nred by means of the sextant, the exact time of the observation being noted. The special chart Is then brought into use, and if there has been no error in the allowance fol wind, it shows exactly what point has been reached on the desired track tC Galway Bay. This is then checked up with the position which should nave been reached according to the measured ground-speed and in the short distance traversed during the first hour there should be no appre. ciable discrepancy.
 "The navigator now has time tc busy himself with settling down fol the journey after the hurried pre- Darations at the start and to pay z title attention to the many call! coming over the wireless. By thi time. he is almost out of range witt his sending apparatus but signals con inue to come in bearing messages o cheer and perhaps some humorou suggestions as to conduct en route, t' which, unhappily the appropriate re plies cannot be sent.
 Another hour passes, and it i
 ime for another observation. Thi s taken in the same way as the first