ALONG A BEAM

Evening Star, Issue 21320, 26 January 1933, Page 7

ALONG A BEAM

HOW PILOTS FLY THEIR WIRELESS EYES Blanketed between clouds and fog, with no gleam of guidance from earth or sky, the up-to-date air pilot “ rides on a radio beam ” —to safety! With his telephone headpiece ticking into his ear the identifying signal pouring in a steady stream from the next landing station, ho finds his way “ blind'’ as surely as if his eyes were glancing over a well-known landscape in ‘ broad daylight. Something of it has been told before’ but now we have more details, and interesting ones, ton. it’s one of the latest triumphs of practical aviation, and “ it is being done every day, every night, and right over our heads,” says Allan A. Barrie, in ‘ Western Flying.’ The Federal Airways System, according to Mr Barrie, “ represents the nerves of American aviation, a network of approximately 19,000 miles of lighted and radio-equipped airways that makes, flying by day or night almost as certain as following the glistening steel of a railway or the marked and leuced border of a highway.” He adds;— The entire set-up of radio beams, revolving . beacons. airways weatherbroadcasting stations, course-markers, and intermediate landing fields is staggering in its entirety. Each of the nation's sixty radiorange beacons shoots a guiding finger in four directions at the same time. Here Mr Barrie invite? us to take a ride on the beam; — Suppose we are flying at 8,000 feet from Los Angelos toward the radiorange station at Fontana, at the south end of Cajon Pass. "Wo put on the headphones and_ hear from. Fontana a dash-dot, an ” N” in Morse code. It shows that we are too far to the right of,the centre of the beam. A STEADY SIGNAL. As we swing to the left, the dash-dot slides into a steady dash, or a continuous monotone signal of about twelve seconds’ duration. This signal is interrupted five times a minute by the station-identifying signal, dot-dash-dot. When the dash of buzz is continuous we know we are headed right tor the beacon station and a Department of Commerce landing field. The beam is approximately seven to ten miles wide', 100 miles from the station, and narrows down to a few feet as we approach the field. Now, inclining to the left, we hear the steady signal break, this time to a dot-dash, letter “ A ” in Morse code. The signal gets louder as we approach the beacon: then breaks off. The interruption tells us that we have flown into the cone of silence above the station, and that the station is directly below. In the event that we cannot see the ground but know that the ceiling and visibility are sufficient, we can glide down through the fog and land at the field. But instead of landing, let us continue through Cajon Pass by turning to the left and picking up the beam that leads out toward the desert. As we go out on this beam with the station now behind us, the clash-dot will again be on the .right side and the dotdash, A, on the left side, with the continuous buzz, as always, in the centre. This north beam suggests a southwest beam from Daggett in the vicinity of the Bald.y Mesa intermediate field. | located at the top, of the Cajon Pass. i CHANGED COURSE. | The course here changes from northwest to north-east toward Daggett. 'The change in direction is indicated by what is known as a marker beacon, which gives out a signal of three sharp dots and can be heard for a distance I of three to six miles from the station. I A radio-marker beacon is operated on 1 the same frequency as that of the 'radio-range course on which it is located. This simplifies beam flying by indicating the exact intersection of two beams. Here our radio can be tuned to the next station, and tho compass changed to, the new beam, all without losing a moment’s time and without wandering a mile off the course. The mail has actually been flown through rain and clouds, blind, for more than 200 miles,” Mr Barrie tells us, pointing out that “.radio-beam and instrument flying are the most rc--1 cent additions to airline flying, and high hopes are held for the future.” And he reminds us that “ at night we also use revolving airway beacons. ] They are especially helpful in bad I weather when it is necessary tc fly i close to the ground with limited visi- ! bility. I Imagine yourself in the cockpit flying in a snow storm at night. The ceiling is coming down, and the visibility is getting short. The four or five beacons and blinkers which you have been watching ahead and behind have I gradually blurred out, and only one ! ahead and one bihind are visible. Even these are beginning to get yellow and fuzzy. MILES AWAY. The situation is probably this: The next field is five to six miles away, and you are going to make it if you can. You have probably just passed a beacon with a red course light, and you know' that ahead you nuist see a blinker, a revolving beacon with a red course light flashing “ I),” another, blinker, and another revolving beacon flashing green, located 200 ft from tlie south-east corner of the landing field. These thoughts run through one s head much more quickly than it takes time to tell. You get to the next beacon with the red course light, and still are 100 ft off the ground by the altimeter. Since blinkers are not us bright as the j beacons, it is possible that the next blinker will not become visible for a few moments after you have passed the beacon. You reach tho blinker, pass it. and look back to be sure it docs not fade out before the green beacon appears. When you see the green Hashing | I ‘,i iiv directly toward it, because you must fly around and look at i„j v.-‘,)u suck to determine the direction of the wind before lauding. The beacon is 51ft high I irciing tlie field for a landing, we dare not go any lower " • 0 i ‘ -t, telephone , wires. We laud over tho green boundary 'i.vu- and taxi to the house at the i icon tower. The house contains blocks foi tiie I wheels, ropes, and pins to stake the ] ship down, covers for motor and cock- ! pit. gasoline and oil. and. most imi portant on n cold night, an electric I stove.