THE R.A.F.

Bay of Plenty Beacon, Volume 3, Issue 264, 29 January 1941, Page 8

THE R.A.F.

TRAINING IN THEORY AND PRACTICE By R.A.F. Air Observer. - It is one of the many additional jobs of the British* navigator to he bomb-aimer. So, after some intensive navigational training, the as* piring youth is posted to a Bombing and Gunnery School to absorb the theory of bombing and engage in I practice bombing exercises at a range attached to the school. According to the instructors, the theory of bombing is the essence of complicity. They call it "a piece of cake." The students don't always agree. In the first place you must understand that British aircraft carry bombs in horizontal stowage, nose forward, unlike some of the German 'planes which stow them vertically. When the bomb leaves the aircraft it is affected by the forward velocity of the aircraft along the aircraft's track. And it has by then succumbed to gravity and thus has a vertical acceleration of 32ft. per second, because Nature's Trade Union ordains that gravity shall work at that rate.

So you can see that a bomb should j remain vertically under the aircraft, although falling down all the time, on a straight course, and that it should increase steadily in down- j ward velocity at a constant rate of j acceleration until it strikes the target, which for British bombs is a , military objective and for German bombs, as likely as not, is a millinery objective. As the bomb falls it will tend to bring its own axis nearer and nearer to the vertical, until from great heights this ideal is reached for all practical purposes. Easy enough, isn't it? But, to the everlasting regret of the instructional staff of the B/G School, this is only what happens to the bomb-aimer's dream —the famous "Ideal Bomb,"-a second cousin to the frictionless plane of .physics, or the taxless State. The "Ideal Bomb" only frequents Bombing and Gunnery Schools, Graphs and Aimamen t Instructional manuals. • The ordinary bc.mb is not so amenable. In the'first place, it is not, like the "Ideal Bomb," perfectly streamlined and so it is retarded by air resistance. In any case it suffers from the disadvantage that it falls in an atmosphere (after Lesson Three of the course), and not in a vacuum as does the "Ideal Bomb. j When the air resistance equals the downward pull of the bomb, the bomb reachevS a certain constant speed, known familiarly as Terminal Velocity, or simply T.V. Even that is not all. Bombs suf--1 fer acutely from air-lag, ground-lag and some Greek symbols, which all ' have something to do with the geo- ' metry and dynamics of the subject. ■ When instructors and pupils reach ' this stage they generally call an ■ armistice in the Theory of Bombing, and advance under a white flag ' to the bomb-sight.

The Bomb Sight To understand the bomb-sight properly, it is assumed by the staff of the B/G School that you must- know the names of the 49 principal part? of that instrument, after which you Ijour them on to an examination answer book, and then are free to baptise them as you feel fit. In short, what this little magical contraption does is to solve mechanically a triangle of velocities (it can even cope with a quadrilateral | of velocities), always assuming that you give it the correct mathematical food. Tins feeding process is done by turning knobs; and for, excitement, an extraordinary variety of knobs is provided, all of which in a most mysterious manner turn the attachment which you least expect to b'.r affected. For those, who have never tamed a real bomb-sight I should explain its food, is Wind and Direction of Wind. Height (corrected for pressure of the atmospheie «uu temperature), Corrected Aii Speei, Terminal Velocity of the bomb used, and course of the aircraft.