SLIPSTREAMS

STREAMS

Helicopters. .

. THE helicopter continues to attract inventors and constructors ; perhaps, not so much in this country as abroad. The Americans, in particular, seem to be firm believers in its possibilities. One of the latest machines of this type has recently been completed by the Curtiss Aeroplane and Motor Co., and is due very shortly for its first test. This machine has been designed by Mr. Bleecker and outwardly resembles in its main features other helicopters, having a vertical shaft on which are mounted revolving planes. It is powered by a 425 h.p. Pratt & Whitney “Wasp ” engine, which also drives four airscrews situated beneath the rotary planes. It is hoped to secure directional control by the utilisation of auxiliary surfaces attached to the revolving planes which, when operated are calculated to alter the angle of incidence of the latter. There is also a form of rudder attached to the body or fuselage of this unique machine. The Bleecker helicopter is

• considered to be a marked advance in design upon earlier efforts and great things are expected of it.

Another helicopter, which has been flown successfully recently, hails from Italy, and is known as the D’Ascanio. It has been flown quite considerably and although it has not risen to any gteat altitudes, its ability to rise and descend vertically and to be under complete control in flight has been amply demonstrated.

” Charting ” Flying Pupils.

The Brooklands School of Plying has, for some time, been operating with a highly systematic method of instruction, which has been working with excellent results. Their scheme ensures that no pupil goes solo without having had the most complete tuition, not merely in fair weather but foul ; at the same time the faults, traits, and progress of each abt initio , are charted on a board in the instructors’ office. This board has sub-divisions appertaining to the various stages of instructional periods, and, according to the pupil’s aptitude, so are these sub-divisions marked off. Another detail of the B.S.F.’s system is the provision of a duplicated report, concerning each individual flight, one copy of which is retained by the pupil, and the other by the instructor ; this report is produced on the next instruction flight, so that all phases of teaching are satisfactorily checked and completed. Yet another feature of the system is the standardization of tuition routine, whereby each instructor uses precisely the same terms and methods.

Contrary to what many might assume, this way of doing things results in a great saving in time, and pupils reach a state of proficiency much more quickly than by less thorough methods of flying training. Incidentally, I think, Captain Davis has something

to boast about in his school, for during the past season, not a single undercarriage has suffered on any of his machines at the hands of his many pupils.

A Two-Stroke Aero Engine.

The development and growing efficiency of the typical two-stroke motor cycle engine is being watched with increasing attention by ,aero engineers just now, and from time to time I hear news of coming designs and experimental units working on the two-cycle principle which may possibly be used later on for aeroplane work. One of these is being constructed in London. It is a five-cylinder air-cooled radial with bore and stroke dimensions of 85 m.m. and 88 m.m., and the estimated horse power is 60 at 2,000 r.p.m. Although a twostroke, it is not valveless, the induction system incorporating poppet valves. The pistons are truncated, as in the Dunelt engine, and the connecting rods, which are tubular, work through ball-slides at the cylinder base. This latter feature is incorporated in order to use the lower bore as a pumping cylinder. Lubrication is of the dry-sump type, with a duplex gear-type pump, carburation is by a single elaudel-Hobson instrument, and ignition is by two B.T.H. magnetos.

The Schneider Trophy.

Following the rather unfortunate situation which arose

some months ago concerning entries for thee1931 Schneider Trophy Race from Italy and France, a meeting of the Federation Aeronautique Internationale has been held in Paris to discuss the position.

In January of this year the committee of the F.A.I. revised the conditions of entry for the contest, the principal alteration being in the sum required on deposit for each machine entered by contestants ; this was raised from £40 to 21,600. In June last, however, a full session of the Federation reversed their committee’s decision, and when Italy tendered her entries for the

1931 event they were sent with a deposit at the lower rate. France later supported this action, with the result that the Royal Aero Club returned all deposits.

At the time, the latter body maintained that the F.A.I. had no right or power to alter the new rules drawn up by its own committee, and at the recent meeting in Paris, Colonel O’Gorman (representing the Royal Aero Club) adhered to this declaration. General Piccio, for Italy and the French representative, Captain de l’Escaille, on the other hand, took the opposite view, although hopes were expressed that a friendly agreement might be brought about before very long. The matter has now been referred to arbitration.

In the meantime it has been officially intimated that America will not enter any machines for the next contest. ” RUDDERBAR