M.Goodall, A.Tagg British Aircraft before the Great War (Schiffer)
Deleted by request of (c)Schiffer Publishing
Flight, December 3, 1915.
AN ORIGINAL IRISH MONOPLANE.
IN these days when the tendency is everywhere towards standardisation it is quite refreshing to be reminded that, great as have been the results achieved with types of wing sections that do not differ greatly among themselves, there are people who do not entirely agree that development is travelling entirely along the right track. One of those, who not only offers this negative criticism but who is of the opinion that he has found a better form of wing, is Mr. J. Cordner, of John Street, Londonderry, who has for a number of years been working upon lines of his own, attacking the problem, rightly or wrongly, in an entirely different way from what has come to be considered orthodox. Mr. Cordner informs us that his machine has done several short flights, during which, he says, the machine was found to possess a very good speed range, leaving the ground at something like 15 m.p.h., while the maximum speed, he states, is very high, how high we are not in a position to say. She also appears, from the short flights possible in the restricted ground available, to have a reasonably good climbing power.
In its present form the Cordner monoplane is the result of years of experiments, first with models and later with full size machines to which reference in the past has been made in "FLIGHT." As experience dictated these were altered and improved, the earlier ones having a tail of similar construction to that of the main planes and an open fuselage. Later on the body was covered in in order to improve the speed. A form of aileron was employed for steering, no vertical rudder being fitted. Engines of various types and h.p. were tried, and the undercarriage redesigned time after time. "Straights" were made, mere hops it is true, but the machine got off the ground. Then turns were attempted and, according to Mr. Cordner, with good results.
In its present form the Cordner monoplane may be said to represent a concession to orthodoxy as far as the body, tail and undercarriage are concerned, but the peculiar wing construction has been retained. Various materials have been tried, the wings having at various times been built up of three-ply wood, covering and all, and at other times a skeleton framework covered with fabric has formed the lifting surfaces. However, in general principle the form of the wings, if not the construction, has been retained.
It is a little difficult to explain the arrangement in words, but the accompanying sketch will, we think, make it perfectly clear. As to the action of this peculiar wing form one cannot always follow the inventor in his claims that it obtains a better "grip" on the air, gives less resistance, more area and better speed range. As regards the first claim. By grip we take it that the inventor means to indicate that the suction on the upper surface of the wing and the pressure on the lower surface are greater than can be obtained with the ordinary form of wing section. With regard to the upper surface it would appear to us that the region of rarified air or "partial vacuum" above the plane would be filled up by the air rushing through the triangular openings below the plane, and that therefore the resulting lift would be reduced. Again, the lower surface may be said to consist of a series of alternate dihedral surfaces tapering towards the rear and negatively dihedral surfaces flattening out towards the rear, which, although certainly presenting a greater surface, would also seem to offer more resistance. If the maximum speed can be attained we quite agree that it should be possible to bring the minimum speed down to a very low figure, especially as the ailerons, if pulled down simultaneously, will, by closing some of the pockets in the rear portion of the wing, act as a very powerful brake. That, as Mr. Cordner claims, the danger of "side slipping" is greatly reduced, if not altogether eliminated, seems reasonable enough in view of the great amount of more or less vertical surface presented by the pockets of the wings. Whatever one's opinion of the merits of this original wing form, it certainly should be given a thorough trial in practice, as for instance by building a pair of wings of the same span and chord as those of some well-known machine when the results could be directly compared.
Regarding the rest of the machine the Cordner monoplane presents nothing startling in the way of deviations from ordinary practice. It is fitted with a new 40 h.p. Anzani engine, and we understand that Mr. Cordner is open to consider the sale of both the machine and patents covering the wing design.