FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1929
1929 - 0244.PDF
the requirements." And the " Moth " was introduced, not as a design likely to win the competition, but as representing the serviceable machine with an engine of higher power than those called for. by the competition rules. When, therefore, the same firm has now produced a high-wing cabin monoplane, one must assume that at least this is due not merely to a " fashion," but because it is considered that the type will be in demand during the next few years. In his admirable paper to the Royal Aeronautical Society last week, Mr. W. S. Farren made a very careful analysis of the subject, " Monoplane or Biplane," and arrived at the conclusion that, on the whole, the biplane is to be preferred, largely because of the greater torsional strength of the biplane wing arrangement, and because of the greater useful load. Mr. Farren, however, based his analysis on fairly large commercial machines, and thus his conclusions do not necessarily apply equally well to smaller machines of the " feeder-line " type. Mr. Farren realised that influences other than aerodynamic and structural ones might be import- ant, and stated in his paper : " Even supposing we can assess all these factors fairly, there is one which may outweigh them all—the reaction of the man in the street. Will our decision on a matter such as I am to discuss influence him for or against travel by air ? Or will it be a matter of indifference to him ? " Neglecting mere fashion, Mr. Farren came to the conclusion that one may expect the general public to be indifferent. Probably that is quite true as regards large FEBRUARY 7, 1929 machine, therefore, must have rather more comfort than the ordinary open two-seater. Such comfort should include not only the actual cabin itself, sheltered from draught, and to a large extent free from noise, but also the view from the windows, the ease with which the cabin can be entered and left, and so forth. Now, with any normal biplane arrange- ment, the lower wing must always be "in the way of the view," as one of the latest popular inane songs has it. Not very much, perhaps, but a little, anyway. To get into the cabin of a biplane a certain amount of scrambling about on the lower wing is necessary. Most people do not object to this, but if one can avoid it, why not do so ? Why should one not try to make it as easy to step into an aeroplane as it is to step into a car ? If it does nothing else, the high- wing monoplane does make this possible, and if there be little to choose between the monoplane and the biplane regarded merely as aircraft, some such considerations as these may legitimately influence the choice. The de Havilland " Hawk Moth " definitely represents an attempt to give in the air the comfort which one usually associates with a good motor car. It is a four-seater, with the occupants placed " sociably " two by two. And in the cabin arrangement, one traces one of those " outside " considerations which may outweigh the merely aircraft ones. From the aerodynamic point of view it .would have been preferable to make a very narrow fuselage, and quite conceivably a good many horse-power would have been SIDE ELEVATION OF THE NEW DE HAVILLAND MONOPLANE on the starboard side. The cabin is entered through two doors commercial aeroplanes. But the smaller " feeder-line " type of machine may be expected to appeal not only to operators of small air lines, but also to the private owner who wants something a little more pretentious than the present type of light 'plane. And here " fashion " will doubtless play a not inconsiderable part. Thus, in considering a machine such as the new de Havilland " Hawk Moth," one should bear in mind that, like all air- craft, it must of necessity represent compromises between conflicting aims. In other words, certain features may have been dictated by aerodynamical considerations, some by structural, and some by practical. As to how much any one feature is influenced by one or the other it is not always easy to judge. Personally, we lean to the view that, not only in the case of the " Hawk Moth," but in almost any machine, the difference between monoplane and biplane on aerodynamic and structural grounds is but small, and other considerations may well determine the ultimate choice. That the mono- plane structure must be a little heavier than the biplane can scarcely be denied. On the other hand, the best mono- plane may be a little " cleaner " than the best biplane. Wre are by no means certain that it is. The one may thus help to balance the other. But one may imagine conditions where other considerations are predominant. The small cabin machine, be it monoplane or biplane, may be regarded as the light car, with the present two-seater light 'plane as the equivalent of the motor cycle and side-car combination. The analogy should not be pressed too far, but does give some sort of basis to work upon. The cabin saved by such a body. But, unfortunately, an aeroplane has to be something more than merely an aircraft. It has to carry people in reasonable comfort. In the " Hawk Moth " the seating accommodation is comfortable. The cabin is wide enough for two to sit side by side without crowding. And there is room to stretch one's legs, as well as to keep them in a number of different positions. Nothing is more tiring than to sit for two or three hours in a narrow seat in which there is no elbow room, and with one's legs in one particular position only. " Pins and needles " are an almost inevitable result, and the unfortunate passenger accustomed to the comfort of a car or railway carriage may have enjoyed the sensation of flying, but will certainly have formed a poor opinion of the comfort which aeroplanes have to offer. And as soon as the novelty of flying wears off, a passenger will very rightly demand a fair degree of comfort. The de Havilland " Hawk Moth " may certainly be claimed to provide this. The sloping wind screen in front gives a very good view forward. The large side windows and the absence of a lower wing affords the occupants an unobstructed view of the ground, and the roof light, which forms the top of the cabin, enables the pilot to look back and up to ascertain if he is being overtaken by another machine. What is the aerodynamic effect of not continuing the wing across the fuselage we do not know. It may be small and it may be large, it may be favourable or unfavourable. But it does give a very excellent view upwards, and makes the cabin quite unusually light and cheerful. The mental effect of this is likely to be 94
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
