246 



NATURE 



[November 6, 19 19 



POSITION AND PROSPECTS OF AVIATION. 



By L. Bairstow, F.R.S. 



''T'HE present phase of scientific development of 

 J- aviation may be said to date from the period 

 1890-1900, and to have its most definite form 

 given by the researches of Langley and Maxim. 

 From Langley 's book were taken the early data 

 on which pioneer designs were prepared, and a 

 protracted controversy arose between Bl^riot and 

 Farman as to the relative merits of the biplane or 

 the monoplane as a result of a statement by 

 Langley which has since proved to need consider- 

 able modification. 



The first notable flight in public appears to have 

 been that of Santos Dumont in 1906, for which 

 he was granted the Deutsch de la Meurthe prize ; 

 this was little more than a long hop, and for the 

 next two years it was clear that one of the larger 

 difficulties of flight was the control of aircraft in 

 the air. 



Flying with reasonable certainty dates from the 

 exhibition flights of the Wright Brothers in 

 France during 1908, and may fairly be ascribed to 

 the introduction by them of wing warping for the 

 purposes of lateral control. Since then progress, 

 both scientifically and industrially, has been very 

 rapid. 



In 1909 the Advisory Committee for Aeronau- 

 tics was formed by the then Prime Minister, 

 Mr. Asquith, with the late Lord Rayleigh as its 

 president. The Committee controlled the activi- 

 ties of the Aeronautical Research Departments of 

 the National Physical Laboratory, and was 

 closely informed of the full-scale research work 

 carried on at the Royal Aircraft Factory. 



The development of the best shape of aeroplane 

 had approached finality somewhat closely in the 

 years 1913-14; on the other hand, owing to the 

 death in an aeroplane accident of Mr. E. Busk, 

 preliminary experiments on the industrial applica- 

 tion of the theory of stability came to a pre- 

 mature end. During the war the attention of 

 scientific workers in aeronautics was devoted 

 to the many applications of existing knowledge 

 rather than to its extension, and it was pointed 

 out by them that the performances of aeroplanes 

 could be predicted approximately with little effort, 

 and that these predictions could be made the basis 

 for an appeal for new designs to meet the in- 

 creasing exigencies connected with fighting in the 

 air. 



On the other hand, no such simple generalisa- 

 tion has been found possible for dealing with 

 stability, with the unfortunate result that designs 

 made to give the necessary speed and rate of 

 climb have been put into use before their con- 

 dition as to stability was fully understood. 

 Defects of stability made themselves felt by a 

 series of accidents peculiar to each type. The 

 analysis of these accidents and suggestions as to 

 remedies came from the existing scientific work 

 on stability. Examination of the categories into 

 NO. 2610, VOL. 104] 



'cSP 



which accidents fall gives, perhaps, the clean 

 idea as to the technical development possible in 

 the next decade. Some 80 per cent, of the total 

 accidents during training are due to loss of speed 

 of the aeroplane and an attempt on the part, 

 of the pilot to turn his aeroplane towards suitable 

 alighting ground. The remaining 20 per cent, 

 are in large part accounted for by failure of the 

 engine to continue to develop power and so to 

 compel descent on unsuitable landing ground. 

 The latter point scarcely needs more than passing 

 comment, for the general history of development 

 in machinery shows that many years are necessary 

 after main ideas have been established before 

 details are satisfactory. Progress made in under- 

 standing the phenomenon connected with fatigue 

 suggests that a moderate reduction of the power 

 expected from existing aeroplane engine designs 

 would lead to an enormous increase in the length 

 of their life. It may therefore be expected that 

 the ordinary precautions taken in the development 

 of an engine will lead to the practical elimination 

 of accidents under the heading of forced landings ; 

 here, again, progress will be accelerated by use 

 of the known scientific data. 



The larger group of accidents mentioned above 

 needs a consideration of design intimately asso- 

 ciated with the pilot's power of control of the 

 aeroplane and its inherent stability. It should 

 not be forgotten that the relation between these 

 two quantities in an aeroplane designed for fight- 

 ing in the air may have little or no connection 

 with the corresponding relation of the properties 

 desirable for civil aeroplanes. This field is as yet 

 comparatively unexplored, and there are strong 

 grounds for believing that an aeroplane can be 

 so designed that the dangerous consequences of 

 error of control by the pilot are greatly reduced ; 

 it is not improbable that the accidents on the 

 score of loss of flying speed can be reduced to 

 some 5 or 10 per cent, of their present magnitude 

 when the necessary skill in design has been 

 acquired. 



The most important of the many difficulties which 

 make it impossible to forecast the future of avia- 

 tion are not technical, but commercial. Develop- 

 ment under the stress of a great war has left an 

 industry capable of producing an enormous 

 number of aircraft. Attention has been given 

 solely to military uses, and aeroplanes are there- 

 fore not specifically designed for civil purposes. 

 At the same time, the civil uses are not clear ; 

 how far aviation will be good for the purposes 

 of carrying mails, passengers, or merchandise 

 is at present almost wholly a matter for con- 

 jecture. 



Pre-war experience was gained in the develop- 

 ment of aircraft which could be flown with a 

 moderate degree of ease and safety, and no lines 

 of commercial communication had been inaugu- 



