FOR OFFICIAL USE.

[Crown Copyright Reserved.]

AERONAUTICS.

TECHNICAL REPORT

OF THE

AERONAUTICAL RESEARCHCOMMITTEE.

FOR THE YEAR 1926-27.

(With APPENDICES.)

L O N D O N :PUBLISHED BY HIS MAJESTY'S STATIONERY OFFICE.

To be purchased directly from H.M. STATIONERY OFFICE at the following addresses :Adastral House, Kingsway, London, W.C.2; 120, George Street, Edinburgh;

York Street, Manchester; l, St. Andrew's Crescent, Cardiff;15, Donegall Square West, Belfast;

or through any Bookseller.

1928.Price £1 15s. Net.

CONTENTS.PAGE

Members of the Committee . . . . . . . . viiiReport of the Committee for the year 1926-27 . . . . 1

APPENDICES TO THE REPORT.Aerodynamics.

(a) General :—(i) Preliminary experiments on two-dimensional flow round

bodies moving through a stationary fluid.—By ProfessorB. Melvill Jones, M.A.. A.F.C.; W. S. Farren, M.B.E.;and Flight Lieut. C. E. W. Lockyer, R.A.F. - - - 54

(ii) The pressures round a cylinder rotating in an air current.—B y A . Thorn, B.Sc., Ph.D. - - - - - - 6 6

(iii) A paradox in fluid motion.—By Dr. H. Lamb, F.R.S. - 78

(ft) Aerofoils and Wing Sections.(i) Tests on Handley Page aerofoil A. 1. and R.A.F. 31.—

Communicated by Messrs. Handley Page, Ltd. - - 82(ii) Model experiments on R.A.F. 31 Aerofoil with Handley

Page Slot.—By H. B. Irvmg, B.Sc.; A. S. Batson, B.Sc.;and D. H. Williams, B.Sc. - - - - - - 114

(iii) Wind tunnel experiments on a symmetrical aerofoil(Gottingen 429 Section).—-By C. N. H. Lock, M.A.;H. C. H. Townend, B.Sc.; and A. G. Gadd - - - 122

(iv) Wind tunnel test of aerofoil M. 2.—By H. Davies, B.A.,A.F.R.Ae.S., and F. B. Bradfield, Math, and Nat. Sci.Trip. Presented by the Director of Scientific Research - 142

(v) Wind tunnel tests of Aerofoil R.A.F. 34.—By H. Davies,B.A., A.F.R.Ae.S. Presented by the Director ofScientific Research . . . . . . . 1 4 7

(vi) The effects of stagger and gap on the aerodynamic pro-perties of biplanes at large angles of incidence.—ByH. B. Irving, B.Sc., and A. S. Batson, B.Sc.—

Part I.—Life, drag and centre of pressure - - 152Part II.—Rolling and yawing moments due to rolling 160

(vii) The characteristics of certain aerofoil sections for infiniteaspect ratio.—By A. S. Hartshorn, B.Sc. Presentedby the Director of Scientific Research - 189

(viii) Wind tunnel tests on a wing covered with monel metalgauze.—By F. B. Bradfield, Maths, and Nat. Sci. Trip.Presented by the Director of Scientific Research - - 198

(e) Stability and Control.(i) Second report on full scale experience with the slot-and-

aileron control fitted to a Bristol Fighter.—By H. L.Stevens, B.A. Presented by the Director of ScientificResearch . . . . . . . . . 2 0 0

(ii) Model tests of a combined slot-and-aileron control on awing of R.A.F. 15 section. Push forward type ofauxiliary.—By F. B. Bradfield, Maths, and Nat. Sci.Trip, and A. S. Hartshorn, B.Sc. Presented by theDirector o f Scientific Research - - - - - 2 0 3

(iii) Slot-and-aileron control on a wing of R.A.F. 31 sectionwith various types of ailerons.—By F. B. Bradfield,Maths, and Nat. Sci. Trip., and A. S. Hartshorn, B.Sc.Presented by the Director of Scientific Research - - 213

* (5)28848 Wt 7147—137/422 375 4/28

IV

PAGE(iv) Flying positions of control surfaces of Bristol Fighter.— -

By "Captain G. T. R. Hill, M.C., M.Sc., F.R.Ae.S. - - 229(v) The full scale determination of the lateral resistance

derivatives of a Bristol Fighter aeroplane.—Part II.—-The determination of the rate of turn

derivatives.—By H. M. Garner, M.A. Presentedby the Director of Scientific Research - - - 235

(vi) Lateral stability with special reference to controlledmotion.—By H. M. Garner, M.A. Presented by theDirector o f Scientific Research - - - - - 2 3 9

(vii) Lateral stability at low speeds.—By S. Seott Hall,B.Sc., D.I.C.—

Part I.—Measurement of rolling moments for threewings at low rates of roll - - - - - 2 5 8

Part II.—Pressure measurements on a wing whilstrotating a t l o w speeds - - - - - - 2 6 5

(viii) Part I.—Rolling and Yawing Moments due to Rolling and toAilerons.—By A. S. Batson, B.Sc. - - - - 271

Part II.—Rolling and Yawing Moments due to Sideslip.—By D. H. Williams, B.Sc., and A. S. Halliday, B.Sc. - 280

(d) Airscrews.(i) Experiments with a family of airscrews, including effect

of tractor and pusher bodies.—Part IV.—On the effect of placing an airscrew in

various positions within the nose of a streamlinebody.—By H. Bateman, B.Sc., A.C.G.I., D.I.C.;H. C. H. Townend, B.Sc.; and T. A. Kirkup - - 291

(ii) On the advantages of an open type of wind tunnel forairscrew tests.—By H. Glauert, M.A., and C. N. H.Lock,M.A. - - - - - - - - - 3 1 8

(iii) The efficiency of an airscrew.—By H. Glauert, M.A.Presented by the Director of Scientific Research - - 328

(iv) The accuracy of the vortex theory of airscrews in thelight of recent experimental work and its application toairscrew design.—By H. Glauert, M.A., and C. N. H.Lock, M.A. - - - - - - - - - 3 3 9

(v) Photographs of the flow round a model screw working inwater, especially in the " Vortex Ring State."—ByC. N. H. Lock, M.A., and H. C. H. Townend, B.Sc. - 355

(vi) The effects of body interference on airscrew performance.—By W. G. Jennings, B.Sc., of the Aeroplane andArmament Experimental Establishment (Home). Pre-sented by the Director of Scientific Research - - 360

(vii) On the contraction of the slipstream of an airscrew.—By H. Glauert, M.A. Presented by the Director ofScientific Research - - - - - - - 3 6 8

(viii) The influence of the airscrew on the aircraft characteristicsof a standard Bristol Fighter aeroplane.—By W. G.Jennings, B.Sc., of the Aeroplane and Armament Experi-mental Establishment. Communicated by the Directoro f Scientific Research - - - - - - - 3 7 9

(e) Performance.(i) The direct measurement of the angle of flight path of an

aeroplane as a means of eliminating the effect of aircurrents on the measurement of lift and drag.—ByE. T. Jones, M.Eng., and H. L. Stevens, B.A. Presentedby the Director of Scientific Research - - - - 383

(ii) Full scale tests of a suspended air log.—By J. K. Hardy,B.A. Presented bv the Director of Scientific Research - 392

PAGE(iii) Full scale and model measurements of lift and drag of

Bristol Fighter with R.A.F. 30 wings.—Part I.—Full scale - . . . . . . 396Part II.—Model experiments - - - - - 3 9 8Part III.—Comparison of model and full scale results.

By A. E. Woodward Nutt, B.A.; R. G. Harris, D.Sc. ;and L. E. Caygill, B.Sc., A.M.I.M.E. Presented by theDirector o f Scientific Research - - - - - 3 9 9

(iv) Full scale measurement of lift and drag of a BristolFighter with slotted upper wings and standard lowerwings.—By J. K. Hardy, B.A. Presented by theDirector o f Scientific Research - - - - - 4 0 2

(v) Lift and drag of the Bristol Fighter with Fairey variablecamber wings.—By E. T. Jones, B.Eng.; L. E. Caygill,B.Sc.; R. G. Harris, D. Sc.; and H. M. Garner, M.A. - 405

(vi) Algebraic formula.' for the performance of an aircraft atfull throttle.—By R. S. Capon, B.A., of the Aeroplaneand Armament Experimental Establishment (Home),Martlesham. Presented by the Director of ScientificResearch - - - - - - - - - 4 1 7

(vii) The application of algebraic formulas to problems of aircraftperformance.—By W. G. Jennings, B.Sc.; N. E. Rowe,B.Sc.; and I. Bowen, B.Sc., of the Aeroplane andand Armament Experimental Establishment. Com-municated by the Director of Scientific Research - - 430

(viii) Note on the reduction of performance tests to the standardatmosphere.—By R. S. Capon of the Aeroplane andArmament Experimental Establishment (Home).Communicated by the Director of Scientific Research - 441

Flutter of Aeroplanes.(i) Accidents to aeroplanes involving nutter of the wings.

Report of the Accidents Investigation Sub-Committee - 449(ii) An investigation on wing flutter.—By R. A. Frazer, B.A.,

B,Sc. . . . . . . . . . . 4 6 8

Airships.(i) Full scale pressure plotting experiments on hull and fins

of H.M.A. R. 33.—By Lt.-Col. Richmond, O.B.E., ofthe Royal Airship Works, Cardington . . . - 490

(ii) The distribution of normal pressures on a prolate spheroid.By Dr. R. Jones, M.A. . . . . . . . 516

(iii) Stresses in a stiff jointed polygonal frame under a systemof loads perpendicular to the plane of the frame.—By J. F. Baker, B.A. Presented by Professor A. J.Sutton Pippard, M.B.E., D.Sc. . . . . . 603

(iv) On the calculation of stresses in the hulls of rigid airships.—By R. V. Southwell, F.R.S., F.R.Ae.S. - - - 612

Engines.(i) Dopes and detonation. Second Report.—By Professor

H. L. Callendar, C.B.E., LL.D., F.R.S. Experimentsmade in the Air Ministry Laboratory at the ImperialCollege of Science, London, under the direction of R. O.King, M.A.SC. (McGill), A.F.R.Ae.S.; by E. W. J.Mardles, D.Sc., F.I.C., and W. J. Stern, A.R.C.S.,D.I.C., B.Sc.; assisted byN.R. Fowler, A.R.C.S., D.I.C.Communicated by the Director of Scientific Research - 661

(ii) Summary of a " Report on anti-knock investigations."—By A. Egerton, F.R.S., and S. F. Gates, B.Sc., M.A. . 692

VI

PAGE(iii) Hydrogen as an auxiliary fuel for a solid injection oil

engine.—By G. F. Mucklow, M.Sc. Communicated byProfessor 4. H. Gibson . . . . . . 706

(iv) On the equivalence between the dynamical system of amulti crank flywheel system and a certain electricalcircuit, with some suggestions for measuring criticalspeeds and shaft stresses by analogy.—-By E. B.Moullin, M.A. . . . . . . . . 7 2 2

(v) Torsional vibration in engines. Effect of fitting a damper,a flywheel, or a crankshaft-driven supercharger.—ByB. C. Carter, D.I.C., A.M.I.Mech.E. Presented by theDirector of Scientific Research - - - - - 731

Materials.

(i) Report on the " Burning" of aluminium.—By J. D.Grogan, B.A. Work performed at the National PhysicalLaboratory for the Engineering Research Board of theDepartment of Scientific and Industrial Research - - 768

(ii) The constitution and age-hardening of some ternary andquaternary alloys of aluminium containing nickel.—-ByKathleen E. Bingham, M.Sc. Work performed at theNational Physical Laboratory for the EngineeringResearch Board of the Department of Scientific andIndustrial Research . . . . . . . 7 8 0

(iii) Report on the accelerated ageing of " Y" alloy.—ByS. L. Archbutt, F.I.C., and J. D. Grogan, B.A. Workperformed for the Engineering Research Board of theDepartment of Scientific and Industrial Research - - 798

(iv) Mechanical properties of pure magnesium and certainmagnesium alloys in the wrought condition. By S. L.Archbutt, P.I.C., and J. W'. Jenkin, B.Sc., Ph.D.Work performed at the National Physical Laboratoryfor the Engineering Research Board of the Departmentof Scientific and Industrial Research. Presented by Dr.W . Rosenhain, F.R.S. - - - - - - - 8 0 8

(v) The variation in the fatigue strength of metals whentested in the presence of different liquids.—By G. D.Lehmann, B.Sc. (Eng.). Communicated by ProfessorC. F. Jenkin. Work performed for the EngineeringResearch Board of the Department of Scientific andIndustrial Research - - - - - - - 8 2 1

(vi) The torsion of circular and elliptical cylinders of homo-geneous aeolotropic materials.—By S. J. Wright, B.A.Work performed for the Engineering Research Boardof the Department of Scientific and Industrial Research 834

Miscellaneous.(i) D. M. Smith's method for the determination of the trans-

verse frequencies of vibration of uniform beams.—ByT. W. K. Clarke, B.A., and V. M. Falkner, B.Sc.Presented by the Director of Scientific Research - - 839

(ii) On a modification of the Chattock Gauge, designed toeliminate the change of the zero with temperature.—ByW. J. Duncan, B.Sc., A.M.I.Mech.E. - - - - 848

(iii) Comparison of Atalanta and model sea-worthiness andfore and aft angle.—By the Staffs of the Marine AircraftExperimental Establishment, Felixstowe, and theWilliam Froude National Tank, National PhysicalLaboratory - - - - - - - - - 8 5 3

Vll

INDEX TO SEBIAL NUMBERS or THE TECHNICAL REPOBTS.

Report No.R. & M. 1029

10301031103210331034

„ 1035103610371038103910401041104210431044

„ 10451046104710481049105110521053105410551056

„ 1057

PAGE70629183419831832876878080879860333944946835549072236020321338320039673182182417612

Report No.R. & M. 1058

10591060106110621063106410651066106710681069107010711072107310741075107610771078107910801082108310841085

PAGE. 839. 271• 229

516• 661• 114• 152

54• 122• 368• 235• 848• 142• 147• 189• 402• 392• 258• 853• 239• 430• 692

441• 66• 379

78• 405

vm

MEMBERS OF THE COMMITTEE.

March 1927.

Sir RICHARD GLAZEBROOK, K.C.B., F.R.S. (Chairman}.Sir JOSEPH PETAVEL, K.B.E., F.R.S. (Vice-Chairman).*Professor L. BAIRSTOW, C.B.E., F.R.S.Dr. R. FERGUSO:NV|-Professor B. M. JONES, A.F.C.Dr. H. LAMB, F.R.S.Professor F. A. LINDEMANST, F.R.S.Lieut.-Colonel M. O'GoRMAN, C.B., D.Sc.Dr. G. C. SIMPSON, C.B., C.B.E., F.R.S.Dr. F. E. SMITH, C.B., C.B.E., F.R.S. JProfessor G. I. TAYLOR, F.R.S.Mr. H. T. TIZARD, C.B., F.R.S.Mr. H. E. WIMPERIS, O.B.E., F.R.Ae.S., M.I.E.E.

Secretary : Mr. J. L. NAYLER.

Assistant Secretary : Mr. E. OWER.

National Physical Laboratory,Teddington, Middlesex.

* Representing the Department of Scientific and Industrial Research,t Representing the War Office,j Representing the Admiralty.

AERONAUTICAL RESEARCHCOMMITTEE.

Report for the Year 1926-27.May, 1927.

Lieut.-Colonel The Rt. Hon. Sir SAMUEL HOARE, Bart..G.B.E., C.M.G., M.P., Secretary of State for Air.

SIR,THE Aeronautical Research Committee submit their report

for the year 1926-27.

The Committee have to report during that period a steadyprogress both in experimental and theoretical work; in manycases, research has indicated new directions for advance inaeronautical science.

Equipment for E>(>'/iim/tlnl II oil (it tJ>e Various ResearchJ^trtbJi^lii (/it* — Duimii tin- jeai the Aeronautical Research( on i iv i t t c t viMted the National Physical Laboratory andinspected all the Departments in which work was being carriedout under their direction. The Flutter Sub-Committee visitedthe N.P.L. to see wind tunnel experiments in progress on this^ubject and also visited Famborough to see certain fractured>pars and experiments bearing thereon. The Engine Sub-Committee also visited the Royal Aircraft Establishment.The Accidents Investigation Sub-Committee and the Air Trans-port Sub-Committee have visited Croydon Aerodrome. TheSeaplane Sub-Committee held a meeting at the Marine AircraftExperimental Establishment, Felixstowe.

Full use has been made of the experimental equipment atthe various establishments where the aeronautical researchco-ordinated by the Committee is in progress, and the researchstaffs at the various establishments have a programme sufficientto keep them fully occupied. Mention is made below of themore important researches completed or in hand during thepast year. The flying skill of the pilots at the R.A.E. has re-sulted hi obtaining a high degree of accuracy in experimentalwork and the Committee wish to place on record their greatindebtedness for the assistance thus rendered. The Committeealso wish to call attention to the excellent progress made atMartlesham in a series of investigations on the measurement ofperformance.

Consideration is now being given to the desirability of erectinga variable density wind tunnel and the Committee hope to makedefinite recommendations as to whether such a tunnel should

be erected in this country. The Committee note with regretthat it has not been possible to make financial provision fora high speed tank at the N.P.L. for seaplane research, but theyare informed that a small high speed tank may be provided atthe B.A.E.

Progress of Research.—In last year's report the Committeewelcomed and encouraged two new developments of that year,namely, the Cierva Autogiro and the Hill Tailless Aeroplane.Both these types of machine are being developed, but no out-standing step in progress can be reported during the past year.

Reference was made in last year's report to an investigationby Professor Callendar on the phenomenon of detonation ininternal combustion engines. The Committee have receiver]from him a second report on the same subject. This relatesto the chemical side of the investigation and suggests an explana-tion, of the cause of detonation in engines using liquid fueKAccording to Professor Callendar, detonation is due to the forma-tion of organic peroxides which become concentrated in thenuclear drops during compression and which ignite the dropssimultaneously when the detonation temperature of the peroxideis reached. This report is published as R. & M. 1062. Otherwork on the same subject has been carried out by Mr. A. C.Egerton,who has studied the detonation of gaseous mixtures in tubet..The gas is ignited by a high tension spark and the progressof the flame recorded photographically for acetylene-oxygen andpentane-oxygen mixtures. The effects of varying the initialtemperature and pressure and those due to the addition of anti-knocks are discussed in the published report R. & M. 1079.

The problem of nutter has been further studied during thepast year. The N.P.L. are now able to demonstrate at willthe various types of nutter that have been experienced in flight.The problem of determining the aerodynamic characteristics ofaircraft during flutter is being attacked quantitatively. Certainrecommendations for the avoidance of dangerous vibrations infuture aircraft have already been put forward while modificationsto existing types of aeroplanes that have exhibited this pheno-menon, with a view to its suppression, have been suggested.

More detailed mention of these and other items of researchare given below and in the appropriate supplements attachedto this report.

Aerodynamics.—The Aerodynamics Sub-Committee advise theCommittee upon work on this subject at the N.P.L., the R.A.E.,and elsewhere, a large part of the detail being discussed byvarious Panels. The Stability and Control Panel deal withresearch on control at low speeds; the Vortex Panel have dis-cussed the application of the Lanchester-Prandtl circulationtheory to airscrew theory as developed by the R.A.E. and N.P.L.;the Scale Effect Panel have considered the application of modelresults to full scale and the advantages that might result from

the construction of a variable density wind tunnel; the DesignPanel have dealt with certain questions of design. Recently anAirscrew Panel lias been appointed to lay down a programme ofexperiments to assist in the design of airscrews of high efficiencywhen the tip speed approaches the velocity of sound.

Stability and Control.—The Committee consider it importantthat routine stability tests should be carried out on new typesof aeroplanes at Martlesham in addition to the performancetests which are already a normal procedure. A series of practicaltests to determine the stability, balance and controllabilityof aeroplanes has therefore been drawn up with a view to trialthere in order to gain knowledge on their practicability forroutine purposes. The scheme has been tentatively tried outat the R.A.E. on the Bristol Fighter and the D.H.9A, and it hasbeen suggested that Martlesham should ultimately make useof a similar scheme of tests for all new types of aircraft.

Further progress has been made by the Air Ministry withfitting the slot-and-aileron control to various aeroplanes and theresults show that this device can be made to give adequate controlwhen an aeroplane is stalled. It has already been tried 011several aeroplanes. The effect on performance has been measuredin some cases and the reduction of the maximum speed of theBristol Fighter did not exceed 2 m.p.h.

The desirability, as a temporary measure pending the intro-duction of the slot-and-aileron control, of fitting a larger finand rudder to the Bristol Fighter has been previously mentionedand action in this connection has been taken by the Air Ministry.Bound up with this question is the amount of rudder power thatshould be provided for all aeroplanes, and with the concurrenceof the Committee the Air Ministry have issued a memorandumto all aircraft designing firms laying down a formula for therudder volume required to give adequate control. The fitting oflarger rudders may involve an increase of weight of the fuselage,but from data which has been put before the Committee, itappears that such increase will not be large in any new designof aeroplane; in any case adequate control of a machine whenstalled is a requirement of the greatest importance and this factmust be continually borne in mind.

The importance of stalling in relation to a serious accidenthas again received careful consideration and reference to thismatter is made elsewhere. With the present day design ofaeroplane, stalling should be avoided in flight, apart from stepstaken to impress on pilots in training what the effect of stallinghas on an aeroplane. If all aeroplanes were designed so asto give powerful control for orientation after stalling, a largenumber of fatal accidents would be avoided, for accidents whichoriginate from other causes frequently have no serious conse-quences unless stalling supervenes. Adequate control is ob-tainable by the use of the slot-and-aileron and an adequate rudder;other means also may be developed in the future. Pending

A 2

the development of some such device a warning to pilots byinstruments of the approach of the stall might be tried out ona large scale with probable advantage in a reduction of thenumber of accidents involving loss of aerodynamic control.

Attention has been paid during the year to the controlcharacteristics of aeroplanes having thick wings; in particular,as exemplified by a well known monoplane, which was stated to beexceptionally controllable particularly at low speeds.

Experiments made both in a wind tunnel on a model and,by experienced pilots, on the machine itself, have shown thatin normal flight the controls of this machine are unusually lightand well balanced.

In stalled flight it is subject to the'dangers common to mostaeroplanes, but as a consequence of the thick high Mft wing thechange of attitude on approaching the stall is specially marked,thus giving warning to the pilot and possibly giving rise to thebelief that the aeroplane is controllable at very low speeds,since it leads the pilot to suppose that his machine is stalledwhen in fact it is not.

A report giving a more detailed account of this work is incourse of preparation.

As aii'ecting the general question of the lateral stability ofaeroplanes, a brief reference should be made to a report byMr. H. M. Garner, R. & M. 1077, on controlled motion. Inthis paper attention is drawn to the importance of retaininga sufficient dihedral angle. Not only will an aeroplane withadequate dihedral be less fatiguing to fly, but in some cases(for example, racing aeroplanes) an inadequate dihedral maymake an aeroplane dangerous.

The problem of spinning has received much considerationduring the year and at the Committee's request a monographon the subject has been prepared. This, which forms a compre-hensive treatment of an important subject, has been carefullycriticised and endorsed by the Stability and Control Panel andthe monograph has gone forward in the names of the two jointauthors for publication as R. & M. 1001, entitled " The Spinningof Aeroplanes." The further development of the subject bythe complete representation of a spin in the wind tunnel is pro-gressing ; it is hoped that this work in conjunction with detailedrecords of the motion of spinning aeroplanes, taken at the R.A.E.,will elucidate those points which are still obscure.

Scale Effect.—The Scale Effect Panel have presented an interimreport after an examination of all the existing evidence on thescale effect of aerofoils and the advantages that might resultfrom the use of a variable density wind tunnel. The evidenceincludes full scale experiments at Farnborough, model tests atthe N.P.L. and at the R.A.E., and published U.S.A. tests carriedo\it in their variable density wind tunnel. Apart from theR.AJF. 15 section, there are no comparative results obtainedbv all three methods.

The evidence available as to the extent to which tunneltests at full Reynolds number may be relied upon to give fullscale results in free flight is, so far as it goes, encouraging, but themodels compared have not been exactly similar and there remainssome uncertainty in the case of R.A.F. 15, the wing on whichBritish full scale data is most complete. The evidence cannot,therefore, yet be regarded as conclusive. Tests on biplanemodels with wings of section R.A.F. 1(5, 19 and 30 have beencarried out by the courtesy and willingness of the XationalAdvisory Committee for Aeronautics and the Panel has yet todiscuss their report before putting forward a final report.

In connection with this subject the Panel recommend experi-ments on a model tunnel of an open jet type, a form which shouldbe considered if it were proposed to construct either a variabledensity, or a new atmospheric, tunnel in this country.

Tailless Aeroplane.—The Committee have watched withinterest the development of the Hill Tailless Aeroplane. Variousexperimental difficulties have been experienced with the lightlyloaded aeroplane of this type, but these have now been overcome.It is understood that the type is being developed.

International Trials.—The Japanese Aeronautical ResearchInstitute have sent to the Committee the results of their testson the International Trials airship model and a note has beenprepared by the X.P L comparing the American, Japaneseand British results. Considerable discrepancies are found betweenthe various results obtained in the complete series of «ind tunnelsin which experiments have been conducted, although there ismoderately good agreement between the tests in Japan, at theU.S. Bureau of Standards, and in the K.P.L. wind tunnel 7 ft.,Xo. 3.

The airship models are at present being tested by ProfessorBairstow in the wind tunnel at the Imperial College of Science,London, and these tests are of special interest on account ofthe design of tunnel which has no drop of static pressure alongits centre line. On the completion of these tests the modelswill go to France.

The International Trials R.A.F. 15 model aerofoil has beentested in Holland and the results agree well with our own tents.This model is now in Japan.

Performance.—During the major portion of the year theDuplex wind tunnel at the N.P.L. has been devoted to testson high speed seaplanes for the Air Ministry. It is understoodthat the results of these tests have proved of considerable valueto the Air Ministry and to the designers of the seaplanes whichmay compete in this year's contest for the Schneider trophy.From the research point of view the work has provided interestinginformation and the Committee have requested that, as far aspossible, flight tests should be made to link up the full scale

6

performance with the model results. Other problems, such asbody drag, are under consideration, but it may be difficult tolay down a profitable line of systematic investigation exceptby the development of some specific design; on such lines theN.P.L. experiments have provided information of considerableinterest.

Another important line of development for high speedaircraft is the design of an airscrew which will work efficientlywhen running at high tip speeds. Some airscrew experimentshave already been made at Farnborough on this subject andtests on aerofoils at very high speeds in a small wind tunnelat the N.P.L. have also produced resxilts of interest. A smallAirscrew Panel has been specially appointed to discuss whatexperiments might most usefully be made in the near future.

For the development of our knowledge of surface frictionon wing sections a series of tests are to be put in hand at theN.P.L. on symmetrical sections of the Joukowski type designedb\ the R.A.E. Measurements of minimum drag and of lift atsmall angles of incidence will be made, to be followed later bypressure measurements over the median section.

Much useful work has been carried out at Martlesham duringthe past year on methods of performance testing and a numberof reports on the subject have been published by the Committee.The new method of performance testing put forward by Mr. Caponhas now been adopted for research purposes and has been acceptedby the Industry. Certain difficulties which arose during theyear in connection with the adequate calibration of instrumenthave now been overcome by co-operation with the N.P.L. Arecent paper from Martlesham deals with the power of the normalengine. It has been generally assumed that the engine powerwas a function of the pressure only, these experiments suggestthat a function of the pressure to the two-thirds and of thedensity to one-third power gives a closer approximation to thetruth, and the whole matter has been made a subject for furtherexperiment.

Fluid Motion.—Interesting experiments have been made at theN .P.L. on the two-dimensional air flow behind a flat plate inclinedat various angles to the wind. The results show that as theinclination of the plate is decreased from 90°, both the frequencyand the velocity with which the individual vortices passdownstream become greater: and that the longitudinal spacingbetween successive vortices becomes smaller. There is anappreciable opening-out of the vortex street with increasingdistance downstream. Measurements of vortex strength showthat vorticity is shed at the same rate from the two edges of theplate; this rate slowly decreases with the inclination of theplate. The position and strength of the vortices thrown offby the plate have been determined and show fair agreementwith Karman's formulae, the longitudinal spacing of the vortices

remaining constant for a distance of several plate widths downwind. Similar measurements of the flow behind a stalled aerofoilare in hand.

An experimental water tank has been erected at Cambridgeby Professor B. M. Jones and Mr. W. S. Farren in which two-dimensional bodies are towed through water. Some preliminaryresults have already been obtained at a Reynolds number ofapproximately 10*, and it is hoped to obtain results at Reynoldsnumbers as high as 3 X 105 (the Reynolds number of normalflight is 3 X 106). The results already obtained with thisapparatus are described in the preliminary report (R. & M. 1065)and show considerable promise. The investigators are con-tinuing this research, a part of the cost of which will be borneby the £1,000 fund for individual investigators.

A study has been made of the characteristics of two-dimensional flow around an aerofoil mounted in a \\ind tunnel.A thorough exploration of velocity was made and the law ofKutta and Joukowski verified. This work has been furtherdiscussed and from a comparison of theory and observation ithas been shown that the forward stagnation point on an aerofoilmounted in a wind tunnel does not, in general, agree in positionwith that for the theoretical flow of an inviscid fluid having anequal circulation (vfcT.2]03ff) .* Some difficulty was experiencedin accounting for a difference between results obtained in theelectrical tank and others by Dr. Kirdany. using the analyticalmethod of Professor Bairstow. It would now appear that thepressure curves estimated from the electrical tank results havenot (with the apparatus then used) the requisite accuracy in thecase of observations taken near the surface of the model.

The attention of T}ho Committee has also been directed toexperiments on the effect of removing the boundary layer by-u"tion at suitable points. These show that in certain instance^a marked improvement in the flow has been effected by thismeans. Some preliminary experiments have been made at theR.A.J3. and other experiments are contemplated either at thatestablishment or at the X.P.L.

Airscrews.—Further progress has been made during the•v ear on the development of the vortex theory of airscrewh.( a reful consideration has been paid to all the available evidenceand the experimental data have been compared with theory. Theseneral agreement is very satisfactory and it is considered thatthe theory is suitable for ordinary design purposes when theairscrew tip speed does not exceed about 900 ft./sec. Somediscrepancies on total thrust and drag occur for small values ofadvance per revolution for airscrews with a small number ofblades and for airscrews with high pitch/diameter ratio;these and other points are dealt with in a published report(R. & M. 1040).

* To be published shortly.

Mr. Glauert at the R.A.E. has developed a theory of theAutogiro, results of which have been communicated in a lectureto the Royal Aeronautical Society. In parallel with this worka number of experiments have been made at the N.P.L. onmodels tested in a wind tunnel and other models have beenobserved whilst dropping from the roof of one of the airshipsheds at Farnborough. The results to date suggest that thetheory gives a close approximation to actual experience in mostrespects, but that there is still a discrepancy between freeflight experiments and the prediction from wind tunnel testsof the vertical rate of fall. It is hoped that experimentsshortly to be put in hand in the Duplex tunnel will clear up thispoint.

Design.—Some attention has been paid to comparisonsbetween French and British methods of stressing and arrange-ments have been made for testing the same aeroplane by bothmethods. The experiments have been carried out but theresults have not yet been discussed.

Some experiments have been made at the JSF.P.L. on aerofoilswith slots using the R.A.F.31 section, the results of which havebeen published as R. & M. 1063. It is hoped as time permitsto make further research on slotted wings, attention being paidspecially to the practical application of the slot as regards theforce required for its adjustment and the need for limiting theangle of incidence at which maximum lift is obtained. Theco-operation of Mr. Handley Page in this work has been welcomedand certain tests carried out by his firm have been published asR. & M. 1055,

Leader Cable.—The Committee have been informed of progresswith the Leader cable and it is hoped that full scale experimentswill be made in the near future. A preliminary report fromthe R.A.E. has drawn attention to a difficulty that may arisefrom the use of this cable. Various schemes are being triedto overcome this difficulty, which arises from the rotationof the coils in the recording instrument as the aeroplane banks.

Engines.—During the year considerable advances havebeen made in the study of the effect of lead ethyl and similarsubstances in stopping detonation in engines. A report(R. & M. 1013) by Professor Callendar and the staff at the AirMinistry Laboratory has been followed by a further reportR. & M. 1062 (see also Engineering, February 4th, llth and]8th, 1927), which greatly extends our knowledge of the modeof combustion of hydrocarbons. It has been shown that theorganic peroxides are formed when combustion begins, andthat these bodiee promote detonation when present in measurablequantities: for instance, small quantities of benzoyl peroxideadded to petrol induce violent detonation. Lead ethyl andsimilar anti-knocks appear to influence rate of combustion mainlyby preventing the accumulation of peroxides. It has also been

shown that peroxides are formed in greater amounts when thefuel is present in the form of a fine spray then when it iscompletely vaporised.

The Committee have also been informed of the results ofindependent work carried out by Mr. A. C. Egerton at theClarendon Laboratory, Oxford. The experimental results ofthis work are in close accord with the results obtained at theAir Ministry Laboratory. In particular, Mr. Egerton showsthat the ignition temperature of liquid fuels is considerablylower when they are in the form of a fuel spray than when theyare vaporised, and that anti-knocks raise the ignition temperaturein air by preventing the formation of intermediate partiallyoxidised products of combustion. On the advice of the Com-mittee a grant has been made to Mr. Egerton to enable him toextend his work.

Although our knowledge of the phenomena of detonationhas thu?> been greatly increased, it cannot, uirfortunately, be*aicl that any important practical result has been achieved,for no available " anti-knock " has been discovered of greatereffectiveness than iron carbonyl or lead ethyl; nor indeed doessuch a discovery seem very probable. The subject is, however,of such importance from the point of view of attaining thehighest thermal efficiency that the Committee consider it desirableto continue the experimental work until a satisfactory explanation"f the whole phenomena is possible.

During the course of the year the Engine Sub-Committeehave been engaged in general investigations on the problems of>upercharging aircraft engines. The general problem to considerin connection with all possible developments of aircraft enginesis how to secure the greatest power with a given weight underdefinite operating conditions. The exact definition of theoperating conditions is important; for example, it does notfollow that a design of engine intended for operating at verygreat heights gives necessarily the lightest power plant for lowheights. The problem is further complicated by the necessityof taking into account fuel consumption, for what matters isnot simply the weight of the engine alone, but the weight of thewhole plant, including the fuel necessary for a given range ofaction.

Any method of supercharging tends to increase fuel con-sumption because lower compression ratios have to be used toavoid detonation. In assessing the value of supercharged enginesit must be remembered that un-supercharged engines can now beconstructed which may consume more than their own weight offuel in a three hours flight. Nothing, therefore, that willdecrease the weight of the engine is of real practical importanceif it increases unduly the weight of fuel which it is necessary tocarry. Exact data on the fuel consumption of superchargedengines are lacking; and the Committee have therefore arrangedfor the construction of a single cylinder unit which will be capable

10

of being supercharged to several atmospheres pressure, andwhich will enable important questions of detonation, fuel con-sumption and heat transfer to be accurately explored.

On the general question of fuel consumption which, as hasalready been implied, becomes of greater importance the morethe weight of an engine is reduced, the Committee draws attentionto the fact that no practical appliance is in use for automaticallycontrolling the supply of fuel from a carburetter to meet changingconditions of atmospheric density. In the case of civilian aircraftthis is not very important, partly because there is no incentiveto fly at great heights for a long time, and partly because underthe conditions of operation a skilled pilot can adjust his petrolsupply accurately by means of a hand control. This is almostimpossible to do in the case of military aircraft where theoperating conditions may change so rapidly and where the pilothas many important matters to attend to, besides controllinghis fuel supply so as to get the highest efficiency. The Com-mittee regard the provision of some suitable automatic arrange-ments as of great importance.

Other important matters under discussion by the EngineSub-Committee include the difficulty of getting sparking plugsto operate satisfactorily for any length of time under the severeconditions to which they are subjected in modern high dutyengines; the torsional vibration of crankshafts ; and the develop-ment of compression ignition engines for use in aircraft. Smallpanels have been appointed to consider these matters in detail.

Elasticity and Fatigue.—Work has continued during the yearon the strength of materials to resist crippling. The presentB.E.S.A. proof test has been investigated as an acceptance testfor thin sheet metal and its unsuitability for bringing out thequalities required has been demonstrated. Whereas experimentshows that the elastic crippling load varies in all cases as thefree width, the theory of South well and Skan indicates that thecrippling load should vary universally as the square of the freewidth. This discrepancy may be due to an additional lateralconstraint imposed by the apparatus and the matter is beinginvestigated theoretically. To clear up the questions in doubtit is proposed to make additional tests on struts or spars madeof thin sheet materials to be supplied by Mcssis. Boulton & Paul,to make crippling tests on the material from the same struts,and to construct an apparatus in which elastic crippling can befurther investigated without the application of any lateralconstraint.

Mr. Brazier, formerly of the R.A.E., has communicated apaper dealing with theoretical and experimental work on thefailure of thin tubes on metal aeroplane spars, R. & M. 1081.The paper constitutes an important step towards the developmentof a rational theory for the design of such members when composedof thin sheet metal. It relates primarily to the conditions ofinstability of the flange members.

11A programme of research on elastic moduli and other

problems on the elastic properties of materials is being under-taken by the Engineering Department of the National PhysicalLaboratory. The first paper on this -work gives the results ofthe values of Poisson's ratio in materials undergoing cyclicalvariations of stress. A high degree of precision was obtainedin tests employing a Lamb lateral strain-meter, an instrumentwhich should prove of great value in attacking various elasticityproblems.

Mention has been made in the previous Annual Report of theslip band phenomena caused by the application of alternatingcouples to a single crystal in the form of a circular cylinder. Itappears from a theoretical paper by Wright, B. & M. 1031, thatthe slip band phenomena observed are in accordance with thosepredicted by an analysis which takes into consideration thetype of elastic symmetry associated with the cubic crystal.

Professor Jenkin has communicated a first report on aninvestigation into the fatigue of metals in the presence of corrosiveagents. The subject of corrosion fatigue is one of considerableimportance and it has been found that the fatigue strength ofmetals when tested in the presence of different liquids was withone exception reduced by the presence of the agent. In thisexception, using sodium chloride, the strength was increasedby about 6 per cent, (see R. & M. 1054).

Light Alloys,—Work at the N.P.L. has proceeded on theproperties of aluminium alloys. In the past, attention hasprimarily been paid to cast alloys and attention was drawn lastyear to the new method of casting whereby sounder materialcould be produced. Further attention has been paid to thissubject and the work has included the effect of passing gases,such as nitrogen,, through the material.

A report has been published 011 burnt aluminium. Theremelting of low grade aluminium produced brittleness which hasbeen traced to the presence of impurities or gaseous inclusions;annealing or bubbling an inert gas through the melt has beenshown to be very beneficial.

Experiments at the N.P.L. have also been made on siliconalloys including " Wilmil " and " Alpax." An aluminium-copper-silicon alloy, 2 per cent, silicon, 3| per cent, copper, was castinto sound ingots which were forged satisfactorily.

In addition to further investigations on casting processes,more attention is to be paid to wrought light alloys available inthe form of rolled sheet or rod or as forgings. All the availablealloys produced commercially at the present time have physicalproperties of much the same order. In the study and searchfor new alloys the addition of suitable elements to form ternaryand qiiaternary alloys is necessary, and work will include theuse of such elements as boron, silicon, beryllium, chromium, &c.

The methods of melting and casting of aluminium alloys willbe considered from the point of view of the removal of gases,

12

fluxes, &e., and an enquiry into the effect of impurities andinclusions on the properties of duralumin and " Y " alloy willbe continued. The constitutional work will be mainly in regardto age hardening and modification. Beryllium may proveiiseful for alloying purposes and experiments on this metal areprogressing.

Further work on magnesium alloys is under consideration.At the R.A.E. work is in hand on the application of laboratory

methods to foundry practice, and in connection with metalairscrews an investigation has commenced on methods of castingwhich aim at the production of sound ingots of large size. Test-including the use of the anodic process is also in progress inconnection with the question of corrosion.

Air Transport.—The Air Transport Sub-Committee haveheld three meetings during the past year. They have assistedthe Accidents Sub-Committee in connection with problems offire prevention and have visited in this connection the Aerodromeof Imperial Airways, Limited, at Croydon.

The Sub-Committee have discussed the problem of tractorand pusher airscrews: for the comfort of passengers there areadvantages in the use of pusher airscrews which will give less,noise in the cabin if placed sufficiently aft. From a preliminaryexamination of the problem made by the R.A.E. at the requestof the Sub-Committee, it seems possible that an aeroplane witha pusher screw can be made as efficient as one having a tractorairscrew, provided suitable nacelles can be designed. Thistechnical probem is now under discussion by the Design Panel.

The Committee welcome the appointment at the end of theyear of Rear-Admiral M. F. Sueter as member of this Sub-Committee. Further, in order to maintain close contact withpractical aspects of air transport problems, Major R. H. Mayo,consulting engineer of Imperial Airways, Ltd., has been invited toattend meetings.

Airnhips.—The Cardington staff have completed the analysisof the full scale pressure plotting experiments on the hull andtins of R.33, to which reference was made in last year's report.Their work is of great interest and forms a very notable additionto full scale research on airships carried out to date in this orin any other country. The volume of work involved was con-siderable and the number of instruments required was large.Measurements were made along a generator of the airship, bothin straight and circling flight, and in pitched flight with excessbuoyancy: pressure measurements were also made on the fins.The general character of the curves obtained from the experimentsis in good agreement with model results. Certain model experi-ments at the N.P.L. on the whirling arm are needed to give astrict comparison between model and full scale experiment andthese are to be put in hand.

Tests have been made in the wind tunnels at the X.P.L. oumodels to determine the resistance, .stability characteristics, and

13

balance of the controls of the ship now under construction forthe Air Ministry with very satisfactory results.

The Committee have been consulted by the Air Council as tothe methods of stressing for airworthiness the two five millioncubic foot airships now under construction. The Air Councilexpressed the desire to be satisfied by the highest possibleauthority that the principles adopted by the designers are assatisfactory as the present state of knowledge permits. In theirreply the Committee stated that the Repot t of the AirshipStressing Panel (R. & M. 800) and the Report of the Airworthinessof Airships Panel (R. & M. 970) together outlined the generalprinciples forming the basis of the required stress calculation*.The question of the application of these general principles toindividual designs was in the opinion oi the Committee bestreferred to individual experts.

It is understood that the Air Council have made satisfactoryarrangements on these lines to determine the airworthiness ofthe new airships. No other questions relating to airships havebeen referred to the Committee.

Two reports describing successful hooking on experimentsfrom an aeroplane to an airship have been received and haveshown that this kind of manoeuvre can be successfullyaccomplished.

Seaplanes.—The Seaplane Sub-Committee have held onemeeting during the year, when they visited Felixstowe anddiscussed reports on research work on the strength of seaplanes.Xo appreciable progress on seaplane research, apart from thaton the strength of hulls, has been made during the past year,and the programme of research in the William Froude Tankremains substantially the same as that of the previous year.In view of the pressure of mercantile work in this tank and of thelack of facilities for obtaining a sufficiently high speed, theSub-Committee do not expect much progress until a high speedtank has been provided.

A preliminary report describing the results of flexibility tests,on the Titania hull has been received and much useful experienceobtained. This report will be written up for publication, andwith a view to doing further work on a steel hull, it has beenrecommended that the R.A.E. should further develop theirapparatus.

Some experiments on the Atalanta with transverse inclinationhave now been completed in the William Froude Tank and thecomparison of the complete experiment^ both full scale andmodel, have been made and will be published shortly asR. & M. 1076.

Accidents.—The Accidents Investigation Sub-Committee havecontinued their enquiries into the causes of accidents to aircraft.Much of their work has consequently been concerned withspecific matters brought to their notice by the Air Ministry orthe Aeronautical Research Committee and has been dealt withby special Panels or in conference with other Sub-Committees.

14

Much of this work is necessarily of a specially confidentialcharacter, other items, e.g., the problem of wing nutter, arediscussed in this Report under the appropriate headings.

The main point to which, as a result of the experience ofpast years, the Sub-Committee again desire to draw attentionis the importance of stalling in relation to serious accidents.Accidents arising from other causes are, if 110 stall occurs,frequently less serious in their consequences; they becomeserious if they are followed by a stall; it is when the aeroplanebecomes uncontrollable that the more dangerous crash ensues.To secure the control of aircraft at low speeds would in theopinion of the Committee greatly reduce both the number andthe serious nature of accidents.

The Committee have also devoted attention to the problemof the prevention of fire in aircraft which sometimes results froma crash; they are now engaged in the preparation of a reportbased on the experience gained in recent years.

Few experiments have been made since the publication of theCommittee's reports on this subject in 1922 and the time hasnow come when the investigation of this important mattermight usefully be carried further. The Sub-Committee haveviewed with interest certain films of experimental crashes lentby the courtesy of the U.S.A., and are prrferably consideringwhether experiments of this character might with advantage bemade in this country in order to investigate more fully the causesof fire in aeroplanes.

The precautionary measure previously recommended of afireproof bulkhead in the single engined aeroplane between theengine and the pilot and the exclusion, as far as possible, of allinflammable matter from the engine side of the bulkhead is atpresent the chief definitely proved precaution. The problem ofthe multi-engined aeroplane is more complex, and while petrolremains the fuel for aircraft engines all efforts must be made toguard against its ignition in bulk. Other matters, such as thedevelopment of a handier fire extinguisher and the use of flares,have been investigated.

The flutter of aeroplanes has also been examined by theAccidents Sub-Committee. The theoretical investigation hasproceeded steadily at the N.P.L. and some reports have alreadybeen published. Wing flutter is very greatly affected by themass distribution and aerodynamic loading of the ailerons, andrecently the N.P.L. have demonstrated in a wind tunnel at willthe types of flutter predicted by the theoretical analysis.

In order to reduce the risk of flutter it appears desirable todesign the ailerons so that their centre of gravity comes on thehinge and to arrange for an appreciable part of the ailerons to beinside the outer interplane struts. Regarded from anotherstandpoint, wing flutter depends, in part, on the elasticity ofthe wing structure and, other things being the same, it is prob-able that a stiffer structure can flutter only at the higher speeds.

1.3

The scientific problem of flutter has, on the recommendation ofthe Accidents Sub-Committee, been referred to a Sub-Committeeconstituted for the purpose of the study of nutter.

Relations with the Aircraft Industry.—In accordance with theTerms of Reference of the Committee there have been during theyear two conferences with representatives of the Society ofBritish Aircraft Constructors. At both meetings a six-monthlystatement of the programme of research wa^ put before theSociety, and after a free discussion of the various items theSociety put forward a number of suggestions. Action hasalready been taken in connection with their proposals.

The arrangements made last year for keeping the Society inclose touch with current research have continued and theCommittee understand that these arrangements have beensatisfactory. The Committee wish to acknowledge the assistancethat has been provided in certain problems by the submission oftechnical details. There has been co-operation with Messrs.Handley Page in research on slotted wings and the Committeehave expressed to the Society their willingness to co-opei-atewith individual firms on other subjects.

Relations mlh the American National Advisory Committee forAe> OP antics.—The cordial relations of past years between theAeronautical 'Research Committee and the American NationalAdvisory Committee for Aeronautics have continued. TheAmerican Committee have tested models of throe wing sectionsin their variable density wind tunnel so as to ascertain the possi-bility of determining by laboratory methods the scale effect onmaximum lift coefficient; the uncertainty on this point is acause of serious difficulty to designers. It i& hoped from theresults of these tests to come to a definite conclusion as to thedesirability of constiucting a variable density wind tunnel inthis country. In any case the ultimate standard of referencewill be, in the view of the Committee, as heretofore, full scaleflight tests carried out with adequate instruments. In order tohelp in the elucidation of the problems in question, the Com-mittee have forwarded to America for the vise of the N.A.C.A.several confidential papers which deal with the discussion ofscale effect.

In addition to the above, the American Committee havekindly supplied a model metal airscrew for comparative tests inclosed and open types of wind tunnel. The airscrew has alreadybeen tested in America in an open type tunnel and tests at theNational Physical Laboratory in a closed type wind tunnel willshortly be completed.

Relations with other bodies abroad.—The Committee exchangepublications and correspond with the Canadian AeronauticalResearch Committee. During the year they have sent toProfessor Parkin at Toronto Universit}' information on the useof experimental water tanks for the testing of seaplane models.

16

Publications are also exchanged in whole or in part with—National Advisory Committee for Aeronautics, Washington,

D.C., U.S.A.Service Technique de 1'Aeronautique, Chaussee de Waterloo,

Rhode St. Genese, Brussels.Directoria de Meteorologia Institute Central, Palacio dos

Estados—4° andar, Praca Marcehal Ancora, Rio deJaneiro, Brazil (meteorological papers).

Associate Air Research Committee, Montreal, Quebec,Canada.

Aerodyiiamisches Institut der Tech. Hochschule, Aachen,Germany.

Aerodynamische Versuchsanstalt, Gottingen, Germany.Rijks-Studiedisnst voor de Luchtvaart, Marine-Etablig.se-

ment, Amsterdam, Holland.Notiziorio Technico e della, Rivista Aeronautica. Viala

Torino, 19, Rome, Italy.Koku-Kenyuzyo (Aeronautical Research Institute), Huka-

gawa-ku, Tokyo, Japan.Personnel.—The Committee wish to record their thanks to

Air Vice-Marshal Sir W. H. G. Salmond, K.C.M.G., K.C.B.,D.S.O., who while holding the post of Air Member for Supplyand Reseaich has been piesent, whenever possible, at the moreimportant discussions and has assisted greatly the work of theCommittee. During the past four months the Committee havewelcomed at their deliberations the presence of his successor.Air Vice-Marshal Sir John Higgins, K.B.E., C.B., D.S.O., A.F.C.

Professor J. D. Cormack, C.M.G., C.B.E., D.Sc., MJnfet.C.E.,retired in accordance with the rota at the end of last year andhe was succeeded by Professor F. A. Lindemann, F.R.S.,Professor of Physics at Oxford University. With this exceptionthe personnel of the Committee has remained unchanged.

A number of changes have been made in the personnel ofSub-Committees and Panels, and a list of members of bodieswhich have been active during the year is appended. Wherepossible the rota of service foi previous years has been continued,but in the case of Sub-Committees or Panels appointed for aspecial purpose, no rota has been fixed; they have been dissolvedon the completion of their Terms of Reference.

The Committee welcome the appointment of a Superintendentof Scientific Research at the Royal Aircraft Establishment.

Finance.—The financial arrangements for the work of theCommittee have remained as in previous years. All researchwork having a direct application to aeronautics is financed byihe Air Ministry. The cost of investigations, which, in additionto their importance to aeronautics, have applications in a widersphere, is met by the Department of Scientific and IndustrialResearch.

Grants to Individual Research Workers.—A sum of £1,000 hasbeen made available to the Committee for the purpose of grants

17

to individual research workers during the year. Grants havebeen made for work on (1) the study of two-dimensional flowin a water tank at Cambridge University, (2) the fatigue ofmaterials at Birmingham University, (3) the completion of aninvestigation on anti-detonation at Oxford University, and(4) the use of Ethylene as a fuel for internal combustionengines at Cambridge University.

Researches at Universities.—In addition to the provision ofthe above grants, the Department of Scientific and IndustrialResearch have financed a research at Oxford University on thefatigue of materials in the presence of corrosive agents, and thecompletion of a research on cyclic strain and the phenomenonof understressing at Liverpool University. Other work is inhand on single cylinder internal combustion engine units atCambridge, Durham and Manchester Universities. Cambridgeand Durham Universities are also co-operating in work on thetorsional vibration of crankshafts with reference to a specialPanel appointed for this purpose.

Sub-Committees.—The following Sub-Committees have metduring the past year :—Accidents Investigation, Aerodynamics,Air Transport, Elasticity and Fatigue, Engine, Mutter, LightAlloys and Seaplane. The Airship Co-ordinating Sub-Committeehave not met since October, 1925. The Terms of Reference tothe various Sub-Committees have been reconsidered and therecommendations made by a small Sub-Committee appointedfor the purpose have been endorsed by the Committee.

The special Sub-Committee appointed to deal with questionsaffecting Kite Balloons have held no meeting but have been keptinformed of the progress of the research. The Relations withIndustry Sub-Committee have met on two occasions and havediscussed informally certain questions with representatives ofthe Society of British Aircraft Constructors. The programme putforward by the Wind Structures Sub-Committee has progressedsteadily; it has not been found necessary to call a meeting.

The Light Alloys Stib-Committee has been reconstituted,with the following Terms of Reference, as an Alloys Sub-Com-mittee :—(1) To supervise general researches on alloys for aero-nautical purposes at the N.P.L. and any other allied researchesreferred to them by the Aeronautical Research Committee; (2) Toadvise on metallurgical researches carried out in the researchestablishments of the Air Ministry; and (3) To report to theAeronautical Research Committee. The new Sub-Committee willco-ordinate work at the N.P.L. and the Royal Aircraft Establish-ment mainly with reference to aluminium and magnesium alloys.Questions relating to steel are not specifically excluded from thepurview of the Sub-Committee, but its duty in this directionwill be confined at present to noting results of value obtained byother bodies when these have a bearing on aeronautical con-struction. Researches on corrosion in hand at the R.A.E. willbe reported to this Sub-Committee.

a 28848 JB

IS

Collection and Collation of Researches in Aeronautics.—Atten-tion was drawn last year to the need of monographs to bring upto date the present state of knowledge in the various branches ofaeronautical science. This matter has been discussed by theCommittee at various times and they have reached the conclusionthat such monographs can only be satisfactorily written by thepersons who have actually been doing research on that particularbranch of the subject, consequently, they will only be issuedat relatively long intervals. Attention may here be called to anexcellent monograph (R. & M. 1001) on the subject of spinningwritten during the past year jointly by Mr. S. B. Gates andMr. L. W. Bryant, at the Royal Aircraft Establishment and atthe National Physical Laboratory respectively.

During discussion, the Society of British Aircraft Constructor;-has raised the more general question of collecting existing aero-nautical data so as to ascertain the gaps in existing knowledge.This knowledge might be collected and written up in the formof critical surveys or resumes on special subjects and it is under-stood that these resumes would be of considerable value to theAeronautical Industry. As their first application would be todesign, the Committee are of opinion that these could best beprepared by a person who normally uses the material for thepurposes of designing aircraft; it is understood that the S.B.A.C.are examining the matter. The Committee have been informedthat as a first step the S.B.A.C. have under preparation an indexof published papers on aeronautical research.

Publications.—The arrangements for publications made inprevious years have been continued and a list is appended of thereports issued during the year. As in previous years, someimportant papers on work carried out under the direction of theCommittee have been offered to and accepted by the RoyalSociety, while other papers have been communicated to TechnicalJournals.

Signed on behalf of the Committee,R. T. GLAZEBROOK,

Chairman.

19

The following reports have been approved for publicationduring the year and can be obtained from H.M. StationeryOffice :—

R.&M.No. Title. Author.

1049

1052

1056

1073

10741078

1080

1030

1033

10341040

1043

1046

1067

1055

1063

1066

AERODYNAMICS.PERFOBMANCE.

The direct measurement of the angle offlight path of an aeroplane as a meansof eliminating the effect of air currentson the measurements of lift and drag.

Full scale and model meastirements oflift and drag of Bristol Fighter withR.A.F. 30 wings.

Algebraic formulae for the performance ofan aircraft at full throttle.

Full scale measurement of lift and dragof a Bristol Fighter with slotted upperwings and standard lower wings.

Full scale tests of a suspended air logThe application of the algebraic formulas

of R. & M. 1056 to problems of aircraftperformance.

Note on the reduction of performancetests to the standard atmosphere.

AIBSCBEWS.Experiments with a family of airscrews,

including effect of tractor and pusherbodies. Part IV. On the effect ofplacing an airscrew in various positionswithin the nose of a streamline body.

On the advantages of an open jet type ofwind tunnel for airscrew tests.

The efficiency of an airscrew - - -The accuracy of the Vortex theory of

airscrews in the light of recent experi-mental work and its application toairscrew design.

Photographs of the flow round a modelscrew working in water especially inthe " Vortex Ring State."

The effect of body interference on airscrewperformance.

On the contraction of the slipstream ofan airscrew.

AEROFOILS AND WING SECTIONS.Tests on Handley Page Aerofoil A. 1 and

R.A.F. 31.Model experiments on R.A.F. 31 aerofoil

with Handley Page slot.Wind tunnel experiments on a symmetrical

aerofoil (GSttingen 429 section).

E. T. Jones andStevens.

Nutt, Harris andCaygill.

Capon.

Hardy.

Hardy.Jennings, Rowe and

Bowen.

Capon.

Bateman, Towiieudand Kirkup.

Grlauert and Lock.

Glauert.Glauert and Lock.

Lock and Townend.

Jennings.

Glauert.

Handley Page, Ltd.

Irving, Batson andWilliams.

Lock, Townend andGadd.

B 2

20

R.&M,No.

1070

10711072

10011047

1048

1051

1059

1060

1064

1068

1075

1077

1032

1065

1041

1042

Title.

AERODYNAMICS—continued.AEBOPOILS AND WING SUCTIONS—cont.

Wind, tunnel test of aerofoil M. 2 -

Wind tunnel test of aerofoil R.A.F. 34 -The characteristics of certain aerofoil

sections for infinite aspect ratio.

STABILITY AND CONTBCXL.The spinning of aeroplanes . . .Model tests of a combined slot-and-aileron

control on a wing of R.A.F. 15 sectionpush forward type of auxiliary.

Slot-and-aileron control on a wing ofR.A.F. 31 section with varkras types ofailerons.

Second report on full scale experiencewith the slot-and-aileron control fittedto a Bristol Fighter.

Rolling and aileron tests on a model ofa Fokker (F. VII.) monoplane wing..With an appendix on lift and dragmeasurements by Williams and Halli-day.

Ftying positions of control surfaces ofBristol Fighter.

The effects of stagger and gap on theaerodynamic properties of biplanes atlarge angles of incidence. Part I. Lift,drag and centre of pressure. Part II.Rolling and yawing moments due torolling.

The full scale determination of the lateralresistance derivatives of a BristolFighter aeroplane. Part II.

Lateral control at low speeds. Part I.'Measurement of rolling moments forthree wings at low rates of roll.Part II. Pressure measurements on awing whilst rotating at low speeds.

Lateral stability with special referenceto controlled motion.

GENERAL.Wind channel tests on a wing covered

with Monel metal gauze.Preliminary experiments on two-dimen-

sional flow round, bodies movingthrough a stationary fluid.

FLUTTER.Accidents to aeroplanes involving flutter

of the wings. Report of the AccidentsInvestigation Sub-Committee.

An investigation on wing flutter

Author.

Davies and Brad-field.

Davies.Hartshorn.

Gates and Bryant.Bradfield and

Hartshorn.

Bradfield andHartshorn.

Stevens.

Batson.

Hill.

Irving, Batson andBurge.

Gamer.

Scott-Hall.

Garner.

Bradfield.

Jones, Farren andLockyer.

Frazer.

21

R. & M.No.

1039

1044

1057

1061

1021

1029

1045

1053

10621079

1031

10351036

1037

1038

1054

1081

Title.

AIRSHIPS.

Stxesses in a stiff jointed polygonal frameunder a system of loads perpendicularto the plane of the frame.

Full scale pressure plotting experimentson hull and fins of H.M.A. R.33.

Oil the calculation of stresses in the hullsof rigid airships. (R. 38 MemorialPrize.)

The distribution of normal pressures overa prolate spheriod.

ENGINES.

The effect of metallic sols in delayingdetonation in internal combustionengines.

Hydrogen as an auxiliary fuel for a solidinjection oil engine.

On the equivalence between the dynamicsystem of a multi crank flywheelsystem and a certain electrical circuit,with some suggestions for measuringcritical speeds and shaft stresses byanalogy.

Torsional vibration in engines. Effectsof fitting a damper, a flywheel, or acrankshaft driven supercharger.

Dopes and detonation (Second Report) -Summary by the Secretary, Engine Sub-

Committee, of a report on anti-knockinvestigations.

MATERIALS.

The torsion of circular and ellipticalcylinders of homogeneous aeolotropicmaterial.

Report on the burning of aluminiumThe constitution and age-hardening of

some ternary and quaternary alloys ofaluminium containing nickel.

Mechanical properties of pure magnesiumand certain magnesium alloys in thewrought condition.

Report on the accelerated ageing of " Y "alloy.

The variation in the fatigue strength ofmetals when tested in the presence ofdifferent liquids.

The elastic instability of thin cylindricalshells and other " thin " sections sub-jected to axial flexure.

Author.

Baker.

Richmond.

Southwell.

Jones.

Sims and Mardles.

Mucklow.

Moullin.

Carter.

Callendar.Egerton and Gates.

Wright.

Grogan.Bingham.

Archbuttkin.

and Jen-

Archbutt and Gro-gan.

Lehmann.

Brazier.

22

R.&M.No. Title. Author.

1058

1069

1076

GENERAL.

D. M. Smith's method for the determina-tion of the transverse frequencies ofvibration of uniform beams.

On a modification of the Chattock gaugedesigned to eliminate the change of thezero with temperature.

Comparison of Atalanta and model sea-worthiness and Fore and Aft angle.

Clark and Falkner.

Duncan.

M.A.E.E., Felix-stowe, and Wil-liam Froude Tank,N.P.L.

The following reports have been accepted by the RoyalSociety :—

Title. Author.

The distribution of normal pressures on a prolate Jones.spheroid.

The elastic instability of thin cylindrical shells and Brazier.other " thin " sections subjected to axial flexure.

23

MEMBERSHIP OP SUB-COMMITTEES AND PANELS.March, 1927.

Accidents Investigation Sub-Committee.—Lieut. -Colonel M.O'GoRMAN, C.B., D.Sc. (Chairman); Professor L. BAIRSTOW,C.B.E.. F.R.S.; Mr. G. B. COCKBURN, O.B.E.; Professor B. M.JONES. M.A., A.F.C.; Major J. P. C. COOPER, M.C., O.B.E..and Lieut.-Colonel E. GOLD, D.S.O., F.R.S. (representing theAir Ministry); Squadron Leader T. H. ENGLAND, D.S.C., A.F.C.(representing the Directorate of Scientific Research); Sir J. E.PETAVEL, K.B.E., F.R.S. (representing the National PhysicalLaboratory); with the Chairman of the A.R.C. (ex officio).

Aerodynamics Sub-Committee.—Professor L. BAIRSTOW, C.B.E.,F.R.S. (Chairman); Mr. W. S. FARREN, M.B.E.; ProfessorB. M. JONES, M.A., A.F.C.; Dr. H. LAMB, F.R.S.; ProfessorF. A. LINDEMANN, F.R.S.; Lieut.-Colonel M. O'GORMAN, C.B.:Professor A. J. SUTTON PIPPARD, M.B.E., D.Sc.; Mr. R. V.SOUTHWELL, F.R.S.; Professor G. I. TAYLOR, F.R.S.; Dr. H. C.WATTS. D.Sc.; Major J. S. BFCHANAN, O.B.E., Mr. R. S. CAPON,B.A.. and Mr R. McKiNNON WOOD, M.B.E., B.A., A.M.I.C.E.,F.R.Ae.S. (representing the Directorate of Scientific Research);Sir J. E. PETAVEL, K.B.E., D.Sc., F.R.S., Mr. E. F. RELF, A.R.C.Sc.and Mr. A. FAGE, A.R.C.Sc., D.I.C. (representing the NationalPhysical Laboratory); with the Chairman of the A.R.C. (exofficio}.(Secretary : Mr. J. L. NAYLER. Assistant Secretary: Mr. E.

OWER.)Airship Co-ordinating Sub-Committee*—-Mr. H. T. TIZARD,

C.B.. F.R.S. (Chairman); Professor L. BAIRSTOW, C.B.E., F.R.S.;Mr. R. V. SOTTTHWELL, F.R.S.

Air Transport Sub-Committee.—Lieut.-Colonel M. O'GORMAN,C.B.. D.Sc. (Chairman); Professor L. BAIRSTOW, C.B.E., F.R.S.;Professor B. M. JONES, M.A., A.F.C.; Air Vice-Marshal Sir W.SEFTON BRANCKER, K.C.B., A.F.C.; Rear-Admiral M. F. SUETER,C.B., M.P.; Major J. S. BUCHANAN, O.B.E. (representing the AirMinistry); Sir J. E. PETAVEL, K.B.E., D.Sc., F.R.S. (representingthe National Physical Laboratory).

(Secretary : Mr. E. OWER.)Alloys Sub-Committee.—Professor G. I. TAYLOR, F.R.S.

(Chairman); Dr. L. AITCHISON, B.Sc., D.I.C.; Professor H. C. H.CARPENTER, F.R.S.; Dr. W. H. HATFIELD ; Dr. R. S. HUTTON,Mr. G. MORTIMER ; Dr. W. ROSENHAIN, F.R.S. (representing theN.P.L.); Mr. D. R. PYE, M.A., and Mr. H. SUTTON (representingthe Directorate of Scientific Research); Mr. J. INNES (representing

x This Sub-Committee has not carried out any special inquiries sinceOctober. 1925.

24

the Directorate of Naval Construction, Admiralty); EngineerCommander E. WILLIAMSON (representing the Engineer-in-Chief,Admiralty); with the Chairman of the A.R.C. (ex officio).

(Secretary : Mr. H. GOTJGH.)

Elasticity and Fatigue Sub-Committee.—Professor C. F. JENKIX,C.B.E., M.A., M.I.C.E. (Chairman); Professor D. HANSON, D.Sc.;Professor F. A. LINDEMANN, F.R.S.; Mr. R. V. SOUTHWELL,F.R.S.; Professor G. I. TAYLOE, F.R.S.; Dr. A. A. GKIFFITHand Mr. D. R. PYE, M.A. (representing the Directorate of ScientificResearch); Professor B. P. HAIGH, D.Sc. (representing theAdmiralty); Dr. W. ROSENHAIN, F.R.S., and Dr. T. E. STANTOX,C.B.E., F.R.S. (representing the National Physical Laboratory);with the Chairman of the A.R.C. (ex officio).

(Secretary : Mr. H. GOTJGH.)

Engine Sub-Committee.—Mr. H. T. TIZAED, C.B., F.R.S.(Chairman); Professor L. BAIESTOW, C.B.E., F.R.S.; ProfessorH. L. CALLEXDAE, F.R.S.; Professor A. H. GIBSON, D.Sc.;Lieut.-Colonel M. O'GoRMAx, C.B.; Mr. H. R. RICAEDO, M.A.;Major G. P. BULMAX, O.B.E. (representing the Directorate ofAeronautical Inspection); Major B. C. CARTER, D.I.C., A.M.I.M.E.,Lieut.-Colonel L. F. R. FELL, D.S.O., O.B.E., Wing CommanderG. B. HYTSTES, D.S.O., and Mr. D. R. PYE, M.A. (representing theDirectorate of Scientific Research); Engineer Captain A. TTJENER,R.N. (representing the Admiralty); Dr. T. E. STANTOX, C.B.E.,F.R.S. (representing the National Physical Laboratory); withthe Chairman of the A.R.C. (ex officio).

(Secretary : Mr. R. W. FEXXIXG.)

Flutter Sub-Committee.—Professor L. BAIESTOW, C.B.E.,F.R.S. (Chairman); Mr. W. S. FAEBEX, M.B.E.; Professor B. M.JONES, M.A., A.F.C.; Dr. H. LAMB, F.R.S.; Mr. R. V. SOUTH-WELL, F.R.S.; Professor G. I. TAYLOE, F.R.S.; Mr. W. D.DOUGLAS and Mr. R. McKiXNON WOOD, M.B.E., B.A., A.M.I.C.E.,F.R.Ae.S. (representing the Directorate of Scientific Research);Mr. E. F. RELF, A.R.C.Sc., and Mr. R. A. FEAZEE, B.A., B.Sc.(representing the National Physical Laboratory); with theChairman of the A.R.C. (ex officio).

(Secretary : Mr. E. OWEE.)

Kite Balloon Sub-Committee.—Professor F. A. LIXDEMAXX,F.R.S. (Chairman); Professor L. BAIESTOW, C.B.E., F.R.S.;Mr. G. M. B. DOBSON, F.R.S., F.Met.S.; Professor G. I. TAYLOE,F.R.S.; Mr. E. F. RELF, A.R.C.Sc., and Mr. H. BATEMAX, B.Sc.,A.C.G.I., D.I.C. (representing the National Physical Laboratory);Flying Officer M. H. STEFF (representing the Director of AirshipDevelopment); with the Chairman of the A.R.C. (ex officio).

(Secretary : Mr. E. OWEE.)

Relations with Industry Sub-Committee.—Sir R. T. GLAZEBEOOK,K.C.B., F.R.S. (Chairman); Professor L. BAIRSTOW, C.B.E.,F.R.S.; Lieut.-Colonel M. O'GORMAN, C.B., D.Sc.; Sir J. E.PETAVEL, K.B.E., D.Sc., F.E.S. (representing the Departmentof Scientific and Industrial Research); Mr. E. F. RELF, A.R.C.Sc.(representing the National Physical Laboratory); Mr. H. E.WIMPERIS, O.B.E., M.A., F.R.Ae.S. (representing the Directorateof Scientific Research).

Seaplane Sub-Committee.—Dr. F. E. SMITH, C.B., C.B.E., F.R.S.(Chairman); Professor L. BAIRSTOW, C.B.E., F.R.S.; Mr. G. S.BAKER, O.B.E., late R.C.N.C. (representing the National PhysicalLaboratory); Major R. E. PENNY and Mr. F. E. COWLIN, B.A.(representing the Directorate of Scientific Research); Mr. R. W. L.GAWN, R.C.N.C. (representing the Admiralty); with the Chairmanof the A.R.C. (ex officio).

Wind Structure Sub-Committee.—Dr. G. C. SIMPSON, F.R.S.(Chairman); Professor L. BAIRSTOW, C.B.E., F.R.S.; ProfessorG. I. TAYLOR, F.R.S.; Lieut.-Colonel M. O'GORMAN, C.B., D.Sc.;with the Chairman of the A.R.C. (ex officio}.

PANELS.AERODYNAMICS SUB-COMMITTEE.

Airscrew Panel.—Dr. H. C. WATTS, D.Sc. (Chairman); Mr.W. S. FARREN, M.B.E.; D. H. LAMB, F.R.S.; Professor G. I.TAYLOR, F.R.S.; Dr. T. E. STANTON, C.B.E., F.R.S. (representingthe National Physical Laboratory); Dr. G. P. DOUGLAS (repre-senting the Directorate of Scientific Research); with the Chairmanof the Aerodynamics Sub-Committee (ex officio).

Design Panel.—Mr. R. V. SOTJTHWELL, F.R.S. (Chairman);Professor L. BAIRSTOW, C.B.E., F.R.S.; Mr. W. S. FARREN,M.B.E.; Professor H. LEVY, F.R.S.E.; Mr. H. L. STEVENS, B.A.,Mr. R. S. CAPON, B.A., and Mr. R. McKiNNON WOOD, M.B.E.,B.A., A.M.I.C.E., F.R.Ae.S. (representing the Directorate ofScientific Research): Mr. E. F. RELF, A.R.C.Sc.; Mr. H. B.IRVING, B.Sc.. and Mr. W. L. COWLEY, A.R.C.Sc., D.I.C.(representing the National Physical Laboratory).

Scale Effect Panel—Professor L. BAIRSTOW, C.B.E., F.R.S.(Chairman); Professor B. M. JONES, M.A., A.F.C.; Mr. R.McKiNNON WOOD, M.B.E., B.A., A.M.I.C.E., F.R.Ae.S. (repre-senting the Directorate of Scientific Research); Mr. E. F. RELF,A.R.C.Sc. (representing the National Physical Laboratory).

Stability and Control Panel.—Professor B. M. JONES, M.A.,A.F.C. (Chairman); Lieut.-Colonel M. O'GORMAN, C.B., D.Sc.;Mr. R. V. SOOTHWELL, F.R.S.; Major J. S. BUCHANAN, O.B.E.,Mr. R. J. GOODMAN CROTJCH, A.F.R.Ae.S., M.I.Ae.E., Mr. H. L.

26

STEVEXS, B.A., and Mr. R. McKixirox WOOD, M.B.E., B.A.,A.M.I.G.E., F.R.Ae.S. (representing the Directorate of ScientificResearch), Mr. E. F. RELF, A.R.C.Sc., Mr. H. B. IRVING, B.Sc.,and Mr. L. W. BRYANT, B.Sc., A.R.C.Sc. (representing theNational Physical Laboratory): with the Chairman of theAerodynamics Sub-Committee (ex afficio).

Vortex Panel.—Professor G. I. TAYLOE, F.R.S. (Chairman);Dr. H. LAMB, F.R.S.; Dr. H. C. WATTS, D.Sc.; Mi-. H. GLAUERT,M.A.; Major A. R. Low, M.A., and Mr. R. McKixxox WOOD,M.B.E., B.A., A.M.I.C.E., F.R.Ae.S. (representing the Directorateof Scientific Research); Mr. C. X. H. LOCK, M.A. (representingthe National Physical Laboratory); with the Chairman of theAerodynamics Sub-Committee (ex officio).

ENGINE SUB-COMMITTEE.Big End Bearings Panel—Mr. H. T. TIZARD, C.B.. F.R.S.

(Chairman); Mr. H. R. RICARDO, M.A.; Lieut.-Colonel H. N.FOSTER (representing the War Office); Engineer Captain A.TURNER (representing the Admiralty); Mr. D. R. PYE, M.A.,and Mr. W. L. TAYLOR (representing the Directorate of ScientificResearch); Dr. T. E. STANTON, C.B.E., F.R.S. (representing theNational Physical Laboratory).

Compression Ignition Panel.—Mr. H. T. TIZARD, C.B., F.R.S.(Chairman); Professor A. H. GIBSOX, D.Sc.; Lieut.-ColonelM. O'GoRMAN, C.B., D.Sc.; Mr. H. R. RICABDO, M.A.; WingCommander T. R. CAVE-BBOWXE-CAVE, C.B.E.; Wing Com-mander G. B. HYNES, D.S.O.; Lieut.-Colonel L. F. R. FELL,D.S.O., O.B.E., and Mr. D. R. PYE, M.A. (representing theDirectorate of Scientific Research).

Sparking Plug Panel.—Lieut.-Colonel M. O'GoRMAX, C.B.,D.Sc. (Chairman); Professor A. H. GIBSON, D.Sc.; Mr. H. R.RICARDO, M.A.; with the Chairman of the Engine Sub-Committee(ex officio).

Torsional Vibration of Crankshafts Panel.—Mi. D. R. PYE,M.A. (Chairman); Dr. G. R. GOLDSBROTJGH ; Mr. E. B. MOTJLLIN,M.A.; Mr. R. V. SOUTHWELL, F.R.S.; Major B. C. CARTER,D.I.C., A.M.I.Mech.E., and Captain A. SWAN, B.Sc., A.M.I.C.E.(representing the Directorate of Scientific Research); with theChairman of the Engine Sub-Committee (ex officio).

University Research Panel.—Mr. H. T. TIZARD. C.B., F.R.S.(Chairman); Professor H. L. CALLENDAR, F.R.S.; ProfessorA. H. GIBSON, D.Sc.; Professor C. HAWKES ; Mr. H. R. RICARDO,M.A.; Major B. C. CARTER, D.I.C., A.M.I.Mech.E., and Mr.D. R. PYE, M.A. (representing the Directorate of ScientificResearch).