FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1917
1917 - 0451.PDF
MAY IO, 1917. ANSWERS TO [As a number of letters reach us signed with initials only, some of which do aot give a complete address, we would point out that such communications cannot be dealt with in our columns. Full name and address, which will not be published, must always be given.—ED.] Notice to Correspondents in General. Applications for commissions in the Royal Naval Air Service should be addressed to the Director of Air Services, Admiralty, S.W. The necessary form and conditions of entry can be obtained from the Secretary of the Admiralty. Applications for commissions in the Royal Flying Corps should be sent to the Director-General of Military Aeronautics, Hotel Cecil, Strand, W.C. Those who wish to enlist in the R.N.A.S. should apply to the nearest naval recruiting station or to the R.N.A.S. Drafting Office, Crystal Palace, S.E. Skilled mechanics are taken whatever their army classification, but unskilled men are only taken if they are classified Bi, B2, or Ci. Recruiting for the R.F.C. is closed for the time being, and . any enquiries should be made to the Officer Commanding, Royal Flying Corps Depot, Farnborough. Enquiries with regard to appointments in the A.I.D. should be addressed to the Chief Inspector, Aeronautical Inspection Department, Hotel Cecil, W.C. 2. "Pilot" (Ilford). We do not think it would be possible to effect a transfer at the present time. Anyway, you must obtain the consent of your commanding officer. E. L. (Chingford). It is impossible to advise you. Your best course would be to place your case before the management of the firm you : are with. ^.. . .. . . , .. „ W. W. (Montreal, Canada). The object of the variable incidence on the Nieuport scout is to provide means for adjusting longitudinal balance. Thus engines of slightly different weight may be "fitted without necessitating any other alteration than that to the incidence of the lower planes. The Nieuport patent specifications cover means for altering the incidence during flight; but this is not, we believe, generally done, any adjustment required being made while the machine is on the ground. As regards the power required to bring the bottom planes back to their normal angle, i.e., the angle at which the centre of pressure was situated on the tubular spar, this would not, we think, be very great. Without giving actual figures, a hypothetical example will illustrate this point. Assume that the length of each bottom plane is 10 ft. and its chord 2 ft. 6 ins. Further, assume a loading of 5 lbs./sq. ft. On a chord length of 2 ft. 6 ins. the travel of the centre of pressure would scarcely exceed 2 ins. each way. This would mean a turning couple, on each wing, of 10 xr; x ; x 0-17 = 21-25 ft. lbs. For the two wings the couple would be • 42-5 ft. lbs. Assume that the lever operating the variable incidence is 2 ft. long, the pull that would have to be ' exerted by the pilot on this lever would then be 42-5-!-2 = 21'25 lbs., which is not excessive. -. As regards the action of the dihedral angle, your reasoning appears to tally with ours, except that you have not taken into account that when a machine having a dihedral angle is banked until one of its wings is horizontal, the pressure on the other has a horizontal component, as well as a smaller vertical lift. This horizontal component is not balanced by a similar and opposite one on the other side, and the machine therefore tends to move towards the side of the depressed wing. C. A. H. (Barnet). We are not quite certain as to what is the cause of the peculiar change in the sound made by an aeroplane according to whether it is close or far away. Certainly we have often observed, as you point out, that when the machine is approaching the note is rather high. When the machine is immediately overhead the sound becomes much deeper, and gradually the note becomes higher as the machine recedes. We are inclined to think that the explanation is this : The sound of an aeroplane is made up of two separate notes, one fairly deep made by the engine, and the other considerably higher, caused by the swift movement of the various parts of the aeroplane through the air. Of these two notes, the higher will carry farther than the deeper. When the machine is quite close, the deep sound is near enough to carry, and is, therefore, the predominant. As the distance increases, the higher note begins to carry better, and is heard over and above the deeper hum of the engine As already stated, we are not certain whether or not this explanation is the correct one. Perhaps some reader will be good enough to give another ? J. W. (Sheffield). " Aeroplane Design," by F. S. Barnwell, would help you. It can be obtained from " FLIGHT " Offices for is. iod. post free. W. B. (Erdington). Pusher biplanes have looped. Your second question we are not permitted to answer until the war is over. Air-cooled (Selby). You cannot do better than study the Wolseley handbook on Renault engines. You can obtain it from " FLIGHT " Offices for 5s. qd. post free. S. G. N. C. (Wandsworth). We have published one or two photographs of machines presented to the Government. It is impossible to give the opinion you ask for, as so much depends upon the^use to which the machine is put. A. E. T. (Birmingham). If passed for General Service you might find difficulty in enlisting, unless you were exceptionally skilled at your trade. J. F. A. A. (Whitley Bay). Several of the " dope " manufacturers issue pamphlets containing hints on the application of dope, &c. The use of poisonous dopes is now prohibited. A. W. B. F. (Farnham). It is doubtful if you could obtain a commission even as Equipment Officer. For particulars as to enlistment, write ' to the R.F.C. recruiting department, The Polytechnic, Regent Street, W. M. E. D. (Southend). You should take every opportunity of studying the subject whether from books or by inspection of actual machines. If possible try and get a position in an aircraft works. G.N. (Pulham). Write to the Secretary of the Adkniralty for a copy of the conditions of entry of officers in the R.N.A.S. It will give you all information. Mechanic (High Wycombe).1. Yes; he gets an allowance for kit. 2. Equipment Officers have to go through a special course of training.3. The allowance is granted when the commission is secured. W. A. F. (A.S.C., M.T., France). There are two distinct methods of firing a machine gun " through" the propeller of an aeroplane. By the first method the gun may be fired at any desired moment irre- spective of the relative position of the propeller. In order to protect the latter from damage the portions of the blades which come in line with the gun are lightly armoured and deflect the small percentage of bullets that strike the pro- peller. The second method consists in gearing the trigger of the machine gun to the engine or propeller shaft by means of a system of cams and levers in such a manner that when a propeller blade is in line with the gun the trigger cannot be pulled, thus preventing firing until the blade has passed the muzzle, when the trigger is released, and the firing continued It should be understood that in both cases the gun is im- movably fixed to the aeroplane, sighting being accomplished by steering the machine itself. Lieut. F. W. (R.F.C.). At the moment the only book available for immediate delivery is " Aeroplane Design," by F. S. Barnwell. This book may be obtained from the offices of " FLIGHT," the price being 2s. iod., post free. Other books dealing with this subject are out of print for a few weeks. With regard to our reply to A. C. (Waltham Abbey) in the issue of " FLIGHT " of April 19th, Mr. S. T. Swaby, of 4, Cross Flatts Row, Beeston, Leeds, writes the following : " Should your correspondent care to go into the matter (the Mersey monoplane.—ED.), I might be able to supply details. I was the designer and partner in the machine, and should be glad to be of any assistance in my power." 451 *
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
