FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1945
1945 - 0971.PDF
MAY 17TH, T945 FLIGHT 54* CORRESPONDENCE Th: Editor does not hold himself responsible for the views expressed by correspondents. Ths nainss and adiresses of the writer'; not necessarily for publication, must in all cases accompany letters. THE MILES M.48 Margin of Error Near the Stall I WAS flattered to read Mr Bage's congratulatory letter inthe issue of Flight, April 26th. Pleased as we are with the performance of the M.48, however, we should hesitate to claimthe very high C L max. of 7.8 with which he credits us. It istrue that the aircraft remains under control down to an indi- cated airspeed of below 25 in.p.h., but, as Mr. Bage will know,it is difficult to ensure an absolutely accurate indication of speed by the conventional instruments when flying very nearthe stall, and an error of a few ni.p.h. at such extremely low airspeeds makes a remarkable difference to the apparent CLmaximum. We do, however, believe that with the Messenger and M.48we have attained a higher lift coefficient than has previously been achieved on any but puiely freak aircraft needing aspecialised piloting technique. n The actual figures for CL max. after correcting for instrumentUiror and position error are 4.56 with engine on and 3.17 with Tngine off. G. H. MILES. PRESSURE CABINS First Demonstrated in 1904 IN the Gazette published by Qantas-Empire Airways, Feb-ruary, 1945, under "Production Postscripts," appears thefollowing item:— '' A British invention now in use makes possible stratosphereflying without oxygen masks or special clothing. A super- charger maintains constant air pressure in the interior of air-craft cabins at any height up to 40,000ft." This method of reaching great heights was first describedby my two late brothers, Horace and Eustace Short, in a joint lecture given before the Royal Aeronautical Society on May29th, 1904. The lecture was illustrated by lantern slides, which I have before me as I write. I was present at the lecture. The drawings were made by Horace and show a hand-drivenpump with two cylinders and a link motion operating the valves in such a manner that only frictional resistance had tobe overcome. , No patent was taken out for this invention, but the priorpublication has been of great value to those who are now design- ing pressure cabins, because the broad principle which is.ofprimary importance in a patent cannot be claimed by anyone. Only details of construction can be claimed, and such, asall inventors know, need not be exactly followed. If any British, American or Russian inventor could claimthe broad principles within the period of the "life" of his patent, large sums in royalties would have to change hands.HUGH OSWALD SHORT, F.R.Ae.S. altitude of 300ft. whether the water is suitable for alighting. In my opinion, the U.S. authorities were generous to allowa limit of 1,oooft. over congested areas. It is the minimum height at which a pilot has a reasonable chance ol making aforced landing comparatively safely in a less dense space. I think roof-top landings are far too hazardous for those inthe street, but a modification to the above law stating that it one was in the circuit of, and within gliding (or single-engined)distance of, an air park, one might violate the regulation, it would be ideal. Mr. Ryder's other examples show that the U.S regulationsbadly need revising. As for parachutes, I am opposed to laws making them compulsory—as, for instance, to equip a four-seater a private owner must pay about ^240. Airlines and ait- taxis should provide them, however. To sum up. Traffic regulations must be strict, as must beairmanship tests, but every effort must be made to cut down cost aj*d unnecessary red tape in order to encourage the privateto the utmost. A SERVICE PILOT. .- •*/. **' Indicator " Has a Word to Say About Flying "KJ^J~$J Discipline and the Private Owner y/VTHYLE some of the restrictions light-heartedly outai5__v * in the article "Only Angels May Fly " (Flight, May 3rd) seem to be a trifle idiotic, I must say that 1 think the generalidea of such " preventive measures " is a good one, and the U.S. Bureau of Air Commerce is at least working on the right lines.In pre-war days the vast majority of accidents to amateur- flown aircraft, in this country at least, were caused by variousforms of stupid flying, such as " pressing^on " when the weather was hopeless, indulging in low-leve^aerobatics or beat-ups.overloading, and rankly careless flying in the circuit. Free- dom to commit suicide is all vei^jiejl when there are only afew hundred aircraft in circubdiorr butHhere must obviously be some form of control aMKSCcipline when\nd if the numbersreach four figures or iBpftjrKven a magisterial assessment of least tend to reducV the number of>es, complete with gats and scowls, course offtheitjvarifous law-breaking •esti*ly\wTt/h/a'nother in the same r £*&• \urt?raft designs. Pte.nstanVgc could not possibly be "ONLY ANGELS MAY FLY" Strict Rules Without Red Tape moral character wouout-and-out anti from using aircpursuits! This article '.issue dealing Fotheringham' effectively used^b^j^? Rtft a well^fained pilot in a reasonablydisciplined and controlled flying.-world, while people flying the kind of aircraft >%exemplifiecL^t>y Mr. Wheeler's design wouldbe in a totally different .category. It seems that at regular intervals the idea of a " foolprool "light aircraft must inevitably be mooted, By all means let us have aircraft which are, as far as possible, viceless in theirhandling qualities—at least as viceless as the Spitfire and the Mosquito!—but it seems to me that we are putting the cartbefore the horse if we try to introduce an extreme of quite W™TI , ^ ,, „ J . >• 1 ..^ 1 * 1 ** theoretical safety at the expense of performance and handlingITH reference to Mr. Ryder s article, Only Angels May qualities. Whatever may be done to make aircraft stallproofFly " (Flight, May 3rd), while I am in complete agree- and accident-proof as far as mere handling is concerned expert-•nent with him in that the private flyer should be encouraged ence js stm necessarv for ultimate safety in all conditionsas much as possible and that strait-jacket regulations are second only to high cost in discouraging him, we must realisethat flying must, and, I hope, will, be far more strictly con- trolled than is motoring.In his article the writer quotes certain examples of U.S. regulations and ridicules them. I have flown, though notcivilly, in both U.S.A. and this country, on both land- and sea- planes.From my own experience I believe that, no matter what restrictions one makes, there will always be someone who pilesup low flying, but the greatest deterrent is the fact that one knows that if one is caught flying under 500ft., whether danger-ously or not, one's flying days are over, and NOT the fear that one might get killed doing it; 90 per • cent, of young pilots1 believe that they are cleverer than all the others that have "pranged" before them. Thus the rule that prevents the ions " * pg bo plandplane descending below 500ft. and the amphibian below 300ft. is fully justified, as it saves the insoluble definition ofwhat is a dangerous altitude. If the margin were 3,000ft. there would be some ground forthe claim that it wastes petrol to climb to the minimum alti- tude for a short flip across a gulf. It is highly undesirableto have many aircraft skidding across the water at 200ft. I also maintain that one can ascertaiu definitely from an INDICATORAIRSCREW QUIZ What Happens if it Flies Off ? I WOULD appreciate your readers' views on a mildly tech-nical problem, the subject of a discussion among my crew. With our aircraft flying straight and climbing slightly, one engine raced beyond control up to over 3,500 r.p.m., the oil pressure failed, and the engine began to seize due to fusing of the bearings and valve mechanism. Had the airscrew not been feathered promptly, and the engine thereby stopped, it is almost certain that the airscrew shaft would have snapped and the airscrew been lost. Now, had this happened, would the airscrew have necessarily cartwheeled to either side, or would it rather have spun away in a straight line forward and downward, until the rotating force imparted by the engine was lost ? The airscrew rotates anti-clockwise viewed from the rear of the aircraft, arid there was no other force due to the attitude of the aircraft since we were practically straight and level. In other words, since the defective engine was a starboard inner, would the airscrew necessarily have flown toward the fuselage, or awav from it ? N. C. SKINNER (Fit. Sgt.), R.A.A.F.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
