FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1942
1942 - 2728.PDF
724 FLIGHT DECEMBER 31st, 1942 Correspondence The Editor does not hold himself responsible for the views expressed by correspondents. The names and addresses of the writers, not necessarily for publication, must in all cases accompany letters. > AN APPRECIATION Service Despite Difficulties SINCE 1 received the September 3rd, 1937, issue of Flight 1 have been fortunate in that I have not missed a single copy and that 1 have each edition up to date. Allow me to say here what a reJiable. interesting and educative journal it is. I have only once answered an advertisement in it; this was to Wright's, Paterson, New Jersey, U.S.A., when I took advantage ot their offer for one of the series of real live prints. 1 hadn't much hope of receiving a reply considering all the difficulties, but 1 have received the whole series of eight grand prints. Will you allow me hereby to call America and say "Thanks, Pal"? GEORGE HOULTON SMITH. THE TORPEDO BOMBER Weird and Wonderful Designs TO restore the peace of mind of your correspondent Mr. T. G. Coultiss, and to dispel the qualms which may have arisen in any other ol your equally literal-minded readers. 1 feel bound to write again -to explain to them that my last letter to you on "The Torpedo Bomber" was hardly written in all seriousness; but having read Mr. Hudson's previous epistle I could not resist the temptation of parodying his design and, if possible, of producing something which would be even less likely ever to become airborne. I really did not believe that anyone could take my letter seriously; but 1 suppose it was a risky thing to do when so many people with magnificent theories but no practical experi ence are displaying their weird and wonderful designs to an open-mouthed audience. The thing which these theoreticians will not appreciate is that the pilot of their fast, high-powered aircraft is compelled, after dropping, to fly at very low altitude almost directly over the target, because of the very wide turning circle of such machines. Moreovei, until a new torpedo is developed, it will not be possible to use the terrific speed which they advocate at the one moment at which it is most wanted, because the torpedo has to be released at such a comparatively low speed. It is interesting also to see that Mr. L. W. Rosenthal, who is so full of contempt for the amateurs' designs, is unable in his article to make any constructive suggestions himself. But, of cqurse, the Editor may have published this item simply as a bait to provoke discussion amongst such fish as would rise! J. R. GODLEY. BOMBER ESCORT Lesson of the Eindhoven Raid IFURTHER to the correspondence appearing under the head ing "Bomber Escort," by Mr. E. J. Griffiths and Mr. S. Greenwood. The policy of opening up a "Daylight Air Front" appears to be more ihan ever overdue. Up to now our daylight offensive appears to be confined to Belgium and Northern France and it is certainly time some effort was made to carry the war into Germany proper. Recent news re the bombing of the Philips' Works at Eind hoven shows up our inability to give the necessary full fighter cover. I believe that on the latter part of the way out to the target the bombers were unprotected. The wireless quoted " Aircraft of Fighter Command provided cover to the bombers when returning from the attack. Twelve of our bombers are missing." Verb sap. The policy of making certain bombers into defensive fighters to convoy the real bomber is certainly like present Naval tactics. No large battleship moves without its escort, and the same formula appears to get our merchant convoys through very successfully. The very illuminating and comprehensive series of articles which appeared in Flight under the most apt title "Fighter Armament" leave little doubt on the trend of the attacker's armaments; we read on page 521: " Weight of fire, rather than rate of fire became the yardstick of efficiency." While every effort is being made in this direction to increase the hitting power of the fighter, nobody appears to advocate a greater weight of fire for the bomber and more armour. Everyone appears to excuse the position on account of the attendant difficulties oi mounting heavier guns, their length, weight of ammunition and turret operation. Certainly there is some justification in this respect, but the policy of fully arming separate machines to act as defensive escort overcomes these difficulties and is surely worth careful consideration. The deadliness of daylight precision-bombing has been clearly demonstrated by the Fortresses, and we must be able to im prove our efforts until such times as we can say no bomber was lost to fighter attack—the bomber must go through and return safely. JOHN CONDON. COMPARISON IN PERFORMANCE Rival Types of Operational Aircraft AFTER reading Mr. Henderson's letter in Flight of Decem ber 3rd I feel compelled to criticise the latter part of his article. To Mr. Henderson's statement that the speed of the Spitfire Mk. V is over 400 m.p.h., I can only say that it has been reliably quoted " as about 370 m.p.h." With regard to the Hurricane IIC, I must admit that the four-cannon armament has greatly increased the destructive power of this great fighter, but at the same time it must be realised that the wing-loading has greatly increased and the speed reduced to 312 m.p.h. by the fitting of external petrol tanks, cannon and air filter. Finally, Mr. Henderson concludes his letter by saying that the Luftwaffe suffers from the lack of certain important equip ment. To this I say that the Germans have a formidable heavy bomber in the Heinkel 177; that power-operated multi-gun turrets have been installed in German aircraft for some time now, e.g., Focke-Wulf Kurier; that the Mosquito is rivalled by the Messerschmitt Me 210; and that the D.B.606 unit in the Heinkel 177 develops 2,300 h.p. ROBERT STEWART. BOOST PRESSURE VARIATION May be Due to Slight Fault ALTHOUGH not being able to give a satisfactory explana tion to "Puzzled's" problem, I would like to point out that F. Ashley's law of supply and demand presumably applies to an engine with an independently driven supercharger and no boost control. This would account for the manifold pressure building up, due to the decrease in crankshaft revs. My own explanation is that the increased boost pressure remaining uncorrected must be due to some slight fault on that one particular engine and does not apply to engines in general. Can any Teader confirm the phenomenon causing "Puzzled's" problem in November 19th issue? K. V. P. No Control at Zero Boost I N reference to the boost question raised by your correspor; dent in a recent issue, I believe the answer falls under tr$ following heads, viz.: Blower efficiency in relation to r.p.m.; the demand of the engine in relation to r.p.m.; and the effect of boost control In the case of the engine quoted, namely, the Rolls-Royce Merlin XX, I believe that at the boost quoted (zero) the r.p.m. will be round about 2,000. At this point a reduction in r.p.m, will not affect the compression ratio of the blower in direct proportion to the r.p.m.( whereas the demand of the engine always follows the i.p.m. closely. «J Thus the demand falls off more rapidly than the compression ratio of the blower. At zero boost, the boost control is out of action owing to the action of the atmospheric change-over cock, so that the throttle opening is fixed. The net effect will be a slight rise in boost pressure. I think this clears the point. I have no doubt that someone will have some curves somewhere to clinch the matter. NAVY PLUMBER.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
