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Aviation History
1955
1955 - 0818.PDF
816 FLIGHT, 10 June 1955 CORRESPONDENCE The Editor of "Flight" does not hold himself responsible for the views expressed by correspondents in these columns;the names and addresses of the writers, not necessarily for publication, must in all cases accompany letters. LANDING RUNWAY Supersonic Fuselage DesignY OUR contributor "W.T.G.," in his article on the SuperSabre in your issue of May 20th, states that the avoidance of high peak suction points is a primary factor in the reduction ofsupersonic drag. It is true that high peak suctions, and therefore velocity, willcause an increase in drag in the transonic region, since they will cause local supersonic conditions. But where the airflow iseverywhere supersonic, pressure distribution depends on the angle through which the airflow is turned. A surface turned atan angle against the airflow will cause a shock-wave and an increase in pressure; a surface turned away from the airflowwill cause an expansion. Under these conditions the peak suc- tion points will not coincide with the points of maximum thick-ness as in subsonic flow. Thus it seems that the main thing to avoid at supersonicspeeds is a large increase in cross-sectional area over a small chordwise distance, since this will cause high pressure over theforward part of the body. If the fuselage of the Super Sabre were of the "Coke-bottle" type, and if it had to contain the samequantity of fuel as the present fuselage, then the fuselage cross- sectional area would have to be greater in the regions of theleading edge and trailing edge of the wing. This fattening of the forward fuselage would cause higher pressures over the fuselagenose, since the surfaces would be inclined at a greater angle against the airflow. Your contributor suggests that the Grumman Tiger and Con-vair F-102 were designed in the light of later knowledge than the Super Sabre. However, the "Coke-bottle" fuseL je was knownabout as long ago as 1949, and probably earlier, ar d so I suggest that the differences in design represent different approaches tothe same problem. B. R. A. BURNS, Church Fenton, Yorks. .-•...-.-.;..-.._;;.... ,;.. ., F/O. "Monticule" Airfields IN order to increase take-off and landing safety and enable aircraftto operate on shorter runways, I suggest the adoption of an airfield design incorporating inclined runways. They would beinclined by construction of the central area of the airfield as an elevation or monticule, so that they would run on the flat top,down its sloping sides, and on to the boundary. An aircraft taking off would gain acceleration as it ran downthe inclined middle section and would attain flying speed after a shorter run. It would take off as soon as it reached the beginningof the final level stretch, the remaining length of which, as far as the boundary, would be available in case the take-off run wasabandoned in emergency. In a landing, the aircraft would land on the level base stretch ofthe offset landing runway; braking would be unnecessary, as the up-gradient would absorb the forward momentum. The offsetrunway would prevent the possibility of collision and the inclined section would be a safeguard against all chances of over-running.Boosters might thus be eliminated and tyre wear and fatigue reduced, and this would lead to improved design. Inclined runwayswould require less land and would increase visi-bility. Fuel would be saved, as the accelerationthe aircraft received as it ran down the gradientwould represent the momentum of the pre-vious'landing, utilized to take the aircraft to thetop instead of being dis- sipated in the brakes andin cutting up the tyres. Mr. H. Ellul's "monticule" airfield shown diagram- matically in plan and cross-section (dictionary definition of a monticule is "a little mount, a hillock, a small eleva- tion"). A and B, inbound and outbound passenger- handling buildings; C, control tower; D, technical buildings. ROAD The circumstances which might cause an aircraft to go roundagain rather than over-run the boundary could not arise when the landing momentum was cancelled during the run up the slope,particularly as a further length of runway would be available at the top; and in a take-off, as flying speed would be assured bythe run down the slope, the necessity to abandon a run should not arise; if it became necessary for some other emergency, thefull length of the final, base section stretch of the runway would be available. London, W.3. HENRY ELLUL. Lawrence and "The Mint" CINCE the publication of The Mint and its review in your^ pages [March 18th] I have been expecting informed comment from your readers. In lifting the lid from conditions at the Uxbridge Recruits*Depot of the early twenties, it may appear that T. E. Lawrence colourfully exposes a poor relation of Belsen or Buchenwald. Andyour reviewer gives me the impression that he considers bad N.C.O.s were mainly responsible. I would disagree with him.No N.C.O. is better than the commanding officer leading or failing to lead him. The pace or standard of subordinates is determined bythe pace of their superiors. Only in the Duke of Plazo Toro's Air Force do corporals lead group captains. The general responsibility for the savage discipline in "T"Section must rest on the staff officers with their "Brigade of Guards" outlook. And the local responsibility rested solely withthe camp commandant. He was a high-ranking officer well known to the Staff, and he was posted to the depot for a purpose. Hewasn't the camp bossman by accident. It is a mistake, I think, to couple with him (as does your reviewer) the drill adjutant. Thelatter was a much junior officer and drill was his bailiwick. He was devoted to it. As well blame a doctor for devotion to medicine.But the camp commandant confused discomfort with discipline. Lawrence has dealt with him. Circumstances placed me (a technical N.C.O. at the time) onthe Recruits' Depot a few months before Lawrence entered. It was hot. N.C.O.s were treated more harshly than were airmen.I was there for two months and afterwards associated with Uxbridge for a year. The drill adjutant ("Stiffy") was a martinetbut he was not mean; rough-tongued but not unfair. The "Brigade of Guards" outlook was not new to the R.A.F./R.F.C. in 1922 either. It was in full evidence in the Guards- dominated Recruits Depot at Farnborough in the fall of 1915(I was there also). The essential difference between the Farnborough Mint andthe Uxbridge Mint was that in the latter a famous author passed through and has now "blown the gaff." Per Ardua ad Lawrencia! Dublin. EDWARD HOCTOR • v • (ex-10716 R.F.C.).Jet Lift "Y"OUR contributor "Quidnunc" [May 13th] has overlooked his•*• best bet. If the lift engines can be deflected in flight, so can the main engines. If he will tilt them upwards until they pro-duce a vertical lift component of 100,000 lb he can dispense with a further ten lift engines; the main engines will still produce ahorizontal thrust component sufficient to give an initial accelera- tion 0.2g. The' maximum acceleration and retardation duringtake-off and landing will be slightly less than before (for which his passengers will be grateful!) but the consumption of purelift fuel will not be increased. In this way he could produce a "Mark IV" model with the same performance as his Mk III buta payload 10,000 lb greater. The last logical development would seem to be the provision ofthe necessary lift engines, fuel and undercarriage in a separate aircraft, to be detached from the airliner as soon as sufficient speedis reached, and to pick it up again before landing. It still remains to be proved, however, that travel at supersonic speeds is worthwhile. Over short distances the time wasted getting to and from the termini (under present-day conditions) destroys its value;while for long journeys the optimum travelling time is about 8-10 hours, irrespective of distance, since this allows the passengerto travel overnight in the time which is normally devoted to no useful purpose. If he can go to bed in London and wake upin New York he has effectively travelled to his destination in no time at all. But if he is really in a hurry, he would be far wiserto stay at home and use the transatlantic telephone. It may be urged that goods cannot be sent by telephone. Thatis true; but the following facts provide an interesting commentary on this. I am in urgent need of a 36-volt metal rectifier for mycharging-board. I can find no retailer who can supply from stock; and the most honest of those I have consulted warns me
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