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Aviation History
1948
1948 - 0297.PDF
MARCH 4TH, 1948 FLIGHT 251 mum refuelling position on its track, and that position isdependent upon the wind component. Refuelling at that posi- tion will permit the receiver to carry maximum payload with-out exceeding maximum gross weight at take-off or iu the air. The flight plan requires two alternate airfields to be!< commended on departure; at least one return alternative airfield must be available above the weather minima, in addi-tion to the departure point; and if the departure point is forecast below the limits after take-off, then a second returnalternate must be designated. The fuel calculations provide for an adequate amount toallow the aircraft to proceed from the designated terminal to the farthest terminal alternate, plus 25 per cent of the amountrequired from the terminal to the alternate airfield, plus one hour's fuel on arrival. For purposes of calculation the last100 gals. (720 lb) of fuel are considered to be unusable, and in flight that amount would normally be deducted from thetotal weight of fuel remaining. jjhe flight plan for the refuelling tests is divided into lour^STtions: i, to the first refuelling position; 2, to return to base and alternates; 3, from the first refuelling position tothe second refuelling position, with secondary destination and its alternatives; 4, from the second refuelling position to theiinal destination and alternates. Eastbound the aircraft would refuel in flight only once. The optimum position may bedefined as the position at which the fuel required at point of departure to the refuelling point and return equals the fuelrequired from the first refuelling point to the second point plus the farthest alternates. For maximum- payload the first refuelling position is socalculated that the weight of fuel required for sections 1 and 2 of the flight plan may equal the weight of fuel required forsection 3. Such an optimum position works out to be one- third of the air distancefrom the take-off to the farthest alternative in sec-tion 3 of the flight plan. It will thus be obviousthat the optimum position will be closer to the pointof departure with a tail wind and greater with ahead wind. The amount of fuelwould be calculated as fol- lows: Section 1—fuel forfirst stage, plus 100 lb/hr, plus stand-ofl 900 lb; Sec-tion 2—from refuelling position to departurepoint, plus ftiel to first alternate, plus 100 lb/hrfuel to farthest alternate, plus stand-off 900 lb, plusresidual fuel 720 lb; Sec- tion 3—fuel for flying fromthe first refuelling point to the second refuelling pointand a secondary destina- tion, plus 100 lb/hr plus ^^_T fuel to the farthest alter- jfc'te",* plus 25 per cent of fuel to the farthest alternate, plusMoo lb stand-off, plus 720 lb residual fuel; Section 4—from the Vefuelling point No. 2 to destination, plus 100 lb/hr, plusfuel to alternate, plus 25 per cent of fuel to alternate, plus (JIK) lb, plus 720 lb. After a series of refuelling flights it will be possible to producecharts from which the optimum distance and the amount of fuel required may be easily and quickly read. The amount>f flight planning, however, remains, and a last-minute change in the weather situation would entail a change of plan, requir-ing probably two hours of weather forecasting and flight ! banning. It was suggested that on this fourth experimental flightilie tanker could have intercepted oft Iceland, but as the met. lorecastiiig through Shannon is prolonged, the captain con-sidered that more time could be saved by refuelling on the ground in Iceland; also, it was doubtful whether the Ganderor Goose Lancasters would be able to fly owing to poor weather conditions at their bases. Flight planning is, therefore, amajor problem in considering the possibilities of flight ^-fuelling. Operational considerations cannot be separated fromconomy, and flight refuelling is still in the early development tagesjit is thus difficult, if not impossible, to asses its value.Ml operational factors must, however, be considered if abso- lute regularity is to be achieved. Although many test flightsiiave been made with success in refuelling nt night and in ••loud, it is doubtful whether it can be 0110 hundred per cent apt. J. Percy. reliable, and for passenger air transportation there must beno greater risk in this operation than in a flight made without refuelling in the air. The technique for refuelling in the air is capable of improve-ment The aircraft refuel when in close company and in the wrong position. Many pilots do not like to have an aircraftformating closely whilst they are unable to see what is going on and therefore unable to take action in an emergency. Atpresent the approximate distance between the two aircraft during the operation is about 100 feet, with the tanker above,to the side and slightly behind. The airline pilot hands over complete responsibility for his 30 or 40 passengers to the pilotof the tanker aircraft. That may seem an exaggerated view- point, but it could in fact be the situation with the presentarrangement, and although flight refuelling pilots are skilled specialists at the present moment, the international scale ofoperation which would make this a practical and economic proposition would entail the recruiting and training of manymore pilots. Alternative Methods Some hold the view that a better position for the tankerwould be within view of the pilot, and a suggestion has been made that it should be stationed below and to the side of thereceiver, with a pump for pressure refuelling in the tanker, and with both aircraft never nearer than 300 feet. It hasalso been seriously suggested that the receiver should tow the tanker. It would, perhaps, be possible for the tanker to takeup a position directly behind the receiver, throttle back about one inch of boost, and then for the receiver to open up tomaintain cruising speed. Although the tanker in this case would be out of sight of the receiver pilot, he would still bein control during the operation. Safety could be guarded by a manual release of the tow rope at both ends. Modern aircraft can climb above bad weather in the NorthAtlantic, and it is obvious that, if refuelling is to be done regularly in complete safety, it must be done in clear air.The tanker must, therefore, be equally capable of climbing above the weather and having, at that height (20,000-25,000feet) a sufficient reserve of power and adequate control to ensure safe manoeuvrability. Tankers must in consequencebe of modern and perhaps special design. That is the main reason why, in my view, the present experiments will provelittle, since ljoth the receiver and the tanker aircraft are unsuit- able for regular flight refuelling. I have already mentioned the crew's reaction to flying inclose proximity to other aircraft. That will be disputed by some pilots in B.S.A.A., who were enthusiastic about thetrials in the South Atlantic; but they were made in good weather conditions. Passenger reaction must also be con-sidered, and I do not believe that the operation will be regarded with complete calm. In conclusion, I am sure that the Ministry and Corporationsare sufficiently interested to experiment further with this revolutionary method of obtaining long-range flying combinedwith heavy payloads. The aircraft are not yet available for giving it a fully convincing trial. ' NOT IN CAMERA A FULL and pleasant evening was spent by employees of theWilliamson Manufacturing Co., Ltd., and their guests at the Cafe Royal on February 21st. Mr. Strachey's restrictive practices made impossible a formaldinner, but the buffet supper was a satisfying alternative and everyone, including the cabaret artists, seemed thoroughly toenjoy themselves, despite the forbidding weather outside. The chairman of the company, Mr. C. M. Williamson, saidthat, although past the normal retiring age, he had no inten- tion of retiring but intended to make provision for 1,750 sharesin the company to be distributed among employees in strict order of length of service. Understandably, thil announce-ment was received with considerable applause. LYONS TRADE FAIR THE Lyons International Trade Fair will open on April 3rdfor nine days until April 12th. In the Palais des Nations Britain will be represented by B.E.A.C. The French Consulateare, issuing passes to established business men and trade buyers will receive a free entry card valid for the duration of the fair.The fair authorities have made arrangements for hotel accom- modation and transport in the nearby towns of Bourg and Aix-les-Bains. In the Grand Palais, Group 56 on the ground floor will be devoted to aviation exhibits. Catalogues will be readyin the middle of March and may be obtained, price 10s post free, through Clifford Martin, Ltd., Piccadilly House, 33,Lower Regent Street, W.i, from whom further information mav be obtained.
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