FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1920
1920 - 1078.PDF
OCTOBER 14, 1920 engines are also based on disposal figures. Item 5 is thetotal cost per complete machine. Item 6 sets out the total cost for the six aeroplanes which we propose to use on thisservice. Item 7 is the value of spare engines necessary, and is based on the provision of a reserve of a third of the totalnumber of engines used in the machines. Item 8 provides for the stock of aeroplane and engine spares which I havecalculated on the basis of 25J of the value of the complete aeroplanes. If anything, this stock of spares is somewhaton the low side, as it will be seen from the operation figures that the whole stock is used up in the course of a year.Item 9 provides for the capital outlay for the motor transport vehicles at the aerodrome for the handling of various materialssupplies, etc. These also would be used for any salvage work that might be necessary. Item 10 provides for machineryand plant at one terminal aerodrome, it being assumed that all the repair work will be carried out at the London end ofthe service. This figure is also on the small side, as it is assumed that the spares will be purchased as complete com-ponents from the Aircraft Constructors, and a minimum of detail constructional work will be carried out in the terminalworkshops. Item 11 provides for working capital, which will undoubtedly be necessary for the purchase of supplies,payment of wages, etc., as well as for the amount of fares and freight receipts which are sure to be outstanding fromtime to time. Item 12 is therefore the total capital outlay in respect of the various types of machines that might beused on the service. Operating CostsTurning to the next statement also shown on Table A: Items 13 and 14 are the maximum and cruising speedsof varying types of machines, but for the purpose of our calculations we have taken the cruising speed, as it iswell know that it is impossible to run aircraft at their maxi- mum speed without involving grave risk of constant break-downs. Item 15 is the number of passengers carried as a full load by each type of aircraft. In this connection it shouldbe noted that the Airco 9 and 16 have practically no provision for carriage of luggage. In the case of the other machinesthere is provision for the carrying of a limited amount of hand luggage in addition to the passengers. Items 16 and17 show the cubic capacity for cargo and the weight of cargo carried in pounds. Item 18 is a statement of general charges,which are set out in detail in Table C, o.i p. 1087. If you will refer first of all to Table C, you will see in the firstcolumn the general charges set out for all single-engined types, assuming that the charges will be the same for all this class ofmachine. Other columns set out the charges for twin-enginedmachines and multiple-engined machines. It will be seen that certain charges are common to all three classes, but thereare other charges which increase proportionately to the number of engines and size of machines. I will not dealwith these costs in detail, but you will, no doubt, examine them, and, I think, see that they are reasonable having regardto the service we are operating. Under this heading will be found the charge for rent at the terminal aerodromes. Itshould be noted that the aerodromes and other facilities are provided by the British and French Governments on paymentof a rent charge. Item 19. Maintenance.—This I have divided under (a)Labour, the details of which are set out in Table D, on p. 1087. These vary according to whether the type of machine is,s ngle, twin or multiple-engined. (b) Spares.—The spares necessary for upkeep per annumare worked out on the basis of 25 per cent, of the value of machines. This is necessarily an estimate, as no one hasany reliable figures to go on. It is probably a fair estimate to take, although it may be somewhat heavy. Item 20 is for the pilots employed on the services, (a)For the principal pilots on all machines, the charge being calculated on the figure now being paid, (b) For the pilot'sassistant at half the pilot's rate. This assistant would be carried only on the twin or multiple-engined machines. Item 21 is the cost of petrol and oil. This is based onthe number of hours flown and petrol is calculated at the new and very heavy price of 4s., while oil is chargedaccording to the class used by the various engines. Item 22 is the cost of insurance of aircraft. I have taken this at15 per cent, of the value, which is slightly higher than has been quoted to some operating companies, and is slightlylower than has been quoted to others. It may therefore be taken as a fair average figure. If there are any insurancerepresentatives present who are willing to state a lower figure I shall be pleased to amend my figure accordingly.On the other hand, it is conceivable that they may wish to increase the rates. Item 23 provides for the depreciation of aircraft and engines. I have based the costs on what are necessarily estimatedfigures of 2,000 hrs.' life for the aeroplane and 3,000 hrs.' life for the engine. It is impossible at this stage to laydown with any certainty the length of life aeroplanes and engines will have, but one can safely say that the firstestimates made were very much too conservative. Foreign Governments, for instance, have taken as a basis for subsidythat the aeroplane will have a life of only 400 hours. This basis has already been shown to be very wide of the mark,certainly for British-made machines, as there are machines and engines today in good condition and in everyday use whichhave already flown 800 hrs. Some operators may say that my estimate is too liberal; if so, it will only emphasise thenecessity for making such progress in construction as will give the aeroplane and its engine longer life. Item 24 is for interest on capital, and this I have takenat 10 per cent. Having regard to the present financial position, it will be agreed that this is quite a reasonablefigure to take, certainly for Aerial Transport companies. If there are any City men in my audience willing to put upmoney at a lower rate of interest, 1 shall be pleased to alter my figure to correspond. Item 25, therefore, gives thetotal cost for the six machines for a total of 6,000 flying hours. Item 26 is the cost per flying-hour per machine.Item 27 is the cost per aircraft mile. Item 28 is the cost per passenger mile. Item 29 is the cost per passenger jou-rneyat 100 per cent, load factor ; that is, the cost of taking one passenger from London to Paris, assuming that each type ofaircraft travels with a full passenger load. Item 30 is the same cost, assuming that the aircraft is only three quartersfull. Item 31 is a similar calculation based on the aircraft being only half full. Items 32 and 33 show the cost per ton/mile and the cost of carrying 1 lb. of goods on the journey with the different load factors. •I have shown three distinct load factors, as in this waythe importance of obtaining as high a load factor as possible is clearly demonstrated. No transport company couldpossibly rely on a 100 per cent, load factor, but it will probably be found that the true load factor lies somewhere betweenthe 50 per cent, and 75 per cent. mark. Item 37 shows the cost per cubic foot of cargo per journeyin each type. It is very important that the cubic capacity should be as large as possible, as taking a machine, for instance,such as the Airco 9, rlthough it is able to carry a useful load of 500 lbs., its cubic capacity is so small that, withordinary freight, not more than 300 lbs. could be carried. It is therefore necessary for the space provided to be co-related to the weight of cargo to keep a low cost under this heading. This brings us to the end of our statement, but in addition,to the above items, it will be noted that there is a terminal transport charge of £\ per passenger journey which has tobe added to the flying costs above. As this charge depends, entirely upon the number of passengers who have to be takenfrom London to Croydon and from Le Bourget to Paxis twhile, of course, it cannot be omitted, I have not added it to the flying costs, but show it separately. Items 38 and 39. While I am not dealing with thequestion of receipts or revenue, I have shown at the foot of Table A a statement of the fares and charges at present inforce on the London-Paris Services, both air and rail. It should be borne in mind that the services of booking agents.for the air service have to be paid for, and this is done by their deducting 5 per cent, to 10 per cent, from the fares,and freight charges. Having dealt with the capital expenditure involved andthe cost of operating, we now come to consider the effect o£ the figures which are laid before us. . . Remarks on Cost of Working It must be realised that these figures are necessarily-estimated, and not the product of actual working. I doubt, very much whether the companies already operating wouldcare to disclose their actual figures of cost, and, even if they did, it would only be for the type of machine they were-actually using. The comparisons made, therefore, may not be altogether fair. For instance, we have taken thedepreciation and insurance at the same rate for all types of machines. This does not bring into consideration anyadvantage which the twin-engined machine, and Certainly the multiple-engined machine, n.ay have in point of relia-bility. If, for instance, the " Bristol " triplane, as the result, of being fitted with four engines, is more reliable in service,and has fewer crashes, then the rate of insurance would undoubtedly be reduced. Correspondingly, the rate de-preciation and cost of maintenance would not be as heavy.. These factors of reliability are, however, so difficult to reflect,in an estimate of this character that I have not attempted. 1080
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
