JAN.-FEB.1970 SUPERSONIC AIR TRANSPORT Table 3 Safety reserves according to TSS-OPS 5.7 M668w 1 Standard mission plus: 001 8747 Missed approach Climb,diversion and 30 min alternate hold at 15,000 ft 600 Enroute reserves (to be determined for each route;might be 3%of block fuel on North Atlantic) 500 2 One-engine failure: L1011 Destination or alternate must be reached with fuel avail- 400 DC 10 able for 30 min hold at 15,000 ft ·CONCORDE 3 Two-engine failure or pressurisation failure: 300 8707320 Any airport appropriate for landing must be reached 8707.1200 No holding 200 100 8314pC4 DC6B on a buggy chassis.Our job is altogether different.Building a supersonic airplane means not only a change in engines and 1940 1950 1960 1970 1980 geometry but also a shift in the state of the art. Indeed, the compromise must be a little more advanced in all respects Fig.5 Maximum takeoff weight trend. than on subsonic aircraft:refinements in design to save from 7.5-10.35%of the takeoff weight.A simple calculation weight,and more automation to alleviate the crew's work- shows that the DOC then drops from 1.3 to 0.94. load since the same functions must be performed in a shorter Assuming the same gains,the subsonic transport's time.Yet thesc advances must be made without com- DOC drops from I down to only 0.83.Now subsonic aireraft promising safety.On the contrary,parallel efforts are are not going to make any weight savings without a corre- made to increase it.Many of the solutions adopted stom sponding increase in the buying price,and,as for fuel con- from these three joint requirements. sumption,there has been far more time to experiment,so that But it so happens that we nourish great hopes from the there is certainly less latitude.Ultimately,as SST technology very hurdles which we find we must clear from the perfor- becomes more commonplace,so the supersonie transport's mance standpoint.For the fact that the weight of fuel is DOC will tend toward that of its subsonic counterpart. 5-8 times the payload also means that 1 saved on fuel DOC will tend toward that of its subsonie counterpart.And consumption means a 5-8%gain in payload. as I was just saying,it is those present narrow margins of ours In other words,the improvement in propulsion efficieney precisely,which give us broad seope for the future. will be far more effective than on subsonic aircraft.On I would like to revert for a moment to the question of the whole,we think that there is every reason to believe that reserves.The over-all design does not depend on them a SSTs will offer a greater development potential than subsonic great deal,but the way the plane is to be operated does to a aireraft. great extent.The quantities of fuel quoted previously This can be established cursorily by reference to the fig- inciude reserves amounting to about 9%of the takeoff ures.Our current estimates are that,given substantially weight.This is a maximum and should be compared with the same weight,the SST will have a DOC of 1.3,if we take the FAA's projected figure of about 8.5%and with 7%or so that of the subsonie transport as 1. of the Anglo-French regulations (TSS-OPS 5.7). To see whether it can be dropped to 1 or even below,let Table 3 provides a very concise summary of the TSS-OPS, us take a look at Table 2,which gives a D0C breakdown per from which you ean see that the requirement provides ample types of cost.The purchase price of the SST may come safety,which,of course,is as it should be. down:the techniques involved,which seem very sophis- In fact even the figure of 7%is arguable,for it hardly ticated at present,will become more conventional,hence seems right to apply worldwide a rule that was formulated less costly.A 10%saving on the buying price would mean primarily with New York and a few other major airports in a 5%saving on the DOC. mind.In fact,TSS-OPS 5.7 does provide for a number of But it is the weight breakdown which will provide the special cases. most signifieant gain.Let us now turn to Fig.6 which Let us nevertheless assume a figure of 7%.This means reproduees the weight breakdown in Table 1. that,under the TSS-OPS 5.7 regulation,airlines are left Assuming coustant prices,highly likely gains of 1%on the with 2%of the takeoff weight with which to optimize the OWE and 5%on fuel consumption would raise the payload flight regularity-payload compromise as they see fit.We be- Pierre Satrc Pierre Satre,born May 4,1909 at Grenoble,France,was educated in Marseille.He is a graduate of Ecole Polytechniqne (Class of 1929)and Ecole Nationale Superieure de l'Acronautique (Class of 1934).He started his career as an Aeronautics Engineer in varioux ministerial offices. In March 1941,he was appointed Chief Engineer at SNCASE-Toulouse (later to be known as Sud Aviation).In this capacity,he was in charge of a number of military and commercial aircraft,among them the Armagnae,Grognard,and Durandal,a Mach-2 fighter plane,and finally the well known Caravelle with rear engines. Appointed Technical Director of Sud Aviation in 1959,he is,specifically,Technical Director of the Concorde projeet. Mr.Satre is an officer of the Legion d'Honneur and Commander of the National Order of Merit and a member of AIAA:he has been awarded the British Silver Medal,as well as numerous other French and foreign medals. He is married and has five children.JAN.-FEB. 1970 SUPERSONIC AIR TRANSPORT Table 3 Safety reserves according to TSS-OPS 5.7 . Standard mission plus: Missed approach Climb, diversion and 30 min alternate hold at 15,000 ft Enroute reserves (to be determined for each route; might be 3% of block fuel on North Atlantic) I One-engine failure: Destination or alternate must be reached with fuel avail￾able for 30 min hold at 15,000 ft > Two-engine failure or pressurization failure: Any airport appropriate for landing must be reached No holding on a buggy chassis. Our job is altogether different. Building a supersonic airplane means not only a change in engines and geometry but also a shift in the state of the art. Indeed, the compromise must be a little more advanced in all respects than on subsonic aircraft: refinements in design to save weight, and more automation to alleviate the crew's work￾load since the same functions must be performed in a shorter time. Yet these advances must be made without com￾promising safety. On the contrary, parallel efforts are made to increase it. Many of the solutions adopted stem from these three joint requirements. But it so happens that we nourish great hopes from the very hurdles which we find we must clear from the perfor￾mance standpoint. For the fact that the weight of fuel is 5-8 times the payload also means that 1% saved on fuel consumption means a 5-8% gain in payload. In other words, the improvement in propulsion efficiency will be far more effective than on subsonic aircraft. On the whole, we think that there is every reason to believe that SSTs will offer a greater development potential than subsonic aircraft. This can be established cursorily by reference to the fig￾ures. Our current estimates are that, given substantially the same weight, the SST will have a DOC of 1.3, if we take that of the subsonic transport as 1. To see whether it can be dropped to 1 or even below, let us take a look at Table 2, which gives a DOC breakdown per types of cost. The purchase price of the SST may come down: the techniques involved, which seem very sophis￾ticated at present, will become more conventional, hence less costly. A 10% saving on the buying price would mean a 5% saving on the DOC. But it is the weight breakdown which will provide the most significant gain. Let us now turn to Fig. 6 which reproduces the weight breakdown in Table 1. Assuming constant prices, highly likely gains of 1% on the OWE and 5% on fuel consumption would raise the payload L 1011 m DC 1 * CONCORDE Fig. 5 Maximum takeolf weight trend. from 7.5-10.35% of the takeoff weight. A simple calculation shows that the DOC then drops from 1.3 to 0.94. Assuming the same gains, the subsonic transport's DOC drops from 1 down to only 0.83. Now subsonic aircraft are not going to make any weight savings without a corre￾sponding increase in the buying price, and, as for fuel con￾sumption, there has been far more time to experiment, so that there is certainly less latitude. Ultimately, as SST technology becomes more commonplace, so the supersonic transport's DOC will tend toward that of its subsonic counterpart. DOC will tend toward that of its subsonic counterpart. And as I was just saying, it is those present narrow margins of ours, precisely, which give us broad scope for the future. I would like to revert for a moment to the question of reserves. The over-all design does not depend on them a great deal, but the way the plane is to be operated does to a great extent. The quantities of fuel quoted previously include reserves amounting to about 9% of the takeoff weight. This is a maximum and should be compared with the FAA's projected figure of about 8.5% and with 7% or so of the Anglo-French regulations (TSS-OPS 5.7). Table 3 provides a very concise summary of the TSS-OPS, from which you can see that the requirement provides ample safety, which, of course, is as it should be. In fact even the figure of 7% is arguable, for it hardly seems right to apply worldwide a rule that was formulated primarily with New York arid a few other major airports in mind. In fact, TSS-OPS 5.7 does provide for a number of special cases. Let us nevertheless assume a figure of 7%. This means that, under the TSS-OPS 5.7 regulation, airlines are left with 2% of the takeoff weight with which to optimize the flight regularity-pay load compromise as they see fit. We be￾Pierre Satre Pierre Satre, born May 4, 1909 at Grenoble, France, was educated in Marseille. He is a graduate of Ecole Poly technique (Class of 1929) and Ecole Nationale Superieure de I'Aeronautique (Class of 1934). He started his career as an Aeronautics Engineer in various ministerial offices. In March 1941, he was appointed Chief Engineer at SNCASE-Toulouse (later to be known as Sud Aviation). In this capacity, he was in charge of a number of military and commercial aircraft, among them the Armagnac, Grognard, and Durandal, a Mach-2 fighter plane, and finally the well known Caravelle with rear engines. Appointed Technical Director of Sud Aviation in 1959, he is, specifically, Technical Director of the Concorde project. Mr. Satre is an officer of the Legion d'Honneur and Commander of the National Order of Merit and a member of AIAA; he has been awarded the British Silver Medal, as well as numerous other French and foreign medals. He is married and has five children