Aircraft Design: Synthesis and Analysis - part 10

Từ dữ liệu này, trọng lượng tối đa cho phép đối với một điều kiện nhất định được thành lập. Leo lên leo lên hoạt động bình thường đến độ cao hành trình được thực hiện tại tốc độ cho nền kinh tế tổng thể tốt nhất (tốc độ cao lên cao) nhanh hơn đáng kể so với tốc độ tốc độ tối đa lên cao, lần lượt là nhanh hơn nhiều so với tốc độ lên cao tối đa cho gradient . | This equation is truly valid only for aircraft with cruise Mach numbers of about . However speed differences of 10 to 20 will affect the IOC by only 2 to 4 . Higher block speeds reduce the IOC. For other ranges the IOC is corrected by using the ratio of IOC IOC1000nm from Figure 16. The latter is derived from the same data as . Figure 16. Breakeven Load Factor To break even at distance d with a yield of y passenger-rnile the revenue must equal the sum of the direct and indirect costs N LF d y DOC N d N LF pass indirect where DOC and pass indirect are taken at distance d N number of pass. seats. LF is the breakeven load factor. Substituting LFbreakeven d DOC y d pass indirect Total operating costs may be used in a complete airline system analysis in which each city-pair is studied to determine total traffic required schedule frequency load factors total income total costs and profit. Simpler presentations of the effect of costs may be shown in the form of passenger load required to pay the DOC as shown for the B707-320B and the B747 in Figure 17. Another type of analysis determines the break-even load factor the load factor required to cover the total costs. Figure 18 shows this type of analysis for the DC-10 B747 DC-8-62 and the B727-200. All three of these economic analyses require establishing not only operating costs but also the yield the average passenger fare per mile. The yield varies greatly with route and is generally different from the basic fare as airlines now determine fares based on the day of the week when the ticket is purchased or whether the traveler will stray over a Saturday night. Figure 17. 271 SEATS DC-10 Thli fonnuln rriTrct tliE avitiffE TMuti al 1OĐD 1 atu-lử tallns of Four rniiior . dữioccEk Infnk Cirri tn BREAKEVEN LOAD FACTORS IPU J Salute Miles . VTEID CENTS PER PASSENGER Miư INDIRECT OPERATING COST G JM CENTS PER AIRCRAFT 4- CENTS PER REVENUE PASSESGLR MILE GO PERCENT BREAKEVEN LOAD FACTOR .