FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1963
1963 - 0088.PDF
The Dart turboprop, with Dowty-Rotol propeller, is familiar all over the world. It is less often seen installed in a low-wing "twin," as in this Avro 74B in service with Aerolineas Argentinas 38,000,000 HOURS . . . and basically good economics can be ruined by careless use of high temperatures. There is really no end to the story of experience, and to the benefits it brings to aircraft designers and operators. A book could be written about Rolls-Royce customer service. This is, after all, the side of a manufacturer that most operators see; and though good engines are the prerequisite of a golden reputation, good service and support are essential to the safeguarding of that reputation. Which brings us to the second part of the story: the engines themselves, starting with the Dart and finishing with the Spey, an engine that in many ways looks like being a Dart replacement. DART Rolls-Royce have built about 4,000 Darts for civil use, and they have logged more than 21m engine hours. Highest overhaul life to date has been achieved by TCA's Darts, which are now being run at 4,400hr. Unscheduled removal rate per l,000hr has been steady during the past five years at about 0.25. Discounting the RDa.12, for the Avro 748MF, the Dart 10 is the highest-rated member of the family, chosen for the Japanese NAMC YS-11. It is expected that it will start life at 1,000hr. Some of the lives achieved by expensive Dart "hot parts" are remarkable; turbine blades. 16,000hr low-pressure and 8,500hr high-pressure; turbine discs, 11,000 LP and 10,000 HP; nozzle guide vanes, 16.000 LP and 8,000 HP; nozzle box, 16,000: flame tubes, 10,000; and discharge nozzles, 12,000. TYNE Despite early difficulties, the graph shows that the Tyne"s overhaul life has climbed at a rate higher than was achieved by the Dart—even the lower-rated Dart 3 and Dart 6. In fact, after Development of the maximum time between overhauls approved by airworthiness authorities for the principal types of Rolls-Royce civil engines, plotted against the period that each type has been in airline operation The record of the rate of in-flight shutdowns and unscheduled removals per thousand hours for the major types of Rolls-Royce civil engines. These curves are for all engines, R-R responsibility nearly two years of service, the TCA's Tyne achievement of 2,000hr between overhauls corresponds with the lives at that time achieved by both the Conway 12 and the Avon. As might be ex pected, overhaul life of Tynes fitted to Vanguards is climbing more slowly than that of engines fitted in CL-44s operated by Flying Tiger, Seaboard and Slick, whose Tynes are increasing in TBO at a rate of 200hr a month. Unscheduled removal rates for the Tyne are now running only a little above the rate achieved by the Dart at a similar age. The high-efficiency 5,000 h.p. turboprop turned out to be one of the most difficult engines Rolls-Royce have ever tackled. The failure rate during the first year of service was the highest suffered by any Rolls-Royce turbine engine, and the required engineering remedies tested the company's reputation perhaps as never before. The engine is now "over the hump." More than 550 Tynes have been delivered, mainly for Vanguards and CL-44s. There is a big potential for this engine in Europe, where the Transall C-160 and Breguet Atlantic military programmes could produce business taking Tyne production up to more than 1,000 engines. Production models of these two aircraft are to be powered by Tynes built by a European manufacturing consortium comprising MAN, FN, Hispano-Suiza and Rolls-Royce. With Vanguard production long-since completed, future civil business for Tynes depends mainly on the freight market, and in particular on the success of die CL-44. The fine economic performance achieved by these aircraft has not, so far, been rewarded with the commercial success that the aircraft merits. The CL-44's toughest competitor is the jet freighter, in the shape of the combination passenger/cargo version of the Boeing 707 and DC-8, with the Lockheed 300 pure-freighter looming in the future. In some ways the air cargo industry is witnessing a repetition of the jet-v-turboprop battle for the passenger market. The decisions of Pan American and TCA to order, respectively, combination 707- 320Cs and DC-8Fs were not entirely based on the commercial appeal of jets in the freight market. They were founded on the real economic advantage of standardizing freight and passenger fleets by means of combination passenger/freight aircraft. Yet it is by no means certain that the jet is going to have it all its own way in the freight field. The ton-mile costs of the CL-44 and the 707-320C are within a penny of each other, and the real commercial distinction between the CL-44 and its jet competitors is the difference between the pick-up truck and the pantechnicon. The CL-44 is a stopping-service freighter rather than a coast-to- coast or shore-to-shore freighter. Where end-to-end traffic justifies the big 50-ton jet freighter, the 30-tonner CL-44 may find the going tough. The present Seaboard World and Flying Tiger CL-44 operations on the North Atlantic are successful thanks partly to MATS contracts and partly to the fact that, to date, the Canadair has been the most competitive freight vehicle on the route. The competitive situation will change this year when the jet freighters appear. What will not change is the flexibility of the CL-44 on those other routes—which for many years will be in the majority—where freight economics depend on sector traffic and on a vehicle with the CL-44's flexibility to exploit it. In this type of market lie the bnghtest hopes for the CL-44 and its Tyne engines—and for the similarly powered Belfast.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
