Eland Performance
The latest available performance figures on the E.L. 6 Eland show ratings of 3,500 Equivalent Horse Power at 12,500 RPM giving 3,150 Shaft Horse Power for take-off at sea level. Other sea level ratings are 2,900 EPH at 12,000 RPM to give 2,600 SHP on maximum continuous operation and 2,280 EHP at 11,500 RPM for 2,045 SHP in the normal cruising condition.
Performance at altitude, 30,000 feet at 400 MPH true air speed, is shown as 2,135 EHP for 12,500 RPM to give 1,760 SHP applying maximum power; 1,835 EHP at 12,000 RPM to give 1,545 SHP at maximum continuous power; 1,490 EPH at 11,500 RPM for 1,300 SHP in the typical cruising condition.
Specific fuel consumption in these various configurations is given as 0.595 for take-off; 0.610 for maximum continuous and 0.650 for normal cruise at sea level; and 0.456 for maximum power, 0.458 for maximum continuous and 0.475 for normal cruise at 30,000 feet.
The Convair 340 which was evaluated by the RCAF at Ottawa in November was powered by two Eland E.L. 6s. The conversion was carried out by Napier in England where an extensive test program was undertaken before the flight to North America.
The flight test program established a considerable improvement in performance for the Eland-powered Convair as compared with the piston engined aircraft.
Among the more important areas of improvement were an increase in permissible all-up weight from 47,200 lb. with piston engines to 53,200 lb. with the Eland turboprops; range with maximum payload for the turboprop version was increased to 970 miles compared with the 250 miles possible with the piston aircraft; block speed over a typical 600-mile stage length at capacity payload rose to 271 mph with the Elands installed compared with the former 233 mph; the turboprop aircraft can reach its cruising height in approximately one third of the time required by one piston powered Liner; calculation of increased earning power, based on 3,000 operating hours a year at a 65 per cent load factor over a stage length of 200 miles, indicates the Eland version would boost the piston-engined version profits by some $84,000 a year.
All of the advantages evident for the converted Convair Liner as a result of the Napier Eland project will be reflected in performance of the Canadair CL-66.
Napier embarked on the Convair Liner conversion as a part of an overall program to speed development of the Eland engine and prove its suitability as a replacement power plant for piston-engined civil aircraft. In addition to the Convair 340, an Elizabeth and a Varsity were fitted with Eland engines.
Prior to the RCAF order with Canadair, Napier sales efforts with respect to the Eland project were concentrated mainly on the conversion of existing piston-powered Convair Liners to turbine power.
Conversions Continue
This phase of the program is to be continued. The Napier company has recently purchased a second Convair Liner, this one the latest 440 Metropolitan type, for conversion to Elands. This work is to be carried out at Santa Monica, Calif., by the PacAero Engineering Corp., which has been appointed as Napier's agents to handle Eland conversions in the United States.
PacAero will also be doing the Eland conversion on three Convair Liners owned by Brazil's REAL Air Lines, which is the first carrier with a Convair fleet to contract for the turboprop version of the airliner. If the first three REAL conversions prove satisfactory, the air line has indicated it will change to Elands on the remainder of its Convair Liner fleet of 17 aircraft.
No over-all cost has been mentioned with respect to the 10 aircraft order which has been placed with Canadair for the new Cosmopolitans. The Napier company, however, has indicated that the value of the order which has been placed for Elands to power the Canadian airliners is between four and five million dollars.
Other than pointing out that all of the companies involved, Canadair, Convair, Napier and the latter's associates in the English Electric Aviation Group, will be combining their efforts in promoting sales of the commercial Cosmopolitan, there has been no detail on commitments and responsibilities to be undertaken by participants in the program. Spokesmen for both Canadair and Napier indicated that arrangements were just now being worked out in final form.
Canadair's entry into the medium-range turboprop transport field is a continuation of an over-all program which got its first big impetus in April, 1957, with announcement that the Canadian company and the Bristol Aeroplane Co. of England had concluded an agreement giving Canadair "extensive rights in specified areas for the production and sale of a Canadair derivation of the Bristol Britannia."
This long range turboprop transport, designated the CL-44C Canadair Liner, will be powered by four British built propeller turbine engines. In the same general configuration as the CL-44 military transport which Canadair is building for the RCAF, the Canadair Liner will be larger than the Bristol Britannia from which it is derived.
The Canadair Liner is being offered to commercial carriers with a promise for delivery in 1960. The swift move into production on the military Cosmopolitans should guarantee at least as good a delivery date on the commercial versions of the medium-range turboprop.
Canadian Aviation, March 1958, p. 22-24, 66