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CF34 family grows
By Patrick Hoeveler
Will the successful CF34 family stretch to a new generation? In the “Tech X” programme, GE's Development section is working on a completely new engine for future business jets which also could serve the role of successor to the best-seller. “There is a lot of potential in Business Aviation in the 10000 lbs and higher thrust class,” says Chuck Nugent, General Manager of the CF34 programme, in an interview with FLUG REVUE. He is not yet prepared to disclose any details about the new powerplant, but it seems likely that the engineers will borrow aerodynamics and materials of the GEnx.
Having stayed out of Business Aviation for a number of years, it was only the partnership with Honda over the HF120 that took GE back into this area. Nugent estimates that the engine, which should be scalable in size between 9000 and 20000 lbs, will take three to four years to develop. “It will have a significantly different mission than regionals and be more focused on fuel burn, weight as well as range. The architecture will be more similar to a widebody application than a CF34.” Despite this, the outcome of Tech X could lay the foundation for a possible CF34 successor.
It is bound to be some years before it comes to full fruition. After all, the latest member of the engine family, the CF34-10A, only completed its first full engine test on 8 October of this year. The engine for the ARJ21 Chinese regional jet developed by AVIC I is based on the CF34-10E and eighty percent of its parts are the same. The difference lies primarily in the new engine nacelle situated at the rear. GE plans to deliver two engines for flight tests at the end of the year, the aircraft rollout now being scheduled for this December. The ARJ21 should then enter into service in 2009, two years later than originally planned. Despite the programme slippage, Nugent is optimistic. “We are very impressed with the pace of the program today. The current leadership of AVIC I is driving this program very aggressivlely to stay on track.” There is even talk at the moment of relocating final assembly of the CF34-10A to China.
Nugent estimates the market potential in China at around 600 aircraft. The main focus is clearly on this region, but there is also the possibility of exports. “We are supporting the Chinese intent to have the aircraft FAA and EASA certified to be able to sell the aircraft abroad. We see opportunities to do that.”
In this way GE will be able to strengthen its position. Over 3,600 CF34 engines are currently in service, and together they have flown over 40 million hours. According to Nugent, another 500 are being added every year, the emphasis having shifted from versions for smaller aircraft to those for larger planes.
The CF34-3, of which there are around 2,300 with 31 million flying hours completed, accounts for the majority of the fleet. “The engine really established an unprecedented dispatch relaibiliy rate of 99,98 percent which means less than two in 10000 delays are due to engine problems.” In his opinion, the 50-seater remains the workforce of many fleets, especially in North America. However, there are no new sales. “It is no longer an active production program for 50 passenrger regional aircraft, but we build a number of them for the Challenger, about a hundred a year.” Nugent does not see strong demand for a new 50-seat type at the moment, though this might change in the next decade.
The best and fastest selling engine at present is the CF34-8 for the Bombardier CRJ700/900/1000 and the Embraer 170/175. Planned production is about 160 engines per year. Although the model has only been in scheduled service since January 2001, 1200 are already in use. Despite this, GE is already offering enhancements such as an upgrade for the early 8C1 variant to the present 8C5 standard.
For the CRJ1000, the engineers are increasing take-off thrust by five percent. The CF34-8C5A2 has suitably modified controls and a modified high-pressure turbine for prolonged life. Whether the changes will become standard for all -8 versions has not yet been decided.
The most powerful member of the family, the CF34-10, has been in service for exactly two years. About 200 have been flying since November 2005 – and have been performing well, according to Nugent. “The dispatch reliability rate is slightly below that of the CF34-3, but is rapidly growing. The customers are pleased.”
The CF34-10 is a completely new engine which resembles the CFM56 more closely than the smaller CF34. Thus, it has the single-stage high-pressure turbine of the larger CFM56 rather than the previous two-stage design. The combustor and aerodynamics in the high-pressure compressor have also been adapted from the CFM56.
At least among the regional jets, the CF34 would appear to have many years of service remaining ahead of it, as Nugent believes. “We have no plans today for a whole next generation engine. We are focused on the existing products.”
From FLUG REVUE 12/2007
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