Mitsubishi Spec To Rival Embraer, BombardierMitsubishi Spec To Rival Embraer, Bombardier RJs
Jun 18, 2007
By Bradley Perrett
Mitsubishi Heavy Industries is aiming straight at the Embraer and Bombardier large regional jets with its sophisticated MRJ proposal and is betting it can beat the Brazilian aircraft with a much smaller cross section, defying the trend toward roomier cabins.
The first detailed specifications, released ahead of an expected early 2008 program launch, show a big rise in installed thrust from earlier sketch data but otherwise stick to the concept of a conventionally arranged jet with pylon-mounted engines under the wing.
Those engines could now come from Pratt & Whitney, which has joined Rolls-Royce and General Electric as a potential supplier. Mitsubishi says Rolls and Pratt are offering new engines; GE's would be a derivative of the CF34 series.
The airframe builder will match the new engine technology with extensive carbon-fiber construction drawn from its experience on the Boeing 787 program, along with that of compatriots Kawasaki Heavy Industries and Fuji Heavy Industries.
The aircraft "will be the first regional jet to adopt composite materials for its airframe on significant scale," states Mitsubishi Heavy.
The original two versions of the aircraft, one with a nominal 70 seats, one with 90, have become six: a standard, extended-range and long-range version for each of the two fuselage lengths.
Any physical differences between the sub-variants are minor, however, since there is only one operational empty weight for each of the two body lengths.
Despite the composite construction, the 70-seat MRJ70's empty weights are higher than those of the corresponding Embraer and Bombardier aircraft, the 170 and CRJ700, evidently because it has the same large wing as the MRJ90.
Hoping the MRJ will become the 787 of regional jets, Mitsubishi says the fly-by-wire aircraft will use 20% less fuel than its competitors.
Analysts ponder if the market will be big enough for Mitsubishi to make money as it competes not just with the two established players but also the upcoming Sukhoi Superjet and Avic I ARJ21 from Russia and China, respectively.
Mitsubishi is more bullish: "Demand for 70- to 90-seat aircraft for the next 20 years will be over 5,000 units due to the market trend of up-sizing from 50-seat RJs and route transfers from mainline jets to large RJs in consequence of high fuel price and low passenger yield."
Describing its aircraft, it adds: "The modern and stylish cabin, with single-aisle four-abreast seating and large overhead bins roomy enough to stow large-size roller bags, will provide passengers with a notably more comfortable flight."
In fact Mitsubishi's crucial choice of cross section, which so greatly influences an aircraft's passenger appeal and development potential, has been miserly.
The cylindrical body has an outside diameter of 2.90 meters. That's greater than the 2.69 meters of the bizjet-derived CRJ series but, surprisingly, is much smaller than the 3.01-meter-wide, 3.35-meter-high double-bubble of Embraer's large regional jets.
The cross-section choice has squeezed down the MRJ's internal width, but the difference with Embraer's is not so great. A published drawing of the cross section shows it to be about 2.68 meters wide at armrest level, compared with Embraer's 2.74 meters. That suggests thinner walls in the Mitsubishi.
Aisle height is almost the same at 2 meters and carry-on bag size is said to be identical, but Mitsubishi's circular cross section naturally has far less under-floor height than Embraer's double-bubble.
Mitsubishi and its government backers have planned a regional jet since at least the 1990s, and the current project dates from 2002. It has progressed far from its original 30-seater concept.
But since the general size and configuration published for this week's Paris air show have not moved far from the brief details issued last year, Mitsubishi Heavy has now clearly settled on the design it wants to build.
Thrust has risen greatly in the latest specification--from 14,900 to 17,100 lb. for the 90-seat version, the MRJ90, and from 13,000 to 14,500 lb. for the MRJ70.
Demands for shorter takeoff field lengths or a faster climb appear to have driven those changes, since the weight of the heaviest version has barely changed.
A launch decision is expected early next year for service in 2012, with the project looking quite likely to proceed following an industry ministry decision to seek budget authorization to subsidize about a third of development costs.
Following the latest fashion, the cabin windows appear big in artist's impressions, and the company says the seats will be unusually thin, for extra leg room.
A cabin mockup and model will be displayed at the Paris air show.
REGIONAL JET SPECIFICATIONS: MITSUBISHI VS. EXISTING RIVALS
MRJ70 MRJ90 CRJ700 Embraer 170 Embraer 190
Passengers 70-80 86-96 70-78 70-78 94-106
Engine Thrust (lb.) 2@14,500 2@17,100 2@12,760 2@13,800 2@18,500
Max Takeoff Weight (tons)* 36.5-40.6 39.4-42.7 33.0-34.9 36.0-37.2 47.8-50.3
Empty Weight (tons) 23.9 24.9 19.7 21.0 27.7
Range (km.)** 1,690-3,910 1,610-3,320 3,708 3,770 4,448
Length/width/ 32.8/30.9/ 35.8/30.9/ 32.5/23.2/ 29.9/26.0/ 36.2/28.7/
height (meters) 10.0 10.0 7.6 9.9 10.6
Cruise Speed (Mach) 0.78 0.78 0.78 0.75 0.78
Takeoff Field Length (meters)* 1,400-1,720 1,520-1,770 1,564-1,851 1,590 2,107
*Depending on sub-variant.
**Max passengers. For Bombardier and Embraer, LR versions only.
Sources: Company specifications.