Mitsubishi to complete MRJ design by end-August
By Leithen Francis
Mitsubishi Aircraft aims to complete the design of its Mitsubishi Regional Jet (MRJ) by the end of August, and is also working on a plan to develop an after-sales support network.
"We are working on the final details so we can freeze the design" by the end of August, says the aircraft-maker's president Hideo Egawa.
It has completed the preliminary design review and is now working on the joint-definition phase, he adds.
Mitsubishi Aircraft announced some major changes last September to the aircraft's design, in response to airline feedback.
The aircraft-maker was originally planning to have the wings made of composite materials but announced last September that the wings would be made of aluminium alloy.
The Boeing 787 has composite wings but Egawa says the wings on smaller aircraft, such as the MRJ, have more curvature. As a consequence, the smaller wings require more structural support inside the wing, he adds.
He also says aircraft wings need to have manholes, to give maintenance engineers access, and that all manholes must be reinforced.
The problem with the MRJ is that the manholes are significant in size in proportion to the wing.
These weight gaining factors mean there is no great benefit in having composite wings for the MRJ, adds Egawa.
Another factor behind the decision is that Mitsubishi is considering having a 100-seat stretched version of the MRJ, says Egawa. It is easier to adjust the size of the wing during the manufacturing process if the wing is made from metal materials, he adds.
Despite the switch to aluminium-alloy wings, Mitsubishi Aircraft still plans to make the aircraft's empennage from composites using vacuum-assisted resin transfer molding, says Egawa.
One advantage of this technique is that Mitsubishi can bake the empennage - to harden it - using a non-pressurised oven. Composite parts manufactured using other techniques often need to go into a pressurised autoclave oven, an expensive piece of equipment.
The MRJ's first flight is due in 2012, with first delivery scheduled for 2014 to launch customer All Nippon Airways (ANA). The airline has ordered 15 MRJ90s with options for 10 more. Besides the 90-seater, Mitsubishi is also designing the MRJ70, a 70-seater.
In an effort to win more customers, Mitsubishi is now working to create a customer support network.
This involves signing up maintenance, repair and overhaul (MRO) firms as approved MRJ facilities.
Mitsubishi Aircraft will also work to ensure there are spare parts warehouses in key locations around the world, so customers have ready access to spares, says Egawa.
There will also be a 24-hr centre that customers can call to speak to MRJ liaison engineers to get technical assistance, he adds.
Source: http://www.flightglobal.com/articles/20 ... ugust.html