The Mitsubishi SpaceJet (, originally named Mitsubishi Regional Jet) was a regional jet project by Japanese company Mitsubishi Aircraft Corporation (MAC), a Mitsubishi Heavy Industries (MHI) subsidiary, that ran from 2007 to 2023.
Work on what would become the SpaceJet can be traced back to 2003 with the backing of the Japanese government; the concept was formally presented by MHI at the Paris Air Show in June 2007 and launched one year later, at which point certification was targeted for 2012, as the first Japanese airliner since the 1962 NAMC YS-11. Extensive design changes were made during the late 2000s, which increased the weight of the airliner and led to commercial impacts. The airframe was made mainly in aluminium; some elements were composed of carbon fibre composites, such as the empennage. The low-wing twinjet was powered by underwing Pratt & Whitney PW1000Gs, and was the first program to select the geared turbofan. In June 2019, Mitsubishi rebranded the Mitsubishi Regional Jet (MRJ, ) program as the SpaceJet. The M90 (originally named MRJ90) was to seat 86 to 96, while the smaller MRJ70 was to accommodate 70 to 80 passengers. The MRJ70 was replaced by the SpaceJet M100, stretched by 1.1 m (3 ft 7 in) to better meet US scope clauses at 76 seats with premium seating. It was comparable with the Embraer E-Jet E2 family.
After a delayed development, the maiden flight of the MRJ90 took place on 11 November 2015. A total of eight test aircraft, seven MRJ90s and one MRJ70, were produced for the flight test programme. As flight testing took longer than expected, the scheduled entry into service was further pushed back. During October 2020, it was announced that the programme had been put on hold; in February 2023, the SpaceJet was officially cancelled altogether. All but one of the test aircraft have been dismantled while the sole remaining airframe has been preserved.
Development Launch
In 2003, the Japanese government started a five-year, ¥50 billion ($420 million) research program to study an indigenous regional jet for 30 to 90 passengers, led by Mitsubishi Heavy Industries (MHI). In 2004, MHI was reportedly focused on a 2m high by 2.8m-wide, four-seat-abreast cabin, seating 30 to 50 passengers, and was hoping to fly a prototype in 2007 and deliver the first aircraft in 2010. One year later, it switched to a larger 70-90 seat category.
During June 2007, MHI launched its concept at the Paris Air Show, showing a full-scale cabin mock-up and aiming to be the first regional jet with an all-composite airframe. At the time, certification was targeted for 2012. Mitsubishi formally offered the MRJ to airlines in October 2007the first Japanese airliner since the NAMC YS-11 which stopped production in 1974after being the first airframer to select the Pratt & Whitney PW1000G geared turbofan offering a 12 percent reduction in thrust specific fuel consumption, rated at thrust on the 70- to 80-seat MRJ70 and 17,000 lb thrust (75.7 kN) on the 86- to 96-seat MRJ90, projecting a ¥150 billion ($1.275 billion) development cost. The NAMC YS-11 of the 1960s was produced at a loss.
On 28 March 2008, MHI officially launched the Mitsubishi Regional Jet program, having secured an initial order for 25 aircraft (15 firm, 10 options) from All Nippon Airways, which was at that time targeting a 2013 introduction. Mitsubishi was targeting a 20 percent share of a 5,000 global sales forecast in the 70-90-seat bracket over 20 years. Flight testing was scheduled for late 2011 and the $1.9-billion program would have needed 300-400 sales to recoup its cost. Mitsubishi Aircraft Corporation (MAC) is a partnership between majority owner Mitsubishi Heavy Industries and minority owner Toyota with design assistance from Subaru Corporation, itself already an aerospace manufacturer. Various other companies would also be involved in the programme, including the American aerospace firm Boeing, who both performed consultancy work and was set to provide customer support.
Design
In September 2009, Mitsubishi unveiled extensive design changes, using aluminium instead of carbon fibre composites for the aircraft's wings and wingbox; the remaining composite parts would make up 10-15 percent of the airframe: the empennage. The cabin height was increased by to and the fuselage height increased to , giving a rounder cabin, wider and higher than its competition. The program was delayed by six months with final design frozen in mid-2010, first flight delayed to the second quarter of 2012 and deliveries to early 2014. Maintenance intervals were expected to be 750 flight hours per A Check and 7,500 flight hours per C check.
As early as December 2008, a 110-seat stretched MRJ100 was publicly under consideration; by March 2011, this option had been subject to a design study. Five years later, it was confirmed to have still been under evaluation.
As the MRJ90 MTOW of 39.6 tons was above the US regional carriers' scope clause of 39 tons, SkyWest and Trans States Holdings could have converted their MRJ90 orders for 100 and 50, respectively, to the 1.4 m shorter MRJ70: 67 percent of the 223 firm MRJ90 orders. However, the MRJ70 was to seat only 69 in two classes and attain the 76 seats scope close limit only in all-economy: Mitsubishi wanted to increase seating within its fuselage to compete with the currently compliant Embraer E-175 and Bombardier CRJ900. Mitsubishi worked on a three-class, 76-seat design, with more premium seating than the MRJ70 but still within the scope-clause MTOW, to be unveiled at the June 2019 Paris Air Show. The reworked MRJ70 was to be called the Space Jet M100 and was expected to receive its type certificate in 2022. Mitsubishi envisaged U.S. production. Program cost was expected to reach ¥800 billion by the projected 2020 debut of the SpaceJet M90.
Assembly
On 15 September 2010, the Mitsubishi Aircraft Corporation announced that it had entered the production drawing phase and was proceeding with the manufacturing process. Assembly of the first aircraft began in April 2011 with construction of the emergency escape for the cockpit. By December 2012, MRJ90 delivery was scheduled for 2017.
A new production facility for the aircraft was built at Komaki Airport in Nagoya, Japan, on land purchased from the government at a total cost of 60 billion yen. The 2015 roll-out of the MRJ took place at Komaki, which had previously been the development site of the Mitsubishi A6M Zero fighter. In early 2013, Pratt & Whitney delayed PW1200G certification to the "latter half" of 2014. Mitsubishi announced in June 2013 that it would establish a quality control facility in Illinois for the sourcing of MRJ components from the United States. In August 2013, Mitsubishi announced a third delay to the program, and that the first flight would take place in the second quarter of 2015 instead of end-2013, while the first delivery to launch customer ANA would take place in the second quarter of 2017 instead of 2015, due to parts delivery problems including Pratt & Whitney engines. On 7 September 2013, a prototype of the left wing and four aluminium sections (forward fuselage, front mid fuselage, aft mid fuselage and aft fuselage) were exhibited, to be assembled in October 2013. Mitsubishi hired foreign experts to help with relations with suppliers, ground tests, flight tests, and certification.
During May 2014, the first MRJ90 was fully assembled; work on other airframes was also proceeding. An official rollout of the first flyable airframe occurred on 18 October 2014. MHI employed new production methods such as integral wing stringers, unusually tight tolerances, shot peening of curved surfaces, and vacuum assisted resin transfer molding, intended to increase quality and thus reduce expensive fault correction to keep price competitive.
Testing
The maiden flight of the MRJ90 took place on 11 November 2015. On 24 December, Mitsubishi announced a one-year delay for the first delivery of the MRJ until mid-2018. The delay was attributed to insufficient wing strength and the redesign of the landing gear for better safety.
Much of the flight testing for the MRJ90 took place in Moses Lake, Washington, at the Grant County International Airport, due to the crowded airspace in Japan causing scheduling difficulties. Static strength tests were completed on 1 November 2016, and confirmed that the airframe could withstand 1.5 times the maximum load.
In January 2017, a further two-year delay was announced, pushing the expected first delivery to mid-2020. This resulted from moving the avionics bay and wiring looms and in March the flight certification program was extended from 2,500 to 3,000 flying hours. Four of the five delays were caused, at least partly, by failures to document work for certification or similar failures. As a result, development cost ballooned to 350 billion yen (US$3.17 billion) implying that the project might never be able to fully recover its costs. Mitsubishi originally planned to use five flight test aircraft and two ground test aircraft but one or two additional aircraft will also be needed following this introduction of a two-year delay to mid-2020.
On 26 April 2017, the fifth MRJ was complete in ANA livery, lacking only engines and nose cone, aircraft number six and seven had their fuselage and wings joined without the tails, and the eighth, the first MRJ70, was at the assembly line start; Mitsubishi planned to manufacture 12 aircraft concurrently: in station one are joined fuselage sections, in station two the landing gear, wings and horizontal stabilisers are attached, in section three the major components are assembled, in outfitting takes place in section four and ground tests in station five, then the completed aircraft moves to painting. Seattle engineering consultants Aerotec L.L.C. saw problems for avionics and its wiring certification: damage could cause single point of failure, due to fire, water flooding from a ruptured waterline, or from part penetration of an engine explosion. This necessitated hardware changes in the bays, now frozen, but the electrical wiring interconnection system had to be reconfigured with hired specialist Latecoere. By June 2017, 940 hours of flight tests had been performed and the four prototypes had an above 98 percent availability. On 21 August, FTA-2 experienced a flameout west of Portland International where it landed; partial damage was confirmed in the PW1200G and the test fleet was grounded until the cause was known. Flight testing resumed on 6 September.
By December 2017, the MRJ test campaign was half complete, covering 1,500 flight hours and less than 1 percent cancelled due to technical issues. The rate was accelerating with tests set up before the January 2017 avionics bay redesign: special runway tests, extreme environment and high altitude tests, to be completed in 2018. An additional flight test aircraft incorporating the redesign was to join the campaign in the second half of 2018, focused on wiring tests such as lightning and high-intensity radio-frequency. Two additional aircraft (10007 and 10010), recently painted white and under structural assembly in December, were expected to join the flight test campaign towards the end of 2018. At the end of the year, the mid-2020 deadline seemed difficult to achieve.
In January 2018, the avionics bay rearrangement and rerouted wiring were almost complete to be adequate for extreme events such as bomb explosions or water ingress underfloor. Upgrades and ground tests were performed on four flight test aircraft from February to March at Moses Lake, preceding flight testing for natural icing, avionics and autopilot, performance, stability and control.
By April 2018, the test fleet had logged 1,900 flight hours.