Japan Airlines (JAL) has entered into a strategic partnership with Boom Supersonic, the Mach 2-plus airliner developer, and has placed purchase options for up to 20 aircraft. 

The Japanese flag carrier becomes the second airline after Virgin Atlantic to reveal its support of the Denver-based supersonic airliner project, which is targeting entry into service in the mid-2020s. Together with the 10 options announced by Virgin in mid-2017, the JAL commitment represents almost half of the 76 options received by Boom to date. Three additional operators for the remaining 46 aircraft remain unidentified.

The Boom concept is targeting supersonic travel at current business-class prices by bringing together a 55-seat design using structures, advanced aerodynamics and propulsion technology that was not available in the 1960s for the development of the Anglo-French Concorde, the world’s first operationally successful supersonic airliner. The delta-winged Boom trijet design is intended to rely on a 10% higher speed than Concorde to achieve high use and shorter sector times on 4,500-nm routes, most of which will be flown over water.

The partnership with JAL includes an investment of $10 million in Boom, which is particularly significant, says Blake Scholl, founder and CEO of the startup aerospace company formerly known as Boom Technology. “This is the first time in history an airline has put real cash into a supersonic transport program, and to us it is a commitment and a demonstration that the customer interest is real,” he says. 

Although Air France and British Airways—the national carriers of France and the UK that co-developed the Concorde—each paid a token price for their fleets in the 1970s, neither contributed substantially toward development costs. And although British Airways was originally directed by the British government to pay £23 million per aircraft against a book price of £35 million ($56 million in 1977 terms), the airline won a guarantee from the government to underwrite its expected losses.

The complex deal with British Airways also included the clause that if the enterprise proved profitable, 80% of the profits would be paid back to the government. This deal was scrapped seven years later when the government ended involvement with the $2 billion project. British Airways did, however, pay  £16 million for a vast multisourced inventory of spare parts.

As a strategic partner for this most recent supersonic project, JAL will be directly involved in shaping several aspects of the program. “You really want to have a customer voice in the development program,” says Scholl. JAL will help define the aircraft’s operating model, maintenance cost targets and areas such as the interior design, catering and cabin layout. “JAL has set a high customer bar and has deep operational experience,” says Scholl, who adds that “every customer wants to have a voice, and several others are already involved.”

JAL, which Scholl says intends to use its supersonic aircraft primarily on busy North Pacific trunk routes to North America, has had a long-term interest in acquiring high-speed transports. Although the Japanese carrier ordered three Concorde aircraft in 1963, these were canceled after the global oil crisis a decade later. Similarly, the airline also provisionally ordered up to eight of the larger Boeing 2707 before the U.S. supersonic effort was also canceled in the early 1970s.

Japan also has a long-running national interest in developing a high-speed air transport capability; studies of supersonic and hypersonic airliner concepts are underway at JAXA, the Japan Aerospace Exploration Agency. JAXA is currently focused on a low-boom, 50-seat supersonic design capable of Mach 1.6 and a range of more than 3,500 nm. However, its projected entry into service is not until the 2030s. “We think we have found a way to make this happen sooner,” says Scholl, referring to his company’s push for mid-2020 service. 

Toward this end, Boom is also “really surprised” at the high level of interest shown by Congress and the White House in advancing legislative support for lifting the current ban on supersonic overland flights. If successful, this could substantially increase the market for commercial high-speed transports. An amendment to the Senate’s fiscal 2018 FAA reauthorization bill, if it becomes legislation, would require the agency to set an “economically feasible and technologically practical” boom standard by early as mid-2020.

Notwithstanding the question of whether the privatization of air traffic control is included, Scholl says: “Should an FAA bill get passed early next year, it will almost certainly include something on supersonic transport—and that will be either good, or really good. Everyone wants to make this happen, and we don’t have to change any regulations to see this work.”

The FAA and the International Civil Aviation Organization (ICAO) are working on a global standard for sonic boom that would lift the prohibition on supersonic flight over land. And NASA plans to fly a low-boom flight demonstrator in 2021, which would collect community response data on the public acceptability of a 75-PNLdB (perceived noise level decibel) boom—down significantly compared to the Concorde’s 105 PNLdB.

Boom is also gearing up to begin assembly of its XB-1 “Baby Boom” supersonic demonstrator, a one-third-scale proof-of-concept vehicle that will pave the way for the airliner. The small delta aircraft, due to fly subsonic in late 2018 and supersonically in 2019, is powered by three General Electric J85-21 engines. Recently completed test work in the buildup to assembly includes completion of structural tests on a composite wing spar at temperatures and loads representative of the Mach 2.2 design cruise condition.

The evaluation was conducted in a specially developed hydraulic test rig in which the spar was subjected to load while being heated in an oven that enclosed the rig. Temperatures inside the test apparatus reached 300F, “which is well above the heat soak operational temperature,” says Scholl. Netherlands-based TenCate Advanced Composites, which provides high-temperature-resistant materials to SpaceX for the Falcon 9 rocket among other programs, is supplying an epoxy-based material system for cooler airframe parts and a higher-temperature-resistant material to handle the hotter stagnation temperatures at the leading edges and nose. On a standard day, the temperature of the latter is forecast to be about 307F.

The airframe will be primarily carbon/epoxy, with intermediate-modulus carbon fibers. Some high-modulus fibers are expected to be used on the wing spar caps, while bismaleimide prepreg will likely be used for the high-temperature leading edges and ribs. “The basic structure is pretty straightforward and we will be using fuel as a heat sink, so the environmental control system will dump the cabin heat into the fuel,” says Scholl.

Boom also continues to evaluate the engine choice for the small airliner and intends to make a final decision in 2018. The preferred option remains a development of an existing commercial core with a new low-pressure spool; the alternative is an all-new clean-sheet design. Both options will be heavily influenced by airframe-propulsion integration considerations, which are “more complex,” says Scholl. “The big trade is on fan diameter,” he adds, noting that larger-diameter fans—while preferred for higher bypass and lower noise on takeoff—drive considerably higher thrust requirements for cruise. This in turn has a significant impact on range and fuel-burn performance.

All these factors play into the engine decision, with takeoff noise being a crucial factor, says Scholl. “We are in conversations with the European Aviation Safety Agency and the FAA, he notes. It will not be louder than anything flying today (such as the Boeing 777-300E, for example). The conversations with the regulators are from a total impact perspective, and where the  best place is to be.”