Boeing Yellowstone Project

Passenger capacity of existing and future Boeing civil aircraft.

Yellowstone was one of three concept finalists in a Boeing Commercial Airplanes project to replace its entire civil aircraft portfolio with advanced technology aircraft. New technologies to be introduced include composite aerostructures, more electrical systems (reduction of hydraulic systems), and more fuel-efficient turbofan engines (such as the Pratt & Whitney PW1000G Geared Turbofan, General Electric GEnx, the CFM International LEAP56, and the Rolls-Royce Trent 1000). The term "Yellowstone" came into use in the lead-up to what became the 787 program. The other to concept families were referred to as the "Glacier" and the "baseline." Yellowstone and Glacier were both fairly radical departures from the conventional twin jet configuration that is now common for all but the largets planes from both Boeing and Airbus.

Each of the concept families started with the idea that there would be three basic size variants that roughly compare to the following current model ranges: - Small or size 1 would be in the same range as the current Boeing 737 family (-600, -700, -800 & -900) and the Airbus A320 family (A318, A319, A320 & A321).

- Medium or size 2 would be in the same range as the Boeing 767 family (-200, -300 & -400) and Airbus A330 family (-200 & -300).

- Large or size 3 would be in the same range as the Boeing 777 and 747 families and the then proposed Airbus A3xx (later A350).

- A low probability optional size 4 was also sometimes discusses which would have been in the size range of the Airbus A380 and larger.

While there was much internal excitement around the initial Yellowstone concept plane which would have most likely been in the size 2 range in its first iteration, no actual final configuration decision had been made before a project security leak occurred and the aviation press began writing about the plane. Boeing's resposne to this security leak was to announce the Yellowstone project as though a decision had already been made. This so called "Sonic Cruiser" program further increased both internal and external belief that this would be the direction chosen, but in point of fact, at the time of the public announcement of the Sonic Cruiser, the actual final configuration decision was still a couple of years off in the program plan and the other two configurations were still very much on the table. This fact was actually disclosed at the time of the so called Sonic Cruiser announcement, however that footnote was largely ignored by both the public and many people within the company.

When a customer direction preference conference was later held at the Port of Seattle's Bell Harbor International Confrence Center, the customers showed a near unanimouse preference for applying the many advanced technologies to the baseline configuration and not the Yellowstone (i.e. Sonic Cruiser) or Glacier airplanes. Some people to this day still refer to the three size aircraft using the Yellowstone terminology (i.e. Y1, Y2 & Y3). There is nothing wrong with this, although it can be a little misleading at times.

It is also worth noting that Boeing planning tries to look well into the future and to always maintain a current planning version of that future. So it is completely fair to say that the Y1 and Y3 size airplanes are still very much a part of that plan. However, it is also true that every new program has to pencil out and is always aggressively compared to the option of doing a major update of the current models. Will a Y1 one day replace the 737Max? Some would say that it came very close to being kicked off instead of the Max. Who knows? The plan is there and will continue to be refined and compared to other options. Actual customer demand and market forces will be the determinates each time this question comes up.

One other point worth noting is Boeing's commitment to what it calls "Lean+" and the whole ethos of continuous improvement. There are many within the company that believe that the current approach being taken with the 737 Max and 777x programs reperesent the best way to go. This belief is that it will always be better to take these two market leading products and periodically make some dramatic improvements to them such as switching to an all composite fuselage. Again, only time will tell as the opportunity for major product decisions arrive.

With these considerations in mind, the rest of the text below is largely correct.

The term "Yellowstone" refers to the technologies, while "Y1" through "Y3" refer to the actual aircraft.

The first of these projects, Y2, has entered service as the Boeing 787.

Yellowstone projects

Yellowstone is divided into three projects:

• Boeing Y1, to replace the Boeing 737 product line. Y1 covers the 100- to 200-passenger market, and is expected to be the second Yellowstone Project aircraft to be developed. Boeing submitted a patent application in November 2009, that was released to the public in August 2010, that envisions an elliptical composite fuselage, and likely signals the company's planning for the 737 successor. In early 2011, Boeing outlined plans for a 737 replacement that would arrive in 2020. But the development of the 737 replacement was pushed back with the decision to launch the 737 MAX, an updated and re-engined version of the 737 in August 2011.

• Boeing Y2, to replace the Boeing 767 product line. It may also replace the 777-200. It covers the 220- to 320-passenger market, and was the first completed Yellowstone project, coming to fruition as the Boeing 787 Dreamliner Y2 initially referred to the highly efficient, more conventional, baseline aircraft for the Sonic Cruiser, which was project "Glacier". The Dreamliner competes with the Airbus A330, A340 and later A350 families.

• Boeing Y3, to replace the 777-300 and 747 product lines. Y3 covers the 300–600+ passenger market, and is expected to be the third Yellowstone Project aircraft to be developed. It will compete with the Airbus A380 family as well as the largest model of the A350 family, the A350-1000, scheduled to be introduced in 2015. In June 2010 it was reported that Emirates, which has the largest fleet of 777s, was in discussions with Boeing about plans to develop a new airliner to replace the 777.

See also

• Boeing 7x7 series
• Boeing 797 hoax

External links

• March 2001 Newsletter, Richard Aboulafia, March, 2001.
• "Future Airliners", Aerospaceweb.org, January 5, 2003. (refers to Yellowstone as the project name for the future Boeing 787)
• "Not if... but when", Flight International, July 6, 2005.
• "History & Development of the Boeing 737", b737.org.uk, October 23, 2005
• "Boeing's answer to the "superjumbo" takes off". The Independent. February 9, 2010.