Sonic Cruiser
Boeing Sonic Cruiser (based on 2001 patent)
Role Jet airliner
Manufacturer Boeing Commercial Airplanes
Introduction 2006–08 (anticipated)[1][2]
Status Proposed design, canceled

The Boeing Sonic Cruiser was a concept jet airliner with a delta wingcanard configuration. It was distinguished from conventional airliners by its delta wing and high-subsonic cruising speed of up to Mach 0.98. Boeing first proposed it in 2001, but airlines generally preferred lower operating costs over higher speed. Boeing ended the Sonic Cruiser project in December 2002 and shifted to the slower (Mach 0.85), but more fuel-efficient 7E7 (later named 787 Dreamliner) airliner.

Design and development

As well as wanting more direct flights, passengers have demonstrated a preference for flights that take less time and aeroplane configurations that enhance comfort. It’s just common sense: people want to go where they want to go, when they want to go, how they want to go. Boeing’s answer to the demand for faster flights, more direct flights and increased comfort is the Sonic Cruiser.

 — Peter Rumsey, Director of New Airplane Product Development, Ingenia, February 2002[2]

The Sonic Cruiser was born from one of numerous outline research and development projects that began in the 1990s at Boeing with the goal to look at potential designs for a possible new near-sonic or supersonic airliner.[3][4][5] The Sonic Cruiser was publicly unveiled on March 29, 2001,[6] shortly after the launch of the A380 by rival Airbus. Boeing had recently withdrawn its proposed 747X derivative from competition with the A380 when not enough airline interest was forthcoming,[7] and instead proposed the Sonic Cruiser as a completely different approach.[5] Instead of the A380's massive capacity, requiring a hub and spoke model of operation, the Sonic Cruiser was designed for rapid point-to-point connections for 200 to 250 passengers.[2][8] Critics stated that Boeing had timed its announcement in an attempt to distract from the launch of the A380.[7]

Boeing's 2001 patent[9] detailed the breadth of delta wing-canard concepts studied, which included a supersonic variant with four engines capable of cruising at Mach 1.5 to 3.0,[10] various tail, engine location, and inlet and outlet configurations,[11] smaller supersonic and subsonic business jets,[12] and what Boeing called a "modular" system, where the cruise speed could be changed from supersonic to near-sonic by an interchangeable nose;[13] the "Sonic Cruiser" was a near-sonic variant.[14] The origin has been traced back to 1995, with the formation of an internal Airplane Creation Process Strategy team, which had designed a plane code-named Project Glacier that strongly resembled the initial Sonic Cruiser drawings by fall 2000.[4] In early 2001, Boeing CEO Alan Mulally began privately publicizing the concept to potential customers, touting its improved speed at an efficiency similar to existing designs.[4]

Don Carty (American Airlines) and Sir Richard Branson (Virgin Atlantic) were openly enthusiastic for the Sonic Cruiser, and Branson expected to make a tentative order of three to six aircraft in May 2001.[7] The March 29, 2001 announcement was followed by a larger media event at the Paris Air Show on June 19, where futurist John Naisbitt and Mulally praised the concept, unveiled as a 140-scale model.[15][16] Popular Science named the Sonic Cruiser to its list of the Best of What's New in 2001.[17]


The Sonic Cruiser is a brand-new class of flying machine. Every other commercial jet airplane has been a further refinement of the 707.

 — Walt Gillette, general manager of the Sonic Cruiser program, Boeing Frontiers, July 2002[8]

Boeing continued to tweak the design through the summer of 2001.[4] Initial sketches released to the public were highly conjectural. A patent drawing filed by Boeing in early 2001 put the baseline aircraft's dimensions at approximately 250 feet (76 m) in length, with a wingspan of 164.9 feet (50.3 m).[9] With a delta wing and canards arrangement, and flying just short of the speed of sound at Mach 0.95–0.98 (about 650 mph (1,050 km/h) at altitude), the Sonic Cruiser promised 15–20% faster speed than conventional airliners without the noise pollution caused by the sonic boom from supersonic travel. As an example, a flight using the Sonic Cruiser from London to Singapore was expected to be two hours shorter than one using a conventional airliner.[2] In addition, the landing and takeoff noise was expected to meet Stage 4 requirements.[18] The aircraft was designed to fly at altitudes in excess of 40,000 ft (12,000 m) to avoid existing air traffic,[2] with a range between 6,000 and 10,000 nautical miles (11,000 and 19,000 km).[8] Boeing estimated the Sonic Cruiser's fuel efficiency would be comparable to best performing twin-engine wide body airliners in 2002 on a per-passenger basis.[8][19]

Boeing intended to use advanced composite and titanium materials to reduce weight and further improve fuel efficiency.[4] In order to successfully build a commercial airplane with such a high advanced materials content (projected to be 60–70% of the airframe by weight), Boeing lined up a consortium of international partners with experience in aerostructures.[7] By the end of 2001, those materials were being applied to an aircraft in Project Yellowstone, a competing project using more conventional airplane designs.[4] That aircraft, being designed under Yellowstone as the replacement for the 757/767, was later announced as the 7E7, with "E" standing for "Efficient".[20][21] As a baseline reference model using advanced materials, the proposed 7E7 would consume 10% less fuel than the Sonic Cruiser, and 17–20% less than the 767-300.[7]

The design team at Boeing was finalizing the Sonic Cruiser configuration throughout 2002.[22][23] Wind tunnel testing and computational fluid dynamics analysis were used to refine the Sonic Cruiser concept.[24] Based on artwork released by Boeing in July 2002, the Sonic Cruiser now sported two taller vertical tails with no inward cant, and the forward canard was set at zero degrees dihedral.[22] By that time, three different designs had been advanced: one was the original canard-delta wing design, and two were more conventional mid-fuselage wing designs in the interest of better compatibility with existing airport jetway equipment, although those two designs were unable to offer the same performance as the original configuration.[7]

Cancellation and subsequent research

In the end, most airlines favored lower operating costs over a marginal increase in speed, and the project did not attract the interest for which Boeing had been hoping.[25] In some cases, the increased speed would lead to operational complications; aircraft could arrive at airports prior to the end of the morning curfew. Demand for air travel fell dramatically after the September 11 attacks, and Boeing began publicizing Project Yellowstone to potential customers for the first time in February and March 2002.[4] Branson, an early supporter of the Sonic Cruiser, was openly skeptical of the aircraft's prospects by July 2002: "Unless more runways are built the Sonic Cruiser is going to struggle because airlines will not have the slots to use the aircraft."[25] None of the prospective operators prioritized improved aircraft speed in a meeting with Boeing held in October 2002.[7]

The Sonic Cruiser project was finally abandoned by December 2002 in favor of the slower but more fuel-efficient Project Yellowstone/7E7 (later renamed Boeing 787 Dreamliner).[7][26][27] Much of the research from the Sonic Cruiser was applied to the 787, including carbon fiber reinforced plastic for the fuselage and wings, bleedless engines, cockpit and avionics design.[28]

In 2010, Boeing published a paper detailing several concepts for a supersonic airliner with reduced passenger count, derived from its work with the Sonic Cruiser and earlier NASA work on a High Speed Civil Transport (HSCT) concept. The concepts, developed under a NASA grant, included the 765-072B (approximately 100 passengers with a cruise at Mach 1.6–1.8), a smaller 765-076E business jet (30 passengers, Mach 1.6), and a larger 765-107B, nicknamed 'Icon-II' (120 passengers, Mach 1.8). All of the concepts had a range less than 6,000 nmi (11,000 km).[29]

On April 16, 2012, Boeing published an application for a patent for an aircraft configuration similar to that of the Sonic Cruiser; the patent was granted in 2014.[30]

See also

Related development



  1. ^ Forecast International/DMS (May 2, 2001). "A380 or Sonic Cruiser: Which is the Future?". Defense-Aerospace. Retrieved 15 February 2019.
  2. ^ a b c d e Rumsey, Peter (February 2002). "Changing the way we fly: Boeing's new Sonic Cruiser". ingenia. No. 11. Archived from the original on 16 February 2019. Retrieved 15 February 2019.
  3. ^ Wallace, James (April 20, 2001). "They said it would never fly but Boeing's 'Engineer X' proved them wrong". Seattle Post-Intelligencer. Archived from the original on March 4, 2016.
  4. ^ a b c d e f g Taylor III, Alex (December 9, 2002). "Boeing's Amazing Sonic Cruiser: It was supposed to change the way the world flies. Instead the world changed". Fortune.
  5. ^ a b Haenggi 2003, pp. 83–86.
  6. ^ "Boeing Focuses Commercial Airplanes Long-Range Product Strategy" (Press release). Seattle: Boeing. March 29, 2001. Archived from the original on August 3, 2003.
  7. ^ a b c d e f g h Norris, Guy (January 7, 2003). "Sonic Cruiser is dead - long live Super Efficient?". Flight International.
  8. ^ a b c d Gunter, Lori (July 2002). "The Need for Speed: Boeing's Sonic Cruiser team focuses on the future". Boeing Frontiers.
  9. ^ a b US Grant 6,575,406 B2, Chester P. Nelson, "Integrated and/or modular high-speed aircraft", issued June 10, 2003, assigned to Boeing Co 
  10. ^ Figures 2–4, US Patent 6,575,406
  11. ^ Figures 8–11 & 18–23, US Patent 6,575,406
  12. ^ Figure 17, US Patent 6,575,406
  13. ^ Figure 24, US Patent 6,575,406
  14. ^ Figures 12–15, US Patent 6,575,406
  15. ^ Sweetman, Bill (September 2015). "The Cult of the Sonic Cruiser". Air & Space Magazine. Smithsonian Institution. Retrieved 14 February 2019.
  16. ^ "Boeing Unveils the Future at Paris Air Show" (Press release). Boeing. Retrieved 14 February 2019.
  17. ^ "Best of What's New 2001: Boeing Pulls a Fast One". Popular Science. December 2001. p. 42. Retrieved 15 February 2019.
  18. ^ "Faster, Longer Range Boeing Commercial Jet". The Boeing Company. 2001. Archived from the original on 10 April 2001.
  19. ^ "Boeing Sonic Cruiser Targets Environmental Performance" (Press release). Boeing. July 22, 2002. Retrieved 14 February 2019.
  20. ^ Allison, Melissa (March 28, 2004). "Resilient Mulally ready to ride success of Boeing's 7E7 jetliner". Chicago Tribune. Retrieved 15 February 2019.
  21. ^ Bonné, Jon (December 17, 2003). "Boeing to build 7E7, in a familiar spot". NBC News. Retrieved 15 February 2019.
  22. ^ a b "Sonic Cruiser – Boeing's Mystery Ship". Archived from the original on 2011-09-30.
  23. ^ "Boeing Updates Sonic Cruiser Configuration" (Press release). Boeing. July 22, 2002. Archived from the original on July 19, 2010.
  24. ^ "Boeing Provides Sonic Cruiser Technology Progress Report" (Press release). Boeing. July 24, 2002. Retrieved 14 February 2019.
  25. ^ a b Harrison, Michael (23 July 2002). "Branson attacks Boeing's Sonic Cruiser". The Independent. Retrieved 15 February 2019.
  26. ^ Wallace, James (December 20, 2002). "No guarantee Boeing's next jetliner will be built here". Seattle Post-Intelligencer.
  27. ^ Harris, Paul (December 21, 2002). "Struggling airlines reject the futuristic Sonic Cruiser". The Guardian.
  28. ^ Wallace, James (June 29, 2007). "How the 787 'Dream' was born". Seattle Post-Intelligencer.
  29. ^ Welge, H. Robert; Nelson, Chester; Bonet, John (June 28 – July 1, 2010). Supersonic Vehicle Systems for the 2020 to 2035 Timeframe (PDF). 28th AIAA Applied Aerodynamics Conference. Chicago, Illinois. Archived from the original (PDF) on July 31, 2016.
  30. ^ US Grant 8,628,040 B2, Matthew D. Moore; Kelly L. Boren & Edward C. Marques et al., "Aircraft configuration", issued January 14, 2014, assigned to Boeing Co