Professional Pilot, October 2016

not only at supersonic but also at transsonic speeds and it gives the aircraft an overall more economic fuel burn rate The key technology is a wing designed for supersonic laminar flow requiring exacting standards of construction during manufacture Aerion says its patented supersonic natural laminar flow SNLF technology makes the SSBJ possible conserving fuel and reducing emissions versus other supersonic designs It allows for efficient cruise at just below the speed of sound and at supersonic speeds up to Mach 15 The wing has SNLF on a majority of its surface where according to Aerion it offers a reduction in friction drag by 70 or more Under laminar flow conditions air flows smoothly across wing surfaces without creating turbulent layers as do conventional swept or delta wing designs Precise wing contours are necessary to achieve supersonic laminar flow new materials such as carbon fiber are used to achieve this Aerion maintains that its SNLF wing reduces total airframe drag by as much as 20 versus a delta wing configuration such as that used by the Concorde A wing section was tested successfully in cooperation with NASA already While todays transsonic wings become inefficient above Mach 086 or so this laminar flow technology allows Aerion to promise acceptable economics in the entire transsonic speed range and even in the supersonic regime The difference in range between supersonic cruise at Mach 14 range 4800 nm and high subsonic or transsonic cruise at Mach 096 range 5200 nm is only 400 nm 130 PROFESSIONAL PILOT October 2016 Note however that the engine manufacturer has not been selected yet and the influence of engine performance on these numbers remains to be seen Finding a suitable SSBJ engine Aerion is hopeful of selecting a propulsion system during 2017 The company reports that it has identified existing core engines suitable for adaptation to the needs of supersonic flight with minimum changes and that it plans to meet Stage 4 noise standards while preserving long range supersonic performance This is a significant challenge with a low bypass supersonic engine Engine selection would enable the company to formally launch the program Aerion is planning on a 1st flight of the AS2 in 2021 and entry into service following FAA certification in 2023 Aerion AS2 construction and performance details While supersonic flight over land is still prohibited Aerion hopes to certify quiet boom supersonic flight at between Mach 11 to 12 once the aircraft is flying and the company shows to authorities that the boom is negligible on the ground at expected speeds at cruise altitude due to the advanced sleek aircraft design Aerion is certainly serious about the AS2 Not only does Aerion have in hand the firm order by Flexjet but they can boast of close cooperation with Airbus to make this supersonic aircraft a realistic proposal Airbus engineers helped design a strong and light 10 spar carbon fiber wing structure as well as using the same method and technique for the structure of the AS2 s fuselage and empennage The main landing gear system minimizes space requirements in the fuselage when retracted Actuators for the flight controls are small and powerful so that they fit into the thin flying surfaces of the AS2 The FBW flight control system itself is based on Airbus Groups vast experience with digital flight control technology The AS2 cabin seats 8 and the cabin cross section gets wider to the rear The galley is forward and the flightdeck requires 2 pilots There are 8 windows planned for the fuselage and theyre larger than those in a Boeing 787 At just over 50 meters in length the AS2 will be an impressive sight on the ramp Takeoff and landing performance are expected to allow operations from most corporate aviation airports with a speed on final approach of just 135 kts Aerion has published some sample routings on its website showing time savings under current legal conditions These use overwater routings as much as practicable to allow for supersonic flight and overland sectors for the rest Time savings vary between 3 hours between Paris and Washington or Honolulu and Sydney Over 5 hours flight time may be saved on the Los Angeles to Sydney route but the time for a fuel stop route distance is 6500 nm while the range is 5200 nm seems to be excluded in this example However most corporate jets will have to refuel as well on this transpacific flight The sample routings are a good illustration as they show well for whom this aircraft might provide an actual benefit The routes have to be mostly over water and within the nonstop range of the Aerion I personally see the first use in government or international organizations When small teams need to be dispatched urgently the supersonic boom may be permissable for state aircraft while costs would be a minor factor Peter Berendsen flies a Boeing 747 as a captain for Lufthansa Airlines He writes regularly for Pro Pilot on aviation related subjects