NASA eyes Mach 1.6 airliners with sonic-boom autopilot

May 7, 2014
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NASA eyes Mach 1.6 airliners with sonic-boom autopilot

The return of commercial supersonic flight at faster-than-Concorde speeds could be one step closer to reality, with NASA developing real-time sonic boom prediction that would be essential to minimizing the impact of shockwaves on land. NASA's goal is a smart pilot aid that could help plan faster-than-sound travel for a jet able to fly at Mach 1.6 - or 1,218 mph - at altitudes of around 50,000 feet.

NASA's software, dubbed CISBoomDA - or Cockpit Interactive Sonic Boom Display Avionics - looks at the so-called "sonic-boom carpet" an aircraft is creating and likely to create in real-time, taking into account the terrain underneath, atmospheric conditions, and the data from the aircraft itself. The result is a colorful arc of potential disruption, though it's not quite ready to push to a cockpit display.

real-time-sonic-boom-nasa

The next step, in fact, is translating that data into something a pilot could comfortably interact with while also responsible for flying an aircraft. NASA has funding for a 2-3 year contract worth up to $350k per year, for a team that can take the CISBoomDA modeling and fettle it into a working, tested cockpit tool suitable for business jet style craft.

A pilot would be able to check the potential disruption left in the wake of supersonic flight, and get assistance in adjusting the flight plan from the system.

"Prediction data are integrated with a real-time, local-area moving-map display that is capable of displaying the aircraft’s currently generated sonic boom footprint at all times. A pilot can choose from a menu of pre-programmed maneuvers—such as accelerations, turns, or pushovers—and the predicted sonic boom footprint for that maneuver appears on the map display. This allows pilots to select or modify a flight path or parameters to either avoid generating a sonic boom or to place the sonic boom in a specific location. The system also provides pilots with guidance on how to execute a chosen maneuver" NASA

NASA's initial hopes had been to build its own demonstrator, but failed to secure the cash required. Instead, it will test the software on a Boeing F/A-18 jet, and then - once its feasibility is confirmed - look at how it could collaborate on designs for a small transport craft capable of supersonic speeds.

That craft would need to produce no greater than 80 PLdB sonic-booms; in contrast, Concorde's booms were in the region of 105 PLdB. Upcoming civil airliner limits in 2017 will demand even quieter jets, and NASA is hoping it can develop aircraft that will undercut the new standards by 10 EPNdB.

CISBoomDA has been patented, and NASA says it's open to licensing the system out as part of its Technology Transfer program for companies keen to build upon it and figure out commercial opportunities. It'll also be important for Federal Aviation Administration monitoring of supersonic aircraft; the FAA is already considering other types of non-traditional flight, running trials of drone monitoring to see how autonomous and remotely-controlled flying vehicles might co-exist in the air.

Meanwhile, NASA is also leading research into alternative designs of craft that could help physically minimize sonic-boom disruptions. One possibility is a telescopic nose boom - dubbed a "quiet spike" - which could help better shape the air flow, though no aerodynamic tweaks will ever remove the sound completely.

SOURCE Aviation Week


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