Business Jet

Why the Supersonic Business Jet is Inevitable – Part 3 (Final Installment)

The Case for the Value of Time: Why the Supersonic Business Jet is Inevitable for the Future

(So here’s a little change of pace.  If you’ve ever wondered what an article for a scholarly journal looks like, here’s an example. )

Part III – The Demand for Time Savings

            The answer lies in the following question: why would a wealthy individual or corporation who could easily pay between $1700 and $3200 to fly first class between New York and Los Angeles[1] choose instead to pay approximately $35,000[2] to fly the same route in a Gulfstream G-550?   The main reason is the opportunity cost for lost productivity during travel, a real economic cost that economists have been studying for several decades.  Gronau (1970) laid the foundation for this argument with his contention that increased travel time was about more than discomfort because time itself is a scarce resource and as such commands a positive price: “A firm equates the value of its employees’ time with their marginal productivity. The employees, in turn, value their own working time at prices that equal their marginal remuneration-their marginal wage rates” (1970, p, 378).  De Vany (1974) went further and concluded that travelers value their time in direct proportion to their wage rate and his findings directly support the contention that time cost is a critical parameter for consideration when comparing modes of travel.  Zamparini and Reggiani (2007) provided a meta-analysis of ninety different studies on the subject of travel time valuation.  They defined a dependent variable they call the value of travel time saved or VTTS and provide the formula for calculating VTTS which includes the independent variables of the cost of travel and the utility cost of travel time from the perspective of the individual traveler (Zamparini & Reggiani, 2007).  So the real opportunity cost of lost travel time for larger earners or wealthy individuals has real value from an economic perspective and that value is tied directly to the earnings of the person doing the traveling.

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Why the Supersonic Business Jet is Inevitable – Part 2

The Case for the Value of Time: Why the Supersonic Business Jet is Inevitable for the Future

(So here’s a little change of pace.  If you’ve ever wondered what an article for a scholarly journal looks like, here’s an example.   I’ll provide several excepts from the paper over the next few days – stay tuned!)

Part II: Technology – Extant or Within Reach

The world’s first attempt into civilian supersonic flight was obviously the British-French Concorde, a miracle of 1960’s era technology that flew for 27 years and transported thousands of passengers back and forth across the Atlantic Ocean (Candel, 2004).  The Concorde was retired in late 2003, ostensibly due to its poor economic performance, but its design and the designs which followed it highlighted the three main technological issues that face any supersonic aircraft, namely the mitigation or elimination of the sonic boom, compliance with ever more restrictive airport noise abatement policies and the minimization of emissions into the atmosphere (Candel, 2004).  With advances in noise reduction and emission control now common in the design of modern jet engines, the mitigation of the sonic boom is probably the most important technological issue facing a civilian supersonic aircraft.

Dealing with the Sonic Boom          

Sonic booms are created by the shock waves produced at altitude by an aircraft traveling at supersonic speeds.  These waves then propagate to the ground, creating a change in pressure and generating a considerable disturbance (Candel, 2004). A graph of the pressure wave over time resembles the letter “N” with a nearly instantaneous initial shock, spiking pressure upward above ambient pressure, followed by a nearly linear decrease to less than ambient pressure over the next several milliseconds, followed by a tail shock that recovers to ambient pressure (Aronstein & Schueler, 2005).  The noise level generated by the Concorde’s boom was 105 PLdb (perceived loudness in decibels), louder than a jack hammer (Warwick, 2011b). Industry is aiming for a reduction to about 70 PLdb which is closer to a conversational noise level (Warwick, 2011b).   The most prevalent design theory to mitigate sonic booms was originated in a series of papers in the 1960’s and 1970’s and hypothesizes that the upward and lower spikes on a supersonic shock wave can be significantly reduced merely by shaping the fuselage and lift-producing surfaces on a supersonic aircraft  to do just that (Morgenstern, Arslan, Lyman, & Vadyak, 2005).  In 2003, the theory was conclusively proven through a series of tests funded by the Defense Advanced Research Projects Agency which used two F-5 aircraft, one left in production configuration and the other specially designed to soften the N-wave and reduce the impact at ground level (Morgenstern et al., 2005).  The tests showed that the shaped aircraft produced a consistent and significant reduction in the propagation of overpressure and sound to ground level, even in a turbulent atmosphere (Morgenstern et al., 2005).  Gulfstream and other aircraft manufacturers performed wind tunnel tests that also confirmed that shaped aircraft designs can reduce the sonic boom to lower levels (Henne, 2005).  Researchers at NASA have produced feasible designs which reduce the sonic boom to the range of 65-75 PLdb  (Welge, Nelson, & Bonet, 2010).  NASA’s N+3 studies have indicated a low boom supersonic business jet could be technologically viable as early as 2015 (Warwick, 2010).   In May of 2012, researchers from Japan further confirmed the theory when they dropped two asymmetric aerodynamic bodies from high-altitude over Sweden and noted that the specially shaped body reduced the sonic boom by 50% (Warwick, 2011b).

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Why the Supersonic Business Jet is Inevitable – Part 1

The Case for the Value of Time: Why the Supersonic Business Jet is Inevitable for the Future

(So here’s a little change of pace.  If you’ve ever wondered what an article for a scholarly journal looks like, here’s an example.   I’ll provide several excepts from the paper over the next few days – stay tuned!)

Background

The business aviation industry seems to be exhibiting a form of schizophrenia where the subject of supersonic business jets (SSBJs) is concerned these days.  Expressing skepticism in the January 2012 issue of Aviation International News, aviation commentator Matt Thurber pronounces a near death sentence on the SSBJ when he writes “(I)s there enough development money to support any supersonic business jet program? Will we ever see a production supersonic business jet? We believe that it’s highly unlikely…” (Thurber, 2012).  Yet only two months prior, at the Dubai Airshow in November 2011, the United Kingdom’s Hypermach Corporation proudly announced that their planned 20-seat SSBJ SonicStar, would be capable of speeds approaching Mach 4.0 by the time it reached certification in 2025 (Trautvetter, 2011).  Hypermach went on to boast that SonicStar’s speed and range would allow it to fly from New York to Dubai in 2 hours and 20 minutes and the aircraft would feature an electromagnetically-induced plasma wave that would absorb the shock wave responsible for the dreaded sonic boom – all for about $180 million per aircraft (Trauvetter, 2011).  In contrast to Hypermach’s optimistic announcement, Joe Lombardo, then president of Gulfstream Aerospace, downplayed his company’s interest in the SSBJ in an interview in late 2010, voicing uncertainty about the regulatory and environmental obstacles to the aircraft’s development and expressing his own skepticism that a market for the aircraft even existed (Garvey & Anselmo, 2010).  But Reno, Nevada-based Aerion would seem to disagree with Lombardo’s pronouncement.  The company unveiled its SSBJ design in 2004 at the National Business Aviation Association convention after conducting a market survey of more than 1,100 operators of large business aircraft and determining there was demand for at least 250-300 supersonic jets (Phillips, 2005).  As of the completion of the initial NASA testing on its patented natural laminar flow technology in late 2010, about the same time Lombardo was interviewed, the company held approximately 50 letters of intent with accompanying deposits for the $80 million-aircraft, comprising an order book worth over $4 billion (Norris, 2010).

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