The history of the SST is disappointing from a technical standpoint; the promise of supersonic travel was dashed primarily because of economics. That same record, from 1969 to 2003, provides a lesson about environmental impacts as a potentially lethal force against the SST. There are renewed, visible interests, such as Aerion, Boom, Aerion SBJ, Spike S-512, HyperMach SonicStar, Next Generation Supersonic Transport, Tupolev Tu-444, Gulfstream X-54, LAPCAT, Reaction Engines A2, Zero Emission Hyper Sonic Transport, SpaceLiner,
plus these interested organizations—
suggest that it may be time to review the five dimensions through which these proposals must navigate.
As with any multi-faceted problem, the distinctions between the five dimensions described below tend to merge, but as integrated as they may be, it is useful to segregate them for discussion.
- First and most recently—the International Community—and to be more specific: ICAO
The Montreal international aviation forum has been the scene of nasty battles over aircraft noise and other environmental impacts. The EU’s position arguably did not fare as well as the US’s. CORSIA is a grand plan to reduce CO2 , but has a long way to go before any real positive impacts are recorded. The Green Party has a strong voice within the pan-European (-UK) governmental body and likely will strongly oppose the SST.
As the article notes, but may not account for some of the SST developers noted above, the Continent does not yet have a visible SST developer. History’s irony is that the Concorde debate was driven heavily by the British and French!
Finally, on a good day, ICAO is s…l…o…w and there may be a chicken v. egg problem. Investors may not be willing to deposit substantial capital in such a venture, while the ICAO machinery may not fully engage until a substantial project is brought to Montreal.
2. The FAA has initiated two rulemaking activities on civil supersonic aircraft noise.
The first activity is a proposed rule for noise certification of supersonic aircraft, and the second is a proposed rule to streamline and clarify the procedures to obtain special flight authorization for conducting supersonic flight-testing in the United States. The subsonic noise certification regulations of 14 CFR part 36 do not apply to supersonic aircraft. The current rulemaking activity related to noise certification of supersonic aircraft will determine the technological and economic basis that supports noise level requirements that are appropriate for supersonic aircraft.
Contrary to some of the statements of the Reason Foundation and the Mercatus Center, the Aircraft Noise Abatement Act of 1968 directed the FAA, after consultation with the Department of Transportation, to “prescribe and amend standards for the measurement of aircraft noise and sonic boom,” and, “… such rules and regulations as the (administrator of the FAA) may find necessary to provide for the control and abatement of aircraft noise and sonic boom.” In 1970, acting under this authority, the FAA proposed a regulation that would restrict operation of civil aircraft at speeds greater than Mach 1, unless authorized by the FAA. The regulation was finalized with minor changes on Mar. 28, 1973 and codified at (now)14 Code of Federal Regulations (CFR) 91.817 and Appendix B to Part 91.
Since Congress basically established those restrictions, it is quite likely that as the NPRM process moves forward, the Hill will have its say. They will be motivated by VERY active citizens groups activated against the existing levels of noise. They will be active participants in the rule-making and have access to science supporting their positions,
On a more positive note, advancing the development of civil supersonic aircraft is a priority on the lists of OMB’s Office of Regulatory and Information Affairs, the Department of Transportation and the Federal Aviation Administration.
It should also be noted that NASA is one of the organizations developing an aircraft.
3. Today’s anti-noise/environmental activists are better organized and expect higher noise thresholds (less sound) than their 1969 counterparts.
Noise abatement technology has reduced impacts by orders of magnitude—
“In 1975, there were about 200 million people flying in the United States, with about 7 million people exposed to what is considered significant aircraft noise. Since then, an FAA study conducted in 2015 showed that the number of people flying in the United States had almost quadrupled yet the number of people exposed to aircraft noise had dropped to around 340,000, or a 94% reduction in aircraft noise exposure. “
These objective numbers do not correlate well with the outcries from citizens around the country and perhaps that dissonance can be attributed to the fact that the measurement of human reaction to noise is called psychoacoustics . Sound is the most subjective of the human senses. Scientists and engineers have quantified the reaction of an ear to the noise of an airplane in decibels. With that logarithmic scale, a psychoacoustician issues precise estimates to the population’s response to a plane. Their numbers are expressed in tenths.
In that hearing is so subjective, raising or lowering expectations can result in auditory responses that are higher or lower than the mathematical projections of the reactions.
To add to this discernible trend, Recent research may have documented some correlation between certain sounds and “noise rage.” The phenomenon is called misophonia, literally “hatred of sound.”
In 2000 scientists defined misophonia as a “condition in which negative emotions, thoughts, and physical reactions are triggered by specific sounds.” Other labels include “select sound sensitivity syndrome” and “sound-rage.” Misophonia has not been classified as an auditory, neurological, or psychiatric condition; so far, no standard diagnostic criteria have been defined. Neither the DSM-IV nor the ICD-10 has included misophonia listed in their referenced problem. Unfortunately, there is little research on its prevalence or treatment.
As the noise has been calibrated as decreasing, the public opposition has increased almost exponentially and has enhances its ability to be heard even more. Here is a small list of the groups:
- National Quiet Skies Coalition – NQSC and they have identified a number of aligned groups
and a list of Members of Congress who have formed a coalition on aviation noise:
Useful reference materials:
4. Congress, surprise, is divided on this subject.
For either side of the debate, a house divided usually means that passing legislation opposing or helping the SST is difficult; without Congressional direction, the Administration needs only to follow the existing laws (see FAA above).
The Congressional Caucus supporting Quiet Skies has already been identified. NOTE: in the past, a Member faced with choosing between a philosophical point, albeit significant, and the likelihood of more jobs, will pick higher employment,
On the proSST side, there is
the US Congress has weighed in—a bill supporting ending the ban on supersonic flight, voices urging moderation and environmental opposition are all before Capitol Hill:
- Senator Lee (R-NV) and Senator Gardiner (R-CO) have introduced a bill which would also establish a deadline for a rulemaking to allow civil supersonic flight over the United States for the first time since 1973 and the section is included in the Senate version of the FAA Reauthorization bill.
- Boom statement on the passage of the Lee-Gardner Amendment
- Could Congress Push Too Fast On Supersonics?
- In Support of the Lee-Gardner Amendment to the FAA Reauthorization Act
- There are many SST prototypes being developed around the world (Japan, Russia and China; US— Aerion). Boom, a Denver based company and a staunch supporter of Lee Gardiner, calls its plane XB-1 will fly at 2.2 times the speed of sound. It supports the bill because it would also establish a deadline for a rulemaking to allow civil supersonic flight over the United States for the first time since 1973.
- The XB-1 is the only proposed commercial supersonic aircraft. The specifications project that this plane would reduce supersonic fuel burn, lower ticket prices, extend aircraft range, and reduce carbon emissions.
- To add to the hopes and expectations of the SST Renaissance industry is new technology which NASA and Rockwell Collins are working on. They have developed “a way to visualize a sonic boom.” The goal is to give pilots a tool with which to adjust their flight plans to reduce the noise heard on the ground. That’s a key obstacle for the new generation of supersonic aircraft, which need to be able to fly over land.
- Another NASA project (this one in conjunction with Lockheed) is based on a hypothesis that they can change the paths of the shockwaves caused by supersonic flight. By simply locating a single engine on top of the plane should create a “sonic thump” instead of the jarring boom.
- In supersonic flight, the plane’s fuselage forces a gap in the air molecules and that phenomena creating shockwaves that are similar to a boat’s bow wave. That wave of air molecules hits the ground surface and creates a sharp noise called the boom carpet.
Congress is subject to a number of winds:
- a good or bad hearing will influence votes at the margin,
- reports from OMB, GAO or any number of think tanks (see below), that substantiate the positives or negatives, will tend to create momentum in that direction,
- foreign developments, especially an announcement that Russia is ready to launch its SST or an ally’s pronouncement in favor/opposition, may cause some Members to reconsider their positions,
The point is that management of the legislative branch is almost as critical to a SST aircraft’s roll out as engineering studies. The numbers can be corrected; once a Senator or Representative changes position in public, the vote is permanently lost.
5, The Think Tank universe is another dimension meriting close attention.
At the moment, the libertarian end of the spectrum is solidly in the SST camp:
- How the FAA Killed Supersonic Flight—And How It Can Revive It … (SST) over the US. Why …Reason.com or Reason Foundation.
These institutions pride themselves on intellectual integrity and will advocate as those considerations drive them. They may assert a hardline when some compromise will work technically, financially and practically. Beware!
The Natural Resources Defense Council, Friends of the Earth, Sierra Club, National Wildlife Federation and others will play a powerful role in this debate.
These five dimensions are the virtual reality of the regulatory/political process. It is easy to forget or even to ignore the impact of these variables, seemingly exogenous to this high-tech proposal. While the engineering, aeronautical, powerplant, noise and other challenges require considerable time, money and focus, any one of these five dimensions could create havoc for the launch of SSTs.
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