Report outlining a forecast of the reintroduction of a commercial supersonic aircraft. An array of monitoring, trend and scenario based techniques are incorporated.

1. 1
Market Forecast of Commercial Supersonic Aviation
Andrew James Wilhelm
Vanderbilt University
2301 Vanderbilt Place
Nashville, TN 37235
+1 (724) 900-0280
andrew.wilhelm@vanderbilt.edu
ABSTRACT
The purpose of this combined forecast is to provide a future
timeline for supersonic commercial aviation and generate
strategies to accommodate related progress. Relevant companies
include a variety of aircraft and jet engine manufacturers. These
companies are primarily concerned with the feasibility of
supersonic aircraft and how to adapt should they be brought to
market. When evaluating this topic, the downfalls of Concorde
identify three critical technologies hindering new development.
These include aircraft noise reduction, hybrid turbofan engines,
and material selection. Utilizing an array of monitoring and trend
forecasting techniques provides estimations of progress in these
areas. This allows for a combined forecast of the reintroduction of
a commercial supersonic aircraft by the year 2028. Along with
this, scenario analysis is performed to identify possible future
outcomes and the ramification of technology adoption. An action
plan is created from these results, which includes suggestions for
managing supersonic aircraft construction. To best compete with
this innovation, subsonic manufacturers should consider hybrid
turbofan engines. Hybrid propulsion systems will maintain market
share and provide capital to develop their own supersonic aircraft.
Keywords
Supersonic aircraft, sonic boom reduction, hybrid turbofan engine,
PETI-9, technology forecast, combined forecast
1. INTRODUCTION
For some time, mankind has been fixated by speed. Perhaps by
natural design, or shear perplexity, the fascination for quick
movement has pushed development of many technologies. From
rum-running during the time of Prohibition, to world record
holder Usain Bolt, people have displayed a near compulsive
obsession to be the fastest. In 1947 Chuck Yeager became the first
pilot to travel faster than the speed of sound. This led to the
production of supersonic military aircraft such as the Convair F-
102 Delta Dagger and the Lockheed SR-71 Blackbird. Following
typical distribution patterns, military technology transitioned into
civilian applications and spurred creation of the Concorde by
British Aircraft Corporation. The only regularly scheduled civilian
supersonic aircraft, Concorde served as the apogee of commercial
air travel. Unmatched today, the aircraft breaks traditional
sigmoid growth curves of the aeronautical sector and stands as an
overshooting outlier. Concorde was retired in 2003, ending the
supersonic era of civilian aviation.
While Concorde suffered from a variety of drawbacks, supersonic
travel remains ever desirable today. The ability to reduce travel
time will result in a number of economic and social
improvements. During its lifespan, Concorde was able to cut
flight duration by more than half. This allowed for twice as many
flights in the same time span, improving operational efficiency.
Along with this, delivering passengers quickly improves moral
and promotes travel. Cargo operators will also benefit from faster
aircraft. Turnaround time directly impacts profit and is a
fundamental aspect of cargo shipment. These benefits highlight
the drivers encouraging advancement of the supersonic aviation
industry.
1.1 Downfalls of Concorde
When trying to forecast the reoccurrence of a commercial
supersonic aircraft, the downfalls of Concorde are paramount.
While serving as a technological spectacle, the aircraft was
plagued with a number of mechanical and economic problems.
British Airways cited the retirement of the aircraft “due to rising
fuel and maintenance cost and a decline in passenger numbers”
[1]. Along with this, the United States Congress labeled Concorde
as “noisy, energy inefficient and environmentally unsound” [2].
At the time, the aircraft was twice as loud as the loudest subsonic
aircraft and had a strong negative response from communities
near airports where it operated. Due to the sonic boom caused by
supersonic flight, the Federal Aviation Administration (FAA)
limits all air travel over land to subsonic speeds [2]. This
significantly restricts the operational abilities of the aircraft and
lessens serviceable areas. All of these factors combined to end
commercial supersonic flight, and must be resolved before new
aircraft are made economical.
1.2 Industry Needs
With an understanding of the demands for supersonic flight,
related companies yield the core issues dictating growth. Aerion
Supersonic, Boom Supersonic, and Spike Aerospace are heavily
vested in production. They directly construct these aircraft and
will experience the greatest impact if proved successful. The
viability of these companies solely depends on the reintroduction
of supersonic commercial aircraft. The next tier involves the
subsonic competition such as Gulfstream Aerospace, Textron
Aviation, and Bombardier Aviation. If supersonic flight is
reintroduced, it will subtract from the subsonic share of the
aviation sector. Finally, ancillary organizations consist of General
Electric Company, Pratt and Whitney, and Rolls-Royce Holdings.
These organizations work in conjunction with aircraft
manufacturers and are moderately influenced by changes in
aircraft specifications.
The goal of this research is to provide leadership, at the
aforementioned companies, guidance regarding what is needed to
develop supersonic aircraft and how to handle market
introduction. Concern is placed on how to rectify the downfalls of
Concorde, as well as an estimation of the timeframe. Existing
technologies, timelines to future innovation, and the consequences
of supersonic flight are included in an industry action plan for
future progress. This is intended to provide associated companies
with the means to prepare for technology adoption.

2. 2
2. METHODOLOGY
The process used to evaluate growth in the supersonic industry
involves several forecasting methodologies. Beginning with the
downfalls of Concorde, three areas of technological advancement
are identified as critical to future success. These are evident as
flaws in Concorde and include operation noise, an inefficient
propulsion system, and high maintenance cost [1,2]. As such,
three forecasts are conducted oriented around solving these
problems and combine to form an overall technology assessment.
The estimate of each subtopic gives insight into the feasibility,
and inception date, of a new supersonic aircraft.
To best evaluate the downfalls of Concorde, different forecasting
methodologies are incorporated for a multilateral assessment. This
research relies on a blend of monitoring and trend forecasting.
The prior is used to discern improvements necessary for adoption
and involved searching areas in the realm of aircraft design.
Various library, patent and publicly available databases were
analyzed and condensed into a list of relevant information [3].
The goal is to identify the existing, and future, developments
being done to rectify the drawbacks of past supersonic endeavors.
This process acknowledges opinions of experts in the field, as
well as indicates information necessary to conduct trend analysis.
Trend forecasting is broken down into two subsections, time
series and causal models [4,5]. Time series models are the most
common form of trend forecasting and involve pattern recognition
within historical data. This is useful as appropriate data reduction
provides clear predictions of future events. In conjunction, causal
models also define future growth of a technology. Occasionally
considered explanatory, causal models “assume that the variable
being forecast is related to other variables in the environment” [4].
This forecast utilizes exponential growth and decay for evaluation
of these models. Furthermore, when describing decay, results are
normalized with respect to the maximum value [5].
Incorporating the specified forecasting techniques, the
methodology of aircraft noise suppression is considered. Patent
identification allows for understanding of efforts to improve sonic
boom reduction techniques. This overview attempts to address the
loud operation noise of Concorde and how future designs will
accommodate more stringent noise requirements. Along with
industry development, NASA research provides quantitative data
for sound suppression. This research begins with the Quiet Spike
experiment and moves to the NASA QueSST project. Ultimately,
results of these experiments govern the timeframe to legal change,
which is a critical factor for supersonic aircraft manufacture.
Another aspect of operation noise involves the engines. A trend of
jet engine sound reduction is used to evaluate this advancement,
and reinforces the need for additional innovation.
A similar process attempts to address the inefficient propulsion
system of Concorde. The monitoring process identified turbofan
engines as a possible substitution for this powerplant. Expanding
on this design, further progress could be facilitated by the
introduction of a hybrid propulsion system. When evaluating this
technology, CO2 emission reduction, relationships between
automobile and aircraft specific fuel consumption (SFC), and the
progress of hybrid vehicles in the automotive industry, are topics
dictating the speed of hybrid turbofan emergence. A time series
estimation of future aircraft CO2 emissions indicates an increase
beyond proposed International Civil Aviation Organization
(ICAO) requirements. Compounding upon this, turbofan SFC
progress has become mostly stagnate. A breakthrough in this area
is needed to meet new ICAO emissions regulations. Attempting to
identify potential sources, a causal model of hybrid automobile
development is incorporated. Electric power has improved
internal combustion (IC) SFC but is limited by battery capacity.
Detailing the projected growth of battery specific power (SP) and
specific energy (SE) yields insight into a substitution for jet fuel.
When rectifying the high maintenance cost of supersonic flight, an
overview of previous structural limitations is considered. This
identifies improvement areas for future design and the material
strength needed. Trend analysis of composite use in aircraft
construction indicates potential substitutions of existing materials.
Additionally, when analyzing the thermal strength of composites,
those suited for supersonic aircraft are recognized.
Once solutions for the downfalls of Concorde are evaluated, a
combined forecast is generated to approximate introduction of the
technology as a whole. The timeframes for each subtopic are
aggregated using a weighted average calculation [6]. Innovations
not yet complete are weighed higher than those already
accomplished. A technological assessment is conducted to
understand intended and unintended consequences of adoption
[7]. These are integrated into a report for existing manufacturers.
When generating a market report, this research begins with
generation of potential future scenarios. This process is broken
down into five steps, beginning with factor analysis [8]. Given
relevant industry research, the critical factors found are ranked
based on a combination of impact and uncertainty [9]. The results
give insight into two key forces dictating progress [8]. These
frame the scenario and yield four unique future outcomes, each of
which is expanded with a short vignette [9]. From here, strengths,
weaknesses, opportunities, threats (SWOT) analysis is conducted
on the scenario deemed most disruptive to 2020 market
conditions. This provides potential obvious priorities, attractive
opportunities, easily defendable, and potentially high-risk aspects
of the future. In turn, these details assist in generation of an
industry action plan for the specified scenario.
2.1 Assumptions and Limitations
Several assumptions are made during the course of this forecast.
First, it is assumed that no radical technology changes
transportation methods. The advancement of hyperloop or rocket
based transportation could render aircraft obsolete. In hand with
this, there is an expectation flying remains a legal way to travel.
Should regulatory agencies deem current aircraft unsafe, as with
the Boeing 737 MAX 8, development of the aviation sector would
change drastically. Finally, it is assumed no catastrophic event
occurs where human focus shifts from progress to survival. While
extreme, current controversial issues, such as climate change or
infection disease outbreak, may trigger a catastrophic type social
response.
3. AIRCRAFT NOISE REDUCTION
3.1 Overview of Low Boom Aircraft Design
Since the first supersonic flight, several changes have been
incorporated into aircraft development. Drag forces associated
with transonic flight (flight slightly below and above Mach 1)
hinders flight around the speed of sound. To accommodate the
unstable transonic region, leading-edge sweep is utilized in wing
design. This allows for faster subsonic travel by delaying
transonic conditions, or critical Mach [10]. While this is ideal for
subsonic flight, it is detrimental to supersonic speeds. Rather than
delay critical Mach, Aerion Supersonic is attempting to maintain
transonic flight without achieving full supersonic flow over the
wing [11]. This is known as Mach cutoff and does not produce a
sonic boom due to laminar flow separation at the trailing edge of
the wing, restricting shockwave formation [11].

3. 3
Figure 1. Aerion Supersonic design [11]
Figure 1 shows the wing platform suited for Mach cutoff. This
will not support fully supersonic speeds but increases the speed of
existing subsonic aircraft. Along with this configuration, Boom
Supersonic is creating a fully supersonic aircraft. The scheme
includes the Whitcomb area rule for reduced drag during
supersonic flight [10]. However, it does not incorporate any sonic
boom reduction techniques, limiting effectiveness.
Figure 2. Boom Supersonic design [12]
Both proposals outline improved lift to drag characteristics for
different regions of the flight envelop. Technological advances
since Concorde have facilitated new possibilities when creating
supersonic aircraft. Integrating the results into further low boom
research may provide aircraft capable of adhering to noise limits.
3.2 Quiet Spike Research
Follow an overview of industry progress, a historical summary of
NASA research provides a background to sonic boom reduction
techniques. Coinciding nearly identically with the final flight of
Concorde, in the early 2000s Gulfstream Aerospace started a joint
research project with NASA addressing the issue of supersonic
noise. The idea was to construct a needle shaped extension on the
nose cone of an aircraft fuselage. The design was intended to
mitigate a sonic boom by creating a weak shock along the narrow
tip of the needle structure. This caused a weaker pressure wave as
the shock progressed along the fuselage [13]. Gulfstream
Aerospace took particular interest in this technology and patented
the device dubbed as Quiet Spike. The core claim of this patent
describes how the device is selectively extendable with increasing
cross section area moving aft along the structure [14].
Figure 3. Quiet Spike extension [14]
The results of this research were as expected and “confirmed the
Quiet Spike’s ability to generate a relatively weak saw-tooth
pattern” [13]. While the technology itself is not enough to
sufficiently suppress a sonic boom, it leads the way to a low boom
experimental vehicle [13].
3.3 NASA QueSST
Moving from Quiet Spike, a collaboration between Lockheed
Martin and NASA was taken up to expand the research. The
previous demonstrator aircraft was a largely unmodified high-
boom airframe [13]. As such, it was not capable of fully
eliminating a sonic boom. The new prototype has been labeled the
X-59 and incorporates several aspects of sonic boom reduction.
Building on the Quiet Spike research carried out a decade prior,
the X-59 aims to overcome previous limitations with a large-scale
supersonic X-plane [13].
Figure 4. X-59 experimental aircraft [15]
This configuration attempts to manipulate the sonic boom,
reducing the shock intensity on the ground [15]. While still under
construction, once completed it will be flown over several
communities to evaluate effectiveness of the noise reduction [15].
The FAA, and other international regulators, will then have the
necessary data to change rules governing supersonic flight over
land [15]. Should this project be successful, it will resolve the
largest legal hurdle restricting industry. Given a potential solution
to the precedence hindering supersonic flight, it is possible to
generate a timeline to completion.
Figure 5. Timeline to supersonic flight approval [15]
The most optimistic forecast for the introduction of new
commercial supersonic aircraft is 2028. This assumes the X-59
test flights are successful. Also, it does not account for any delays
in the approval process.
First X-59 flights
X-59 delivery to NASA
Community flights
Data presented to
regulatory agencies
Regulations updated
Manufactureres verify
aircraft adhere to new rules
Approval for new aircraft
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
Year

4. 4
3.4 Engine Noise Reduction
In conjunction with a high-boom airframe, a loud propulsion
system contributed to the operational noise of Concorde. This
system was the Olympus 593 powerplant, which consisted of
afterburning turbojet engines originally implemented on the Avro
Vulcan V-Bomber [16]. Cutting edge at the time, this engine
produced more than 30,000 lbs. of static takeoff thrust and was
capable of sustained supersonic flight [16]. Furthermore, the
overall thermal efficiency was high enough to be considered for
commercial applications. This provided a platform designed for
25,000 hours of operation and was a well-tested machine. The use
of this engine had a negative impact on noise limitations,
although. When evaluating aircraft engines, a turbofan is much
quieter due to the bypass flow around the engine core. The
increased mass flow rate requires a lower velocity to achieve
comparable thrust, reducing noise [17]. A turbojet engine does not
have a bypass flow, and relies strictly on high speed air to
generate power. To facilitate supersonic speeds, an afterburner
was added to the Olympus 593, near the nozzle, to further
increase the flow velocity [16]. Figure 6 shows engine operation
noise of Concorde compared to all other subsonic aircraft.
Figure 6. Jet engine noise reduction [17]
There is a clear decreasing trend associated with subsonic aircraft
engine noise. Sound reduction has been driven mostly by
increasingly restrictive legal regulations. In 1969, rules were put
in place limiting noise level [17]. Called stage 2, guidelines
measured acoustic levels at three certifications points in flight,
takeoff, flyover, and approach. Further reductions were introduced
in 1977 and 2006, stage 3 and 4 respectively, and lessened total
sound output by 13 dBs. Forcing jet engine manufacturers to
innovate, these regulations have caused improvements to engine
bypass flow, optimal combustion cycle parameters, and ideal
turbine blade selection [17].
4. HYBRID TURBOFAN TECHNOLOGY
4.1 Overview of Hybrid Turbofan Engines
Brought to market in the early 1940’s, the jet engine was a radical
invention for the aviation sector. At the time, most aircraft utilized
a piston powered propulsion system and had limited performance
abilities. The introduction of jet engines prompted an industry
shift, allowing for higher aircraft speeds and a larger flight
envelop. Originally comprised of three main components, a
compressor, a combustion chamber, and a turbine, early variations
are called turbojets [18]. Turbofan engines evolved from this
design, with implementation of aforementioned bypass flow [18].
Following the historical overview, endeavors aimed at improving
operational capabilities are explained. As described, the bypass
flow of a jet engine is a crucial aspect when considering fuel
economy. Further increasing this ratio is prominent in aircraft
propulsion system design and has been successful at reducing fuel
consumption [19]. However, technological limitations are
beginning to hamper progress. A radical change is necessary to
break asymptotical boundaries of turbofan performance. When
evaluating the automotive sector, alternative fuels are a significant
driver of growth. The most notable being electric hybrid vehicles
[20]. While inconsequential at first, advances have allowed for a
competitive product when compared to pure IC engines.
Developments of this innovation are beginning to have
implications on jet engine manufacture.
Figure 7. Hybrid turbofan engine design [21]
Figure 7 shows a possible hybrid turbofan patented by Boeing Co.
The addition of an electric motor, item 406, onto the drive shaft
highlights the design and provides additional thrust [21]. The
patent was published in 2019 and is indicative of an industry shift.
Along with new patents, aviation experts have a favorable opinion
on electric aircraft.
Figure 8. Expert opinion for future aircraft propulsion [22]
Experts believe, on average, hybrid electric and fully electric
aircraft will be introduced in the years 2035 and 2042,
respectively [22]. This details an overview of expected growth
and yields a baseline for subsequent research.
4.2 CO2 Emission Reduction
When considering CO2 emissions, especially pertaining to
automobiles, the Clean Air Act of 1970 is essential. This piece of
US legislation has governed air quality standards since initiation
and was enacted to minimize pollution caused by the growing
number of motor vehicles [23]. Upheld by the Environment
Protection Agency (EPA), automobile manufacturers have been
forced to develop ways of improving efficiency, while
0
20
40
60
80
100
1955 1975 1995 2015 2035
PercentageofMaximum(%)
Year
Subsonic Aircraft Concorde

5. 5
maintaining performance. However, jet engines were never
subject to these restrictive emissions requirements and were not
forced to evaluate fuel economy. As such, SFC refinement has
occurred at a slower pace than other design parameters. The
convergence of automotive and turbofan SFC is described by
Figure 9.
Figure 9. Turbofan and automobile SFC [18,19,24]
Gas turbine engines are generally more efficient than an IC
counterpart but have been outpaced by IC SFC improvements.
Without legal regulations dictating fuel economy, there has been
no incentive for jet engine makers to consider this aspect. The
EPA has identified this as a concern and attributes 12 percent of
all transportation greenhouse gases to aircraft use [23]. This
organization, along with ICAO, have begun setting a standard for
international aircraft CO2 emissions. Projecting these reductions
into the future describes the expected growth of technology, air
traffic management (ATM), and alternative fuels [25].
Figure 10. Suggested aircraft emissions limitations [25]
The composite reduction displays alternative fuels as the largest
potential source for CO2 elimination. Aeronautical technologies,
such as enhanced drag characteristics and lower structural weight,
are a factor but not as critical as propulsion system design [25].
To overcome this, a form of hybrid system is anticipated by the
year 2030, with the goal of reducing CO2 emissions by 50% in
2050 [25]. While not specifically declaring electric power as the
source, it presents a need for change.
4.3 Battery Specific Power
Following explanation of the drive to curtail aircraft CO2
production, innovation needed to facilitate this is investigated. In
the automotive industry, advancement has been provided in the
form of hybrid electric vehicles. Other alternative fuels have been
suggested but electricity is the emerging exemplar. However,
limitations of hybrid electric automobiles include inferior power
generation and a reduced range. This is due to a lower SP and SE
output by the batteries, in relation to petroleum fuel. Improvement
to these design parameters is key for implementation on aircraft.
Fostering progress, the Automotive Council of the United
Kingdom (UK) has set goals regarding battery capabilities [26].
Figure 11. Expected growth of battery specific power [26]
Figure 11 displays the SP ratings of existing battery cells and
plots desired growth set by the UK. When looking at SP, a
potential replacement for jet fuel will occur around the year 2035.
This aspect is critical in maintaining the thrust to weight ratio of
an aircraft. While new cells will likely produce more power than
jet fuel, the SE is expected to be lower [26]. Less energy per unit
volume will require batteries larger than existing fuel tanks.
5. MATERIAL SELECTION
5.1 Overview of Structural Design
Beginning with construction of the first aircraft, structural design
has been a crucial aspect of the process. Early variations were
comprised of wood and cloth, with a transition to aluminum
occurring in the 1920’s. This has been the material of choice for
aircraft since. Industry success is attributed to the strong,
lightweight aspects of the material and has generated several
different alloy compositions. When considering Concorde, the
design was mostly aluminum, which became a limitation [27].
Figure 12. Thermal stress on Concorde at Mach 2 [27]
0
20
40
60
80
100
1945 1965 1985 2005 2025
PercentageofmaxSFC(%)
Year
EPA est. Automobile SFC Turbofan SFC
0
400
800
1,200
1,600
2,000
2020 2025 2030 2035 2040 2045 2050
CO2Emissions(Mt)
Year
Alt Fuels ATM
Technology Unchecked Growth
ICAO Goal
0
2
4
6
8
10
12
14
2015 2020 2025 2030 2035 2040
SpecificPower(kW/kg)
Year
Existing Cells UK Roadmap Jet Fuel

6. 6
The upper thermal limit of aluminum is around 100 degrees
Celsius. As shown by Figure 12, parts of Concorde exceeded this,
expressing a cause for high maintenance cost. To address this
concern, a new material is necessary for structural design.
5.2 Growth of Composites
While aluminum has been widely used in aircraft construction, the
market has begun to transition to alternative materials.
Composites are an example of this, as they are being introduced to
aircraft construction. Comprised of fibers laminated with a resin
or glue, composites are more lightweight than aluminum [28].
This makes for a new choice when considering material selection.
Figure 13. Substitution of aircraft construction material [28]
As such, composite use has increased significantly since 1990,
with the majority of aircraft components utilizing the material in
2010 [28]. Growth in this area indicates a potential substitution
for aluminum in aircraft structures. Manufacturing cost for certain
composite materials remains high but is expected to decrease. As
this occurs, more aircraft makers will favor this option as a
lightweight alternative.
5.3 Polyimide Composites
Given the growth of composites in aircraft design, different types
are discussed. The important factor, when evaluating a material
suited for supersonic flight, is the thermal stress. As previously
indicated, the maximum thermal stress of aluminum is slightly
below that required by Concorde [29]. This caused high
maintenance costs to repair damaged sections of the airframe.
Evaluating the maximum abilities of new composite materials is
necessary in identifying a replacement material.
Figure 14. Thermal stress of various materials [29]
Figure 14 shows how titanium has a measured maximum thermal
stress far beyond the demands required. However, due to
difficulty manufacturing, and a large price, this material is rarely
used. Composites, made up of epoxy, BMI, ethers or polyimides
are a possible substitution due to lower cost [29]. The most
promising of these are polyimide variations. NASA has conducted
research estimating the use of polyimides in hypersonic
applications. During this project they patented a compound known
as PETI-9 [30]. A resin intended to adhere together composite
fibers, PETI-9 maintains a low weight and a high thermal
strength.
Figure 15. Thermal stress of various materials [30]
As such, it could be incorporated into supersonic aircraft design,
replacing the inadequate aluminum alloy predecessor. If possible,
this could provide the material needed to sustain supersonic flight,
without large maintenance cost.
6. FORECAST SUMMARY
6.1 Combined Forecast
Summarizing the forecast of aircraft noise reduction, hybrid
turbofan design, and material use, allows for a combined forecast
of next generation supersonic commercial aircraft. The process
involves a weighted average of timeframes associated with each
subtopic [6]. Some of the technologies discussed are already
possible and will be weighed less. On the other hand, those with
more uncertainty are weighed higher.
Table 1. Weighing of combined forecast
Weight Forecast
Low Boom Airframes 0.40 2028
Hybrid Aircraft Engines 0.25 2030
High Power Batteries 0.15 2035
Polyimide Composite Use 0.10 2020
Stage 4 Engine Noise 0.05 2020
Improved Lift to Drag Ratio 0.05 2020
Combined Forecast 2028
The weighing structure favors low boom airframes and hybrid
aircraft engines above other related technologies. These are the
remaining advances necessary to facilitate supersonic flight.
While polyimide composites and improved lift to drag ratios are
important, these aspects have been addressed and probable
solutions are possible. Given this analysis, sonic boom reduction
is the largest obstacle to new aircraft and is weighted as such.
When considering supersonic aviation as a whole, the estimated
date of introduction is 2030.
0
20
40
60
80
100
1960 1980 2000 2020 2040
StructuralWeightAttributedto
Composites(%)
Year
Composite Material Traditional Material
Forecast Actual
0
100
200
300
400
Aluminum
Titanium
Epoxy
BMI
Cyanate
Ethers
Polyimides
Temperature(DegC)
Material Type
Measured Theoretical

7. 7
6.2 Technological Assessment
Following the combined forecast, an assessment of technology
impacts is made. The goal is to evaluate the positive and negative
implications of technology adoption. As previously stated,
supersonic travel has a number of commercial benefits. Higher
speed allows for a greater travel range and opens up new
destinations for airports. Along with this, turnaround time for
cargo operators will improve user experience and profit margins
by delivering goods quicker. There are some drawbacks to this
technology, however. Should this form of transportation gain
popularity, it may put strain on other methods. High speed trains,
hyperloops, or even rocket based transportation will suffer or
disappear from the market. Furthermore, increased demand of
new construction materials may affect supply chains in
unexpected way, hindering growth. This assessment feeds further
scenario development designed to recognize potential market
changes and how they can be anticipated.
7. SCENARIO DEVELOPMENT
7.1 Factor Analysis
The first step in scenario development is factor analysis. This
process identifies the most impactful and uncertain areas of
industry development. Evaluating different components of the
supersonic aviation sector has identified several technologies
pertinent to change. These relate to topics indicated in the
combined forecast.
Table 2. Technologies considered in scenario creation
Impact Uncertainty
Underlying
Force
Low Boom
Airframes
0.8 0.8
Technological
Legal
Hybrid Aircraft
Engines
0.8 0.6
Technological
Legal
High Power
Batteries
0.5 0.4 Technological
Polyimide
Composite Use
0.5 0.3 Technological
Supersonic
Turbofan
0.4 0.2 Technological
Improved Lift to
Drag Ratio
0.2 0.2 Technological
Factors with the largest impact and uncertainty are low boom
airframes and hybrid aircraft engines. Either one of these
innovations would cause a dramatic market shift and are hard to
estimate. Slightly less than these, polyimide composite use is
more certain but would still have a significant impact. Supersonic
turbofans and improved lift to drag ratios are important but not as
essential. All of the factors indicated are dictated by technological
or legal restrictions. As such, scenario creation will focus on how
these underlying forces affect the most impactful and uncertain
characteristics of supersonic aviation.
7.2 Scenario Creation
With the aspects influencing growth, four future scenarios are
generated. Relying on factor analysis, differences are discerned
between the realities. This provides details of potential outcomes
of adoption, allowing for further understanding.
Table 3. Scenario matrix
Noise Restriction
Remain Unchanged Changed
TechnologicalAdvancement
AdvancementSuccessful
Slow but silent
• Noise reduction is made
but not enough to
facilitate supersonic
travel
• Hybrid aircraft adoption
takes place
• More fuel-efficient
aircraft solidify the form
of transportation
• Flights become cheaper
Supersonic revolution
• Low boom and hybrid
aircraft possible
• Travel industry growth
due to expanded aircraft
range
• Travel speed solidifies
the form of
transportation
• The cost of flights
remains mostly
unchanged
AdvancementUnsuccessful
Business as usual
• Low boom technology
not possible
• Hybrid turbofan
adoption does not take
place
• Aviation sector remains
unchanged
• Industry vulnerable to
displacement by other
forms of transportation
(hyperloop, rocket, etc.)
The skies are thunderous
• Low boom technology
not possible
• Travel industry growth
due to expanded aircraft
range
• Inefficient aircraft
increase CO2 emissions
• Social response to loud
aircraft threatens form of
transportation
The four situations imagined revolve around aircraft noise
restriction, as well as, technological advancement in sonic boom
reduction and hybrid aircraft engines. These depict the most likely
progression of the aviation sector given project research. While
some are more probable than others, they are all plausible
outcomes.
7.2.1 Business as Usual Vignette
In this situation industry advancement continues along the same
path as past performance. Imagine a typical day at the airport. A
family is getting set for a big trip and in the background, the roar
of jet propulsion fills the silence. People line up at the terminal
gates, where they will board aircraft just as they have many times
before. Once settled in the flight crew does their final checks as
the engines start to spool up. Within minutes the exhilaration of
takeoff provides an exciting start to an adventurous trip. Shortly
after, the passengers start to settle in for the long haul as they
prepare for a typical plane ride.
7.2.2 The Skies are Thunderous Vignette
If aircraft noise suppression lags the legal shift allowing
supersonic aircraft, the future will be loud. Kids playing outside
look up to an aircraft that used to have a subtle sound. Now there
is a loud crack, sounding like thunder. The sonic boom doesn’t
rock the ground but startles the neighbors’ dog, who is barking
like mad. No broken windows or broken bones but the peace has
been disturbed. All for the small shadow darting across the sky at
60,000 feet. This has become common place, and while
bothersome around airports, the economic impacts of supersonic
travel outweigh the cost. A minor disturbance does not deter
prosperity of the aviation industry.

8. 8
7.2.3 Slow but Silent Vignette
Should advances in hybrid turbofan technologies enter the market,
life of airline grounds crew will be an unfamiliar experience.
Previously muffled by heavy duty headphones, the airport
terminal is quiet. No distraction or disruptions, rather a peaceful,
pleasant atmosphere. Fuel lines are now replaced by electric
plugs, which generates a slight hum when connected to an aircraft.
Taxing the aircraft out to a runway produces nothing but a woosh.
This is followed by a soft acceleration through the traditional
takeoff phases. As an aircraft touches down for landing, the sound
of squeaking brakes echo above all else. The drowning engine
noise is no longer present.
7.2.4 Supersonic Revolution Vignette
The last scenario analyzed includes the introduction of both
hybrid aircraft engines and low boom technology. Envision
planning a vacation with several different destinations. With cross
country travel taking a fraction of the time, there is more desire to
do so. Waking up in New York, grabbing lunch in Los Angeles,
and getting to sleep in Sydney, all in one day, is the new normal.
The more pleasant experience causes bustling airports with
expanded ranges of destinations. Cramped aircraft now feel more
comfortable knowing the destination will arrive sooner. All of
these benefits come with understanding that new supersonic
aircraft emit little to no greenhouse gases. Quiet, quick and
efficient now define the aviation industry, which has
overshadowed all other forms of transportation.
7.3 SWOT Analysis
Given four potential futures for the aviation industry, a SWOT
analysis is the next step in creating a plan to address these
changes. In this case, the supersonic revolution scenario is
selected as it would be the largest disruption to 2020 market
conditions. SWOT examination breaks the scenario into more
useful descriptions by considering strengths and weaknesses.
Table 4. SWOT matrix
Helpful Harmful
Internal
Strengths
• Current client base in the
aviation sector
• Satisfactory engine noise
reduction
• Successful subsonic
airframe
Weaknesses
• Most designs delay
supersonic flow in favor
of subsonic flow
• Little plans for a hybrid
engine
• Expensive aircraft design
External
Opportunities
• Chance to implement
composites in design
• Existing supersonic inlet
implementation
• Lower cost with hybrid
propulsion system
Threats
• Competing supersonic
aircraft
• Lagging introduction of
composites
• Engine pylons suited for
subsonic thrust
When evaluating the introduction of supersonic aircraft, subsonic
manufacturers will still hold the majority of market share,
retaining their dominate position. However, weaknesses include
inferior design, with competing supersonic aircraft becoming
threatening. To help overcome these risks, this scenario
recognizes the opportunity to incorporate a hybrid propulsion
system in subsonic aircraft.
Table 5. Strategy matrix
Strengths Weaknesses
Opportunities
Priorities
• Continue delivery of
subsonic aircraft
• Improve lift to drag ratio
implementation
• Reduce manufacturing
cost
Improvements
• Integration of hybrid
propulsion system
• Expansion of aircraft
range
• Introduction of composite
airframes
Threats
Defendable
• Efforts to utilize transonic
flight
• Competing manufacturers
entering market
• More stringent noise
requirements
High risk
• A successful low boom
technology
• Lack of area ruled
airframe
• Experience with
supersonic thrust
Table 5 summarizes different implications of supersonic aircraft.
This information is best utilized with a market plan, which gives
insight into areas of improvement and strength. An effective
strategy will cover the high-risk aspects while exploiting new
opportunities for growth.
8. CONCLUSIONS
In conclusion, this report details the innovations needed to
reintroduce supersonic aircraft. Technologies including sonic
boom reduction, hybrid propulsion systems, and advanced
structural design are at the forefront of the discussion. Analysis of
these topics indicate commercial supersonic travel will be possible
again by the year 2028. Considering this timeframe, an action plan
is necessary to prepare the aviation industry for reintroduction of
the design.
When generating an action plan, SWOT analysis of the supersonic
revolution scenario is performed. Early indicators of occurrence
revolve around the NASA QueSST project. The more successful,
the sooner the scenario will play out. To anticipate this, obvious
future priorities are the delivery of quality subsonic aircraft and
continuous reduction of construction costs. Moving from these,
attractive opportunities involve the inclusion of composites and
hybrid propulsion systems. While a fully supersonic aircraft may
be out of reach for existing makers, composites could be included
in future designs. Hybrid propulsion systems are less developed
but possible without reorganizing the entire sector. Should these
be utilized, subsonic aircraft could defend against transonic cruise,
as the product would be competitive. However, if fully supersonic
flight is made easily accessible, current manufacturers will need to
invest heavily to catch up to new technologies. Low boom
airframes, and area ruling, will need to be incorporated in future
designs, which will substantially deviate from prior concepts. This
will be costly, and may not result in a successful product, causing
a lag in development.
In all, this forecast recommends industry consider hybrid turbofan
engines when generating future designs. Regardless of low boom
techniques, the ability to reduce fuel consumption is a high
priority for airlines. This would make subsonic travel economical
enough to protect against the potential of supersonic aircraft.
Also, hybrid technologies may give existing makers the time and
resources to create supersonic aircraft of their own.

9. 9
9. REFERENCES
[1] AIRLINE INDUSTRY INFORMATION. 2003. Concorde
aircraft to operate last commercial flight. http://search.
proquest.com/docview/210531991.
[2] BROOKS, J. 1978. Aircraft noise and the Concorde, House
Committee on Government Operations TR No. 95-879.
United States Congress, Washington, D.C.
[3] VAN SCHAACK, A.J. 2020. Overview of monitoring
forecasting. Unpublished manuscript, Vanderbilt University,
Nashville, TN.
[4] SANDERS, N. 2015. Statistical forecasting models. In
Forecasting fundamentals, N. Sanders, Ed., Business Expert
Press, New York, NY, 75-88.
[5] VAN SCHAACK, A.J. 2020. Overview of trend forecasting.
Unpublished manuscript, Vanderbilt University, Nashville,
TN.
[6] ARMSTRONG, J.S. 2001. Combining forecast. In Principles
of forecasting: A handbook for researchers and practitioners,
J.S. ARMSTRONG, Ed., Kluwer Academic Publishing,
Norwell, MA, 417-439.
[7] VAN SCHAACK, A.J. 2020. Consequences of technology.
Unpublished manuscript, Vanderbilt University, Nashville,
TN.
[8] VAN SCHAACK, A.J. 2020. Overview of scenario
forecasting. Unpublished manuscript, Vanderbilt University,
Nashville, TN.
[9] OGILVY, J. 2015. Scenario planning and strategic
forecasting. https://www.forbes.com/sites/stratfor
/2015/01/08/scenario-planning-and-strategic-forecasting.
[10] LOFTIN, L.K. 1985. Quest for performance: The evolution
of modern aircraft, National Aeronautics and Space
Administration TR No. NASA-SP-468.
https://ntrs.nasa.gov/search.jsp?R=19850023776.
[11] TRACY, R.R. 1996. High-efficiency, supersonic aircraft.
U.S. Patent No. 5,322,242. Washington, DC: U.S. Patent and
Trademark Office.
[12] SCHOLL, N.B., WILDING, J., KRALL, J., BERRYANN,
A., AND REID, M. 2018. Commercial supersonic aircraft
and associated systems and methods. U.S. U.S. Patent
Application No. 15/811,327. Washington, DC: U.S. Patent
and Trademark Office.
[13] BENSON, L. 2013. Quieting the boom: The shaped sonic
boom demonstrator and the quest for quiet supersonic flight.
National Aeronautics and Space Administration,
Washington, D.C.
[14] HENNE, P., HOWE, D., WOLZ, R., AND HANCOCK, J.T.
2004. Supersonic aircraft with spike for controlling and
reducing sonic boom. U.S. Patent No. 6,698,684.
Washington, DC: U.S. Patent and Trademark Office.
[15] NATIONAL AERONAUTICS AND SPACE
ADMINISTRATION. 2018. https://www.nasa.gov/mission_
pages/lowboom/mission.
[16] JOHN, D. 1967. Bristol Siddeley/SNECMA Olympus 593
powerplant for Concorde, Bristol Siddeley Engines Limited
TR No. 67-GT-8. The American Society of Mechanical
Engineers, New York, NY.
[17] HUFF, D.L. 2013. NASA Glenn’s contributions to aircraft
engine noise research, National Aeronautics and Space
Administration TR No. NASA-TP-2013-217818. https://
ntrs.nasa.gov/search.jsp?R=20140006523.
[18] SOARES, C. 2015. Historical development of the gas
turbine. In Gas turbines (second edition), C. SOARES, Ed.,
Butterworth-Heinemann, Oxford, United Kingdom, 41-92.
[19] ASOLIMAN, I.M., EHAB, M. AND MAHROUS, A.M.
2018. Performance analysis of high bypass turbofan engine
Trent 1000-A. In Proceedings of the international
undergraduate research conference, IUGRC 2018, Cairo,
Egypt, July 2018, IUGRC, Cairo, Egypt, 1-9.
[20] ENVIRONMENTAL PROTECTION AGENCY. 2020. The
2019 EPA automotive trends report, United States
Environmental Protection Agency TR No. EPA-420-R-20-
006. https://www.epa.gov/automotive-trends.
[21] MACKIN, S.G. 2019. Hybrid propulsion engines for aircraft.
U.S. Patent No. 322,379A1. Washington, DC: U.S. Patent
and Trademark Office.
[22] THOMSON, R., SACHDEVA, N., BAUM, M., LEPINE,
P.L., KIRSCHSTEIN, T., BAILLY, N. AND MARTINEZ,
N. 2018. Aircraft electrical propulsion-onwards and upwards,
Roland Berger LTD. https://www.roland berger.com/public
ations/publication_pdf/roland_berger_aircraft_electrical_pro
pulsion_2.pdf.
[23] ENVIRONMENTAL PROTECTION AGENCY. 2020.
Overview of the Clean Air Act and air pollution.
https://www.epa.gov/clean-air-act-overview.
[24] PEETERS, P.M., MIDDEL, J. AND HOOLHORST, A.
2005. Fuel efficiency of commercial aircraft, National
Aerospace Laboratory NLR TR No. NLR-CR-2005-669.
https://www.transportenvironment.org/sites/te/files/media/20
05-12_nlr_aviation_fuel_efficiency.pdf.
[25] HUPE, J. et al. 2016. ICAO environmental report 2016,
International Civil Aviation Organization.
https://www.icao.int/environmental-protection/Pages/
env2016.aspx.
[26] REGNART, J. 2018. Roadmaps explored-understanding the
battery challenges from chemistry to recycling.
https://www.apcuk.co.uk/news/roadmaps-explored-
understanding-battery-challenges-chemistry-recycling.
[27] FROST, S. 2017. Material marvels: Concorde. Materials
World magazine. https://www.iom3.org/materials-world-
magazine/feature/2017/jun/01/material-marvels-concorde.
[28] NATIONAL RESEARCH COUNCIL. 1997. Airframe. In
U.S. supersonic commercial aircraft: Assessing NASA’s high
speed research program. NATIONAL RESEARCH
COUNCIL, Ed., The National Academies Press,
Washington, DC, 61-90.
[29] HAO, L.C., SAPUAN, S.M. AND HASSAN, M.R. 2014. A
review of the flammability factors of kenaf and allied fibre
reinforced polymer composites. Advances in Materials
Science and Engineering, 2014, 1, 1-8.
[30] CONNELL, J.G., SMITH, J.G. AND HERGENROTHER,
P.M. 2002. Composition of and method for making high
performance resins for infusion and transfer molding
processes. U.S. Patent No. 6,359,107. Washington, DC: U.S.
Patent and Trademark Office.