Aircraft manufacturers of several nations are developing technology for the
next plateau of international aviation competition: the longrange,
environmentally-acceptable second generation supersonic passenger transport,
which could be flying by 2010.
Predicting large-scale increases in demand forlong-haul overwater passenger
transportation early in the next century, market experts see a need for some 500
next generation supersonic transports worth an estimated $200 billion and140,000
Capturing a major share of that market is vitally important to a U.S. aerospace
industrythat is transitioning from a traditionally defense-dominated product
line to a commercially driven manufacturing activity. To help boost the
industry's competitiveness, NASA is conducting a High Speed Research (HSR)
program that addresses the highest priority, highest risk technologies for a
High Speed Civil Transport (HSCT). The HSR program is intended to demonstrate
the technical feasibility of the vehicle; the decision to proceed with
full-scale development will be up to industry.
The program is being conducted as a national team effort with shared
government / industry funding and responsibilities. The team includes NASA's
Langley, Lewis and Ames Research Centers and Dryden Flight Research Center;
engine manufacturers GE Aircraft Engines and Pratt & Whitney division of United
Technologies; airframe manufacturers The Boeing Company, McDonnell Douglas
Corporation and Rockwell North American Aircraft Division; other manufacturers;
materials suppliers; and academic institutions.
The team has established a baseline design concept that serves as a common
configuration for investigations. A full-scale craft of this design would have a
maximum cruise speed of Mach 2.4, or about 1600 miles per hour, only marginally
faster than the currently operational Anglo-French Concorde supersonic
transport. However, the HSCT would have about double the range and triple the
passenger capacity of the Concorde, and it would operate at an affordable ticket
price, estimatedat 20 percent above comparable subsonic flight fares.
Phase I of the HSR program, which began in 1990 and continued through 1995,
focused on environmental challenges: engine emission effects on the atmosphere,
airport noise and the sonic boom. Much research remains to be accomplished in
these and other areas, but Phase I established some clear lines of approach to
major problems and spawned confidence among team members that environmental
concerns can be satisfied.
Phase II, initiated in 1994, focuses on thetechnology advances needed for
economic viability, principally weight reductions in every aspect of the
baseline configuration, because weight affects not only the aircraft's
performance but its acquisition cost, operating costs and environmental
compatibility. In materialsand structures, the HSR team is developing, analyzing
and verifying the technology for trimming the baseline airframe by 30-40
percent; in aerodynamics, a major goal is to minimize air drag to enable a
substantial increase in range; propulsion research looks for environment-related
and general efficiency improvements in critical engine components, such as inlet
systems. Phase II includes computational and wind tunnel analyses of the
baseline HSCT and alternative designs. Other research involves ground and flight
simulations aimed at development of advanced control systems, flight deck
instrumentation and displays.
In 1996, the HSR program moved beyond laboratory investigations into the actual
supersonic flight realm through a NASA agreement with the Russian Tupolev Design
Bureau, developers of the first supersonic transport, the TU-144, which first
flew in passenger service in 1977. Under the agreement, a modified TU-144LL
supersonic flying laboratory is providing up-to-date information of "real
world" conditions in which the next generation supersonic transport will fly.
TheTU-144LL rolled out of its hangar on March 17 to begin a six-month, 32 flight
The TU-144LL fly at Mach 2.3, or about 1500 miles per hour, close to the
speed of the HSCT baseline concept (Mach 2.4) and is thusan ideal vehicle for
NASA studies of high temperature materials and structures, acoustics, supersonic
aerodynamics and supersonic propulsion.
The TU-144LL is one of 17 TU-144s built. The major modification for the HSR work
is a change of engines. The original engines were replaced by newer and larger
NK-321 augmented turbofans initially employed to power Tupolev's TU-160
Blackjack bomber. Among anumber of other upgrades and modifications, the
jetliner's passenger seats were removed to make room for the six NASA/U.S.
industry experiments' instrumentation and data collection systems. Two
additional experiments are to be conducted on the ground using aTU-144 engine.
The flight deck portion of the HSR programalso progressed to flight status in
1996 with aseries of tests to investigate a "synthetic vision" concept that
could obviate the need for forward-facing cockpit windows. The reasonfor this
departure from conventional design philosophy is the fact that a supersonic
transport of the baseline configuration would land nose-high -- as do the
Concorde and the TU144 -- with the flight deck 45 feet above the runway and more
than 50 feet forward of the landing gear. In that position, the pilots have no
view of the runway ahead of them.
In the first generation supersonic transports -- the Concorde and the TU-144 --
the forward vision problem was solved by use of a mechanism that lowers -- or
"droops" -- the forward part of the nose section for takeoffs and landings and
thereby affords a clear view forward. The mechanism, however, imposes a heavy
weight penalty that is not considered acceptable for the second generation
A potential solution devised by the HSR team is the external visibility system
(EVS), a group of sensors and imaging systems that would feed large-format
cockpit displays of high resolution imagery and computer graphics. The EVS could
eliminate forward-looking cockpit windows and obviate the need for the heavy,
expensive mechanical nose-drooping system.
In the second generation supersonic transport, the EVS could save thousands
of pounds of droop mechanism weight, weight that could be used to allow
increased passenger capacity or greater range. The synthetic vision system might
also find utility in subsonic air transportation, allowing pilots to fly and
land safely inlow visibility conditions; that would enable increasing the number
of flights in poor weather, reducing terminal delays and cutting costs for
airlines and passengers.
The HSR synthetic vision system was tested in a series of flights in 1995-96 at
NASA's Wallops(Virginia) Flight Facility and at Langley Air Force Base in
Hampton, Virginia. Sensors tested included a digital video camera, three
infrared cameras and two microwave radar systems. The tests were flown on
Langley Research Center's Transport Systems Research Vehicle (TSRV), a Boeing
737 equipped with awindow less research cockpit in the passenger section in
addition to the normal windowed cockpit, and in a Westinghouse BAC 1-11 avionics
The flight test program consisted of two phases. During the sensor data
collection phase, the TSRV and the BAC 1-11 flew typical approach, cruise and
holding patterns, testing the capability of the sensors to detect airborne
traffic and ground objects. During the pilot-inthe-loop phase, the TSRV flew
approaches and landings controlled from the research cockpitand tested the
pilots' ability to control and land the aircraft relying only on
sensor/computer-generated images and symbology.
All planned in-flight test points were achieved, and extensive data was
collected from the radar, infrared and video sensors. More than 80 window less
piloted approaches and landings were successfully conducted by pilots from
Langley and Ames Research Centers, Boeingand McDonnell Douglas. Initial pilot
comments and performance reports were encouraging with respect to the
feasibility of using sensor/symbology displays for flight path control.
In addition to the principal members of the HSR team, the flight deck research
included Honeywell, Inc., Phoenix, Arizona; Rockwell Collins, Cedar Rapids,
Iowa; FLIR Systems, Portland, Oregon; and Westinghouse Electric Corporation.
Welcome to the Aeronautics Learning Laboratory for Science Technology and Research (ALLSTAR). This site is enhanced for the latest technologies on the Internet. more