US History/US History (Bureau Development Inc.)(1991).ISO/dp/0001/00017.txt

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$Unique_ID{USH00017}
$Pretitle{2}
$Title{NASA, The First 25 Years 1958-1983
Chapter 2  Aeronautics}
$Subtitle{}
$Author{Thorne, Muriel M., Technical Monitor & Editor}
$Affiliation{NASA}
$Subject{research
aircraft
flight
engine
wing
program
nasa
air
new
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$Volume{}
$Date{1983}
$Log{}
Book:        NASA, The First 25 Years 1958-1983
Author:      Thorne, Muriel M., Technical Monitor & Editor
Affiliation: NASA
Date:        1983

Chapter 2  Aeronautics

     The first A in NASA stands for aeronautics.  In 1983 your students accept
aviation as an integral part of their lives.  Contrast for them air travel in
1958 and now - propeller planes and jet transportation, 70-passenger airliners
and jumbo jets that carry over 400 people, the dominant sea travel of 25 years
ago and today's regular SST flights across the Atlantic.

     Flying is so accepted a part of life that the immense strides made in
just 25 years are hardly remembered.  Nor is it recognized that most of the
advances of these 25 years began with research in NASA's laboratories.  The
aeronautical research of the National Advisory Committee for Aeronautics
(NACA) was assigned to NASA in its charter, including the objectives:

     - The expansion of human knowledge of phenomena in the atmosphere. . .

     - The improvement of the usefulness, performance, speed, safety, and
efficiency of aeronautical . . . vehicles;

     - The preservation of the role of the United States as a leader in
aeronautical . . . science and technology;

     - The most effective utilization of the scientific and engineering
resources of the United States in order to avoid unnecessary duplication of
effort, facilities and equipment.

     With some of the most sophisticated aeronautical laboratories and flight
test facilities, NASA's research has continued that of the NACA.  At the major
aeronautical centers - Ames Research Center (ARC), Dryden light Research
Facility (DFRF), Langley Research Center (LaRC), Lewis Research Center (LeRC)
- NASA scientists, engineers, and test pilots work closely with universities,
other government agancies, and U. S. industry in a wide range of programs and
projects.

     Aeronautics is a many-faceted subject that can be studied from several
different approaches.  First, chronologically, by investigating the attempts,
successes, and failures of would-be fliers through history.  Or by discipline
- aerodynamics, guidance and navigation, materials and structures, propulsion.

     A third method is to study the tools of aeronautic research: mathematical
and physical analysis, now largely computerized; wind tunnels; simulators; and
full-scale flight research.

     Finally, there are the programs themselves.  In examining individual
projects, history, discipline, and tool come together to provide an overall
view of little-known but challenging areas of aeronautical research.  The
following list is an introduction to aeronautics at NASA - the research
subjects, their aims, and their results.

X-15
March 25, 1960 - October 24, 1968

     The X-15 - a 15-meter (50-foot-long), black, stub-winged, rocket-powered
flight research craft with a conventional nose-wheel and skids mounted at the
rear for landing - was a true aerospace vehicle.  With wings and aerodynamic
controls it traveled like an airplane in the atmosphere, and in flight beyond
the atmosphere, like a spacecraft.

     It was launched from beneath the wing of a B-52 at an altitude of 13,716
meters (45,000 feet).  After its drop, the rocket engine was fired and the
craft climbed in a steep trajectory, then nosed over to descend in a glide to
a landing.

     Through a series of progressive steps, the X-15 set new altitude (17,960
m or more than 67 mi) and speed (6.7 times the speed of sound) records.  Its
199-flight program contributed important data about weightlessness,
aerodynamic heat, atmospheric entry, the effect of noise on aircraft
materials, and piloting techniques.

     The X-15 was a joint NASA/Air Force/Navy project.  First piloted by A.
Scott Crossfield, both Neil Armstrong, commander of Apollo 11, and Joe Engle,
commander of the Shuttle's second flight, were among the pilots who flew the
X-15 into unexplored areas of flight.

Supersonic Cruise Aircraft Research (SCAR)

     NASA researchers worked throughout the 1960's on technologies for
supersonic transport.  By 1971, Boeing's Supersonic Commercial Air Transport
(SCAT) was ready for production, but concerns about noise, economy, and
pollution prevented further funding.  Convinced that supersonic transport
research would eventually pay off, in 1973 the government funded the
Supersonic Cruise Aircraft Research (SCAR) program.  Nine years of a
sustained, focused technology program involving NASA and major U. S.
propulsion and airframe companies resulted in significant improvements over
earlier supersonic transport concepts.  By the early 1980's, the SCAR program
had developed technologies permitting a greatly increased range, greater
passenger capacity, lighter weight, and cleaner quieter more efficient
engines.

Terminal-Configured Vehicle (TCV)

     With the continually growing use of air transportation, air terminal
problems increased:  approach and landing in bad weather safety and efficiency
in controlling high-density traffic, and noise of aircraft in take-off and
landing over densely populated areas.

     Recently renamed Advanced Transport Operating Systems Program (ATOPS),
the Terminal-Configured Vehicle (TCV) is a research tool, a standard Boeing
737 twin-jet transport with a second cockpit in the passenger cabin.  Equipped
with state-of-the-art instrumentation, the second cockpit is the flight center
for the research, while safety pilots fly in the conventional cockpit for
backup.  In 1979 the TCV was used to demonstrate the Microwave Landing System
(MLS) and Area Navigation in efficient descent and airport approach paths and
precision flight control.  Its success led to the International Civil Aviation
Organizations adoption of MLS as the world standard.

Pivoting Wing

     Several decades ago Robert T. Jones, NASA scientist at ARC, invented the
concept of an aircraft wing that could pivot up to 60 degrees in flight; years
of analysis and wind tunnel tests suggested the results would be considerable
fuel economy.

     A small, piloted research aircraft called Ames-Dryden-1 (AD-1) was built,
and in 1979 made its first flight.  During takeoff, landing, and lowspeed
cruise, the AD-1 flies with wings at right angles to the fuselage. At higher
speeds, the wing pivots so that the right half sweeps forward and the left
half sweeps back.  The pivoted wing decreases air drag, allowing the plane
increased speed.  The AD-1 flight research program, completed in 1981, tested
the pivoting wing in 39 flights at speeds up to 185 mph.

HiMAT

     Highly Maneuverable Aircraft Technology (HiMAT) is a NASA/Air Force
flight research program to study and test advanced fighter aircraft
technologies.

     The HiMAT vehicle is a 44-percent scale model with wing tip-mounted
winglets and a small forward canard wing for high maneuverability.  It
consists of a core design to which modular components can be attached easily
and replaced, a format that allows low-cost testing of a variety of concepts.

     In 1979 the remotely-controlled research aircraft made its first flight.
The following year it achieved near-maximum design maneuverability at
sustained near-supersonic speeds, and in 1981 its flight testing was expanded
to transonic speeds.

     The HiMAT flight test program ended in January 1983.  The vehicles had
performed superbly with maneuverability equal to or above the goals of the
design.


Lifting Bodies

     Aeronautical research does not often extend to the problems of
spacecraft.  An aerospace vehicle, such as the Space Shuttle orbiter, to fly
in the atmosphere safely, must be aerodynamically stable and maneuverable at
hypersonic, supersonic, transonic, and subsonic speeds.  Known as a lifting
body, this type of craft was researched for many years before its application
to an aerospace flight.

     NASA has had three experimental lifting bodies, which are wingless and
achieve the aerodynamic lift and maneuverability necessary for flight from
their body shape alone.  The first, ARC's M2, featured a flat top and round
belly.  The second, HL-10, was developed at LaRC and had a rounded top and
flat belly.  The third is the NASA/AF X-24.  The vehicles were carried aloft
by a B-52 and released to glide to landings on a dry lake bed.  The X-24B had
made 33 successful flights when the program was completed in 1975.

Forward Swept Wing (FSW)

     The Forward Swept Wing (FSW) offers the potential for high performance
design with both civil and military applications.  In a joint program with the
Defense Advanced Research Projects Agency, NASA is testing the unusual wing
which is swept forward at a 30 degree angle to the fuselage.

     Wind tunnel tests, composite element tests, and simulations indicate the
FSW design should give greater maneuverability at transonic speeds and
superior low-speed performance.  To avoid structural deflection of the wing,
its design calls for laying up the composite material plys in definite
patterns.  The X-29A is scheduled for demonstrator flights at the Dryden
Facility early in 1984.

Quiet Engine Research

     The Lewis Research Center has led the investigation for reducing noise
and pollution produced by airplanes.  Beginning in the late 1960's, the Quiet
Engine program focused on developing an engine with noise levels 15 to 20 PNdB
(Perceived Noise Decibels) below levels then in use.  The results: (1) a high
bypass ratio turbofan engine to help produce thrust with low velocity air; and
(2) a retrofittable acoustic nacelle, an engine housing lined with sound
absorption material.

Quiet, Clean, Short-haul Experimental Engine (QCSEE)

     In the late 1970's, the QCSEE program began testing two research engines
at LeRC.  One engine is mounted beneath the wing, and the other is designed
for placement above the wing.  Developed for a Short Takeoff and Landing
(STOL) aircraft but applicable to the larger commercial airliners, these
engines direct their exhaust downward with wing flaps to add lift for short
take-off and landing.  Tests have demonstrated the engines ability to operate
at a noise level 60 to 75 percent below that of engines now in service. Carbon
monoxide and unburned hydrocarbon emissions have also been dramatically
reduced.

Quiet, Clean, General Aviation Turbofan Engine (QCGATE)

     The QCGATE program was directed toward meeting U.S. environmental
standards for general aviation engines.  An existing turbojet or turbofan
engine core was used in the experimental, quiet high-bypass turbofan engine
which incorporated the latest quiet engine technologies.  In 1980 the QCGATE
program was completed with the resulting research engines producing from 50 to
60 percent less noise than the most quiet current business jets.

V/STOL Research

     NASA is developing a number of new flight technologies for safe, clean,
quiet, and efficient Vertical and Short Takeoff and Landing (V/STOL) aircraft.

     Two VTOL programs, Rotor Systems Research Aircraft (RSRA) and Tilt Rotor
Research Aircraft (TRRA), are joint NASA-Army projects.  In STOL research,
NASA is experimenting with propulsive-lift concepts with the Quiet Short-haul
Research Aircraft (QSRA).

Rotor Systems Research Aircraft (RSRA)

     The Rotor Systems Research Aircraft (RSRA) is designed to test various
advanced rotor systems.  Able to fly as a conventional helicopter, the RSRA
also flies with wings to assist the lift and is able to operate in a wide
range of speeds.  The two RSRA currently in use are helping to develop
technologies for safer, quieter more reliable helicopter performance.

Tilt Rotor Research Aircraft (TRRA)

     The XV-15 Tilt Rotor Research Aircraft (TRRA) employs two large rotors to
combine the advantages of a helicopters vertical lift with an airplanes
cruising speed.  In the air the rotors tilt forward to become propellers for
cruising.  This versatile aircraft can take off and land vertically, hover and
fly forward, sideways, or rearward.

     The TRRA is potentially valuable as a commercial commuter liner operating
out of close-to-city heliports.  In 1981 the TRRA completed the
proof-of-concept flight research phase.  It flew twice as fast and twice as
far as a helicopter on an equal amount of fuel and achieved a top speed of 557
km/h (346 mph).

Quiet Short-haul Research Aircraft (QSRA)

     An experimental vehicle, the Quiet Short-haul Research Aircraft (QSRA)
addresses airport congestion and noise problems.  The QSRA has demonstrated
the effectiveness of propulsive-lift technology, where the engines exhaust is
directed over the wing surfaces, which increases lift and allows quiet
takeoffs and landings from short runways.

     In 1981 the QSRA completed a flight evaluation series during which
government, military, airline, and industry pilots flew the aircraft.

Aircraft Energy Efficiency (ACEE)

     In response to a U.S. Senate request in 1975, NASA established the
Aircraft Energy Efficiency (ACEE) program to develop fuel-saving technologies
for both existing and future aircraft.  Using an inter-disciplinary approach,
ACEE includes six major technology programs to explore ways to improve both
engine and airframe performance: more efficient wings and propellers; new
composite materials for airframes that are lighter and more economical than
metal; ways to make todays jet engine more fuel efficient; new engine
technologies for energy-saving aircraft of the future.

Energy-Efficient Transport (EET)

     An important factor in flight efficiency is the shape of an aircraft and
the resulting flow of air over its surfaces in flight.  Developing improved
wing designs is a major task of the Energy-Efficient Transport (EET) program.

     NASA's supercritical wing is shaped to minimize air drag without loss of
lift.  It also increases volume for fuel storage while improving structural
efficiency of the wing, leading to lower weight.  A welldesigned supercritical
wing can reduce fuel consumption 10 to 15 percent.  Further fuel efficiency
can be achieved with the use of nearly vertical winglets installed on the
wingtips of aircraft, which help to reduce air drag and produce thrust.

Laminar Flow Control (LFC)

     The smooth flow of air over the surfaces of an airplane, called laminar
flow, occurs at low speeds.  At cruising speeds, however flow becomes
turbulent, causing drag and reduced efficiency.  The Laminar Flow Control
(LFC) program aims to achieve smooth air flow at cruising speeds.  Technology
combining the promising concept of lightweight suction systems to remove
portions of turbulent air through multiple slots or tiny holes on the wing
surface with the new supercritical wing designs is being tested for use on
commercial aircraft in the 1990's.  The LFC program has combined detailed
analysis and model testing in its early phases of research and development.
Flight testing, the third phase of the program, is scheduled to extend through
September 1986.

Advanced Turboprop (ATP)

     Renewed interest in fuel economy has the more fuel-efficient turboprop
engine being reconsidered and improved for future use.  Odd-looking new multi-
bladed propellers are being developed for use on a turboshaft engine.  The
improved turboprop aircraft is expected to compete favorably with jetliners
for speed and noise, but be more fuel efficient.

     The three-phased Advanced Turbo prop (ATP) program is testing small scale
propeller models to establish proof-of-concept.  In the second phase,
large-scale propellers will be used to validate structural dynamics, and in
the third, a full-scale experimental propeller will be tested in flight.

Engine Component Improvement (ECI)

     The Engine Component Improvement (ECI) program objectives were to reduce
the cycle of wear and deterioration that affects fuel efficiency of jet
engines.  ECI developed new components for existing engine designs to resist
the erosion, leaking, and warping responsible for efficiency loss; a highly
effective seal for the turbine engine to prevent the engines high-pressure
gases from leaking out of the main flow path and remain effective under
conditions that cause conventional seals to fail; new materials or ceramic
coatings that can reduce erosion and corrosion of turbine blades; and improved
aerodynamic design of the compressor and blades that contributes to engine
efficiency.  Major successes of the ECI program were realized early in the
1980's and have become available for use in the new Boeing 767 and the
McDonnell Douglas DC-9 Series 80 aircraft.

Energy Efficient Engine (E3)

     The Energy Efficient Engine (E3) program is planning a completely new
engine design for use after 1990.  Using the standard building-block technique
of engine manufacturers, NASA researchers and engineers refine each new
component to develop a core design to which the fan, turbine, and exhaust
nozzle are added.  The E3 program is scheduled to complete testing of new
components early in the 1980's.

     One area of study focuses on increasing the engines cycle pressure ratio
and turbine operating temperature, converting a greater proportion of fuel
into energy.  Another component mixes the engine's cool bypass air with the
hot core stream, increasing propulsion without added fuel.  These E3
components will also help to reduce noise and exhaust pollution.

Composite Materials

     Unnecessary weight adds to the amount of fuel needed for flight, so the
ACEE program has been developing technology for new lightweight composite
materials for airframe construction.

     Conventional aircraft are constructed primarily with alloys of aluminum,
magnesium, titanium, and steel; the new composite materials consist of
graphite, glass, or Kevlar(R) fibers arranged in a matrix, generally epoxy. By
arrangement of the fiber orientation, the great strength of these materials
can be directed along a line or in random directions.  Light, yet strong and
stiff, the materials offer possible weight reductions of 25 percent or more.
Beginning with secondary structures not critical to flight safety, some new
materials have been flight-tested.  The goal is to monitor the materials in
daily use on a commercial airline, where the normal wear on the pieces can be
observed; because they replace metal parts on aircraft in service, each new
part will be certified by the Federal Aviation Administration (FAA).  Eventual
testing of a complete wing and fuselage will provide a design base for future
energy efficient aircraft.

Aeronautical Safety

     Todays aircraft incorporate many improvements developed over the years to
make them safer for flight in both good and bad weather, and to increase
safety during takeoff and landing.

Crashdynamics

     Recent studies have included an investigation of airplane crashdynamics
information with the intent of increasing the survivability of passengers in
an accident.  For several years, NASA has been deliberately crashing
controlled, extensively instrumented aircraft, both single- and twin-engined.

     The planes, containing anthropomorphic dummies harnessed in the crew and
passenger seats, are crashed onto a runway from a test rig.  The data
collected helps researchers understand how an aircraft absorbs the energy of
impact and transfers the shock to passengers.  The tests include the study of
improved seats, harnesses, and crushable sub-floor and fuselage structures.

Fireworthiness

     In a related effort, NASA researchers at the Ames and Johnson Centers are
developing fire resistant materials for use inside cabins.  One concept uses
fire resistant wrappings over conventional polyurethane foam cushions. Another
fire resistant, lightweight polymide seat cushion has been developed at
Johnson and is being evaluated in service by three airlines.  Similar
lightweight fireworthy materials are being applied to ceiling, wall, and floor
panels.

     Less flammable jet fuels are also under development, most notably the
British-developed AMK safety fuel, FM-9.  Full-scale tests have demonstrated
the new fuel's ability to prevent major fires caused by ignition of jet fuel
during and after a crash.  Along with the FAA, NASA has been testing the
safety fuel and evaluating its compatibility with the most common engine in
service.

Automated Pilot Advisory System

     For general aviation pilots operating out of small uncontrolled
airfields, NASA has developed and successfully demonstrated the Automated
Pilot Advisory System (APAS) to provide weather traffic, and airport
information.  The APAS includes a tracking radar, weather sensors, a computer
and a transmitter.

     Computer-generated voices broadcast traffic information every 20 seconds
within three miles of the airport, and every two minutes, information on
airport identification, active runway, wind speed and direction, barometric
pressure, and temperature.

Stall/Spin Research

     The stall/spin phenomenon has been a major cause of accidents in general
aviation.  A stall occurs when the angle of attack of the wing increases to
the point where air across the wing separates instead of following the upper
surface; this causes a loss of lift.  Following a stall, an airplane sometimes
will begin to spin downward at a rapid rate.  Stall/spin tests have ranged
from early studies with models in wind tunnels and special spin tunnels to
more recent use of simulators and full-scale flight research vehicles.

     In the 1970's a large-scale effort focused on vertical tail designs and
went on to develop a number of leading-edge wing extensions.  These extensions
have been shown to make test airplanes significantly more resistant to spin.

     The stall/spin research has produced a large body of data that aids
industry in the design of safer airplanes.

Icing Research

     An increasing demand for all-weather flights brought on by advances in
avionics systems, has brought a renewed interest in improving aircraft
performance under icing conditions.  Current research is aimed toward
developing lightweight, lowpower consumption, cost-effective ice protection
systems.  Analysis, wind tunnel testing, and flight research are being used to
validate the effectiveness of these protection systems.

     In 1982, NASA developed a long term icing research program in cooperation
with the Army, Air Force, FAA, and the governments of Canada and Great Britain
to evaluate icing instrumentation that had been tested at Lewis.  The Center
also initiated research on protection systems for airfoil leading edges, using
an electro-impulse concept.  NASA also provides the FAA with icing research
data to support upgraded aircraft certification, particularly for rotorcraft.

Aviation Safety Reporting System

     In cooperation with the FAA, NASA completed in 1982 the development of
the Aviation Safety Reporting System (ASRA), a voluntary, confidential,
nonputative reporting system designed to surface deficiencies in the National
Aviation System before accidents occur.  Since April 19, 1976, the System has
received more than 30,000 reports, issued 740 alert bulletins, and published
240 reports.

For The Classroom

     1.   Research topics:

     The uses of general aviation

     Compare a large metropolitan airport and a small general aviation airport

     Airport terminals - the early structures, contemporary complexes,
airports of the future

     How the local airport, or lack of one, affects a community

     2.  Plan a field trip to your local airport.

     3.  Have students list as many types of aircraft as they can, their
characteristics and their uses.  How are they alike?  different?

     4.  Have your students research Reynolds and Mach numbers; differentiate
between subsonic, supersonic, transonic, and hypersonic speeds.

     5.  The difference between laminar and turbulent flow can be easily
demonstrated with a burning piece of punk or stage cigarette in an ash tray;
note the smooth flow upward which abruptly changes to turbulent. The same
effect can be shown with a stream of water from a faucet.  The point at which
the flow changes from laminar to turbulent is at the Reynolds number.  To show
how an aircraft flies, i.e., the flow around the wing, one can demonstrate the
coanda effect by placing ones finger (or a test tube) in the water flow.