Non-Partisan Congressional Budget Office CBO
Long-Term Budget Outlook
Submit Government Guide
Submit Press Release
The American Recovery
and Reinvestment Act of 2009
Energy Star Homes
Presidential Energy Address
Computer Buyers Guide
Women's Small Business
Computers & Energy Star
Consumer News Articles
CD Manufacturing Services
Cosmetic Surgery and Financing
LASIK Procedures and Costs
Organic Baby Furniture
Gov sites - Jobs
Rebuild Your Home
Drug and Alcohol
Costs and Fees
& Credit Cards
Stock Market Basics
Global Warming Facts
U.S. Immigration and Visas
Government Health Guides
The Privacy Story
By President Bush
Marriage and Health
Marriage and Teen Attitudes
Happy vs. Unhappy
Marriage and Health
Recipe for Happy Marriage
Sleep and Marriage Study
100 Q & A's of
Home Buying FAQ
Home Buying Loans
Tips For Home Buyers
Energy Efficient Homes
U.S. Immigration and Visas
Department Travel Tips
Other Online Guides
Cessna Private Jets
It is the fastest, most efficient business jet ever to race across the sky. Capable of flying at near supersonic speeds, an exciting addition to Cessna's fleet
of private aircraft has pushed the envelope of general aviation to new performance levels.
NASA's Langley Research Center and the Cessna Aircraft Company of Wichita, Kansas have had a long, beneficial relationship. Starting with use of supercritical wing technology developed by NASA in the 1970s, Cessna has repeatedly called upon NASA's know-how and use of its test facilities. On this latest venture into business-class jet aircraft building, a highly swept, second-generation supercritical wing was designed, capable of Mach .92 and supporting the aircraft to a maximum altitude of 51,000 feet.
To help in the development of the unprecedented aircraft, Citation X, Cessna retained as a special consultant, Richard Whitcomb, a retiree from NASA Langley and the inventor of the supercritical airfoil.
A supercritical airfoil enhances an airplane's performance in a critical flight area--the transonic regime (speeds near Mach 1). High-speed subsonic aircraft can experience mixed subsonic and supersonic airflow, and at some point over the wing, airflow exceeds the speed of sound. At this point, the airflow surface suddenly changes, creating a standing shock wave. In turn, this phenomenon results in excessive drag, and therefore a loss in efficiency. Supercritical wings change the shape of the airflow by flattening the upper surface of the wing, which minimizes the effect of the shock wave. Low drag contributes to an aircraft's fuel efficiency.
NASA joined forces with Cessna to assist in the development of the largest, most complex aircraft ever pursued by the company. As a U.S. airframe manufac turer, Cessna had full access to the research, personnel, and facilities of NASA. For instance, Langley's one-of-a-kind Transonic Dynamics Wind Tunnel proved extremely valuable. The tunnel has a 16-foot square test section and is capable of operating at Mach numbers up to 1.2. Along with gathering data on the private jet's wing design, the facility also helped in measuring the unsteady aerodynamic pressure from air loads on the new business jet's wing design. The wind tunnel data were used to validate Cessna's flutter analysis.
business plane benefited by NASA wind tunnel research, work in composite
materials, and aerodynamic expertise.
Flutter is defined as an unstable, self-generated
oscillation of an airfoil and associated structure. If left unchecked,
flutter can practically shake an aircraft apart. While conventional,
lower-speed business jets test flutter boundaries in flight test, more
intensive testing was considered prudent for the new and unique Cessna
aircraft prior to flight testing.
A quarter-scale fuselage and wing model underwent weeks of exhaustive
flutter and unsteady pressure tests in the NASA tunnel. Langley's wind
tunnel was perfect for the job. According to Cessna's Engineering
Director, Ellis Brady, no other general aviation test model had ever
measured as much of this type of data. "These tests gave us an
added measure of assurance and confidence in the safety of this
aircraft," Brady notes.
NASA also collaborated on the Cessna project by providing
computational time on its number-crunching Cray computer. This aspect of
testing was particularly useful to Langley engineers because the
business jet's high-speed wing provided invaluable correlative test data
for NASA computer programs used for evaluating transonic structural
Langley also aided Cessna in the acoustics area. Research conducted
at Langley, and at Virginia Polytechnic Institute and State University
under a NASA grant, contributed to the design and implementation of the
business jet's active noise control system. This approach reduces or
nulls out noise by introducing a countering soundwave at the same level
and frequency, but shifted out of phase.
Much less directly, Langley also contributed to the aircraft's
lightweight structure. Advanced composite material technology applied to
the Cessna craft can be traced to pioneering Langley research in
developing fiber-resin material systems. Over two decades of study in
this area have yielded a dependable database, at the same time
establishing that composite materials, versus aluminum, can be safely
used on aircraft.
The collaboration between Cessna and NASA was award-winning in many
ways. The aircraft was recognized as the top aeronautical achievement in
the United States for 1996, with Cessna receiving a prestigious Robert
J. Collier Trophy.
As the fastest commercially-built aircraft in the United States, only
one non-military aircraft presently in service worldwide is fastert--he
Concorde. The business plane combines cruising speed with true
intercontinental and transatlantic range. Taking just 67 months from
concept to design completion, the Cessna Citation X aircraft has already
accumulated several thousand flying hours, and is winging its way into
the record books.
|Winging its way across
a sky near you, Cessna's newest addition to private business jets tapped
NASA aeronautical research and technology development.
iTunes Gospel Rock Music
Rock version of
the Lord's Prayer
a unique find...