Drucella Andersen 
Headquarters, Washington, D.C.                                      
November 14, 1991
(Phone:  202/453-8613)

Don Haley 
Ames-Dryden Flight Research Facility, Edwards, Calif. 
(Phone:  805/258-3456)


RELEASE:  91-188
 
NASA F-16XL ACHIEVES FIRST SUPERSONIC FLIGHT LAMINAR FLOW   


   For the first time, a NASA research plane has demonstrated 
laminar (smooth) airflow over a significant part of an 
aircraft's wing while flying at supersonic speeds.  The 
experiment was an important step in a program that could 
increase the flight efficiency and reduce fuel consumption of 
future high-speed civil transports.

   Supersonic laminar flow occurred in a series of 28 flights 
with the
F-16XL at NASA's Ames-Dryden Flight Research Facility, Edwards, 
Calif.  The aircraft mounted a suction device, or glove, to 
remove turbulent air moving over a test area on the upper wing 
surface.  Rockwell International, El Segundo, Calif., designed 
the glove.  It was installed on the aircraft by Fiberset, 
Mojave, Calif.

   Current aircraft have turbulent airflow over a large part of 
their wings.  Aerodynamic drag from this turbulence lowers 
aircraft flight performance and fuel efficiency.  Reducing the 
turbulent layers of air produces laminar flow that aircraft 
designers say would yield considerable fuel savings in a 
commercial-size transport, even with the added weight of an 
active suction system built into the wings.

   "We got very good results," said Marta Bohn-Meyer, 
Ames-Dryden's laminar flow project manager.  "It's something 
that has never been done before at supersonic speeds.  Now we 
can begin building a data base for research that could apply to 
a future high-speed civil transport."


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   The experimental titanium wing section on the F-16XL's left 
wing, commonly called an active (suction) glove, draws off  
most of the turbulent surface air through millions of tiny 
laser-cut holes.  A foam and fiberglass fairing blends the 
raised glove shape into the wing's upper surface.  The test 
section and fairing covers about 40 percent of the top of the 
wing and about 50 percent of its leading edge.

   Researchers confirmed that laminar flow existed over a 
significant part of the test section at speeds up to almost 
1200 mph and altitudes above 50,000 feet. The instrumented area 
is now being expanded and future test flights will study the 
flow characteristics over a larger part of the glove.

   Data from the F-16XL flights will help engineers at NASA's 
Langley Research Center, Hampton, Va., design a much larger 
experimental device that should achieve laminar flow over more 
than half an aircraft's wing.  It will be flown on another 
F-16XL at Ames-Dryden in the second phase of NASA's supersonic 
laminar flow research program through late 1995.

   The F-16XLs, whose delta-wing design and sustained 
supersonic speeds make them excellent testbeds for laminar flow 
research, are on loan to NASA from the U.S. Air Force.  The 
initial flight program took place under a cooperative agreement 
between NASA and Rockwell.  The second phase will be managed by 
Langley Research Center, with flight research at Ames-Dryden.   
                                                     -end-

EDITORS NOTE:  A photo is available to media representatives to 
illustrate this release by calling 202/453-8375.

Color:  91-HC-731          B&W:  91-H-831