Drucella Andersen
Headquarters, Washington, D.C.                                        
February 12, 1992
(Phone:  202/453-8613)

Don Nolan
Ames-Dryden Flight Research Facility, Edwards, Calif.
(Phone:  805/258-3447)

Linda Ellis
Lewis Research Center, Cleveland
(Phone:  216/433-2900)


RELEASE:  92-23

NASA TESTS FIBER OPTIC SENSORS FOR AIRCRAFT CONTROL SYSTEMS


     Flight tests with a NASA research aircraft are exploring the 
potential 
of fiber optic sensors in critical aircraft flight control systems.  
Researchers 
believe fiber optics will improve flight control, engine 
performance and 
safety.

     Fiber optics have two potential advantages in flight control 
systems.  A 
light-conducting fiber optic cable weighs less and is smaller than 
electrical 
copper wire.  Fiber optics also are immune to electrical 
interference caused 
by lightning, radar and other strong radio sources that can disrupt 
a plane's 
electronic control systems. 

     The first NASA plane to fly with fiber optic sensors is the 
F-15 Highly 
Integrated Digital Electronic Control (HIDEC) aircraft at 
Ames-Dryden Flight 
Research Facility, Edwards, Calif.  Initial flights are evaluating 
the fiber optic 
sensor technology, installation methods and how the sensors 
function in 
typical aerial maneuvers. 

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     Two fiber optic sensors -- one to check engine speed and 
another to 
gauge engine turbine exhaust temperature -- have been successfully 
tested 
on the F-15.  The research is part of the Fiber Optic Control 
System 
Integration program managed by NASA's Lewis Research Center, 
Cleveland.  
The program is jointly funded by NASA and the U.S. Navy's Naval Air 
Systems 
Command. 

     "Our next step is to flight test multiple fiber optics on our 
F-18 
Systems Research Aircraft," said Dennis Bessette, F-18 Project 
Manager.  
"On that airplane, researchers already are installing fiber optic 
cables to 10 
sensors that we expect to test by the fall of 1992.  The sensors 
will monitor 
aircraft surface positions, pilot stick inputs, temperature, air 
pressure and 
nose wheel steering." 

     Bendix Engine Control Division of Allied Signal Aerospace Co., 
South 
Bend, Ind., developed the engine speed sensor.  The engine 
temperature 
sensor was produced by Conax Buffalo Corp., Buffalo, N.Y. 

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