markf%Nosc@usiiden.UUCP (07/18/85)
From: <crash!usiiden!markf@Nosc> NASA will begin a series of simulated airline flights to operationally test new techniques designed to help smooth the air flow over aircraft wings. * Previously reseach has shown that smooth or laminar air flow can reduce aerodynamic drag from 25 to 40 percent under laboratory conditions and could provide significant fuel savings. However, in actual flight, laminar flow can be disrupted and distributed by insects, ice and other obstructions adhering to the leading edges of an aircraft's wing. * NASA Ames-Dryden Flight Research Facility, Edwards, Calif. has installed on its business sized JetStar aircraft two experimental laminar flow control devices incorporating techniques to help prevent leading edge contamination. * The simulated airline service flights will be flown in widely separated areas of the U.S. to experience a wide variety of contaminant conditions. * The JetStar will be based at various NASA installations and at commercial airports and will fly in and out of different airports to obtain information on various takeoff and landing situations that might affect the test articles. NASA will conduct the simulated airline service flights just as an airline would under normal air traffic rules and regulations. * While based at the different airports to obtain information on various takeoff and landing situations that might effect the test articles. NASA will conduct the simulated airline service flights just as an airline would under normal air traffic rules and regulations. * While based at the different installations throughout the country, researchers plan up to four flights each day during a 2-week period to gather as much information as possible on performance of the test articles. * The two leading edge test articles, one installed on each wing of the JetStar, incorporate insect and ice protection with laminar flow control. Tests conducted on the JetStar in 1976 showed that the leading edge could be kept free of insects if it was kept wet while encountering them. * The test article installed on the left wing uses suction through 27 0.003 inch spanwise slots on the upper and lower surface to maintain laminar flow. A propylene glycol methyl ether (PGME)/ water mixture is discharged through several slots at the wing leading edge and flows back over the wing for insect impact protection. This article was manufactured for NASA by Lockheed-Georgia. * The test article on the right wing uses suction through approximately 1 million 0.0025 inch diameter holes in the titanium skin to maintain laminar flow on the upper surface of the article. For insect impact protection, a shield is extended much like a wing leading edge flap on commercial transports. The shield is retracted at 6,000 feet altitude. Spray nozzles behind the shield can be used to spray the PGME/water mixture on the test article for additional protection. * For ice prevention during winter conditions, glycol is forced through the right wing's porous metal section of the shield leading edge in additon to the PGME/water spray. This article was manufactured for NASA by McDonnell-Douglas. * Since the simulated airline service flights are planned to approximate commercial flights as closely as possible, NASA officials are meeting with commercial airline officials to define what test conditions they would like to see flown and will incorporate the results of these discussions into flight planning. Researchers also are contacting entomologists in areas of the country that the JetStar will fly to determine the insect activity in each area. * The JetStar is configured as a "flying control room" with test instrumentation aboard. There are three consoles with data displays for researchers, who also have the ability to adjust the suction on the test articles if conditions warrant. * The JetStar will carry the Knollenberg probe, mounted atop the aircraft, to precisely measure the number and size of ice and water particles encountered in flight. A charge patch, located on the pylon that holds the probe, measures the static electric charge caused by particles in the air rubbing across the patch surface and gives a qualitative measure of ice and water particles. Correlation of the probe and patch data could calibrate the charge measurements in a simple cockpit display. Pilots could use the display to detect ice particles. * The first series of operational flights is presently scheduled for mid July. The JetStar will fly in and out of Hartsfield Airport, Atlanta, Ga. * The program is a cooperative effort with NASA's Langley Research Center. * From Debra J. Rahn Headquarters, Washington, D.C. and Nancy Lovato Ames Dryden Flight Research Facility, Edwards, Calif. * ----------------------------------------------------------------- correction -> a recent posting on the net concerning proposals for Commercial Development of Space was from Northeastern in Boston not Northwestern which is in Chicago.