Abbreviated Full-Scale Flight Test Investigation of the Lockheed L1011 Trailing Vortex System Using Tower Fly-By Technique
Abstract
A brief flight test program was conducted at the National Aviation Facilities Experimental Center (NAFEC) to investigate the time-history characteristics of the vortex system of a Lockheed L1011 airplane in terminal area-type operations using a 140-foot high instrumented tower. Vortex rotational flow velocities were measured by hot-film anemometers, vortex flow visualization--as outlined by tower-mounted smoke granades--was deocumented, and meteorological data was recorded. In addition, data on aircraft track, performance, and configuration were gathered. The test results show that: (1) the L1011 vortex system was more persistent and intense than that of other heavy jet transport (300,000 lb) aircraft tested by NAFEC, but did not persist for more than 2 minutes; (2) vortex dissipation was due primarily to vortex breakdown (bursting); (3) vortex core diameters were on the average about 5, 4, and 2 feet in diameter for the landing, approach, and takeoff configurations, respectively; (4) peak recorded tangential velocities, were 126, 135, and 224 feet per second for these same respective configurations; (5) vortex lateral movement in-ground effect was approximately (pi/6.6)b, above ground level; and (6) average vortex descent velocities approached 6 feet per second out of ground effect. Color illustrations reproduced in black and white.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1976
- Accession Number
- ADA028095
Entities
People
- Leo J. Garodz