Details:

Personal Author:
Garodz, Leo J. ; Clawson, Kirk L.
Garodz, Leo J. ; Clawson, Kirk L. Less -
Corporate Authors:
Air Resources Laboratories
NOAA Program & Office:
OAR (Oceanic and Atmospheric Research)ARL (Air Resources Laboratory)
Description:
The number of large wing-mounted twin-engine jet transport aircraft in operation in the Nationa Airspace System (NAS) has significantly increased over the past few years. Very little is known about the vortex wake characteristics of these aircraft, particularly in takeoff and landing configurations. Since aircraft classification and Air Traffic Control (ATC) separation criteria in terminal area flight operations are based primarily on the aircraft vortext wake hazard, the FAA undertook a flight test program in the fall of 1990 to investigate the vortex wakes of the Boeing 757-200 and 767-200. The tests were conducted at the NOAA vortex test facility near Idaho Falls, Idaho. This report presents the results of the flight tests using the tower flyby technique. Included are characterizations of vortex wakes as a function of aircraft configuration and performance, and ambient atmospheric ocnditions. Very high vortext tangential velocities were created by the B757 aircraft, with the most intense vortext measured at 326 feet per second (fps). Vortext velocities generated by the B757 were approximately 50% higher than those of the B767 at similar vortex ages younger than 60 seconds. The oldest vortices generated by the B757 were much younger than those generated by the B767, and were 84 and 135 s, respectively. The most intense vortices were generated under stable or near-neutral atmospheric conditions. Richardson Number, air temperature gradient, and wind speed were good general indicators of the Vθmax-vortex age envelope. The 3° glide slope did not produce vortices that were statistically significantly greater in intensity. The Hoffman-Joubert logarithmic model adequately predicted vortext velocity profiles in which Vθmax was ≥ 50 fps. Further flight testing of the B757 was recommended as a basis upon which to review present ATC separation standards for this aircraft.
Keywords:
[+]
Vortex-motion Wakes (Aerodynamics)
Series:
NOAA technical memorandum ERL ARL ; 199 v2
Document Type:
Technical Memorandum
License:
https://creativecommons.org/publicdomain/zero/1.0/
Rights Information:
CC0 Public Domain
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:9bb1b67d05e62ef533dcd7cb91bb096448d9b9bca54ebe4ff77f425f8ed3def1
Download URL:
https://repository.library.noaa.gov/view/noaa/32466/noaa_32466_DS1.pdf
File Type:

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