| Title | B-747 Vortex Alleviation Flight Tests : Ground-Based Sensor Measurements and Addendum |
|---|---|
| Record ID | 42179 |
| Personal Name Creator |
Burnham, D. C. |
| Source | 188p. in various pagings |
| Corporate Creator | John A. Volpe National Transportation Systems Center (U.S.) |
| Publisher | United States. Department of Transportation. Federal Aviation Administration |
| Publication Date | 19820101 |
| Language | English |
| Abstract | In 1979, a series of B-747 flight tests were carried out to study the wake-vortex alleviation produced by deploying spoilers in the landing configuration. The alleviation achieved was examined by encounters of probe aircraft and by velocity profile measurements made by a ground-based Laser Doppler Velocimeter. For the first time these two types of measurements were analyzed in a way which allowed direct comparison; they showed reasonable agreement. The velocimeter measurements can be used to evaluate the vortex-induced rolling moment on any following aircraft at any separation. The spoiler alleviation was found to be insufficient to assure safe landings of small aircraft at reduced separation behind the B-747. The persistence of the alleviated vortices appears to be due to the wing-tip vortices which dominate the roll-up of the spoiler-alleviated wake. The addition of rapid roll inputs to the spoiler deployment produced much more effective alleviation, but at the expense of an unacceptable ride quality in the generating aircraft. |
| Public Note | Summary, Introduction, Test description, Data analysis, Results, Recommendations, References, Appendix |
| Rosap ID | dot:9405 |
| Rosap URL | https://rosap.ntl.bts.gov/view/dot/9405 |
| TRT Terms | Wakes; Vortices; Flight tests; Laser doppler velocimeters; Takeoff; Landing |
| General Subjects | Aircraft wake vortices; Vortex alleviation; Laser doppler velocimeter; Vortex decay; Takeoffs; Landings; Vortex generators |
| Classification | NTL - AVIATION - Air Traffic Control; NTL - AVIATION - Aviation Energy and Environment |
| Geographical Coverage |
United States |
| Report Number | DOT-TSC-FAA-81-19; FAA-RD-81-99 |
| Availability | Volpe National Transportation Systems Center, Technical Reference Center |
| Resource type | Tech Report |
| URL | https://ntlrepository.blob.core.windows.net/lib/42000/42100/42179/DOT-TSC-FAA-81-19.pdf |
| Alternative URL | https://ntlrepository.blob.core.windows.net/lib/42000/42100/42179/DOT-VNTSC-FAA-81-19_addendum.pdf |
| Format | |
| Database | NTL Digital Repository |