NASA Scientific and Technical Aerospace Reports

incidents, study air traffic control process improvement, validate the current U.S. air defense posture and, conceivably, many
more applications.
Derived from text
Surveillance; Data Bases; Data Processing; Images; Remote Control
05
AIRCRAFT DESIGN, TESTING AND PERFORMANCE
Includes all stages of design of aircraft and aircraft structures and systems. Also includes aircraft testing, performance and evaluation,
and aircraft and flight simulation technology. For related information see also 18 Spacecraft Design, Testing and Performance and 39
Structural Mechanics. For land transportation vehicles see 85 Technology Utilization and Surface Transportation.
20060001710 Southampton Univ., UK
Practical Adaptive Noise Reduction in the Aircraft Cockpit Environment
Powell, G. A.; Darlington, P.; Wheeler, P. D.; IEEE International Conference on Acoustics, Speech, and Signal Processing
(ICASSP ‘87); Volume 1; 1987, pp. 6.2.1-6.2.4; In English; See also 20060001583
Contract(s)/Grant(s): A94B/3594; Copyright; Avail.: Other Sources
This paper presents some preliminary results from adaptive noise cancellation experiments performed in a fighter aircraft
cockpit simulator. The sound field and noise levels used in the experiment were very much more realistic than those used in
previously reported experiments and the adaptive noise cancellation was performed in real time, using man mountable, Texas
instruments TMS 320 based hardware. The results confirm earlier assertions and indicate that generally, software and ‘off line’
simulations have yielded optimistic results.
Author
Cockpit Simulators; Fighter Aircraft; Noise Reduction
20060001770 Northrop Grumman Corp., El Segundo, CA USA
AFRL/NASA Shaped Sonic Boom Experiment Flight Test Program. Delivery Order 0021: Origins and Overview of the
Shaped Sonic Boom Demonstration Program
Pawlowski, Joseph W.; Graham, David H.; Boccadoro, Charles H.; Coen, Peter G.; Maglieri, Domenic J.; Jan. 1, 2005; 41 pp.;
In English; Original contains color illustrations
Contract(s)/Grant(s): F33615-00-D-3054-0021; Proj-A03T
Report No.(s): AD-A440153; AFRL-VA-WP-TP-2005-300; No Copyright; Avail.: Defense Technical Information Center
(DTIC)
The goal of the DARPA Shaped Sonic Boom Demonstration (SSBD) Program was to demonstrate for the first time in
flight that sonic booms can be substantially reduced by incorporating specialized aircraft shaping techniques. Although
mitigation of the sonic boom via specialized shaping techniques was theorized decades ago, until now this theory had never
been tested with a flight vehicle subjected to actual flight conditions in a real atmosphere. The demonstrative success, which
occurred on 27 August 2003 with repeat flights in the supersonic corridor at Edwards Air Force Base, is a critical milestone
in the development of next-generation supersonic aircraft that could one day fly unrestricted over land and help usher in a new
era of time-critical air transport. Pressure measurements obtained on the ground and in the air confirmed that the specific
modifications made to a Northrop Grumman F-5E aircraft not only changed the shape of the shock wave signature emanating
from the aircraft, but also produced a ‘flat-top’ signature whose shape persisted, as predicted, as the pressure waves propagated
through the atmosphere to the ground. This accomplishment represents a major advance towards reducing the startling and
potentially damaging noise of a sonic boom. This paper describes the evolution of the SSBD program, including the rationale
for test article selection, and provides an overview of the history-making accomplishments achieved during the SSBD effort,
as well as the follow-on AFRL/NASA Shaped Sonic Boom Experiment (SSBE) Program, whose goal was to further evaluate
the characteristics and robustness of shaped boom signatures. The report includes 23 briefing charts that summarize its content.
DTIC
Acoustic Properties; Flight Tests; Noise Reduction; Shapes; Signatures; Sonic Booms; Supersonic Aircraft
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