Blunt-leading-edge raked wingtips

US6089502A · kind A · utility

Assignee

• The Boeing Company · US

Inventors

• Larry L. Herrick · Redmond, US
• C. Byram Bays-Muchmore · Bellevue, US
• Michael S. Hoffman · Greenwich, US
• Louis L. LeGrand · Seattle, US
• Steven S. Ogg · Carlsbad, US
• Bernard P. Paul, Jr. · Lynnwood, US
• Kenneth D. Visser · Potsdam, US
• Stephen L. Wells · Bothell, US

Key dates

• Filing date: Jun 12, 1998
• Grant date: Jul 18, 2000
• Expiry date: Jun 12, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T50/10
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

An airplane having a fuselage (11), opposed main wings (12), and blunt-leading-edge raked wingtips (8) is provided. Each main wing includes an outboard end (9) and a leading edge (14) having an outboard end leading-edge nose and nose radius. One blunt raked wingtip (8) is located at each main wing outboard end (9) and includes a leading edge (20) swept back from the main wing leading edge (14). Each blunt raked wingtip (8) further includes a plurality of local airfoils each having a leading-edge nose radius and a chord. The nose radius is greater than about 2% of the local chord for the majority of the airfoils. The relative bluntness of the raked wingtips minimizes boundary-layer separation, drag associated with boundary-layer separation, and premature buffeting of the aircraft during low speed flight.