Accession Number:

AD0872818

Title:

Buffet Characteristics of the Model F-4 Airplane in the Transonic Flight Regime.

Descriptive Note:

Final rept. Sep-Oct 69,

Corporate Author:

MCDONNELL AIRCRAFT CO ST LOUIS MO

Personal Author(s):

• Cohen, Marshall

Report Date:

1970-04-01

Pagination or Media Count:

245.0

Abstract:

A flight test program was carried out to study the transonic buffet characteristics of the Model F-4 airplane. There were two objectives, the first being to determine the ability of a group of specially installed instrumentation to predict initial airflow separation and pilot indication of buffet onset. This instrumentation included wingtip and pilot seat accelerometer, wing root bending moment strain gages, upper and lower wing surface static pressure taps with ability to measure dynamic characteristics at various chordwise and spanwise locations, total pressure rake behing the wing trailing edge flap, aileron and stabilator acutator rod axial strain gages, and wing tufts. The second objective was, using data determined from the above instrumentation, to analyze the effects of wing configuration changes on buffet characteristics in the transonic flight regime. There were seven wing configurations tested. These included wing leading edge maneuvering slats with three trailing edge flap positions, leading edge flaps deflected 8 degrees with the same three trailing edge flap positions, and clean configuration no high lift devices deflected. At each flight condition the aircraft was put through a wind-up-turn maneuver to angles of attack higher than where pilot indicated buffet onset. Author

Descriptors:

• *BUFFETING
• *JET FIGHTERS
• TRANSONIC CHARACTERISTICS
• FLIGHT TESTING
• FLOW SEPARATION
• INSTRUMENTATION
• AERODYNAMIC CONTROL SURFACES
• LEADING EDGES
• TRAILING EDGES
• ANGLE OF ATTACK

Subject Categories:

• Attack and Fighter Aircraft
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE