Flight Investigation of the Low-Speed Characteristics of a 45 deg Swept-Wing Fighter-Type Airplane with Blowing Boundary-Layer Control Applied to the Leading- and Trailing-Edge Flaps

A flight investigation has been conducted to study how pilots use the high lift available with blowing-type boundary-layer control applied to the leading- and trailing-edge flaps of a 45 deg. swept-wing airplane. The study includes documentation of the low-speed handling qualities as well as the pilots' evaluations of the landing-approach characteristics. All the pilots who flew the airplane considered it more comfortable to fly at low speeds than any other F-100 configuration they had flown. The major improvements noted were the reduced stall speed, the improved longitudinal stability at high lift, and the reduction in low-speed buffet. The study has shown the minimum comfortable landing-approach speeds are between 120.5 and 126.5 knots compared to 134 for the airplane with a slatted leading edge and the same trailing-edge flap. The limiting factors in the pilots' choices of landing-approach speeds were the limits of ability to control flight-path angle, lack of visibility, trim change with thrust, low static directional stability, and sluggish longitudinal control. Several of these factors were found to be associated with the high angles of attack, between 13 deg. and 15 deg., required for the low approach speeds. The angle of attack for maximum lift coefficient was 28 deg

“Working the System”—British American Tobacco's Influence on the European Union Treaty and Its Implications for Policy: An Analysis of Internal Tobacco Industry Documents

Katherine Smith and colleagues investigate the ways in which British American Tobacco influenced the European Union Treaty so that new EU policies advance the interests of major corporations, including those that produce products damaging to health

A Flight Examination of Operating Problems of V/STOL Aircraft in STOL-Type Landing and Approach

A flight investigation has been conducted using a large twin-engine cargo aircraft to isolate the problems associated with operating propeller-driven aircraft in the STOL speed range where appreciable engine power is used to augment aerodynamic lift. The problems considered would also be representative of those of a large overloaded VTOL aircraft operating in an STOL manner with comparable thrust-to-weight ratios. The study showed that operation at low approach speeds was compromised by the necessity of maintaining high thrust to generate high lift and yet achieving the low lift-drag ratios needed for steep descents. The useable range of airspeed and flight path angle was limited by the pilot's demand for a positive climb margin at the approach speed, a suitable stall margin, and a control and/or performance margin for one engine inoperative. The optimum approach angle over an obstacle was found to be a compromise between obtaining the shortest air distance and the lowest touchdown velocity. In order to realize the greatest low-speed potential from STOL designs, the stability and control characteristics must be satisfactory

NACA Research Memorandums

Report presenting tests to determine the flight characteristics of an F-86A airplane equipped with an area-suction boundary-layer-control system on the flaps and to investigate the possible operational problems which may arise on a flight installation of boundary-layer control. Results regarding the airplane with slatted leading edge, suction requirements, airplane with suction flap and various leading-edge configurations, factors affecting flap lift increment, and operational characteristics of boundary-layer control are provided

NACA Research Memorandums

Report presenting a flight investigation to determine the low-speed flight characteristics of a 45 degree swept-wing fighter-type airplane with boundary-layer control on the trailing-edge flaps. The effectiveness of the flap with and without boundary-layer control was determined in conjunction with several slat modifications. The study also included low-speed flying qualities and a pilot evaluation of the operational use of the boundary-layer control system in landing approaches

NACA Research Memorandums

Report presenting tests to determine the flight characteristics of an F-86 airplane equipped with a blowing-type boundary-layer-control installation on the trailing-edge flaps. The effectiveness of the flap was determined in conjunction with slatted leading edges and an inflatable rubber boot on the leading edge. Measurements were made of lift, drag, flow requirements, and computations for take-off, climb, and landing