Flight evaluation of curved path MLS precision approaches in a Falcon 20 aircraft

A Falcon 20 aircraft belonging to the National Research Council (NRC) was used for the demonstration and evaluation of curved, segmented approaches using the Microwave Landing System (MLS) as a position sensor. A total of over 80 approaches flown by pilots from Transport Canada, the Department of National Defence and NRC confirmed that curved...

Torque and thrust from five-hole pressure probe measurements in the near slipstream of a propeller in compressible flow

A momentum analysis has been performed of the flow through a propeller in compressible flow, leading to integral expressions for torque and thrust in terms of local flow quantities such as flow angles, total pressure and Mach number, that can be derived from live-hole pressure probe measurements in the near slipstream. Such data, obtained for...

Support interference assessment in rotary experiments using the orbital platform concept

A flow visualization study was undertaken to investigate the unobstructed vortical flows generated by a cone-cylinder model in steady coning motion at high angle of attack. Using an orbital platform apparatus in a water tunnel, spatial measurements of vortex breakdown could be made with and without a rotary support sector downstream of the model...

Influence of the transonic doublet in the farfield of a lifting airfoil

A method is described for calculation of the transonic doublet and its inclusion in the farfield boundary condition of a finite-volume, time-stepping solver of the Euler equations. Also discussed is the assessment of the wall interference on a lifting, supercritical airfoil, which takes into account the doublet effect at wind tunnel walls.

The effects of tailwinds and control cross coupling on rotorcraft handling qualities for steep, decelerating instrument approaches and missed approaches

The expansion of the rotorcraft instrument flight envelope to allow steep, decelerating approaches to low speeds and altitudes will profoundly improve the utility of these vehicles. As a supplement to previously published investigations by the National Research Council of Canada in the Bell 205 Airborne Simulator, a research program was...

Measurements of wing and fin buffering on the standard dynamics model

This report is concerned with a wind tunnel investigation of wing and fin buffeting measured on the Standard Dynamics Model, a generic fighter aircraft configuration. Buffering was investigated for three modes - the fin bending mode and the wing symmetrie and anti-symmetrie bending modes. Testing was conducted in the IAR 2m x 3m low-speed wind...

Flow-field interference produced by an asymmetrical support strut

The interference flow field associated with an asymmetrical strut-mounted aircraft model was studied visually and through floor pressure measurements in a low-speed wind tunnel. The work was undertaken to shed light on the unsteady interference phenomena which are expected to prevail in oscillatory tests. The conditions under which direct...

Trajectories and stability of trailing vortices very near the ground

The behaviour of the trailing vortices of a Harvard aircraft used as the spraying vehicle during a set of experiments in aerial spraying over flat terrain for agricultural applications is discussed. The aircraft flew at a nominal attitude of 3 m (10 ft.) above ground at a speed of 56.7 m/s (110 knots). The stability and trajectory of a chosen...

Flight evaluation of curved MLS precision approaches in a Twin Otter Aircraft. Phase II

Phase II flight testing of curved, segmented approaches using a Microwave Landing System (MLS) was conducted on a Twin Otter aircraft belonging to the Canadian National Research Council's Institute for Aerospace Research (IAR). Precision guidance algorithms were developed for approaches with track angle changes exceeding 180°. Software...

A Kalman filter integrated navigation design for the IAR Twin Otter Atmospheric Research Aircraft

The IAR Twin Otter Atmospheric Research Aircraft has a continuing requirement for more accurate, inertially-based navigation data for both track recovery and the calculation of wind gust components. This navigational accuracy is necessary, not just during post-flight analysis, but also for realtime, in-flight guidance and wind computation....

Tracking performance requirements for rotorcraft instrument approaches to reduced minima. Phase 1: Preliminary study

The ability to track approach guidance (position and speed) to a low decision height (50 feet) when performing a steep instrument approach (6 to 9 degrees) in a rotoreraft clearly has a profound effect on the success of the approach. This report describes a preliminary attempl to define approach tracking standards for such approaches and...

A system for the digital image analysis of spray samples

A system for analyzing spray samples based on an electronic digitizing camera is described. The implementation and development of both the hardware and the software are discussed as well as the system performance. The system is capable of digitizing a sample into 1504 by 3008 pixels using 256 gray levels. The resolution is 10 μm at the image...

Turbulent boundary layer solution for two-dimensional compressible flow using mixing length and k-ε turbulence models

The continuity, momentum and energy equations for two-dimensional compressible turbulent boundary layers are solved using the k-ε turbulence model and the extended mixing length approach to calculate the shear stress terms. The finite difference equations are set up applying Keller's box scheme and the resulting tridiagonal matrix system is...

The effect of mass wind angle and erection technique on the aeroelastic behaviour of a cable-stayed bridge model

This report presents the results of an aeroelastic investigation into the dynamic response of a cable-stayed bridge to wind loading. The investigation is a continuation of an earlier study in which the deck response was investigated for nine deck sections in three different flows, (Ref. 1). The present investigation used a plate girder section...

Determination of handling qualities and display requirements for helicopter instrument flight during decelerating approaches to slow speeds

This paper discusses the most recent phase of a series of experiments performed jointly by the National Aeronautical Establishment and the United States Federal Aviation Administration under Memorandum of Agreement AIA-CA-31. The experiment was aimed at determining the helicopter instrument flight handling qualities requirements when performing...

The use of hot-film technique for boundary layer studies on a 21%thick airfoil

A heat transfer method of studying boundary layer flows over airfoils at transsonic test conditions has been investigated. The method employs very thin DISA hot-film gauges housing Constant Temperature Anemometer probes. Provided that the thickness dimension of the films remains less than the critical disturbances height for inducing transition...