Approximate method for determining the potential flow about an arbitrary aerofoil section in a two-dimensional finite stream with particular reference to large stream deflections

The flow about and on the surface of an aerofoil section in a finite stream and that about and on the surface of the same aerofoil section in an infinite symmetrical cascade are compared. It is shown that, for most cases of practical interest, the differences are small for stream deflection angles up to 90 degrees. Thus, the approximate flow...

The limiting surface temperature for spontaneous ingnition of fuel vapour/air mixtures in high speed aircraft

Whereas in the past the temperature of aircraft tank walls or structures enclosing fuel or vapour have been well below the spontanecus ignition temperature, as aircraft speeds approach Mach 3 this is no langer the case, and it becomes essential to know with certainty what are the risks of ignition. In this Note the critical spontaneous ignition...

Experimental thrust augmentation of a variable geometry, two-dimensional, central nozzle ejector

The model controlled method for the development of variable stability aircraft

A flight investigation of the effects of weathercock stability on V/Stol aircraft directional handling qualities

An investigation into the effects of various levels of weathercock stability on directional bandling qualities boundaries. defined in terms of angular rate damping versus control sensitivity. was undertaken using a V/STOL air borne simulator. The visual flight task performed by the pilots included hovering turns. in the presence of a sirnulated...

Results of recent investigations of v/stol control and response requirements using variable stability helicopters

Theoretical predictions, based on a pilot-aircraft system, of root mean square control response, root mean square heading response and minimum pilot gain were found to correlate well with pilot opinion assessments of the directional control and response requirements for flight of simulated V/STOL aircraft in turbulence. The comparisons were made...

Results of recent investigations of V/Stol control and response requirements using variable stability helicopters

Theor etical predictions I based on a pilot-aircr aft system, of root mean square contral response, root mean square heading response and minimum pilot gain were found ta correlate well with pilot opinion assessments of tbe directional control and response requirements for flight of simulated V/STOL aircraft in turbulence. Tbe comparisons were...

Note on the gust allevation factor for helicopters and autogyros

Expressions are given for estimating the nor mal acceleration response of helicopters and autogyros to the vertical turbulence component. A gust alleviation [actor analogous to that used for fixed-wing aircra[t is derived in terms of forward velocity and the vertical damping parameter. This gust a lleviation factor compares closely with that...

A flight investigation of laterial-directional handling qualities for V/Stol aircraft in low speed manoeuvring flight

This report is based on NRC, NAE LTR-FR-12, 1969 which was prepared for the United States Air Force by the Flight Research Section, National Aeronautical Establishment, National Research Council of Canada, Ottawa, under the sponsorship of the Air Force Flight Dynamics Laboratory, Research and Technology Division, Air Force Systems Command,...

A suggested method for estimating patch length from turbulence measurements using results from low altitude flights by a T-33 aircraft

When an aircraft encounters a patch of turbulence, the RMS turbulence intensity is usually constant only over a portion of the total period of exposure. A method is suggested for estimating the patch length as a function of intensity for turbulence encounters that have two or more regions of different turbulence intensities. It makes use of the...

Measurements of the statistical properties of atmospheric turbulence at altitudes below 1000 feet

Measured statistical properties of the three components of turbulence are presented for research flights at four altitudes below 1000 feet over flat terrain and two altitudes below 1000 feet over hilly terrain. The measured power spectral density distributions were closely approximated by the von Karman spectral shape. The derived scales of the...

Estimates of the lateral-directional stability derivatives of a helicopter from flight measurements

The lateral-directional stability derivatives for a medium-sized single rotor helicopter have been estimated for three different forward speeds. The analysis technique is based on a least squares quasilinearization method which employs a specially formatted parameter vector so that reliable a priori estimates can be used to assist convergence....

Modification of V/stol instrument approach geometry as a means of compensation for along-track wind effects

The influence of wind on the low speed approach and landing considerations for V/STOL aircraft poses new problems which, although neglected for conventional aircraft, may require specific solutions for these new designs. A novel method to allow for significant along-track wind effects, including shears, is proposed whereby the approach geometry...

Capabilities of the NRCC/NAE flight impact simulator facility

This report describes the NRCC/NAE Flight Impact Facility in which birdstrike tests on aircraft parts can be carried out. Technical Information is given on the capabilities of the pneumatic cannon used to fire real bird carcasses against stationary targets, and on the auxiliary apparatus and instrumentation available at the Facility.