The airspeed of an airplane is determined by means of a device which includes an upstream cylindrical member and a downstream disc-like member spaced from said cylindrical member by a predetermined distance. Oscillations are produced in the air which passes around the cylindrical and disc structures and the frequency of the oscillations are measured. The frequency of the oscillations is directly related to the velocity of the fluid thus providing a direct determination of airspeed. The altitude ...

An indication of altitude variation about a preselected altitude is provided from a real time altitude information input signal in response to an altitude alert control signal which is proportional to a pair of complementary sinusoidal functions, sine and cosine, of the altitude variation. The uncorrected altitude information and the preselected altitude information are both fed to fine and coarse transolvers which each provide the sine and cosine functions of the angular equivalent of the altit...

The airspeed of an airplane is determined by means of a device which includes an upstream cylindrical member and a downstream disc-like member spaced from said cylindrical member by a predetermined distance. Oscillations are produced in the air which passes around the cylindrical and disc structures and the frequency of the oscillations are measured. The frequency of the oscillations is directly related to the velocity of the fluid thus providing a direct determination of airspeed. The altitude ...

A streamlined super-pressure balloon, in a substantially collapsed prelaunch condition, ascends vertically expanding to superpressure at float altitude. The weight distribution of the balloon envelope and payload maintains the center of gravity below the center of buoyancy and the changing geometric relationship between the center of gravity and center of buoyancy is such to effect rotation of the balloon from a vertical ascent attitude to a horizontal flight position at float altitude.

An altitude control system for guiding a submarine vehicle in such manner to search for and hunt along a reference altitude above the sea floor having a sonar range signal generator, a vehicle pitch signal generator, an adjustable reference altitude voltage source, and a series-connected summing amplifier and direct current level detector coupled to the aforesaid range and pitch signal generators and said reference altitude voltage source for automatically regulating the control surfaces of said...

An apparatus particularly suitable for use during aircraft landing and departures under conditions of minimum visibility wherein a signal is provided to the pilot of the aircraft when the aircraft has reached any one of a series of preselected altitudes. The apparatus consisting of an altitude sensing device adapted to provide an output pulse as the aircraft reaches each of a series of preselected altitudes, an actuating device capable of receiving the pulse, interpreting the pulse and activatin...

A surface based altitude measuring system for accurately measuring the altitude of an airborne vehicle consisting in part of two antennas for producing narrow fan beams which intersect in space, so that the altitude of an aircraft which flies through the two beams can be accurately determined. The radar echo which returns from the aircraft determines the slant range of the aircraft from the antennas, and the time interval between the interceptions of the two beams by the aircraft is related to t...

An altimeter system including a barometric sensing device, an output device including an encoder and a synchro transmitter effective to provide an electrical output corresponding to the altitude sensed by the sensing device, and a control device including a first device for registering a prescribed altitude and a second device for registering the altitude represented by the electrical output of the output device. Each of the first and second register devices includes a mechanical counter and a p...

In an altitude and vertical speed indicator for aircraft, an altitude indicator includes a graduated scale vertically mobile past a fixed marker and a vertical speed indicator includes a pointer rotatable about the point of intersection of a straight line segment through the fixed marker and a straight line segment through the pointer and pointing towards the mobile scale. The angle defined by the fixed marker and the pointer is representative of the vertical speed value.

Embodiments of the invention provide a method and apparatus for indicating aircraft height relative to an obstruction in a terrain awareness warning system. The method includes receiving data indicative of geographic features of an obstruction, lateral distance of the geographic feature from an aircraft, height and flight path of the aircraft, calculating a projected height of the aircraft at the location of the obstruction using the data, generating a result signal, and displaying a colored ind...