Abstract:
A wind shear warning system (10) monitors the flight path of an aircraft and wind shear (16) in the vicinity of the aircraft and generates an advisory or cautionary message (34) for the pilot based both on the magnitude (20, 22) of the wind shear and the flight path of the aircraft. When the aircraft is flying a normal flight path, a wind shear warning is generated only when relatively high negative wind shears are present. If the flight path of the aircraft is not normal, for example, if the aircraft is below the glide slope (18) or descending too rapidly (14), a cautionary alert is given at lower values of wind shear. The alert or warning (54) is selected to provide the pilot with information defining the nature of the hazard or potential hazard being encoutered.
Abstract:
A Coriolis rate sensor for determining both angular rate and linear acceleration with respect to three orthogonal axes. A first embodiment of the rate sensor (10) includes three pairs of accelerometers (26, 28 and 30) mounted on counter-rotating frame members (20, 22). The accelerometers are mounted with their sensitive axes antiparallel with each other, forming an acute angle with the common axis (40) about which the upper and lower frame members are counter-rotated back and forth in a dither motion. The upper and lower frame members are connected to a baseplate (12) by flex links (32), which are aligned radially about the axis. The flex links provide a relatively rigid support (in compression) between the frame members and the centrally disposed baseplate, yet readily permit counter-rotation of the two frame members. A link (56) prevents all but relative rotational movement between the frame members and baseplate. A pair of electromagnetic coils (42) and pole pieces (50) provide a sinusoidal driving force to counter-rotate the upper and lower frame members relative to each other to ensure that the upper and lower frame members are directly coupled to each other and to the baseplate. In a second embodiment of the rate sensor (100), eight accelerometers (102, 104, 106 and 108) are mounted with two pairs on an upper counter-rotating member and two pairs on a lower counter-rotating member.
Abstract:
A Coriolis rate sensor comprising first (120) and second (122) accelerometers with their force sensing axes parallel to a common sensing axis. The accelerometers (120, 122) are vibrated along arcs (16) in response to a periodic drive signal (150) at a first frequency, each arc being tangent to a vibration axis normal to the sensing axis. The accelerometer output signals (130, 132) are demodulated (104, 106) to determine angular rate, as well as to detect the phase shift between the drive signal (150) and the periodic components of the output signals (130, 132). In one arrangement, the detected phase shifts are used to drive a phase servo that tends to reduce the bias error caused by interaction between the phase shifts (160, 170) and misalignments (164, 174) of the accelerometers (120, 122) with respect to the sensing axis. In another arrangement, the phase shifts (160, 170) are used to calculate a bias term (178) for correcting the measured angular rate. A single accelerometer (14) embodiment is also described.
Abstract:
A guidance system for landing an aircraft is described which uses a source of signals identifiable with the aircraft and a ground station which is linked to the aircraft. Specifically, the ground station includes a receiver (51) which is connected to one or more pairs of antennas (52, 53, 54, 55) having a fixed, overlapping, directional sensitive pattern (52a, 53a, 54a, 55a) symmetrically located relative to the center of the landing path, a receiver and a processor (60) for measuring the relative sensitivity of the signals received at the antennas and for using the relative signal intensity to determine the location of the aircraft (61) relative to the center of the landing path.
Abstract:
A magnetometer sensor for a borehole survey. The magnetometer features a bobbin (30) made from a metal alloy such as copper-nickel, which has a very low magnetic permeability, on the order of 1.0001, which can be joined to a magnetic metal alloy, such as Permalloy, by welding, which can be treated by annealing at a temperature of 1500 degrees Fahrenheit and which has a thermal coefficient of expansion generally on the order of the magnetic alloy. In one particular embodiment, the magnetometer sensor comprises a strip of magnetic metal alloy wrapped around the aforesaid bobbin (30) to define a magnetic core, one excitation winding (36) wrapped around the core, a plastic frame (38) for carrying the magnetic core and excitation winding and at least one sense winding (50) wrapped around the frame, the core and the excitation winding.
Abstract:
A novel memory system (10) for use with aircraft which utilize warning and advisory systems such as ground proximity warning systems, and warning systems whose warning criteria are modifiable as a function of the topographical characteristics associated with specific geographical areas over which the aircraft is flying. In accordance with the invention topographical data for specific geographical regions is mapped into various individual memory devices (EPROM's 20-1 through 20-16) and powering only one device at a time by means of a decoder (40) whereby the power dissipation of the entire memory system is limited to that of only one memory device regardless of the number of memory devices in the system.
Abstract:
A system (10) for warning the pilot of a tactical aircraft in a tactical maneuver such as a dive of the point at which recovery must be immediately initiated to prevent the aircraft from descending below a minimum desired altitude. The system monitors and the altitude (16), descent rate (14) pitch angle (10) of the aircraft and the roll angle (34) of the aircraft, and issues a voice warning (30, 32) when recovery must be initiated. The system also includes means (10') to provide warnings of dangerous flight conditions during non-tactical or common route segments of a flight such as the take-off, landing and cruise segments of a flight. Circuitry (40) responsive to the arming of the weapons of the aircraft enables the tactical warning portion of the system and disables certain functions of the non-tactical portion of the system that may cause false warnings to be generated during tactical maneuvers.
Abstract:
A wind shear detection and alerting system (30) compares inertially derived accelerations (32, 34) with air speed rate (52) to provide a wind shear warning signal. Inertially derived accelerations are used instead of urely inertial accelerations because purely inertial systems generally require a vertical gyro. By utilizing angle of attack (alpha) and flight path angle (gamma) instead of pitch signal () in the calculation, no vertical gyro signal is required and the system will be responsive to vertical as well as horizontal shear conditions. An enhanced version of the system is also compensated for roll angle (O/), with the roll angle being derived from the rate of change of heading (psi) to avoid the need for a vertical gyro. The alerting system is capable of providing visual and aural warnings for a variety of wind shear conditions, such as, head shear, tail shear, head shear followed by tail shear and wind shear, trend. The warning system is also capable of providing a wind shear warning which is a function of the radio altitude (112) of the aircraft.
Abstract:
An aircraft flight data recorder housing (12) comprising a titanium alloy having a nominal composition of 15 weight percent vanadium, 3 weight percent chromium, 3 weight percent tin, and 3 weight percent aluminum with the balance being titanium and, within limitations, certain trace elements. The alloy is simultaneously hot formed and solution heat treated at temperatures on the order of 1400oF to 1500oF to fabricate the recorder housing (12).
Abstract:
A channel propagation simulator simulates a multi-diversity branch signal channel, which simulator uses in a preferred embodiment appropriate filter means, such as a plurality of tapped delay lines 11, 14, each capable of representing the impulse response of a diversity branch by means of correlated tap multipliers 12, 12A, 15, 15A . . . 15N, i.e., multipliers using correlated weighting signals 12', 12'A, 15', 15'A . . . 15'N as supplied from a matrix weighting correlator 19. The correlated weighted signals are combined for each diversity branch by suitable summation circuits 13, 16 to provide the diversity branch simulated outputs. By using correlated weighting signals, the simulator can more accurately reproduces the statistical behavior of a given communications link and verify that a given modem will satisfy the communication link specifications.