United Technologies Corporation

Coltec Industries, Inc.

Chandler Evans Inc.

Nicholas D Lappos

Donald W Fowler

David H Sweet

James J Howlett

Charles E Greenberg

David M Walsh

Raymond D Zagranski

James B Dryfoos

James F Keller

Gregory P Wright

Richard P Meisner

Don L Adams

Stuart C Wright

Phillip J Gold

Mark A Johnston

Lorren Stiles

Charles W Evans

Robert W Rice

Joan A Edwards

An integrated fire and flight control (IFFC) system determines a ballistic firing solution based on the position of targets relative to a helicopter and also based on the type of weapons to be fired. An elevation command is determined based on the required change in helicopter attitude to achieve the ballistic firing solution that, combined with the estimated time required to perform the aim and release of weapons, provides an estimate of deceleration and velocity loss that will occur. A forward acceleration and velocity profile is determined based on the desire to make a symmetrical maneuver sequence involving a nose down acceleration to achieve the acceleration and velocity profile that will be canceled by the subsequent deceleration and velocity loss during the pitch up maneuver to the ballistic firing solution. The forward acceleration and velocity profile is used to provide a pilot with a forward acceleration command that directs the pilot to fly a nose down attitude until the required forward acceleration and velocity profile is achieved. Alternatively, the acceleration profile is coupled to a flight control wherein a pre-launch maneuver feedforward command signal is summed with a side arm controller control command signal as the primary input to a rotor mixing function and a pre-launch commanded rate signal is summed with a side arm controller commanded rate signal to provide the primary input to an automatic flight control system, to thereby automatically control the aircraft to assume an attitude necessary to achieve the desired forward acceleration and velocity profile. A terminal phase maneuver is calculated to thereby return the aircraft to the previous attitude, velocity hold, hover hold or position hold condition prior to commencement of the pre-launch maneuver.

Helicopter integrated fire and flight control having a pre-launch and

A fire control system (55) azimuth command and elevation command provides a flight control system attitude reference in response to operation of the flight control system in a coupled aiming mode. The coupled aiming mode is engaged in response to the continuous operation of a pilot switch (920) the azimuth command and elevation command being below respective threshold magnitudes (940, 941), and the operation of the fire control system (55). During operation in the coupled aiming mode, the azimuth command and elevation command replace the yaw attitude feedback error signal and pitch attitude error signal, respectively, as the aircraft attitude reference. During integration of the fire control system and the flight control system, the flight control system is made less sensitive to small pilot command stick inputs below a stick input threshold magnitude, so that small or inadvertent pilot commanded yaw and pitch maneuvers will not affect the yaw and pitch attitude reference commanded by the fire control system azimuth and elevation commands. However, intended pilot commanded yaw and pitch maneuvers (70) maintain full authority at all times.

Helicopter integrated fire and flight control having azimuth and pitch

An integrated time/limit exceedance cue system including a plurality of dedicated subsystem sensors, a processing unit, and a graphics generating/processing unit that is operative to generate an event dependent, time varying visual cue indicative of the exceedance of an established normal operating limit of a specific aircraft subsystem and operation thereof in a time critical exceedance condition. The time varying visual cue provides a relative indication of the elapsed time of operation of the specific subsystem in the time critical exceedance condition. The time varying visual cue is a symbolic image in the form of an outline, having a predetermined length, that defines a void region. The void region is proportionately opaqued or 'filled in' in correspondence with the elapsed time of operation of the specific subsystem in the time critical exceedance condition. The outline of the visual cue may be shaped and/or have a spatial orientation that is cognitively connected to the particular subsystem and/or to a symbolic image or display representing the specific generated status data provided by the dedicated subsystem sensors for monitoring the operation of the particular subsystem. The cue system may provide a corrective action cue in conjunction with the time varying visual cue that provides information as to the appropriate recovery procedure to restore the particular subsystem to operation within its established normal operating range.

Integrated time/limit exceedance cue system

During operation of an integrated fire and flight control (IFFC) system in a coupled aiming mode, the occurrence of a weapon (172), weapon mount (145) or sensor (146) reaching a constraint limit (210) indices a fade-in of a constraint limiting axis command signal (140) for a respective attitude axis as the aircraft attitude reference, replacing the flight control system attitude feedback error signal (111) for the respective attitude axis. The constraint limiting axis command signals provide the aircraft attitude reference only while the pilot manually depresses and holds an enable switch (920). The pilot command stick input (90) remains the primary input to the IFFC system to thereby provide override capability for pilot command maneuvers.

Helicopter integrated fire and flight control having constraint limiting

During operation of a flight control system in a coordinated area bombing mode, one pair in a group of pairs of fire control azimuth coordinate error signal and elevation coordinate error signals are faded-in as the aircraft yaw attitude reference and pitch attitude reference, respectively. Each pair is respectively indicative of the change in aircraft yaw attitude and pitch attitude for an aircraft reference axis to be aligned with an aiming line of sight. The aiming line of sight corresponds to a target location within a selected target area. A firing signal is provided in response to both the azimuth and elevation coordinate error signals being below respective threshold magnitudes, and the next pair in the group of pairs of azimuth and elevation coordinate error signals provide the aircraft attitude reference. A selected weapon is fired in response to the firing signal.

Helicopter integrated fire and flight control having coordinated area

During operation of a flight control system in a coupled aiming mode, wherein a fire control system (55) azimuth command and elevation command provide an aircraft attitude reference, a bank angle calculation function (1077) provides a bank angle signal to place the aircraft in a roll angle which results in a substantially coordinated turn. The bank angle signal is determined primarily as a function of an aiming line of sight heading rate for small azimuth commands, and is determined primarily as a function of aircraft heading rate for large azimuth commands. Additionally, the bank angle initially comprises a component as a function of aircraft lateral acceleration for driving aircraft lateral acceleration to zero, and after the aircraft assumes a roll attitude for turn coordination, the bank angle comprises a component as a function of aircraft side slip for driving aircraft side slip to zero. Automatic turn coordination is disabled if the pilot maneuvers the aircraft to avoid a coordinated turn, and is re-enabled if the pilot maneuvers the aircraft into a coordinated turn attitude. A rate feedback path (143) is provided during operation in the coupled aiming mode wherein aircraft yaw and pitch rate error signals are respectively replaced by the rate of change of the azimuth command and the elevation command. During operation in the coupled aiming mode, intended pilot commanded maneuvers maintain full authority at all times.

Helicopter integrated fire and flight control system having turn

A helicopter flight control system includes an automatic turn coordination system which provides a coordinating yaw command signal to the tail rotor of the helicopter. The system stores on command a trim attitude (e.g., signals indicative of bank angle, lateral ground speed, and lateral acceleration) about which automatic turn coordination is provided, thus providing the pilot with automatic turn coordination about attitudes other than wings level.

Automatic turn coordination trim control for rotary wing aircraft

The reference speed for a helicopter engine is incremented or decremented (237, 239) in dependence upon whether a specific range (miles per unit of fuel) has increased or decreased (236a) in a current period of time compared to the next preceding period of time, separated therefrom by at least 20 seconds (243, 244) to thereby set engine speed for minimizing use of fuel over distance traveled. Fuel is sampled only during steady flight (250-255).

Range maximizing, stable, helicopter cruise fuel conservation

The speed 54,56 of the free turbine 40 of a helicopter engine 22 is compared 134,138 with the speed 142,140 of the helicopter rotor 10 to indicate 106,108 a specific magnitude of autorotation and the deceleration 150 of the rotor above either one of two threshold magnitudes 220,222 (dependent on the magnitude of autorotation) is utilized 81,68,69 to increase fuel flow 72 to the engine according to a specific schedule 160,162 determined by the type of autorotation, in anticipation of rotor speed droop which would otherwise occur during recovery from the autorotation maneuver.

Helicopter control with multiple schedule rotor speed decay anticipator

A helicopter engine speed reference (66) is increased (113, 103-105) in response to heavy rotor loading (108). The reference speed is faded up (113, 104) at a rather rapid rate to 107% of rated speed (114). After a fixed time interval (118), reduced rotor loading (119) will cause the reference speed to be faded down slowly (120, 103-105) to rated speed (121). If torque exceeds 111% of rated torque (117), the reference speed is similarly faded down (120, 103-105).

Helicopter, high rotor load speed enhancement

Primary logic (116-128) for engine failure detection in a multi-engine aircraft is based on thresholds for engine torque (Q), gas generator speed (NG), power turbine inner stage temperature (T5), power turbine speed (NF), throttle setting (PLA), and throttle manipulation (PLADOT).

Detection of engine failure in a multi-engine aircraft

A device useful for verifying and setting the minimal resistive force setting of a collective stick in an aircraft using a collective stick is disclosed. The device is permanently attached to the collective stick and may be used by the pilot at any time. A method of setting the minimal resistive force setting on an aircraft using a collective stick is also disclosed.

Collective stick force-check device

The power required for a helicopter to hover is generated (14, 82) as the ratio of current operating power in forward flight (12, 77) determined (10, 73) from data relating operating power in forward flight to power required for hover for the aircraft. The power required to hover is compared (18, 83) with the maximum power available developed (16, FIG. 2; FIG. 3) by an engine model algorithm utilizing actual engine parameters. The comparison of maximum power to power required for hover is utilized to provide an indication (22) to the pilot. The viability of the indication is indicated by a 'ready' indication (26).

Helicopter power available to hover indicator

A fuel control (23) for an aircraft engine (10) employs super contingency logic (76) in response to low rotor speed of a helicopter (130) engine failure (131) or entry into an avoid region of a flight regime following engine failure (133) to alter (161, 166-169) limits on the gas generator (30) of a free turbine gas engine (10), whereby following engine failure or in periods of extreme power need, risk of stressing an engine to its failure point is undertaken in favor of acquiring enough power to avoid a certain crash.

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Milford, CT, United States of America

Nicholas D Lappos