The Cool City Stability Augmentation System (SAS) is designed for light to medium sized helicopters to improve basic airframe stability and reduce the upsets encountered in turbulence.

Consisting of an analog computer, with internal solid-state rate sensors, two series actuators (pitch/roll), and an annunciator/switch; the SAS system works by detecting and counteracting high-rate perturbations. The series actuators, installed in the rotorcraft’s primary control tubes, are very high-rate, low authority, electromechanical actuators. The actuators operate with approximately 10% control travel authority and take less than a second to move full actuator travel. For unquestioned safety, the actuators have internal electrical and mechanical stops.

Unlike other systems on the market that use parallel servos for SAS functions, the Cool City SAS-100 system incorporates series actuators for SAS operation. The use of series actuators in the system is important because it results in the operation of the SAS being transparent to the pilot and does not provide adverse feedback into the cyclic stick that would be detrimental to the training environment.

Operation of the Cool City SAS System is approved throughout the full flight envelope, from start-up to shut-down. The SAS System improves rotorcraft safety by reducing pilot workload and fatigue, while improving the quality of ride for all occupants.

With Cool City’s building block philosophy, you may later add the two or three axis digital helicopter autopilot to complete your rotorcraft’s automatic flight control system; and…without a substantial loss of your initial investment.

Contact your nearest Cool City Avionics dealer to discuss how the SAS-100 can improve your flight environment.

SAS-100 System Diagram
SAS-100 System Diagram

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The Cool City Force Trim System is designed to give the pilots of light to medium-sized helicopters some “hands free” time to perform other activities, or just relax for a bit. The system holds the cyclic in its position at the time the system was activated by pressing a switch on the cyclic. It also reduces the pilot’s stress and fatigue, by giving him a few minutes of relaxation time.

Once activated, the system holds the cyclic in place using a force gradient system that provides a “force feel” as the control is moved away from its center “engage” position.

he system is light weight, less than 5 lbs. installed, and is upgradeable to most of our other products, including our full-function, 3-axis Autopilot/SCAS system,  the HFC-150.

The FT-100 is engaged and disengaged by using a switch mounted on the instrument panel. It can also be interrupted, by use of a convenient “Trim Release” switch mounted on the cyclic grip, for short-term maneuvering or re-centering.

FT-100 System Diagram

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The unique SASPlus (SFT-100) system combines a Stability Augmentation   System with a Force Trim System.

The SAS provides roll and pitch stabilization that improves the handling qualities of the helicopter, while being transparent to the pilot.  It increases basic aircraft stability by opposing low-amplitude upsets from any cause.  With the SFT-100 installed, the SAS function will reduce the amplitude of any turbulence upset and eliminate many of the smaller motions or disturbances. Most of the small upsets to the aircraft are not detected by the pilot, thus requiring no effort to react to them.

The Force Trim function gives the pilot an “extra hand” that holds the cyclic in place using a Force Gradient system that provides a “force feel” as the control is moved away from its center “engage” position.

The unique SAS+FT combination gives the pilot hands-free operation for short periods to perform other “housekeeping” activities, often without significant heading or altitude drift.

The SAS and Force Trim functions are engaged and disengaged by using a pair of switches in the panel-mounted controller. The FT function can also be interrupted by use of a convenient “Trim Release” switch mounted on the cyclic grip for short-term maneuvering or re-centering.

The SAS is FAA-approved for full-time operation throughout the flight envelope ….. from take-off to landing.

System weight is less than 13 pounds, installed.

SFT-100 (SASPlus) System Diagram

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The Cool City HAP-100 Helicopter Autopilot System is a two-axis (roll/pitch) rate/attitude based AP. The HAP-100 brings unparalleled performance and safety to light and medium-sized rotorcraft at a fraction of the cost of systems that were designed many years ago.

The HAP-100 provides a two-axis rate/attitude-based autopilot system, increasing the pilot’s ability to handle the workload extremes of the rotorcraft cockpit environment. Available modes of the HAP-100 include: HDG (heading mode), IAS (indicated airspeed), ALT (altitude hold), VS (vertical speed), LNAV (lateral navigation), and VNAV (vertical navigation).

In addition, an autopilot failure will still leave the pilot with the option of Force Trim mode to hold the cyclic in the position of engagement; therefore, the pilot still has the ability to remove his hands from the cyclic for a short period for other duties without the worry of the helicopter deviating from the intended path.

As designed, the Cool City HAP-100 will interface with essentially all models of installed attitude gyros, electronic flight instrument systems, and/or air data systems with outputs for the digital flight control system.

To learn about these, and other exciting attributes of the HAP-100, contact your nearest dealer.

HAP-100 System Diagram
HAP-100 System Diagram

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The Cool City HAP-150 Helicopter Autopilot System is a three-axis (roll/pitch/yaw) rate/attitude based AP. The HAP-150 brings unparalleled performance and safety to light and medium-sized rotorcraft at a fraction of the cost of systems that were designed many years ago.

The HAP-150 provides a three-axis rate/attitude based autopilot system, increasing the pilot’s ability to handle the workload extremes of the rotorcraft cockpit environment. Available modes of the HAP-150 include: HDG (heading mode), IAS (indicated airspeed), ALT (altitude hold), VS (vertical speed), LNAV (lateral navigation), and VNAV (vertical navigation).

The Yaw Damper engages with the autopilot; however, it may be operated alone or turned off, as the pilot desires. The Yaw Damper function also monitors collective inputs to provide rudder movement to offset collective changes.

In addition, an autopilot failure will still leave the pilot with the option of Force Trim mode to hold the cyclic in the position of engagement; therefore, the pilot still has the ability to remove his hands from the cyclic for a short period for other duties without the worry of the helicopter deviating from the intended path.

As designed, the Cool City HAP-150 will interface with essentially all models of installed attitude gyros, electronic flight instrument systems, and/or air data systems with outputs for the digital flight control system.

To learn about these, and other exciting attributes of the HAP-150, contact your nearest dealer.

HAP-150 System Diagram
HAP-150 System Diagram

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The Cool City HFC-100 Helicopter Flight Control System is the ultimate in two axis autopilot (AP) and stability control and augmentation systems (SCAS). Consisting of a two-axis (roll/pitch) rate-based SCAS and two-axis (roll/pitch) rate/attitude based AP, the HFC-100 brings unparalleled performance and safety to light and medium sized rotorcraft at a fraction of the cost of systems that were designed many years ago.
Included in the HFC-100, a rate-based Stability Control and Augmentation System improves basic rotorcraft stability and reduces the high-rate perturbations encountered in turbulence. The SCAS series actuators, installed in the rotorcraft’s primary control tubes, are very high-rate, low authority, electromechanical actuators. The actuators operate with approximately 10% control travel authority and take less than a second to move full actuator travel. For unquestioned safety, the actuators have internal electrical and mechanical stops.

Operation of the Cool City SCAS is approved throughout the full flight envelope, from start-up to shut-down, and is virtually transparent to the pilot. The SCAS System improves rotorcraft safety by reducing pilot workload and fatigue, while improving the quality of ride for all occupants.

In addition to the safety and ride-quality improvements of the SCAS, the HFC-100 provides a two-axis rate/attitude based autopilot system, increasing the pilot’s ability to handle the workload extremes of the rotorcraft cockpit environment. Although the SCAS and autopilot electronics are contained within a single box, the two systems are independent. Each has their own power inputs and internal power supplies; with a failure in one system not adversely affecting the remaining system. In addition, an autopilot failure will still leave the pilot with the option of Force Trim mode to hold the cyclic in the position of engagement; therefore, the pilot still has the ability to remove his hands from the cyclic for a short period for other duties without the worry of the helicopter deviating from the intended path.

As designed, the Cool City HFC-100 will interface with essentially all models of installed attitude gyros, electronic flight instrument systems, and/or air data systems with outputs for the digital flight control system.

To learn about these, and other exciting attributes of the HFC-100, contact your nearest dealer.

HFC-100 System Diagram
HFC-100 System Diagram

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The Cool City HFC-150 Helicopter Flight Control System is the ultimate in a three-axis autopilot (AP) and two-axis stability control and augmentation systems (SCAS). Consisting of a two-axis (roll/pitch) rate-based SCAS and three-axis (roll/pitch/yaw) rate/attitude based AP, the HFC-150 brings unparalleled performance and safety to light and medium sized rotorcraft at a fraction of the cost of systems that were designed many years ago.

Included in the HFC-150, a rate-based Stability Control and Augmentation System improves basic rotorcraft stability and reduces the high-rate perturbations encountered in turbulence. The SCAS series actuators, installed in the rotorcraft’s primary control tubes, are very high-rate, low authority, electromechanical actuators. The actuators operate with approximately 10% control travel authority and take less than a second to move full actuator travel. For unquestioned safety, the actuators have internal electrical and mechanical stops.

Operation of the Cool City SCAS is approved throughout the full flight envelope, from start-up to shut-down, and is virtually transparent to the pilot. The SCAS System improves rotorcraft safety by reducing pilot workload and fatigue, while improving the quality of ride for all occupants.

In addition to the safety and ride-quality improvements of the SCAS, the HFC-150 provides a three-axis rate/attitude based autopilot system, increasing the pilot’s ability to handle the workload extremes of the rotorcraft cockpit environment. Although the SCAS and autopilot electronics are contained within a single box, the two systems are independent. Each has their own power inputs and internal power supplies; with a failure in one system not adversely affecting the remaining system. In addition, an autopilot failure will still leave the pilot with the option of Force Trim mode to hold the cyclic in the position of engagement; therefore, the pilot still has the ability to remove his hands from the cyclic for a short period for other duties without the worry of the helicopter deviating from the intended path.

As designed, the Cool City HFC-150 will interface with essentially all models of installed attitude gyros, electronic flight instrument systems, and/or air data systems with outputs for the digital flight control system.

To learn about these, and other exciting attributes of the HFC-150, contact your nearest dealer.

HFC-150 System Diagram
HFC-150 System Diagram

View System Diagram PDF file