AUTOMATIC FLIGHT CONTROL SYSTEM AFCS

1. AUTOMATIC FLIGHT CONTROL SYSTEM(AFCS) Presented by CW3 Martin Dadswell

2. PURPOSE: To develop the Student Instructor Pilot�s understanding of the Automatic Flight Control System NEED: You will be instructing this subject in the near future

3. TOPICS OF DISCUSSION Auto Flight Control System What is Stability? Stability Augmentation System TRIM Flight Path Stabilization Malfunction Analysis

4. WHAT IS AFCS? AFCS enhances the stability and handling qualities of the UH60 helicopter. It is comprised of four subsystems: Stability Augmentation System (SAS) Trim Systems Flight Path Stabilization (FPS) Stabilator (previously discussed)

5. WHAT IS STABILITY? Create a cool drawing on the dry erase board at this time.

6. Stability, in physics and engineering, the property of a body that causes it to return to its original position or motion as a result of the action of the so-called restoring forces, or torques, once the body has been disturbed from a condition of equilibrium or steady motion.

7. STABILITY AUGMENTATION SYSTEM (SAS) Purpose: Provide dynamic stability through short term rate dampening in the pitch, roll, and yaw axis. SAS systems: SAS 1 & SAS 2 Control Authority: Each SAS has 5% control authority, for a total of 10%

8. SAS 1 Components: SAS1 amplifier (analog) is located in the avionics compartment Three SAS actuators Input Signals: Pitch - rate gyro in the #1 stabilator amplifier Roll - pilot�s (number 2) vertical gyro Yaw - yaw rate gyro in the SAS1 amplifier additional signals - #1 filtered lateral accelerometer, airspeed transducer

10. SAS 2 Components: SAS2 is the SAS/FPS computer (digital) Three SAS actuators Input Signals: Pitch - rate gyro in the #2 stabilator amplifier Roll - roll rate gyro in the avionics compartment Yaw - yaw rate gyro in the avionics compartment

11. SAS 2 Additional Signals #1 & #2 filtered lateral accelerometer rate gyro in the #1 Stabilator amplifier air data transducer

13. TRIM SYSTEM Purpose: Provide a gradient force, maintains position of the cyclic and tail rotor controls Components: two electromechanical actuators, and one electrohydromechanical actuator TRIM REL switch on the cyclic, and pedal micro switches on the directional control pedals monitored by the SAS/FPS computer

14. TRIM SYSTEM Slip Clutches both the roll and yaw trim actuators incorporate slip clutches to allow the pilots to make control inputs should either actuator jam 13 pounds maximum in the roll 80 pounds maximum in the yaw

16. FLIGHT PATH STABILIZATION Purpose: Enhances static stability through long term rate dampening in the pitch, roll, and yaw axis. Components: SAS/FPS computer, and three trim actuators Control Authority: When coupled with trim, 100% control authority

17. FLIGHT PATH STABILIZATION The following systems must be on and operational for FPS to function 100% SAS 1 and/or SAS 2 Boost Trim Stabilator in AUTO mode enhances FPS operation, but is not required

18. FLIGHT PATH STABILIZATION FPS provides the following functions:

20. MALFUNCTION ANALYSIS

32. QUESTIONS ?