1. Functions of the Stabilator
Instructor:
CW2 Scott Paul Rogers

2. STABILATOR TLO: To reinforce basic system fundamentals
for the UH-60 IPC.

3. STABILATOR SYSTEM
The Stabilator is a variable angle of incidence airfoil
that enhances aircraft handling qualities in the pitch
axis. The system performs both static and dynamic
stability.

4. STABILATOR SYSTEM AMPLIFIERS POSITION INDICATORS ACTUATORS AIRSPEED
SENSORS
ACCELEROMETERS

5. STABILATOR ACTUATORS Identical Actuators Tail Pylon
Position the Stabilator
Screw Jack Drive
D/C ESS BUS (#1)
# 2 #1

6. STABILATOR AMPLIFIERS
Identical Amplifiers
Aft Overhead Cabin
Pitch Rate Gyros
Auto/ manual control
# 1
# 2

7. AIRSPEED SENSORS Airspeed transducer Air data transducer
Cockpit bulkheads
DC signal knts
Signal to Stab Amps
AIR DATA

8. LATERAL ACCELEROMETER
Bank to turn rate
DC signal to amplifier
Mounted in cabin

9. COLLECTIVE POSITION TRANSDUCERS
On mixing unit
Forward #1 amplifier
DC signal to amplifier #2 #1

10. POSITION INDICATORS

11. CYCLIC MOUNTED STABILATOR SLEW SWITCH

12. STABILATOR CONTROL PANEL

13. STABILATOR
5 FUNCTIONS

14. STABILATOR FUNCTIONS Align stabilator and main rotor down wash in low
speed flight to minimize nose-up attitude resulting
from downwash.

15. STABILATOR FUNCTIONS
Decrease angle of incidence with increased airspeed
to improve static stability.

16. STABILATOR FUNCTIONS
Provide collective coupling to minimize pitch attitude
excursions due to collective inputs from the pilot.

17. STABILATOR FUNCTIONS Provide side slip to pitch coupling to reduce
susceptibility to gusts or out of trim condition.

18. STABILATOR FUNCTIONS Provide pitch rate feedback to improve dynamic
stability

19. EMERGENCY PROCEDURES

20. AUTO MODE FAILURE
1. Cyclic mounted stabilator slew-up switch - Adjust if necessary to arrest nose down pitch rate.

21. AUTO MODE FAILURE
2. AUTO CONTROL switch - Press ON once.

22. AUTO MODE FAILURE If automatic control is not regained:
3. Manually slew stabilator - Adjust to 0 for flight above 40 KIAS or full down when airspeed is below 40 KIAS. The preferred method of manually slewing the stabilator up is to use the cyclic mounted stabilator slew-up switch.
4. LAND AS SOON AS PRACTICABLE.

23. AUTO MODE FAILURE If manual control is not possible:
5. STAB POS indicator - Check and fly at or below KIAS LIMITS shown on placard.
6. LAND AS SOON AS PRACTICABLE.

24. UNCOMMANDED NOSE DOWN 1. Cyclic - Adjust as required.
2. Collective - Maintain or increase.
3. Cyclic mounted stabilator slew-up
switch - Adjust as required to arrest
nose down pitch rate.

25. UNCOMMANDED NOSE DOWN
4. MAN SLEW switch - Adjust to 0 at 40 KIAS and full down at airspeeds below 40 KIAS.

26. UNCOMMANDED NOSE DOWN
5. LAND AS SOON AS PRACTICABLE.

27. UNCOMMANDED NOSE UP 1. Cyclic - Adjust as required.
2. Collective - Reduce as required.

28. UNCOMMANDED NOSE UP
4. MAN SLEW switch - Adjust to 0 at 40 KIAS and full down at airspeeds below 40 KIAS.

29. UNCOMMANDED NOSE UP
5. LAND AS SOON AS PRACTICABLE.

30. WARNINGS
If the airspeed fault advisory light is illuminated, continued
flight above 70 KIAS with the stabilator in the AUTO MODE
is unsafe since a loss of the airspeed signal from the remaining
airspeed sensor would result in the stabilator slewing full-down

31. WARNINGS If acceleration is continued or collective is decreased with
the stabilator in a trailing edge down position, longitudinal
control will be lost. The stabilator shall be slewed to 0
above 40 KIAS and full-down when airspeed is less than
40 KIAS.

32. WARNINGS Pressing the AUTO CONTROL RESET button after a
failure occurs results in the automatic mode coming on
for one second. If a hardover signal to one actuator is
present, the stabilator could move 4 to 5 in that one second
before another auto mode failure occurs. Subsequent
reset attempts could result in the stabilator moving to
an unsafe position.

33. WARNINGS If the stabilator AUTO mode repeatedly disengages during
a flight, flight above 70 knots is prohibited with the stabilator
in to AUTO mode.

34. QUESTIONS?