STALL WARNING SYSTEM 1. DESCRIPTION A.

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1 STALL WARNING SYSTEM 1. DESCRIPTION A. Stall Warning System - Serials w/o Perspective Avionics The airplane uses an electro-pneumatic stall warning system. As the angle of attack increases and the airplane approaches an aerodynamic stall, the stagnation point moves lower on the leading edge causing low pressure on the upper leading edge to increase. As low pressure passes over the stall warning port located on the leading edge of the right wing, negative pressure is sensed by a pressure switch which activates the stall warning horn. The stall warning horn, located on the top flange of the LH center console rib, is a piezo-ceramic audio indicator. Serials & subs before SB 2X-27-15: When activated, the horn supplies a continuous 9 db, 200 Hz tone. Serials & subs after SB 2X-27-15: When activated, the horn supplies a continuous 95 db, 2000 Hz tone. The pressure switch, located on the mid-console LH side panel, is a normally open, diaphragm-operated switch. The switch is powered by 2 VDC supplied through the 2-amp STALL WARNING circuit breaker on the Essential Bus. B. Stall Warning System - Serials w/ Perspective Avionics and w/o FIKI The airplane uses an electro-pneumatic stall warning system. As the angle of attack increases and the airplane approaches an aerodynamic stall, the stagnation point moves lower on the leading edge causing low pressure on the upper leading edge to increase. Serials thru : As low pressure passes over the stall warning port located on the leading edge of the right wing, negative pressure is sensed by a pressure switch which activates the stall warning horn. The stall warning horn, located on the upper surface of the GIA #2 rack, is a piezoceramic audio indicator which, when activated, supplies a continuous 9 db, 200 Hz tone. Serials & subs, 22T-0001 & subs: As low pressure passes over the stall warning port located on the leading edge of the right wing, negative pressure is sensed by a pressure switch which provides a signal to the avionics system to activate the aural stall warning and enables the Crew Alerting System (CAS) to display a STALL annunciation on the PFD. The pressure switch, located on the mid-console LH side panel, is a normally open, diaphragm-operated switch. The switch is powered by 2 VDC supplied through the 2-amp STALL WARNING circuit breaker on the Essential Bus. C. Stall Warning System - Serials w/ FIKI The airplane uses an electro-mechanical lift transducer, mounted on the leading edge of the right wing. As the angle of attack increases, the stagnation point moves below the transducer, increasing the upward pressure on the spring loaded vane. The movement of the vane produces an electrical output that is sent to a stall warning computer located under cabin access panel CF3R. The stall warning computer provides a signal to the avionics system to activate the aural stall warning and enables the Crew Alerting System (CAS) to display a STALL annunciation on the PFD. The transducer is powered by exciter voltage supplied by the stall warning computer. The stall warning computer is powered by 2 VDC supplied through the 5-amp STALL WARNING circuit breaker on the Essential Bus. All Page 1

2 2. MAINTENANCE PRACTICES A. Stall Warning Horn - Serials w/o Perspective Avionics (See Figure 1) (1) Removal - Stall Warning Horn (a) Remove glareshield. (Refer to 25-10) (b) Remove MFD. (Refer to 31-60) (c) Disconnect stall warning horn electrical connector. (d) Serials & subs before SB 2X-27-15: Remove screws, washers, and nuts securing horn to console rib. Remove horn from airplane. (e) Serials & subs after SB 2X-27-15: Remove bolt and nut securing horn assembly mounting bracket to console rib. Remove horn assembly from airplane. (2) Installation - Stall Warning Horn (a) Serials & subs before SB 2X-27-15: Position horn to console rib and secure with screws, washers, and nuts. (b) Serials & subs after SB 2X-27-15: Position horn assembly mounting bracket to console rib at a 5 o ±5 o angle and secure with bolt and nut. (c) Connect stall warning horn electrical connector. (d) Install MFD. (Refer to 31-60) (e) Install glareshield. (Refer to 25-10) (f) Perform Operational Check - Stall Warning System - Ground. (Refer to ) (g) Perform Operational Check - Stall Warning System - Flight. (Refer to ) Page 2 Serials w/o Perspective Avionics

3 B. Stall Warning Horn - Serials thru w/ Perspective Avionics (See Figure 1) (1) Removal - Stall Warning Horn (a) Remove MFD. (Refer to 31-60) (b) Disconnect stall warning horn electrical connector. (c) Remove screws and nuts securing horn to GIA #2 rack. Remove horn from airplane. (2) Installation - Stall Warning Horn (a) Position horn to GIA #2 rack and secure with screws and nuts. (b) Connect stall warning horn electrical connector. (c) Install MFD. (Refer to 31-60) (d) Perform Operational Check - Stall Warning System - Ground. (Refer to ) (e) Perform Operational Check - Stall Warning System - Flight. (Refer to ) Serials thru w/ Perspective Avionics Page 3 31 May 2011

4 C. Stall Warning Pressure Switch - Serials w/o FIKI (See Figure 1) (1) Removal - Stall Warning Pressure Switch (a) Set BAT 1, BAT 2, and AVIONICS switches to OFF positions. (b) Pull STALL WARNING circuit breaker. (c) Remove LH mid-console circuit breaker trim panel. (Refer to 25-10) (d) Open circuit breaker panel. (e) Disconnect pressure switch electrical connector. (f) Disconnect stall warning line from pressure switch. (g) Remove screws, washers, and nuts securing pressure switch to console. Remove pressure switch from airplane. (2) Installation - Stall Warning Pressure Switch (a) Position pressure switch to console and secure with screws, washers, and nuts. (b) Connect stall warning line to pressure switch. (c) Connect pressure switch electrical connector. (d) Close circuit breaker panel. (e) Install LH mid-console circuit breaker trim panel. (Refer to 25-10) (f) Reset STALL WARNING circuit breaker. (g) Perform Operational Check - Stall Warning System - Ground. (Refer to ) (h) Perform Operational Check - Stall Warning System - Flight. (Refer to ) (3) Operational Check - Stall Warning System - Ground (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Suction Cup - Any Source Application of negative pressure. (b) On RH wing leading edge, clean area surrounding stall warning port. (c) Moisten suction cup and firmly press cup over stall warning port. (d) Activate stall warning pressure switch by sharply pulling suction cup directly away from stall warning port. Verify horn sounds audible warning signal. () Operational Check - Stall Warning System - Flight WARNING: The following Operational Check must be performed by a Cirrus Design authorized test pilot. (a) Remove access cap covering stall warning pressure switch located on lower portion of the left mid-console circuit breaker trim panel. (b) Perform Operational Check - Stall Warning System - Ground. (Refer to ) (c) In smooth air and at an altitude appropriate for stalls, place airplane in stall attitude. (d) Record airplane speed that stall warning signal sounds. (e) Record airplane speed that stall occurred. (f) Stall warning signal should sound 5 to 10 KIAS prior to stall. (g) If necessary, adjust stall warning pressure switch until stall warning signal sounds 5 to 10 KIAS prior to stall. 1 Rotating the adjustment screw 1 full turn clockwise will raise the speed at which the stall warning horn sounds by approximately 2 knots. 2 Rotating the adjustment screw 1 full turn counterclockwise will lower the speed at which the stall warning horn sounds by approximately 2 knots. Page Serials w/o FIKI

5 LH INBOARD CONSOLE RIB º ±5º Serials & subs w/o Perspective Avionics after SB 2X CENTER CONSOLE Serials & subs w/o Perspective Avionics before SB 2X FUSELAGE 1 2 GIA #2 RACK Serials thru w/ Perspective Avionics. Serials & subs, 22T-0001 & subs w/ Basic / Basic² Ice Protection, and/or Serials & subs w/ Perspective Avionics. FUSELAGE Serials & subs w/o Ice Protection, and Serials & subs w/o Perspective Avionics. 13 NOTE CABIN FLOOR Position bracket to rib at a 5º ±5º angle to the rib, and secure using bolt and nut. 7 9 LEGEND 1. Stall Warning Horn 2. Screw 3. Washer. Nut 5. Electrical Connector 6. Electro-Pneumatic Switch 7. Spring Clamp. Pneumatic Line 9. Tee Fitting 10. Tie Down 11. Fitting 12. Plug 13. Grommet 1. Bolt SR22_MM27_130E Serials w/o FIKI Figure 1 Stall Warning System- Serials w/o FIKI (Sheet 1 of 2) Page 5 31 May 2011

6 STALL WARNING ENCLOSURE Serials thru w/o Ice Protection. POROUS PANEL (RED) Serials thru w/ Ice Protection LEADING EDGE PANEL Serials thru , & subs, 22T-0001 & subs w/o FIKI. LEGEND. Nut. Pneumatic Line 10. Tie Down 15. Bulkhead Union 16. Nylon Insert 17. O-Ring 1. Olive SR22_MM27_167B Page 6 Figure 1 Stall Warning System - Serials w/o FIKI (Sheet 2 of 2) Serials w/o FIKI

7 D. Stall Warning Lift Transducer - Serials w/ FIKI (See Figure 2) (1) Removal - Stall Warning Lift Transducer (a) Set BAT 1, BAT 2, and AVIONICS switches to OFF positions. (b) Pull STALL WARNING circuit breaker. (c) Pull STALL VANE HEAT circuit breaker. (d) Remove screws securing lift transducer to wing. (e) Disconnect wing wire harness connectors from lift transducer pigtail connectors. (f) Remove lift transducer from wing. (2) Installation - Stall Warning Lift Transducer (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Sealant (Refer to 51-30) (Refer to 51-30) Seal perimeter of lift transducer. (b) (c) (d) (e) (f) Connect wing wire harness connectors to lift transducer pigtail connectors. Position lift transducer to wing and secure with screws. Apply sealant to perimeter of lift transducer. Reset STALL VANE HEAT circuit breaker. Test lift transducer heat. 1 On bolster panel, set PITOT HEAT switch to ON. CAUTION: The surfaces of the heated stall vane and plate are very hot. Do not touch or injury will occur. 2 Carefully feel for heat near lift transducer stall vane and plate. 3 Set PITOT HEAT switch to OFF. (g) Reset STALL WARNING circuit breaker. (h) Perform Operational Check - Stall Warning System - Ground. (Refer to ) (i) Perform Operational Check - Stall Warning System - Flight. (Refer to ) (3) Functional Test - Stall Warning Lift Transducer (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Ohmmeter - Any Source Measure resistance. (b) Remove wing access panel RW9. (Refer to 06-00) (c) Disconnect P2 connector from lift transducer. (d) Using ohmmeter, measure resistance of lift transducer components. 1 Measure pins A and E to verify case heater resistance equals 39.0 ± 5. ohms. 2 Measure pins B and C to verify mounting plate #1 resistance equals 9.2 ± 1. ohms. 3 Measure pins D and G to verify mounting plate #2 resistance equals 9.2 ± 1. ohms. Measure pins F and G to verify vane heater resistance equals 37.2 ± 5.6 ohms. (e) Connect P2 connector to lift transducer. (f) Install wing access panel RW9. (Refer to 06-00) Serials w/ FIKI Page 7

8 E. Stall Warning Computer - Serials w/ FIKI (See Figure 2) (1) Removal - Stall Warning Computer (a) Set BAT 1, BAT 2, and AVIONICS switches to OFF positions. (b) Pull STALL WARNING circuit breaker. (c) Remove access panel CF3R. (Refer to 06-00) (d) Disconnect electrical connector from stall warning computer. (e) Remove screws securing stall warning computer to fuselage floor. Remove stall warning computer from airplane. (2) Installation - Stall Warning Computer (a) If installing a new or different stall warning computer, perform Adjustment/Test - Stall Warning Computer Switch Settings. (Refer to ) (b) Position stall warning computer to fuselage floor and secure with screws. (c) Connect electrical connector to stall warning computer. (d) Reset STALL WARNING circuit breaker. (e) Perform Operational Check - Stall Warning System - Ground. (Refer to ) (f) Install access panel CF3R. (Refer to 06-00) (3) Adjustment/Test - Stall Warning Computer Switch Settings (a) Loosen screws securing switch access covers to existing and new computers. (b) Verify switch positions of existing computer match values entered in aircraft logbook. (c) Adjust SW and VR rotary switch settings on new computer to match existing computer switch settings. (d) Record switch settings in aircraft logbook. (e) On stall warning computers, rotate switch access covers to closed positions and tighten screws. () Operational Check - Stall Warning System - Ground (a) Acquire necessary tools, equipment, and supplies. Description P/N or Spec. Supplier Purpose Wooden Tongue Depressor - Any Source Fixture. (b) Remove access panel CF3R. (Refer to 06-00) (c) Loosen screws securing switch access cover to stall warning computer. Note: Switch access cover is marked with relative location of SW and VR rotary switches and LED indicators marked VAL (Valid), LTF (Lift Transducer Fault), AIR (Air Mode), and ICE (Ice Protection On). (d) (e) (f) (g) Set BAT1 switch to ON position. On stall warning computer, verify red LTF LED is not on. Set FLAPS switch to 100% position. On stall warning computer, verify that VAL and AIR LEDs are on (green). CAUTION: The surfaces of the heated stall vane and plate are very hot. Do not touch or injury will occur. Page (h) (i) On right wing, use wooden tongue depressor to gently apply upward pressure on tab of lift transducer and note stall warning horn sounds. Set FLAPS switch to UP position. Serials w/ FIKI

9 (j) (k) Set BAT1 switch to OFF position. On stall warning computer, rotate switch access cover to closed position and tighten screws. (l) Install access panel CF3R. (Refer to 06-00) (5) Operational Check - Stall Warning System - Flight WARNING: The following Operational Check must be performed by a Cirrus Design authorized test pilot. (a) Remove access panel CF3R. (Refer to 06-00) (b) Loosen screws securing switch access cover to stall warning computer. Note: Switch access cover is marked with relative location of SW and VR rotary switches and LED indicators marked VAL (Valid), LTF (Lift Transducer Fault), AIR (Air Mode), and ICE (Ice Protection On). (c) (d) (e) In smooth air and at an altitude appropriate for stalls, place airplane in stall attitude. Record airplane speed that stall warning signal sounds. Record airplane speed that stall occurred. Note: Stall warning signal should sound 5 to 10 KIAS prior to stall. (f) If stall warning signal does not sound 5 to 10 KIAS prior to stall, adjust the SW -position rotary switch. 1 Rotate clockwise, one detent at a time, to decrease speed at which stall warning horn sounds. 2 Rotate counter-clockwise, one detent at a time, to increase speed at which stall warning horn sounds. (g) On stall warning computer, rotate switch access cover to closed position and tighten screws. (h) Install access panel CF3R. (Refer to 06-00) Serials w/ FIKI Page 9

10 RH OUTBOARD POROUS PANEL CF3R AFT FLOOR 3 SWITCH ACCESS COVER LEGEND 1. Stall Transducer 2. Screw 3. Connector. Stall Computer SR22_MM27_299 Page 10 Figure 2 Stall Warning System- Serials w/ FIKI Serials w/ FIKI