Table 1 Stall Detection Maintenance and Operational Procedure

1. 
   Connect the pressure outlet of one pitot/static test set to the right pitot head, and the pressure outlet of the other test set to the operative wing stall detector vent.
   
2. 
   Confirm that No.6 static vent orifices on each static vent plate are clear of obstruction.
   
3. 
   Energize PE busbar.
   
4. 
   At the pitot head connection, apply sequentially the pressure (P) values given in Table 2, and in each case slowly increase pressure (V) to the stall detector vent until the stick shaker motor operates. Note V pressure at each point.
   
5. 
   Verify that V pressures meet requirements of Table 2, and then release pressures.
   

Table 2 provides a V/P ratio of 0.71 ± 0.02 on increasing pressure, when checked using Millimeter(s) (mm) water.

When A.S.I. gauges (calibrated in knots) are used as alternative to mm water gauge, the readings will not provide the same ratio as mm water to knots as conversion is not linear. Reference Check Pressures Table 2.

6. 
   Remove test set connection from pitot head and apply increasing pressure to stall detector vent until stick shaker motor operates. Maintain this vent pressure, reconnect test set to pitot head and apply increasing pressure (P) until warning system cuts out. Verify that, at cutout, the pressure (P) was between 76.5 and 86.0 mm water (70 ± 2 knots). Release pressures.
   
7. 
   Disconnect and remove test sets.
   
8. 
   De-energize busbar.
   

1. 
   Ensure power is removed from aircraft.
   
2. 
   To bypass LH Wing Flap microswitches:
   

• 
  Remove 2nd (from the rear) overwing access panel on LH side, using quick release fasteners.
  
• 
  Locate terminal block JBA, remove nut from JBA8, and remove the wire marked A8JB:W1:55:W1:JD3L. Stow wire to safely isolate the 15/45 Flap LH microswitch.
  
• 
  Remove nut from JBA7, and remove the wire marked A7JB:W1:55:W1:P1N from JBA7 and place on JBA8. This isolates the 0 Flap LH microswitch and provides 28V to the SSU 1.
  
• 
  Replace nuts on JBA7 and JBA8 terminal blocks and replace overwing access panel.
  

• 
  Remove 2nd (from the rear) overwing access panel on LH side, using quick release fasteners.
  
• 
  Locate terminal block KB, remove nut from KB8, and remove the wire marked 8KB:W2:55:W2:KD4L. Stow wire to safely isolate the 15/45 Flap RH microswitch.
  
• 
  • Remove nut from KB7, and remove the wire marked 7KB:W2:55:W2:P2N from KB7 and place on KB8. This isolates the 0 Flap RH microswitch and provides 28V to the SSU 2.
  
• 
  • Replace nuts on KB7 and KB8. terminal blocks and replace overwing access panel.