(7)  
Perform leakage test of auxiliary pitot-static system No. 2 (Ref 34-11-00).

 (8)  
Close MACH WARN circuit breaker on panel P12.

 (9)  
Provide electrical power (Ref 24-22-00).

 (10)
 Perform operational test of mach airspeed warning system (Ref 34-14-00).

 (11)
 Remove electrical power if no longer required (Ref 24-22-00).

 4.  Mach Airspeed Warning Test Switch - Removal/Installation________________________________________________________
 A.  General
 (1)  The mach airspeed warning test switch is located on the mach airspeed warning test module on pilots' overhead panel P5. The module also contains the overrotation test switch. The module has one connector on the rear.
 B.  Remove Test Switch
 (1)  
Open MACH WARN circuit breaker.

 (2)  
Remove control panel by releasing four quick-release fasteners.

 (3)  
Disconnect electrical connector from rear of test module.

 C.  Install Test Switch
 (1)  
Connect electrical connector to rear of test module.

 (2)  
Place module in proper location on overhead panel P5 and rotate the four quick-release fasteners.

 (3)  
Close MACH WARN circuit breaker on panel P12.

 (4)  
Apply electrical power (Ref 24-22-00).

 (5)  
Perform system operational test (Ref 34-14-00).

 (6)  
Remove electrical power if no longer required (Ref 24-22-00).

 5.  Mach Airspeed-Gear Down Airspeed Selector Switch -__________________________________________________ Removal/Installation____________________
 A.  General
 (1)  The mach airspeed-gear down airspeed selector switch is located on the main equipment center, next to the gear down dispatch airspeed warning switch.
 B.  Remove Mach Airspeed-Gear Down Airspeed Selector Switch
 (1)  
Open MACH WARN circuit breaker.

 (2)  
Raise switch guard.

 (3)  
Disconnect electrical wires from rear of switch. Note connections so new switch can be installed correctly.

 (4)  
Unthread attachment nut and remove switch.

 C.  Install Mach Airspeed-Gear Down Airspeed Selector Switch
 (1)  
Install switch and tighten attachment nut.

 (2)  
Connect electrical wires to rear of selector switch.

 EFFECTIVITY
 
 ALL  01 Page 203  Oct 10/7334-14-00
 (3)
Close switch guard.

 (4)
Close MACH WARN circuit breaker.

 D. Perform system operational test (Ref 34-14-00).
 EFFECTIVITY

 
 ALL  01 Page 204  Oct 10/7334-14-00
 MACH AIRSPEED WARNING SYSTEM - ADJUSTMENT/TEST
______________________________________________
 1.  General
_______
 A.  This section consists of an operational test and a system test. The operational test gives a quick checkout of mach warning test switch and warning clacker. The system test also tests mach airspeed warning switch over various ranges of altitude and airspeed.
 2.  Reference Procedures
____________________
 A.  12-11-01, Servicing
 B.  24-22-00, Maintenance Practices (Apply Power)
 C.  34-11-00, Maintenance Practices (Pressurization)
 3.  Operational Test - Mach Airspeed Warning System
_______________________________________________
 A.  General
 (1)  Successful completion of operational test assures proper operation of all electrical portions of warning system. Pressure and mechanical portions of airspeed switch are not checked except to verify that circuit is complete through the contacts on rocking shafts.
 B.  Test Mach Airspeed Warning System Operation
 (1)  
Provide electrical power (Ref 24-22-00).

 (2)  
On pilots' overhead panel P5, set RADIO MASTER BUS - ESSENTIAL switch to ON position.

 (3)  
On electrical circuit breaker panel P12, verify that MACH WARN circuit breaker is closed.

 (4)  
Verify that pitot-static system is at ambient pressure and no maintenance work is in progress.

 (5)  
Ensure that there is no clacking sound on flight deck.

 (6)  
On airplanes with supplementary fuel tanks, verify that at least one tank is not empty (Ref 12-11-01).

 (7)  
Verify that mach airspeed-gear down airspeed selector switch is in NORMAL VMO position.
　
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