B. Connect static system hose to quick-disconnect fitting on rear of indicator case.
C. Slide indicator into position in instrument panel and secure with instrument mounting clamp.
CAUTION: INSERT INDICATOR INTO PANEL WITH CARE TO AVOID STRESS AND/OR
_______
DAMAGE TO CABLE AND PNEUMATIC HOSE.
D. Ensure panel light circuit breakers on main power circuit breaker panel P6 are closed.
E. Provide electrical power (Ref 24-22-00).
F. Ensure indicator illumination lights are on.
G. Perform vertical velocity indicator test (Ref 34-13-01 A/T), if desired.
H. Remove electrical power if no longer required (Ref 24-22-00).
EFFECTIVITY
ALL 10 Page 401 Apr 25/8734-13-01
INSTANTANEOUS VERTICAL VELOCITY INDICATOR - ADJUSTMENT/TEST
___________________________________________________________
1. Instantaneous Vertical Velocity Indicator Test
______________________________________________
A. General
(1) This test verifies proper installation of the vertical velocity indicator and is valid for either the captain's or first officer's indicator.
B. Referenced Procedures
(1) 24-22-00, Maintenance Practices (Apply Power)
C. Equipment and Materials
(1)
Pneumatic test unit
(2)
Pitot-Static System Probe Adapter - T856-660, or equivalent
D. Prepare for Test
(1)
Check that static source select valve is in NORMAL position.
(2)
Wet pitot-static probe adapter and install on upper left pitot-static probe to check captain's indicator or on upper right probe to check first officer's indicator.
CAUTION: ENSURE THAT PROBE ADAPTER IS FLUSHED WITH WATER OR OXY-
_______ TECH BEFORE INSTALLING OR ADAPTER MAY BE DAMAGED. A SOLUTION CONSISTING OF HALF PURE ETHYLENE GLYCOL AND HALF WATER SHOULD BE USED IN FREEZING TEMPERATURES DOWN TO -40.F. TO PREVENT PROBE MISALIGNMENT, TEST HOSES AND ADAPTERS MUST BE SUPPORTED IN SUCH A WAY AS TO ADD NO ETRA WEIGHT ON PROBE.
(3)
Temporarily seal static port S2 on lower right auxiliary pitot-static probe to check captain's indicator or static port S2 on lower left auxiliary probe to check first officer's indicator.
(4)
Connect static (vacuum) source in pneumatic test unit through the static control and cutoff valves to static port Sl on probe adapter.
E. Test Instantaneous Vertical Velocity Indicator
(1) Operate pneumatic test unit and static control valve to apply a vacuum equivalent to the ambient pressure minus 5.25 (|0.25) inches Hg or 5000 feet above airport altitude as indicated on captain's or first officer's indicator and on test gages.
CAUTION: RATE OF APPLICATION OR RELEASE OF VACUUM MUST BE
_______ EQUIVALENT TO A CLIMB OR DESCENT RATE OF LESS THAN 3000 FEET PER MINUTE.
(2)
When required vacuum has been reached and has stabilized in static system, close cutoff valve. Read and record immediately, indication on test gages. Accuracy of reading must be | 0.01 inches of mercury or | 20 feet of altitude.
(3)
After 1 minute, read and record indication on test gages. Vacuum must not have decreased by more than 0.07 inch Hg or an equivalent decrease of 80 feet in indicated altitude.
(4)
Release vacuum on static system, observing caution in step (1) above
EFFECTIVITY
ALL 01 Page 501 Apr 25/9734-13-01
(5) Remove adapter and seals from pitot-static probes and secure test
unit. CAUTION:_______VISUALLY CHECK EACH PROBE AND VERIFY NO COLORED TAPE REMAINS ON THE PROBES.
(6)
Check that panel light circuit breakers on main power circuit breaker panel P6 are closed.
(7)
Provide electrical power (Ref 24-22-00).
(8)
Check that indicator illumination lights are on.
(9)
Remove electrical power if no longer required (Ref 24-22-00).
NOTE: The adjustment screw range for zeroing the pneumatic vertical
____ velocity indicators is from 400 ft./min. down to 400 ft./min. UP. The instrument cannot be harmed by turning the zero adjustment screw too far in either direction. Recalibration of the IVVI is not necessary after the zero-adjustment is accomplished, but if it cannot be zeroed, the instrument must be recalibrated.
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