barfield 1811GA Series User Instruction Manual

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barfield 1811GA Series User Instruction Manual Manual pdf 34 page image

56-101-00184 / 00185 Rev. I CH. 3September 24, 2014 Page 22 of 56Note: If the airspeed pointer indication increases, the leak is in the pitot system.If the pointer decreases, the leak is in the static system.(3) After the test completes, gradually open CROSSBLEED CONTROL (#8) CCW fully.(4) Return system to ambient, by gradually opening the PITOT VENT (#17). Take carenot to exceed vertical speed indicator range.(5) Once system has returned to ambient, open the PITOT VENT (#17) and theSTATIC VENT (#10) fully CCW. Disconnect the aircraft lines from the PITOT (#1)and the STATIC T (#6) ports.(6) Gradually open (CCW) the STATIC (#7) and PITOT (#19) controls to bleed offsupply tanks.Note: Vacuum or pressure supply may remain without causing adverse effect tothe T/S.(7) When PRESSURE GAUGE (#18) and VACUUM GAUGE (#9) have returned tozero, close the PITOT (#19) and STATIC (#7) controls fully (CW).F. Vertical Speed Indicator (VSI) OperationCaution: The VERTICAL SPEED INDICATOR is very delicate. When in use, alwaysmonitor the indication and operate the T/S valves carefully so that the fullscale reading of the T/S or the aircraft VSI (i.e., the climb indicator) is notexceeded.Note: The VERTICAL SPEED (#3) control is closed normally to separate the VSI (#4)from the STATIC system. The VSI function can be paired with the Static systemat any time by following these instructions. If the VSI is paired with the Staticsystem when the system is at a pressure other than ambient (i.e., static systemvented), a temporary altitude reading results until the VSI case pressureequalizes with the static system pressure.(1) Verify that the PITOT (#19) and STATIC (#7) controls are closed (CW).(2) While monitoring the VSI (#4), gently open (CCW) the VERTICAL SPEED (#3)control.Note: Do not exceed full-scale reading.(3) As the VSI case pressure equalizes wit the static system, the indicated rate willbegin to decrease. Continue to gently open (CCW) the VERTICAL SPEED (#3)control without exceeding the full-scale reading until VSI (#4) returns to zeroreading. Open the VERTICAL SPEED (#3) control fully (CCW). (The VSI (#4)readings indicate the rate of change in the static system when the VERTICALSPEED (#3) control is fully open.)(4) Verify the aircraft vertical speed (climb) indicator accuracy by comparing thereadings with the T/S VSI (#4) with corrections applied.