Aircraft Technical Manual
Jabiru Aircraft
Pty Ltd
J120, J160, J170, J200/J400, J230/J430, J250/J450 Variants
This document is controlled while it remains on the Jabiru server. Once this no longer applies the document becomes uncontrolled.
ISSUE
1
2
3
4
5
Dated: 29th October 2014
Issued By: AS
Page: 251 of 298
11.5.3 Static Pressure System Inspection & Leakage Test
Required Tools:
Suction test equipment
Parts and Material:
Replacement instruments (if required)
Mild soap and water
Replacement connections (if required)
Type of Maintenance:
Line Maintenance
Level of Certification:
L2 or LAME (A&P or LSA Repairman / Maintenance)
Return to Service:
L2 or LAME (A&P or LSA Repairman / Maintenance)
The following procedures outline inspection and testing processes for the static pressure system.
Before testing, ensure the static system is free from entrapped moisture by checking the low points of
the system as noted above.
Ensure the static system is free from restrictions by blowing through it. Restricted flow must be
rectified immediately.
Ensure no alternations of airframe have been made which would affect the relationship between air
pressure in the static pressure system and truce ambient static air pressure for any flight
configuration. For example, ensure that the static probe at the tip of the tail is straight and that both
the static ports are clear and open.
Negative Pressure Test:
-
Attach a source of suction to static pressure source opening. Figure 191 shows one method of
obtaining suction.
-
Slowly apply suction until the altimeter indicates a 1000-foot increase in altitude.
CAUTION
When applying or releasing suction, do not exceed the range of either the vertical speed
indicator or the airspeed indicator.
-
Cut off suction source to maintain a “closed” system for one minute. Leakage shall not exceed
100 feet altitude loss as indicated on the altimeter.
-
If leakage rate is within tolerance, slowly release suction source.
NOTE: If leakage rate exceeds maximum allowable, first tighten all connections, then repeat
leakage test. If leakage rate still exceeds maximum allowable use the following procedure:
Fault Location Tests:
-
Disconnect static pressure lines from airspeed indicator and vertical speed indicator
-
Use suitable fittings to connect lines together so that the altimeter is the
only
instrument still
connected into the static pressure system.
-
Repeat leakage test to check whether static pressure system or the bypassed instruments are
the cause of the leakage. If instruments are at fault, they must be repaired by an “appropriately
authorised repair station”, or replaced. If static pressure system is at fault, use the following
procedure to locate the leakage:
Attach a source of positive pressure to the static source opening. Figure 191 shows one
method of obtaining positive pressure.
Slowly apply positive pressure until altimeter indicates a 500-foot decrease in altitude and
maintain this altimeter indication while checking for leaks.
To find leaks, coat line connectors and static course flange with solution of mild soap and
water. Watch for bubbles to locate leaks.
Tighten leaking connections. Repair or replace parts found to be defective.
-
Reconnect airspeed and vertical speed indicators into static pressure systems and repeat
negative pressure test detailed above.
