Aircraft Service Manual
Jabiru Aircraft
Pty Ltd
JTM001-1
J120, J160, J170, J200/J400, J230/J430, J250/J450 Variants
REVISION
1
Dated: Nov 2011
Issued By: SW
Page: 199 of 233
Ensure no alternations of airframe have been made which would affect pressure present in the pitot
system during flight. For example, ensure that the pitot probe on the wing strut is straight and that
the static opening at the tip is clear and open.
To check pitot system for leaks:
-
Place a piece of rubber or plastic tubing over pitot tube, close opposite end of tubing and slowly
roll up tube until airspeed indicator registers in the cruise range.
-
Secure tube and after a few minutes recheck airspeed indicator. Any leakage will have reduced
the pressure in the system, resulting in a lower airspeed indication.
-
Slowly unroll tubing before removing it, so pressure may be released gradually - otherwise
instrument may be damaged.
-
If the test reveals a leak in the system, check all connections for tightness.
15.5.5 BLOWING OUT LINES
Condensation may collect at points in the pitot system and produce a partial obstruction. To clear
line, disconnect airspeed indicator. Using low pressure air, blow from indicator end of line toward
pitot tube.
CAUTION
Never blow through pitot or static lines towards the instruments.
Like pitot lines, static lines must be kept clear and connections tight. When necessary, disconnect
static line at first instrument to which it is connected, then blow the line clear with low pressure air.
Check all static pressure lines for tightness. If hose or hose connections are used, check for general
condition and clamps for security. Replace hose which has cracked, hardened or shows signs of
deterioration.
15.5.6 REMOVAL & INSTALLATION OF COMPONENTS
To remove pitot mast probe, remove the two rivets fastening it to the wing strut and pull it out from
the strut far enough to disconnect the pitot line.
For details of the Dynon pitot, refer to Section 7.11.
The static probe is fixed and cannot be removed. Limited access may be available through the fin
top strobe mount (where equipped)
– otherwise an access hole must be cut into the fin. Consult
Jabiru Aircraft or our local approved representative before making access holes.
In all cases, installation of tubing will be simplified if a guide wire is drawn in as the tubing is
removed. When replacing tubing and fittings, tighten connections firmly, but avoid over-tightening
and distortion of fittings or tubing.
15.5.7 TROUBLE SHOOTING
– PITOT STATIC SYSTEM
Table 15
– Trouble Shooting – Pitot-Static System
Trouble
Probable Cause
Remedy
Low or sluggish airspeed
indication (normal
airspeed and vertical
speed)
Pitot tube obstructed, leak or
obstruction in pitot line
Test pitot tube and line for leaks
or obstructions. Blow out tube
and line, repair or replace
damaged line.
Incorrect or sluggish
response (all 3
instruments)
Leaks or obstruction in static line
Test line for leaks and
obstructions. Repair or replace
line, blow out obstructed line.
