Cessna 177 SERIES Service Manual

15-17. TROUBLE SHOOTING--PITOT STATIC SYSTEM.
TROUBLE PROBABLE CAUSE REMEDY
LOW
OR SLUGGISH AIRSPEED
Pitot tube obstructed,
leak or
Test pitot tube and
line for leaks
INDICATION.
(Normal altimeter
obstruction
in pitot
line.
or obstructions.
Blow out
tube
and vertical
speed. )
and line, repair or replace
dam-
aged line.
INCORRECT
OR SLUGGISH
Leaks or obstruction
in static
Test line for leaks and
obstruc-
RESPONSE.
(all three
line.
tions. Repair or
replace line,
instruments.
)
blow out obstructed line.
15-18.
TRUE AIRSPEED
INDICATOR. A true air-
dicator. Holding
this setting, move
retainer (6) until
speed
indicator may
be installed. This
indicator,
60°F aligns
with zero pressure
altitude,
then tighten
equipped
with a conversion
ring, may be
rotated until
mounting screws
(5) and replace
decorative
cover (4).
pressure
altitude is aligned with
outside air tempera-
ture,
then airspeed
indicated
on
the instrument
is
read
NOTE
as true airspeed on the adjustable ring. Refer to fig-
ure 15-2
for removal and installation.
Upon installa-
Beginning with
serial 17702314, true
airspeed
tion, before tightening
mounting screws
(5), calibrate
indicators are graduated
in knots. Therefore,
instrument as
follows: Rotate
ring (7) until
120 mph
use 105 knots
instead of
120 miles per
hour
on the adjustable
ring aligns with 120
mph on the in-
in the above calibration
procedure.
15-19. TROUBLE SHOOTING--AIRSPEED INDICATOR.
TROUBLE
PROBABLE
CAUSE
REMEDY
HAND FAILS
TO RESPOND.
Pitot pressure connection
not Test
line and connection for
leaks.
properly
connected to pres-
Repair or replace damaged line,
sure line from pitot
tube. tighten
connections.
Pitot or static
lines clogged. Check
line for obstructions. Blow
out
lines.
INCORRECT
INDICATION
Leak in pitot
or static lines.
Test lines and
connections for
OR HAND OSCILLATES.
leaks. Repair
or replace dam-
aged
lines, tighten
connections.
Defective mechanism
or
Substitute
known-good
indicator
leaking
diaphragm.
and check
reading. Replace
instrument.
HAND VIBRATES.
Excessive
vibration.
Check panel shock
mounts.
Re-
place defective shock mounts.
Excessive
tubing vibration.
Check clamps and
line connections
for security. Tighten clamps and
connections, replace tubing with
flexible
hose.
Change
5
15-7

Cessna 177 SERIES Specifications

General

Manufacturer	Cessna
Engine Type	Piston
Wingspan	35 ft 6 in (10.82 m)
Seating Capacity	4
Number Built	4, 295
Engine	Lycoming O-360
Horsepower	180 hp
Maximum Takeoff Weight	2, 500 lb (1, 134 kg)