Fuel Contamination; Revision 4 - Cessna 172SPHUSR05 Pilot Operating Handbook

S ECTION 8
HAN DL I N G , S E RVICE

FUEL CONTAMINATION

Fuel contamination is usually the resu lt of foreign material
present in the fuel system, and may consist of water, rust, sand , dirt,
m icrobes or bacterial g rowth . I n additio n , additives that are not
co mpatible with fuel or fuel system co mponents can cause the fuel
to become contaminated .
Before each fl ight and after each refueling, use a clear sampler
cup and drai n at least a cupful of fuel from each fuel tank drain
location and fro m the fuel strainer qu ick d rain valve to determine if
contaminants are present, and to ensure the airplane has been
fueled with the proper grade of fuel.
I
lf contamination is detected , drain
fuel reservoi r and fuel selector qu ick drain valves and then gently
rock the wi ngs and lower the tail to the g round to move any
add itional contaminants to th e sampli ng poi nts . Take repeated
I
samples fro m al l fuel drain poi nts u ntil
removed . If, after repeated sampl ing, evidence of contamination sti l l
exists , t h e airplane should not b e flown . Tanks should b e d rained
and system
evidence of contamination must be removed before fu rther flig ht. If
the airplane has been serviced with the improper fuel grade, defuel
completely and refuel with the correct grade. Do not fly the airplane
with contaminated or u napproved fuel .
I n add ition , Owners/Operators who are not acq uainted with a
particu lar fixed base operator should be assu red that the fuel supply
h as been checked for contami nation and is properly filtered before
al lowi ng the airplane to be serviced . Fuel tanks shou ld be kept fu l l
between flights , provided weight and balance considerations wi l l
perm it, t o redu ce t h e possibil ity o f water condensing on t h e wal ls of
partially fi lled tanks.
To fu rther reduce the possibility of contaminated fuel, routi ne
mai ntenance of the fuel system sho uld be performed i n accordance
with the airplane Mai ntenance Manual . Only the proper fuel , as
reco mmended in this handbook, shou ld be used , and fuel additives
should not be used u nless approved by Cessna and the Federal
Aviation Ad min istration.
8-20
&
MAINTENANCE
pu rged by qual ified
fuel drain poi nts i ncluding the
a l l
contamination has been
a l l
mai ntenance personnel . All
C ESSNA
MODEL 1 72S
:

Revision 4