NOTE: In the fuselage crown area, airplanes used for livestock transportation
will require and receive more frequent preventive maintenance than rec-ommended in Volume 2.

D. Dry all insulation blankets before reinstallation.

E. No additional preventive maintenance is proposed for occasional transporta-tion of small animals, except that where there is obvious contamination from
animal wastes, local cleaning should be performed followed by treatment with
water displacing corrosion inhibiting compounds.

Volume 1

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Page 2
OCT 01/01

STANDARD PREVENTIVE MAINTENANCE METHODS
MICROBIAL GROWTH IN INTEGRAL FUEL TANKS

1. General

tanks has been encountered due to microbial

A.  Corrosion of integral fuel
fuel tanks

growth. Micro-organisms enter the tank with the fuel. Airplane

also frequently contain some water which either enters the tank with the
thrive

fuel or is the result of condensation within the tank. The microbes
slime or matted

at the water/fuel interface and multiply rapidly forming a
cannot be

growth within the tank. This matted growth traps water so that it
removed by normal slumping procedures. Corrosion is produced when the pro-
the fuel tank eventually break

tective finishes on the lower surfaces of
down under continuous exposure to water soaked microbial growth mats and the
by-products of microbial growth.

humid cli-

B.  The incidence of microbial contamination of fuel is higher in hot
where the

mates, therefore the possibility of fuel tank corrosion increases
airplanes operate in these regions (Fig. 1).

Figure 1 Areas which are at high risk of developing
microbiological contaimination

ALTHOUGH THE SHADED AREAS ARE CONSIDERED AS HIGH RISK AREAS, PROBLEMS
IT IS VERY IMPOR-
CAUTION:

HAVE BEEN ENCOUNTERED IN MOST PARTS OF THE WORLD.
TANT THAT PROPER FUEL SYSTEM MAINTENANCE IS PRACTICED AT ALL TIMES.

Volume 1

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Page 1
OCT 01/02

STANDARD PREVENTIVE MAINTENANCE METHODS
MICROBIAL GROWTH IN INTEGRAL FUEL TANKS

2. Detection of Microbial Contamination

A.  Personnel involved in slumping fuel tanks should be advised to report any
evidence of slime in the water and fuel removed from the airplane.

B.  You can check fuel for micro-organisms with the Microbe-Monitor Test Kit
from Air BP, V8P482. This kit contains two bottles. You put a fuel sample in
each bottle with a hypodermic syringe. One bottle contains liquid to sustain
the microbes, while the other contains a similar liquid with biocide added.
A dye in the sample bottles will change color to tell you within 48 hours if
the fuel sample is contaminated. An alternate test kit, the Hum-Bug Detector
Kit from Humanoids Technical Services Inc. V47186 is acceptable. Another
　
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