3.1.1. Appearance Test
(a) Fill a suitable container (preferably a white porcelain or approved appropriate white epoxy powder coated bucket) with approximately 1 gallon of fuel.
CAUTION: CONTAINERS
MUST BE BONDED, REGARDLESS OF CONTAINER MATERIAL
(b)
Let the sample settle
for 1 minute to remove air bubbles
(c)
Place the clean bucket on a level
surface and inspect the bottom for water droplets, solid contaminants,
hazy/cloudy condition, brown slime and observe the color of the fuel
CAUTION: TO DETERMINE THE DIFFERENCE BETWEEN A HAZE CAUSED BY ENTRAINED
WATER OR AIR BUBBLES, IT MAY BE NECESSARY TO PERFORM A WATER DETECTION TEST (Ref.
[Section 3.3]).
(d)
Examine the sample for
solids and/or sediment on the bottom of the bucket. Sample clarity can be
checked by placing a small, shiny object with definition on the bucket's
bottom. If the fuel is dry, the definition can be easily distinguished. The
amount of sediment observed can be described by a letter category
NOTE 1: The presence of contamination is much more evident when
the sample is taken from a pressurized system. Samples removed from a static
system may indicate little contamination when significant contamination
actually can be found under flow or pressurized conditions.
NOTE 2: Ensure the fuel sampling tap is free
of loose contaminants.
WARNING: IF A PINK OR REDDISH DISCOLORATION IS
OBSERVED, PERFORM A REFEREE WHITE BUCKET TEST FOR POSSIBLE DYE CONTAMINATION.
CAUTION: COPPER
COINS SHOULD NOT BE USED TO AID IN DETERMINING PRODUCT CLEANLINESS AS COPPER IS
KNOWN FUEL CONTAMINANT.
3.1.1.1. Visual
Appearance Test Rating
(a) Solids
Contaminant and Moisture Indicators
Table 3.1.1. Rating of Sample
|
Solids Contaminant Indicators
|
Moisture Content Indicators
|
Other Possible Contaminants
|
|
1. Clean
|
A. Bright
|
Record any observation as per table 3.1.4. If any observed,
further investigation is required.
|
|
2. Slight Particulate Matter
|
B. Hazy
|
|
3. Particulate Matter
|
C. Cloudy
|
|
4. Dirty
|
D. Wet (Free Water)
|
|
|
E. Surfactants
|
(b) Rating
Definitions
Table 3.1.2. Solids Contaminant Indicators
|
Rating
|
Rating Guide
|
|
Clean
|
Refers to lack of particles, silt or sediment, flakes,
dye, rust or solids
|
|
Slight Particulate Matter
|
Contains several fine to moderate sized particles
|
|
Particulate Matter
|
A sample in which many small particles may be seen
floating or settled on the bottom
|
|
Dirty
|
Discoloration or many particles dispersed in the fuel or
settled on the bottom
|
Table 3.1.3. Moisture Content Indicators
|
Rating
|
Rating Guide
|
|
Bright
|
Brightness is a quality independent of the color of the
sample and refers to the lack of suspended or free water in the sample.
Bright fuel tends to sparkle.
|
|
Hazy
|
A condition resulting from fine droplets of moisture
dispersed throughout the sample producing a dull hazy appearance. This can be
a temporary condition brought about by a drop in temperature. During the
first minute, the fuel can appear hazy due to air bubbles.
|
|
Cloudy
|
The result of extremely fine droplets of water dispersed
throughout the sample giving it a milky appearance
|
|
Wet
|
Any form of free water appearing as droplets or bulk
water on the bottom of the bucket or clinging to the sides
|
|
Surfactants
|
Slime in the bottom of the bucket or at the fuel/water
interface appearing as a dark brown/black layer, scum or lacy material
floating in or on the sample
|
Table 3.1.4.. Other Possible Contaminants
|
Description of Sample Appearance
|
Possible CauseA
|
|
Slime on bottom of
container or at fuel/water interface, appearing as dark brown/black scum or
lacy material floating in the fuel or at the interface with water.
|
surfactant or microbial
contamination
|
|
The presence of
anaerobic bacteria often causes a pungent odor, similar to rotten eggs.
|
microbiological activity
|
|
Unusual appearance,
color or odor, or both.
|
other product
cross-contamination
|
|
Fuel dyes can cause
red, green, blue, or any color combination in aviation fuel.
|
dye contamination
|
|
Darkened, discolored,
and possibly more viscous, fuel with abnormal odor.
|
fuel aging
|
3.1.1.2. Action Required if Red Dye is Detected
(Referee White Bucket Test)
(a)
The White Bucket test
shall be used to inspect for red dye contamination. The referee White Bucket
shall be the white porcelain bucket or
approved white epoxy coated bucket obtained from Gammon Technical Products,
GTP-1746B or GTP-1746C. powder coated bucket manufactured by Gammon Technical Products,
GTP-1748B. This
test requires collecting approximately a two (2) gallon sample with a fuel
depth of 6 inches, +/- 1.0 inch. The inspector (with normal vision or wearing
corrective non-tinted lenses) performs a visual examination of the fuel for
color under normal daylight conditions, or in any well-lighted room such as an
office with fluorescent lighting. If the inspector is not sure of the fuel
color, a consensus of the color should be obtained from several individuals
1)
Jet fuel with no
visible red tint should be judged acceptable for use in aircraft
2)
A red tint resulting
from refinery processing will usually disappear when exposed to light. Jet fuel
is acceptable for use if the red tint disappears in less than 30 minutes after
being exposed to light
(b)
Jet fuel produced by
blending a red dyed fuel with a non-dyed fuel may be acceptable, providing the
resulting fuel has no visible red tint, and fuel satisfies [ASTM D1655]
specifications. Blending is not to be performed at an airport fuel storage
facility without prior authorization by affected airline(s)
NOTE: Reference:
Boeing Service Letter, dated 27 August 1998, ATA: 2800.00, Aircraft Use
of Dyed Fuels.
Porcelain and
porcelain enamel coated white buckets were discontinued 7 years ago. If any are
still available and in good condition, they could still be used.