Acid and Alkaline Contamination
If a parachute assembly is suspected of having
acid or alkaline contamination, it must be tested
with a pH test paper. A pH reading of 5.0 to 9.0
is in the safe zone. Readings below 5.0 indicate
excess acidity, and readings above 9.0 indicate
excess alkalinity. By following the steps listed
below, you will be able to conduct a proper
inspection to determine if a stain is acid or
alkaline. You need to have distilled water and a
pH test paper kit (full range and short range).
MAKE SURE THAT THE TESTING
AREA IS FREE OF CONTAMINANTS
TO AVOID FALSE READINGS OR
DAMAGE TO THE ASSEMBLY.
To perform an acid and alkaline contaminant
inspection properly, you should take the following
1. First, dampen the suspected area with
2. Place a piece of full-range test paper (0.0
to 14.0 pH) on the dampened area. Compare the
color of the paper with the chart samples to
determine the approximate pH and which specific
short-range test paper to use.
3. Place the short-range test paper indicated
by step 2 on the dampened area. The color the
paper changes to will indicate the pH factor of
the affected area. By matching the test strip with
the applicable range color chart supplied with the
pH indicator kit, you can determine the strength
of the acid or alkaline present.
NOTE: You must be careful not to let the
suspected contaminated area come into
contact with any other area, as this could
spread the damage.
4. Treat contaminated areas of the para-
chute assembly in accordance with NAVAIR
Those stains caused by contact with acid, oil,
and salt water are the most harmful to nylon and
should be removed as quickly as possible to
prevent further deterioration of the material.
Although sun rays do not stain, they are most
harmful to nylon. Parachutes and components
must be kept out of the direct sunlight.
INSPECTING FOR WEAR AND
Wear in a parachute is not difficult to detect.
Chafing at the comers or on outside surfaces is
where the most wear occurs. Parts of parachutes
and related equipment showing excessive wear
should be replaced or repaired, the work to be
accomplished at the lowest maintenance level
capable of performing the task.
PILOT PARACHUTE INSPECTION
Inspect the fabric drag surfaces, rib pockets,
lift webs, seams, and suspension lines for signs
of contamination, cuts, tears, burns, fraying, and
loose or missing stitches. Inspect the vane material
for defects and deterioration. Inspect for seam
separation along the seam area where the vane
attaches to the cone and suspension lines. Yarn
separation is acceptable; however, replace the
pilot chute if the vane material contains holes, rips
or tears. Inspect the spring assembly for sufficient
tension and bends. Replace ail loose or broken
tackings. There is little that you can repair on a
pilot parachute. If any damage is found, you must
replace the pilot parachute in accordance with
Inspecting the canopy requires the most time.
You must take your time in order to be certain
that you dont miss any defects. NAVAIR
13-600-4-6-3 and NAVAIR 13-1-6.2 spell out the
step-by-step procedures for this inspection. Any
damage must be recorded on a canopy damage
chart. (See figure 1-15.) To inspect the canopy for
possible defects or damage, you should take the
Lay the canopy on a clean packing table
nameplate gore is facing down.
Place tension on the canopy.