Bell OH-58A Technical Manual page 138

TM 55-1520-228-BD
ROTORS
2. Smooth damage; remove all rough
edges.
3. Clean area around damage and
completely around blade where tape is
to be applied.
4. Cover hole with a chordwise layer
of tape, top and bottom of blade.
Extend ends of tape 2 inches beyond
area of damage, Figure 7-4.
Wrap a second layer of tape chord-
5.
wise over the first layer and around
the entire blade.
inches with outside edge of top toward
trailing edge.
6. Wrap exact number of tape wraps on
de at approximately same
opposite si
span locati on.
7. Record BDAR action taken. When
mission is complete, as soon as
practical, repair the equipment/system
ard maintenance procedures.
using stand
7-7. MAIN ROTOR BLADE, HOLE 1 T0 4
INCHES DIAMETER MAXIMUM.
GENERAL INFORMATION: A medium size
hole in the honeycomb core area, Figure
7-3, of a main rotor blade can be tem-
porarily repaired by fashioning a patch
using aluminum foil as a plugging
material. Removal of blade is not
necessary. This repair is limited to
certain areas of the blade as shown in
Figure 7-5.
Adjustment of blade
LIMITATIONS:
balance may be required after repair.
Inspection of repaired area after each
flight would be required.
PERSONNEL/TIME REQUIRED:
. 2 Soldiers
. 1 Hour
7-6
Overlap ends by 3
MATERIALS/TOOLS REQUIRED:
. Army Green Tape, Maximum Width
Available; 3 Inches Minimum or
Aluminized Tape (item 50, Appx C)
. Fiberglass or Aluminum Wafers
. Aluminum Foil or Other Filler
Material (item 18, Appx C)
. Adhesive Package
PROCEDURAL STEPS:
1. Position blades for access to damage
area. Support blades to prevent movement
and droop.
2. Smooth damage; remove all rough edges.
3. Clean area around damage and com-
pletely around blade where tape is to
be applied.
Make a plug of crushed aluminum foil
4.
or other filler material shaped to fit
in the hole. Do not make the plug too
dense; voids should be about 1/4 inch.
Apply spots of adhesive to the aluminum
sheet before crushing so plug will have
some strength. Apply adhesive sparsely
to the finished plug in the area where
it will come in contact with the blade
sandwich material.
5. Insert plug in hole. Hole should
be well packed,
6. Cut out a fiberglass or aluminum
wafer so it just fits over the hole
without overlapping the external blade
skin. Apply adhesive to the bottom of
the wafer where it comes in contact with
the aluminum plug, and close the hole.
7. Cover hole with Army green tape.
Tape should extend 2 inches beyond edge
of the hole, Figure 7-4.