Robinson R66 - Repair of Main Rotor Blades; Sealing, Filling, and Fairing

62-50 Repair of Main Rotor Blades
WARNING
Unauthorized repairs to rotor blades have caused fatal crashes.
CAUTION
Do NOT use power tools, chemical paint strippers, or chemical
corrosion removers to repair main rotor blades.
NOTE
Refer to § 20-70 for approved materials.
1. Measure damage per § 62-40.
2. Polish out blade damage using 220 grit or finer wet-or-dry aluminum-oxide abrasive
paper, and finish with 320 grit or finer wet-or-dry abrasive paper.
3. A fine-toothed file may be used along the spar and trailing edge, provided the area is finished
with 320 grit or finer wet-or-dry abrasive paper. Hand-sand or file in spanwise direction.
4. Remove only the material necessary to reach the bottom of the damage, and to blend
the reworked area to the radius or dimension required. Visually inspect and verify all
damage is removed.
5. Measure reworked area and verify material removed and/or new chord dimension is
permissible per § 62-40.
6. Seal and fill per § 62-51, as required. Paint per § 62-52, as required.
7. Track and balance main rotor per Chapter 18, as required.
62-51 Sealing, Filling, and Fairing
1. Clean area needing sealing, filling, and fairing with QSOL 220.
2. a. Apply B270-27 adhesive to seal all exposed bond joints except at tip of blade and
4–6 inches of outboard end of skin/spar joint; remove excess adhesive.
b. Apply B270-1 sealant to seal tip of blade and 4–6 inches of outboard end of skin/
spar joint; remove excess sealant. Cure for 2–3 hours at 125° ± 25° or air dry for
72 hours minimum.
3. Using 240 grit or finer wet-or-dry aluminum-oxide abrasive paper, hand-sand cured
adhesive in spanwise direction to a smooth, aerodynamic finish, congruent with the
blade airfoil. Do not remove metal.
4. Hand-sand surrounding painted surface until 25% primer remains. Keep bare metal to
a minimum.
JUL 2020 Chapter 62 Main Rotor Page 62.27