Robinsons R66 - 62-40 Inspection of Main Rotor Blades; 62-41 Scratches and Corrosion

62-40 Inspection of Main Rotor Blades
NOTE
Main rotor blades are 14 CFR § 27.602 critical parts. Notify RHC
Technical Support when voids exceeding the limits specified in
the instructions below are found, providing blade serial number,
helicopter serial number, time in service for the rotor blade, and
location and size of the voids that exceed the limits.
NOTE
The inspection criteria in this section applies to blade damage
that occurs after blade manufacturing (including shipping
and handling and time in service). Damage after blade
manufacturing usually exhibits paint scuffing, scratches, or
freshly-exposed metal in the form of scratches in the finish. If
a blade manufacturing irregularity is suspected, contact RHC
Technical Support.
CAUTION
A blade may be repaired more than one time. However, in no
case can more than the maximum material be removed or the
maximum dent depth be exceeded in any one location.
A. Measuring Damage
1. Refer to Figure 62-9. Measure blade damage using a straight edge and a thickness
gage. Keep straight edge parallel with the leading and trailing edges.
2. If blades are installed on the helicopter, measure damage using the shortest straight
edge possible to span damaged area. Using a straight edge of excessive length will
cause a false reading due to natural droop of the blade.
B. Measuring Material Removed After Repair
1. Use calipers or micrometers and compare measurements before and after repair to
estimate amount of material removed.
2. Use a straight edge and thickness gage to measure repaired areas less than 2 inches
across in the blade skins and spar.
62-41 Scratches and Corrosion
A. Skins and Doublers
1. Refer to Figure 62-10. Verify damage does not exceed the following limits:
a. 0.0040 inch maximum depth for scratches more than 15º spanwise on skins
and doublers.
b. 0.0060 inch maximum depth for scratches less than 15º spanwise on skins and
doublers.
2. Refer to § 62-50 for repair procedures for damage within limits. Blend out scratches
or corrosion on blade skins or doublers with a 0.10 inch blend radius.
MAY 2015 Chapter 62 Main Rotor Page 62.19