INFORMATION LETTER #2002-2
S-58/S-58T and S-61/H-3 Tail Rotor Blade Erosion
has received a number of tail rotor blades with tip cap and abrasion
strip damage, upon detailed inspection we found that the tip cap mount
landing has been severely eroded, as illustrated in the following picture.
This damage is the reason many blades have been removed from service,
SCRAP. Sikorsky only allows repairs to this area if the erosion has
not exceeded .125”, which many do.
has received authorization to increase the amount of repairable erosion
thus saving numerous blades. The main point in this information letter
is, maintain your abrasion strip and tip cap. Many of the blades exhibit
this damage to some degree. Tip caps severely eroded or improperly
fit and severe erosion to the abrasion strip are the cause. If the
tip cap and abrasion strip do not make firm contact with each other
in this area you will have a problem. Some of the blades received at
ABS came in repairable condition but after removing the tip cap and
abrasion strip the problem was uncovered.
picture below is a tail blade purchased by an operator and installed
on the aircraft in as is condition. When the abrasion strip was found
to be voided ABS was contracted for the repairs. The previous owner
had replaced the tip cap, and did a good job, but did not address the
erosion thus the cover up of hidden damage.
This notice is for information purposes only and does not condemn any blade
without a more detailed inspection.