INFORMATION LETTER #2002-2

Sikorsky S-58/S-58T and S-61/H-3 Tail Rotor Blade Erosion

ABS 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.

ABS 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.

The 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.