Coast Guard Grounds Some Search-and-Rescue Helicopters As It Struggles to Find Spare Parts

The gearboxes for the 65 are cast magnesium and as such are highly susceptible to galvanic corrosion (not to mention extremely difficult to replace). In addition, at least as of 2015, the Coast Guard utilized an ineffective corrosion inhibition process that was damaged during routine maintenance. While ALC's maintenance techs are phenomenal at keeping those helicopters running, any corrosion/pitting >.040" forced them to scrap those gearboxes. The main gearbox was around $500k, and the tail gearbox was $50-100k if I remember correctly. As of June 2015, the Coast Guard had scrapped over $5m worth of 65 gearboxes (main and tail). Even then, the manufacturer took at least 6 months to ship parts for the aircraft.

Two things could have significantly reduced the amount of waste here and kept this problem to a more manageable level. 1) utilize the proper corrosion inhibition processes that can withstand regular preventative maintenance. Cost: ~$500k to setup, comparable operating costs to existing process 2) adopt a cold spray system to return scrapped gearboxes to service. Cold spray essentially accelerates microscopic particles out of a supersonic nozzle to deposit on the part, which can then be machined back to the original dimensions. Cost: $200k.

Given the outright denial of its existence in 2015 by senior leadership at ALC, I'm not surprised this problem has reached such a significant level.

I worked in contracting/procurement for communication equipment back in the mid 80s...we had a terrible time finding parts. We often had to buy back surplus parts that had been sold off by the government years before.

I had that problem with radar repair. Common resistors were no loger in the supply chain and would not be ordered on a new contract. My CWO went to Radio Shack to get them for me and I returned the radar to service after more than a year of being down. They told me when I returned from Korea that it couldn't be done, nobody was able to get it up. I told them give me 4 months and I would do it, and I got it done on time.