C-130 mystery solved

[Monello]

For years, a strange problem with the U.S. Air Force's C-130 aircraft had pilots and crews reporting sickness, discomfort and, in some cases, excruciating pain after routine flight missions. The phenomenon remained a mystery until February, when reservists at Keesler Air Force Base took the initiative to solve the mystery. They made a tiny discovery that's affecting airplanes worldwide.

The technicians noticed something strange. They were finding tiny metal shards in the pressurization system's air lines.

Read more here: http://www.sunherald.com/2015/04/09/6168089/in-flight-mystery-keesler-airmen.html#storylink=cpy​

The metal particles were coming from a corroded rivet, no larger than a pencil point, inside an air valve.The corrosion had remained hidden for years because every other part of that valve is stainless steel. But not the tiny rivet, which is composed of plain pot metal -- an inexpensive, low-quality alloy.

Moisture in the air could cause the rivet to rust and fall apart. Whenever the pressurization system was used, the air in the lines would push the metal particles to another valve at the very front of the system. Maintenance personnel sometimes found them there but couldn't work out where they came from.

Read more here: http://www.sunherald.com/2015/04/09/6168089/in-flight-mystery-keesler-airmen.html#storylink=cpy​

story

 

[Vince]

This must be a new valve that they screwed up in manufacture. Didn't have the problem with the old ones.

 

[PeoplesElbow]

This must be a new valve that they screwed up in manufacture. Didn't have the problem with the old ones.

From the article

Problems with the C-130J's pressurization system cropped up after 2004, when Lockheed Martin implemented field installations of new check valves, Rials said.

Read more here: http://www.sunherald.com/2015/04/09/6168089_in-flight-mystery-keesler-airmen.html?rh=1#storylink=cpy

 

[edinsomd]

You mean besides having their engines mounted upside-down?

 

[Vince]

You mean besides having their engines mounted upside-down?

Only P-3's are upside down.

 

[glhs837]

Hanging from your wings is wrong. (please ignore any bird you see ) In any case, this particular case highlights a growing problem of supply chain control and cost reduction. How far down the supply chain do you micromanage each individual piece part? Or require the main vendor to do so? Big companies cannot afford to make each piece part or subassembly in house, and so they are subbed out. And unless the specification for that piece or subassembly calls out every physical aspect perfectly, this sort of thing can happen. Might be the original vendor had an in-house requirement that all rivets used in environmental control systems be stainless, and whomever wrote the contract for the subcontract wasn't aware of that. "Everybody knows there's moisture in such a system, they would be idiots to not know that"

Might be the main vendor subbed out the larger piece, and the sub then subbed out the individual piece, so the main vendor never had any visibility into the making of that small piece. Quite a rabbit hole it turns into.

 

[edinsomd]

Only P-3's are upside down.