C-130 maintenance crews solve mystery illness

For years, after landing from missions, some C-130 crews, including C-130J crews, were reporting that they were having physiological effects related to the pressurization system. Crews would report that they felt like they were still flying when they were back on the ground, and that the pressurization would not respond to either automatic or manual control on the flight they had completed. Crews would end up vomiting, having nasal cavity, and eye pressure problems as a result.

Maintenance crews would ground the aircraft, but would never find anything wrong. Over the years they tried every fix there was, with the usual result being that the system would work a few flights, then the problem would start up again. During the system checks, they were finding metal shavings, that they sent to Lockheed in an attempt to identify them, but nothing was discovered.

In February, maintenance crews from Keesler AFB in Mississippi decided to solve the mystery. They spent two days stripping the system from an aircraft, replacing parts from front to back. Finally they found the problem. A tiny rivet in an air valve was made of pot metal, not stainless steel, and as a result the moisture in the air was corroding it until pieces were falling off it, causing a blockage in the system. The blockage would move down the line, so when they checked it was gone, in another part of the system where they weren't looking.

They replaced 13 of 20 valves, and as a result all C-130 units will be regularly inspecting the valves, and Lockheed will be sending out a notice to all operators of C-130 aircraft.

BILOXI, Miss. — 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 a handful of reservists at Keesler Air Force Base took the initiative to solve the mystery. They made a tiny discovery that's affecting airplanes worldwide.

The problem was with the pressurization system on the C-130 Hercules — the longest-produced and perhaps most-popular aircraft in military history. The versatile airplane serves as an attack gunship, a troop transport, a surveillance plane and many other roles.

Keesler's famed Hurricane Hunters fly the C-130J for weather reconnaissance.

In February, maintenance technicians from the 403rd Wing began a hunt for a solution to the problem. At times, the C-130s' pressurization systems could not be controlled manually or automatically. Cabins would over-pressurize at certain altitudes, causing the physiological problems.

The health effects typically surfaced after the flights. Crew members were on the ground yet still felt as if they were in the air, Tech. Sgt. Fernando Betancourt said.

www.military1.com...

That figures that it was the tiniest of problems.

I'm glad they got it sorted out.

a reply to: Zaphod58

Good for them. Hope they got nice pat on the back for solving the mystery.

a reply to: Answer

The smallest things will kill you faster than just about anything sometimes.

a reply to: Zaphod58

How the heck do you get one bolt made out of pot metal while all of the rest are stainless steel?

Made in China maybe?

As a tinbasher would rather work on a C-130 than a 747 anyday...

a reply to: Darkblade71

The company making the valve went the cheapest route. The rivet in question isn't technically part of the system, so it wasn't required to be stainless steel, like the rest of the system was, so pot metal was acceptable. They didn't think about what would happen with it being exposed to constant moisture, because it wasn't a problem for the rest of the system.

a reply to: Zaphod58

Ah! I see!
(Said the blind man)


I can't imagine flying something and always wondering/worrying about if the pressurization "does it again".
That in itself would drive me batty,
and then to have it happen.
Glad they got that figured out.

a reply to: Darkblade71

And to have it happening on the J models, which are still coming off the assembly line would be even more infuriating.

The only C130 flight I was ever on was from Ft. Worth NAS, to Ft. Knox Kentucky, well Louisville(we bused from the tarmac to the base, I guess there is nowhere on base to land). It was hot when we left, freezing in the air, and hot when we landed, and trying to sleep crammed together, shivering on webbed seating added up to the 2nd most uncomfortable flight of my life(the first included a Chinook, a crew chief, a bucket and a steady drip of a hydraulic leak being caught and poured into a makeshift resevior, by the look on his face it was a common occurrence but a drastic situation none the less. I was advised to only worry if it stopped dripping/pouring.) My trip was in 98' I believe, was this why our area was NOT pressurized or temp controlled? Maybe we stayed low enough to not require it? Would above 10k ft or so be a danger to us in the back?

just curious

a reply to: wastedown

You can go up to about 18,000 without any real problems. A lot of times they pressurize the back end but don't heat it. That's a lot of area to heat, when most of the time the cargo doesn't care one way or the other.

I've heard that there are top of the line trucks made with metals that are subject to galvanic corrosion from day 1.
The way I heard it is that they use stainless connected to ferrous steel (or something like that) to construct the bulk of the trailer, which renders it doomed from the start, rain or shine. Just a matter of time. The guy who told me this is sort of a mensa type who tells his story to anyone who will listen (had no choice) and it's a big part of his storied intelligence quotient. Because of his discovery, his family business thrived since they narrowly avoided purchasing a large fleet of trailers-all thanks to his genius and foresight.

# 444

originally posted by: wastedown
It was hot when we left, freezing in the air, and hot when we landed, and trying to sleep crammed together, shivering on webbed seating added up to the 2nd most uncomfortable flight of my life...

Like a second home, they are.

But when they start burning, it really gets your attention.

It's hoping to find and crack troubleshoots like this that get me out of bed at 4:15am on day shift. Well done boys on finding it.

LEE.

a reply to: Blackfinger
Typical sheetie! I bet you would change your tune if I gave you a choice between 744 and 380 though. And I'm pretty sure now as to where you have worked. H85 was it?

LEE.