Depleted Uranium

[tinyclark]

I know this has come up before, and I swear I saw a drawing of a counterweight made with depleted uranium, but I can't find anything on it now.

I even looked up all the old weights from the A model drawings, and no luck.

Does anyone know for sure, and have a reference, that uranium was used on the C-130?

[DC10FE]

Tiny,

That always used to be one of the "gotcha" questions on a check ride. I was always told the elevator counterweights were made of depleted uranium.

Don R.

[Mikey_G]

Not DU, but related, I heard on the older herks the side and overhead emergency escape hatch handles used to contain small amounts of radioactive material that would glow. I can't confirm if that's valid or one of those "F with the new guys jokes".

[Bob L]

Part Number 398370-3 and -4 Elevator Counter Balance Weights are made from depleted Uranium. However, Part Number 398370-5 and -6 Elevator Counter Balance Weights are made from Tungsten and were incorporated into production on aircraft 5536 and consistently installed from aircraft 5539 and subsequent. The -5 and -6 Counter Balance Weights are a direct replacement for the -3 and -4.

[NATOPS1]

The overhead and side excape hatches had "buttons" that were radioactive. They screwed in to the handle, the handle itself is not radioactive. I think the Paratroop doors also had a "button" attached at the upper hand hold area....

The Inflight refueling Para-drogues had "Isolights" that were/are radioactive.

I'll see if I can pull up a picture or two.

Edited February 11, 2010 by NATOPS1

[Plaprad]

There's some avionics with radioactive components. I'd have to check with my buddy to find out which ones.

As for the counterweights, I've never seen a DU one. I was told for years they were, but I think there's a reg that anything like that has to be marked.

[jetcal1]

Not DU, but related, I heard on the older herks the side and overhead emergency escape hatch handles used to contain small amounts of radioactive material that would glow. I can't confirm if that's valid or one of those "F with the new guys jokes".

Nope, probably true. it was probably Radium. The same stuff was used on old indicators and watch faces.

[tinyclark]

Part Number 398370-3 and -4 Elevator Counter Balance Weights are made from depleted Uranium. However, Part Number 398370-5 and -6 Elevator Counter Balance Weights are made from Tungsten and were incorporated into production on aircraft 5536 and consistently installed from aircraft 5539 and subsequent. The -5 and -6 Counter Balance Weights are a direct replacement for the -3 and -4.

Thanks!!

I can't find any IPB that shows the -3 or -4 weight assemblies to be installed on our aircraft. Maybe they used them for foreign military sales so they didn't have to bury it...

Edited February 11, 2010 by tinyclark

[SonnyJ]

From J-23: Stretched airplanes have an inboard elevator counterweight of depleted uranium. While depleted uranium emits low-level radiation, radioactivity of the counterweight has been reduced to a level where most servicing tasks are not hazardous. This counterweight is located on the elevator torque tube inside the lower portion of the empennage.

[davis]

Not DU, but related, I heard on the older herks the side and overhead emergency escape hatch handles used to contain small amounts of radioactive material that would glow. I can't confirm if that's valid or one of those "F with the new guys jokes".

This was true, It was a small screw in button about as big around as a dime and a 1/2"in. thick at all emergency exits and they would glow.

[Wombat]

This was true, It was a small screw in button about as big around as a dime and a 1/2"in. thick at all emergency exits and they would glow.

The exit "cat's eyes" were tritium. They idea was that if you were in the dark you reach for the glowing marker and you'd find the release handle. After we had a marker stolen, I had one checked by a lab. Their reply was that the stainless steel wafer the tritium is painted on will do more harm that the tritium.

We have dismantled quite a few A and B models in Tucson and have not yet found any DU counterweights. I notice though that several C-130's now in storage have unpainted elevator tip weights. Maybe cad plated or tungsten? DU looks like carbon when oxidized and is usually stamped for ID purposes.