New J-Model Center Wing Box with higher hours?

[Jansen]

Can somebody verify this?

Apparently the J-model uses a center wing box similar to the 1990s era H model Hercules. However, the new Rolls-Royce AE2100D3 engines create a lot more stress, so Lockheed Martin improved the CWB and started installing them in all new production Herks in FY 2009. They supposedly have a higher EBH as well (80k vs 60k).

There was supposedly an offer of two early aircraft to Canada in 2009, but those were turned down because they would not match to the other 15 on order. The Canadian Forces instead waited until June for their first two aircraft, which used the new CWB.

[Plaprad]

I know that there are two seperate wing boxes. Apparently there's an upgraded box and a J specific box. Pretty much all I know on the topic.

[P3_Super_Bee]

I know that there are two seperate wing boxes. Apparently there's an upgraded box and a J specific box. Pretty much all I know on the topic.

That's the way I'm seeing it. Only one type for the "J", and then the Upgraded one being built for E/H fleet replacements. I see if I can dig up some info.

[HeyChief]

There is an Enhanced Ceneter Wing box (SOF CWB) for both the E/H CWB replacement and for the J-model. I know that all the new HCJ and MCJ were supposed to get this Enhanced CWB and that it was supposed to be standard on J's from I beleive it was either 2010 or 2011 onward. Perhaps one of the depot folks or Lockheed guys can confirm this?

When I left the service, they were still trying to figure out what the total EBH service life would be for these new enhanced CWBs..for the E/H replacement it was 90K+

[nmcdaris]

there are two differnt types of boxes installed during a center wing box replacement one for reg H models and a differnt type for MC models im told the one for the MC models are soposed to take higher stress

[hklm]

The first two airplanes were USAF line Birds.

Our aircraft we have purchased were purchased with the extended life wing box.

[HeyChief]

there are two differnt types of boxes installed during a center wing box replacement one for reg H models and a differnt type for MC models im told the one for the MC models are soposed to take higher stress

That may very well be..when I got out..I was under the impression that AMC had funded for the same Enhanced CWB that the SOF aircraft were getting

[US Herk]

That may very well be..when I got out..I was under the impression that AMC had funded for the same Enhanced CWB that the SOF aircraft were getting

ALL MC/HC receive the SOF CWB and as of a year ago or so, all J are delivered with SOF CWB (now called Extended Life CWB, I think). To my knowledge, AMC did not get any E/H CWB replaced with the SOF CWB, but that doesn't mean recent/future replacements aren't getting it since Lockheed is only building SOF CWB now, I think...but not sure on that last point (rumor only).

The SOF CWB are good to 85K EBH vs 45K EBH for regular CWB.

The SOF CWB weighs almost 1000 pounds more than a standard CWB.

[Jdenson]

From what I understand about the CWB is that the first models of J's had the exact same CWB that all other c-130 have. I heard that one of the first J's that rolled off the line went through a CWB inspection after a period of time just to see how it was handling, from what I heard is that it did not go as they would have thought. Since the J's nacelles and propellers are not as heavy and the J does not have externals(except the USCG), this ads more stress to the wing box, more wing flex from less weight holding the wings down. It seems that this was over looked in the design of the J's and it is good that it is getting fixed.

[Jansen]

The first two airplanes were USAF line Birds.

Our aircraft we have purchased were purchased with the extended life wing box.

That's pretty much in line with what I was told. All the FY10 production Jays apparently have the new center wing box, and that's why we declined the swap offer for the 2009 birds (also USAF).

[Jansen]

From what I understand about the CWB is that the first models of J's had the exact same CWB that all other c-130 have. I heard that one of the first J's that rolled off the line went through a CWB inspection after a period of time just to see how it was handling, from what I heard is that it did not go as they would have thought. Since the J's nacelles and propellers are not as heavy and the J does not have externals(except the USCG), this ads more stress to the wing box, more wing flex from less weight holding the wings down. It seems that this was over looked in the design of the J's and it is good that it is getting fixed.

All of the USMC KC-130J aircraft have external tanks.

With all of the added power from the new engines and the high cost of a CWB replacement, there is more than enough justification for the new extended life CWB in production. I definitely think Lockheed Martin made the right call there, and my question requesting confirmation of the new EL CWB has been answered. The only thing I'm still wondering about is when they started making it standard, FY09 or FY10, and which plane was first.

[hklm]

Bang on the money!!

[Jansen]

From Service News Magazine V30 #2:

Late C-130H and C-130J Center Wings

In the early 1990s following the design of the SOF center wing, some of the SOF durability enhancements were incorporated into the C-130H production center wing at Lockheed Martin Aeronautics Serial Numbers 5306. These were specific improvements to local areas of the center wing; while improving the durability of those local areas, it did not significantly affect the overall service life of the center wing. The C-130J center wing is the same configuration as the late C-130H center wing. Some of the durability improvements incorporated into the late C-130H and C-130J center wing include:

• Hi-Tigue fastener system was added at SN 5215 replacing many Lockbolts, Hi-Loks

and Taper-Loks. Most structural fasteners are interference fit steel Hi-Tigue pins with

steel nuts. The Taper-Lok fastener remains at fatigue critical joints.

• New front and rear beam webs - Additionally, the front beam web splice was moved

inboard from Wing Station (WS) 174 to WS 168.

• New wing attach angles at WS 61 with improved stress corrosion cracking resistance

- These attach angles were designed with thicker legs and prevents these from being

replacement parts for older aircraft unless a new center wing is installed

simultaneously.

• A new lower front beam cap - The beam cap was reshaped in the area of Wing

Station 174.

Of course this has now been supplanted by the new extended life center wing.