KC-130J Fuel Tanks in cargo hold?

magicdragon · by **magicdragon** » 04 Mar 2015, 12:50

I was just reading the news story about the role of KC-130J aircraft in operation Inherent Resolve.

The aircraft can carry 92 passengers, 6 pallets or combinations of the two. Although they excel at this, another important mission is refueling Marine and coalition aircraft during crisis response and contingency operations.

...

It can carry about 60,000 lbs. of fuel in order to support refueling missions for MV-22 Ospreys, F-16 Fighting Falcons, F-18 Hornets, or AV-8B Harriers, said Fair.

This got me wondering...

1) Can the KC-130J combine both transport and refueling roles in one mission, or does the aircraft need to be reconfigured for refueling?
2) In a refueling mission, is all the fuel stored in the KC-130's fuel tanks + the underwing fuel tanks? Or is the cargo hold used to carry extra fuel? If so, how much?
3) the 60,000lbs of fuel in the article - is that just internal fuel (+pods)? If so, can the aircraft still transport cargo as well?

sorry for all the questions - any insights appreciated!

md

Whity · by **Whity** » 04 Mar 2015, 22:33

magicdragon wrote:1) Can the KC-130J combine both transport and refueling roles in one mission, or does the aircraft need to be reconfigured for refueling?
2) In a refueling mission, is all the fuel stored in the KC-130's fuel tanks + the underwing fuel tanks? Or is the cargo hold used to carry extra fuel? If so, how much?
3) the 60,000lbs of fuel in the article - is that just internal fuel (+pods)? If so, can the aircraft still transport cargo as well?

(1) It can combine both transport and refueling. The cargo compartment can be used for cargo on a refueling mission if it doesn't hold the optional 3,600 gallon fuselage tank (see (2)).

(2) A KC-130J can carry an aluminum 3,600 gallon (13,627 liter) fuel tank inside the cargo compartment should the mission require it. The Marines and Navy use this tank too in their KC-130T's.

: 3,600 gallon fuselage tank; fuselage_tank.jpg (18.74 KiB) Viewed 62586 times

(3) The KC-130J has 8,455 gallons (57,500lbs) of fuel from the wing and external tanks. It can then still plenty of cargo as well. Adding the 3,600 gallon (24,392lbs) fuel tank limits that space.

wbh · by **wbh** » 15 Jun 2015, 01:20

Normally it is either /or cargo or tanker. The fuselage tank is installed on a pallet , which is then loaded into the airplane using the dual rail cargo/airdrop system. Fuel is transrerred to the Inflight refueling hoses from the fuselage tank through the single point refueling/dump plumbing. Fuselage tank fuel can also be routed through the crossfeed manifold to the engines. Limited cargo can be carried with the fuselage tank installed , but then you need to be aware of gross weight /CG limitations.
WBH

Jon · by **Jon** » 16 Jun 2015, 15:01

How often is the KC-130 switched out between refueling and cargo roles for a specific aircraft? Don't need a number but an idea. A few times a week, almost never etc...

wbh · by **wbh** » 16 Jun 2015, 19:51

I realy don't know .My tanker experience all comes from flight test either at Lockheed or contact Depots. The change out however ,once the palletized tank came into play with the advent of the Brooks & Perkins rail system can be accompliched rather quickly.

Jon · by **Jon** » 17 Jun 2015, 02:36

When did it become a pallet system, is that only with the J's?

wbh · by **wbh** » 17 Jun 2015, 15:21

It started in production with the KC-130 R's. The KC-130 F's were retrofitted such that the palletized Fus Tank became standard.

patriot0311 · by **patriot0311** » 07 Mar 2017, 09:08

Jon wrote:How often is the KC-130 switched out between refueling and cargo roles for a specific aircraft? Don't need a number but an idea. A few times a week, almost never etc...

Our primary mission was In Flight Refueling. We normally kept the fuse tanks in all but one or mebbe two "cargo frames". Even with the fuse tank in, we still carried a chitt load of pax and whatever else we could stuff into it, (from the Class 6 store at Lajes, usually :wink:

). We normally had a fuse tank in when we did long over water trips. We could IFR or ground transfer fuel out of any fuel source we had in the airplane.

patriot0311 · by **patriot0311** » 07 Mar 2017, 09:13

wbh wrote:Normally it is either /or cargo or tanker. The fuselage tank is installed on a pallet , which is then loaded into the airplane using the dual rail cargo/airdrop system. Fuel is transrerred to the Inflight refueling hoses from the fuselage tank through the single point refueling/dump plumbing. Fuselage tank fuel can also be routed through the crossfeed manifold to the engines. Limited cargo can be carried with the fuselage tank installed , but then you need to be aware of gross weight /CG limitations.
WBH

The IFR plumbing was separate from the dump system.

wbh · by **wbh** » 07 Mar 2017, 20:18

Reference NAVAIR 0175GAG-1 the fuse tank pumps feed the Dump Manifold, The fuel is prevented from going overboard by the Dump Valve , the Reel Fuel valve routes the fuel from the Dump Manifold to the Reel hoses. what I have presented is the KC-130R fuel system. the KC-130F system is different due to the fact that "F'" were essentially "B" Models with fuel systems prior to C-130E, AF 63-7767 , LAC 3383 where the SPR & Dump system were separate.

tbarlow · by **tbarlow** » 20 Mar 2017, 09:48

The aircraft can carry 92 passengers, 6 pallets or combinations of the two. Although they excel at this, another important mission is refueling Marine and coalition aircraft during crisis response and contingency operations.

It can carry about 60,000 lbs. of fuel in order to support refueling missions for MV-22 Ospreys, F-16 Fighting Falcons, F-18 Hornets, or AV-8B Harriers, said Fair.

It was known in the air force as the "Bladder Bird" ...

wbh · by **wbh** » 06 Aug 2017, 04:06

One note of EXTREME CAUTION , never feed all 4 engines from the Fuse Tank to the crossfeed Manifold. All the protection you have is a 23 PSI "tank empty " light and if the pressure drops that low with all 4 on crossfeed from the fuse tank it's too late .
Best advice feed only 2 engines at a time from the fuse tank ( symmetrical engines ). Calculate FF vs Time vs quantity to be safe.

melvinsmiley · by **melvinsmiley** » 09 May 2018, 20:01

wbh wrote:One note of EXTREME CAUTION , never feed all 4 engines from the Fuse Tank to the crossfeed Manifold. All the protection you have is a 23 PSI "tank empty " light and if the pressure drops that low with all 4 on crossfeed from the fuse tank it's too late .
Best advice feed only 2 engines at a time from the fuse tank ( symmetrical engines ). Calculate FF vs Time vs quantity to be safe.

This would only an issue if you secured the main boost pumps. And none of us would ever do that unless we were trimming wing fuel for whatever reason. When we crossfed off of the fuse tank, aux tanks or externals we always left the main boost pumps running. Always.

wbh · by **wbh** » 10 May 2018, 19:49

I agree that what you say is 100% correct and proper fuel management and what I described could cause a 4 engine flameout.
Feeding all engines off the fuse tank without the main/aux /externals on is suspected in the "4 engine flameout" on an
HC-130P sometime back, over the Pacific at night.This accident prompted much speculation over the subject of a "4 engine flameout".

melvinsmiley · by **melvinsmiley** » 11 May 2018, 13:20

wbh wrote:I agree that what you say is 100% correct and proper fuel management and what I described could cause a 4 engine flameout.
Feeding all engines off the fuse tank without the main/aux /externals on is suspected in the "4 engine flameout" on an
HC-130P sometime back, over the Pacific at night.This accident prompted much speculation over the subject of a "4 engine flameout".

King 56. As I understand it, that aircraft was equipped with Benson Tanks. The transfer pump in those had the same limitations has the main boost pumps (15-24 psi). I imagine to use them, one would have to secure the main boost pump of the tank you were feeding. I've never used them myself.