Moab

[ShawnC]

As most of you know the USAF know has the largest conventional bomb, the MOAB, and it was tested earlier this week in FL.

February 27, 2003: The U.S. Air Force is developing a new, 2nd generation, ten ton large, low air burst bomb. It will replace the older "Daisy Cutter" 7.5 ton bomb developed during the 1960s. This was a 7.5 ton bomb using a semi-liquid explosive for clearing landing zones in the Vietnam jungle. The terms "Daisy Cutter" actually comes from the four foot probe at the bottom of the bomb which triggered the explosion without creating a crater (helicopters don't like to land in craters.) The probe was later replaced with a radar altimeter fuze, but the nickname "Daisy Cutter" stuck. The official designation was BLU-82 (or "Big Blue"). Until the BLU-82 came along, the biggest non-nuclear explosion obtainable was with a FAE (Fuel Air Explosives). FAE works by dropping a bomb that is actually a large aerosol dispenser. When the FAE "explodes" it first dispenses a large cloud of flammable material (anything like gasoline or propane will work). The cloud is then ignited and huge explosion results. There's one drawback, the size and density of the aerosol cloud depends a lot on the wind, air temperature and humidity. So the power of the explosion will vary a lot. But it's difficult to get a FAE to work in a bomb larger than 2000 pounds. So the replacement for the BLU-82 bomb, called MOAB (Massive Ordnance Air Burst) simply uses more of the slurry of ammonium nitrate and powdered aluminum. In dry, dusty conditions, the Daisy Cutter produces a mushroom cloud similar to that created by a nuclear explosion (and for the same reason, the sheer size of the explosion creates an upward pull that sends up a "mushroom" of smoke and dust on a column of smoke). In addition to a more powerful explosion, MOAB doesn’t need a parachute, like the Daisy Cutter, but uses a GPS (like JDAM) and an aerodynamic body to detonate the bomb at a precise area. Thus the MOAB can be dropped from a higher altitude (like outside the range of machine-guns and rifles). Like the Daisy Cutter, MOAB is shoved out the back of a cargo aircraft (usually a C-130, but since the MOAB uses GPS and higher altitude drops, the C-17 can probably be used as well.) MOAB is a highly destructive and terrifying weapon. If used in Iraq, it would demoralize any Iraqi troops in the vicinity who survived the explosion. The force of a MOAB explosion is sufficient to knock over tanks and kill any people within several hundred meters of the detonation. After the 1991 Gulf War, the United States started to get rid of it's various FAE weapons. But some were left in the inventory when the Afghanistan came along and the success of Daisy Cutters there, plus the new Russian research in FAE weapons, led to the new American research effort. There may be larger, or simply more powerful, FAE weapons in the works. But for the moment, MOAB, using pretty old fashioned technology, is the biggest non-nuclear bomb around.

http://www.lazyeights.net/Avion/moab.jpg
http://www.lazyeights.net/Avion/moabrear.jpg

Heres a vid of the test in FL
http://www.lazyeights.net/movies/moab.mpeg

 

[LearLove]

If i'm not mistaken the brits had a 22 or 25,000 lb bomb in WW2. They bropped it from the Lancaster I think it was called the Grand Slam.

 

[LearLove]

Is it me or is that a Dash 8........

Above the C-130 is that a Dash. Looking at the tail it looks like a DHC8 but then again maybe a C-12/king air. However it looks to be high winged like the Dash. I know the Air Force uses 2 Dashes in FL (calles E-9A's ?) with special equipment to clear test ranges. Could that be what it is above the Herc? Whatever it is I hope its there for testing/chase/range clearing or someone is in deep dodo. Can you say ASAP or NASA form.

 

[ShawnC]

If i'm not mistaken the brits had a 22 or 25,000 lb bomb in WW2. They bropped it from the Lancaster I think it was called the Grand Slam.

Well it couldn't have ever been used, a 22,000 bomb would only leave 500 gallons of fuel 25% full.

With the 25,000lb bomb it wouldn't have any fuel.

The Avro Lancaster according to Janes, and a gross weight of 61,500 lbs, and an empty weight of 36,500lbs. It carries a max fuel of 2154 gallons.

 

[ShawnC]

Ok I'm an idiot I looked up on the internet, the Avro Lancaster was used for a 22,000 lbs bomb, but I still assertian that it couldn't have carried much fuel. I would hate to be the pilot, watching every gallon.

 

[banned username 2]

Ok I'm an idiot I looked up on the internet, the Avro Lancaster was used for a 22,000 lbs bomb, but I still assertian that it couldn't have carried much fuel. I would hate to be the pilot, watching every gallon.

Don't forget in war times (especially back then) they did "whatever it takes" to get the mission done, if it meant taking off 10,000 lbs over gross, so be it, they just hoped it would fly...

 

[LR25]

There is some pretty neat footage of those dam busting Lancasters.

 

[46Driver]

Over on the www.pprune.org website, they are showing photos of the 44,000 lb T-12 bomb that the USAAF built back in the 40's or 50's. It was designed to be dropped by the B-36. That is one BIG bomb.....

 

[jergar999]

I know there are both peacetime and wartime gross weights for most aircraft, maybe that is the disparity. The C130 crash fire fighting this summer is suspected of overstressing the main spar by constantly operating at the wartime weight.

 

[LR25]

I hear Avbug coming.

Seriously, he has intimite knowledge of that kind of ops. and that aircraft paticularly.

Good to have you back Bug!

 

[avbug]

Jergar999, C-130 wartime weight? The C-130 is operated within limitations, period. The C-130A model had a 124,000 lb max gross takeoff weight, and was restricted in it's tanked version in the Hemet conversion, to 120,000 lbs. Later model hercs' operated at much greater weights.

I don't know where the guesswork on T-130 came from, but it's wrong. Nobody suspects it of operating overgross. Prior to acceptance for tanker operations, it was specifically configured for electronic intelligence operations, and didn't operate at close to gross weights then, either.

The fact is that T-130 was provided a limitation of 4,000 lbs. below the standard weight for a C-130A. It was never operated at, or in excess of that lesser limitation, either.

Operating regularly in severe to extreme turbulence, on the other hand...

 

[Hovernut]

Don't tell me those folks named it for the

M other
O f
A ll
B ombs

when they came up with that acronym.

Moab, Ut, would just assume it be called:

B omb
I s
G igantic

A nd
P acks
P owerful
L ethal
E xplosion

 

[jergar999]

Avbug,

Thanks for the info. I had flown into Cedar City a few days after the fact, and the NTSB personnel there were speculating that weight was the factor in the wing spar failure. I personally have no knowledge of the C130, just passing along what I had heard. Are there any military aircraft with different weights for war and peace time, or is that a misconception I picked up somewhere?

 

[avbug]

The C-130A had no spar. It had two shear webs that essentially formed the fore and aft fuel cell walls, but wasn't really what could be called much of a load bearing member. If you climbed into the wing, you'd find it is essentially ribs and skin, with corrogated planking on the wing center section.

It's a three part wing, with two outer sections, and a center section which is part of the fuselage airframe.

When the skin cracks, the wing comes off...as it's done before. Every C-130 in the fleet had cracked wings, every season. In fairness, as very detailed inspections are presently being performed, so did all the P-3's and P2V's. One DC-4 was discovered this winter to have some 56 cracks in the wing.

It's all about the turbulence, and kicking loose the load while maintaining altitude or a slight descent. The wings are trying to lift that weight, while the crew is trying to force the airplane down. Upon drop, a terrific bending moment is placed on the wing, at a time when it's already being flexed up and down violently.

The drop is flown close to terrain, almost always in mountainous terrain, and generally in notable winds...which are generally driving the fire. The result is a lot of turbulence, and a lot of stress on the airframe.

I was in T-130 several years ago when a company herc behind us lost the flight engineer, who was ejected out of his seat due to turbulence. He bounced off the overhead panel, and hit the cockpit floor behind his seat. He hit the ceiling again, then ended up hitting the floor in the cargo bay, an didn't make it back for the drop. I bunked with him that night; he was sore and not a little unhappy.