The effect of the explosion would still be devastating, regardless of the placement of the fuel tanks. The concussive force of the blast would almost certainly:

A) Blow the nearest three rows into the next three rows (with about a 100% fatality rate for all involved) and

B) Puncture the skin. B is really much worse.. Understand that when that 350mph+ wind now starts pulling at that metal it is like a hand, and it will rip the skin off like peeling a bannana, taking away various necessary bits of electronics that might be needed to guide, land, or communicate. The nearest six rows, all weakened by the blast and collision from the first three will probably then seperate from the aircraft.

You can also add:

C) Explosive decompression at altitude. While B is happening, everything and I mean everything from pens and glasses to glassware and food carts which is not nailed or bolted down will start to be sucked out of the aircraft. It will be like sitting in a Force 10 Hurricane at point blank range.

To get an idea, take a look at any page involving the Aloha Flight 243. http://www.aloha.net/~icarus/

Understand.. these guys were a few miles from the airport when they had explosive decompression of only the top part of the fuselage, and there was NO bomb on board wreaking havoc at the time. They barely made it onto the ground and that they did is both a testament to the pilots skills and the folks at Boeing.

1000mi out over the Atlantic? Your chances are slim to none. And slim left town.

This is not to scare anyone, but the point is this. Even a small Semtex/C4 bomb, probably less than a pound or two (as was in Pan Am 103) can absolutely bring down an aircraft. Not necessarily by sheer immediate destructive power, but by puncturing the skin of the aircraft, destroying control surfaces and letting wind resistance proceed to shear parts of the aircraft away.

Regards,
-Bouncer-