“...I would think it would be easier to take a few feet off the length of the bomb that to re-engineer the wings on a B-52.” [21twelve, post 19]
“Just my thoughts. Three feet shorter and more powerful chemicals.” [Doc91678, post 29]
The reality is exactly the opposite.
There is no extra space inside a bomb’s case: just enough for a specified quantity of the main charge, initiators, fuzing, sometimes guidance components. Even the smallest change affects everything else, sometimes in unforeseen ways.
And changing external dimensions affects a great deal more than the size and weight. It affects the weapon’s center of gravity and aerodynamic characteristics. Munitions are never simply hammered into shape and hung on a warplane: they must be tested in every likely flight regime, at different airspeeds, altitudes, dive (or climb) angles, roll states, and more. The design goal is safe and expeditious separation of munition from aircraft.
Some work can be done in part with wind tunnel tests and scale models, but live flight test is always required before the munition and airframe combination is certified by DoD’s Non-Nuclear Munitions Safety Board. And it must be done for every combination of munition and aircraft that might be used. Certification testing takes weeks and weeks, even when all goes well; sometimes problems are uncovered (like the munition flying back up and hitting the airframe); then the munition - or its mounting and launching systems, or both - must be modified. Then certification starts all over again. Ultimately, entire books filled with graphs and tables are compiled, to enable users to figure out what a munition does and how to use it, in a hurry.
So if one already-certified munition is changed, all the different aircraft for which it had been certified must be re-tested and re-certified.
Only when all the certifications have been completed, can munition performance and effectiveness testing begin. These tests collect the data used by unit weapons officers sortie planners, and campaign planners at higher levels to decide what munition will be employed against what target, and in what manner.
Effects on target are not the only consideration here: extremely critical safety data is collected at the same time, to give the planners and aircrews vital information on how low they can fly and still launch the munition, how fast they must fly to escape fragments or blast from their own munitions, what dive/climb angles are permissible, what fuze delays can be used, how closely other craft in the formation (if any) can follow, etc, etc.
For munitions containing electronics - almost all these days - electromagnetic compatibility and interference tests are conducted at the same time. Aircrews need to know if radar, radio, navigation systems, self-defense systems, etc on the aircraft can be operated without inadvertently triggering the munition. Same information is needed about ground support systems that operate in the vicinity of the warplane or munition: radar, beacons, many others.
Concerning the “power” of the main charge, the term is too vague to permit short, simple answers. Nonnuclear explosives have a great many attributes: are we talking about total heat energy evolved? Brisance? Detonation velocity? Stability? Sensitivity to heat? Shock? There are many others.
It can never be as simple as swapping in a different chemical.
Wow, a munitions expert answers the questions. And here all I expected was a yes.
Then there’s the possibility of modifying the bomb bay to accommodate the MOAB.