Experimental explosives: Airmen turn legacy bombs into precision munitions
Senior Airman Jimmy Mills observes Airman Joseph Goodus line up a guided bomb unit to the mounting brackets under the wing of an F-16 Fighting Falcon. This particular bomb will test an experimental height-of-burst sensor. (U.S. Air Force photo/Staff Sgt. Desiree N. Palacios)
During World War II and the Vietnam War, bombs weren’t technological marvels. They were little more than metal tubes with explosives inside and a fuse designed to set them off on impact. It took hundreds of bombs to destroy a target, with a good measure of luck thrown in. Today’s bombs are much more precise. Guided by lasers or Global Positioning Systems, they still use many of the leftover bomb casings from previous wars, but are able to hit a target with accuracy measured in inches. However, it’s the bombs of tomorrow that promise true smarts.
Eglin Air Force Base, Fla., is home to the Air Armament Center. Among other things, engineers at the center develop new munitions technologies and possess the ability to design, build and test those experimental munitions. In terms of bombs, the center’s latest innovation is making bombs flexible enough to give pilots more options than ever before.
According to Tech. Sgt. Wayne Beauchamp, a munitions Airman assigned to the 46th Test Wing, current bomb technology allows for precision delivery of munitions. But these smart bombs can be tailored, creating a specific bomb for a specific mission. For instance, the GBU-38 is a GPS-guided bomb built on the Mk-82 bomb casing, the same casings used during the Vietnam War. The guidance system allows the pilot to give the bomb a set of coordinates, drop it and leave the area while the bomb steers itself to the target. It works great for stationary targets, but what if the pilot is on a mission to destroy a weapons cache only to find that the weapons are now on a moving convoy or that the cache is split and the pilot now needs to take out more than a single target? That’s a problem being researched by AAC specialists.
Engineers at AAC have developed a bomb that incorporates laser and GPS guidance systems with a height-of-burst capability. This would give the pilot the option to change bombs as the mission changes, eliminating the need to return to base, change munitions and re-engage, a costly process in time and dollars. The height-of-burst capability, or HOB, would enable the pilot to set the altitude of the bomb’s detonation. Current bombs can be set to explode above the ground, causing significantly more damage, but at the cost of increased collateral damage. Allowing the pilot to determine the exact parameters would give tremendous flexibility to the pre-loaded arsenal.
Once the engineers develop the technology and the parts are built, the next task falls on munitions Airmen who build the bomb to order.
“We work with the engineers to build bombs never before tested,” Sergeant Beauchamp said, pointing to a finished pair of GBU-54s fitted with the new HOB sensor. The sensor, like all experimental parts, is painted orange. “In this case it’s an inert bomb with holes drilled in it so we will be able to see if the fuse goes off at the right time.”
These bombs eventually will be fitted with the fuse, loaded on to one of the 46th Training Wing’s fighters and dropped. “Seeing the one-of-a-kind bombs we make dropped is definitely the best part of the job,” Sergeant Beauchamp said grinning.
Once the munitions Airmen build the bomb, it’s delivered to weapons loading personnel at an awaiting aircraft and loaded by armament specialists. On this day, the bomb was fitted to an F-16 Fighting Falcon.
According to Master Sgt. Greg Young, NCOIC of weapons standardization for the 46th TW’s weapons flight, experimental weapons undergo a unique set of tests long before they hit the earth for the first time.
“One of the first things we do is a ground mount of the weapon onto an aircraft to make sure it fits properly,” he said. “Since we use existing bomb casings for many of the weapons, we know ahead of time that a bomb should fit, but we need to physically check it to make sure.”
Sergeant Young said the fit test is followed by an electromagnetic interference test to make sure the bomb is able to “talk” to the aircraft properly. The EMI test is followed by a flutter test.
“A flutter test is where we attach the munition to the aircraft and the pilot flies it through certain maneuvers to ensure it can handle the forces from the flight without falling apart or damaging pieces,” said Sergeant Young.
After the flutter test, the weapons Airmen take the bomb through a series of separation tests. During these, the bomb is fitted to a special rack that replicates those on the aircraft. They release the inert bomb from the rack using the same systems found on the aircraft. This allows them to see whether the new bomb releases properly and whether it would arm at the right time.
Only after these tests are done does the bomb get dropped. Most of the time, AAC researchers use bombs filled with concrete instead of live munitions, but they do possess the capability to design, build and test live munitions, sometimes remarkably fast.
“We’ve tested and fielded bombs in a matter of months,” said Sergeant Beauchamp. He uses the new small diameter bomb as an example. “It all depends on the needs of the warfighters on the ground. If they have an urgent need for a particular weapon we can prioritize it.”
Though the AAC engineers are capable of developing munitions on completely new platforms, like the SDB that uses a special mounting rack and bomb casings, much of the work brings new life to old bombs, sometimes very old bombs.
“I’ve seen bomb casings come in that are brand new,” said Sergeant Beauchamp. “I’ve also seen casings from the 1940s that become some of the most sophisticated bombs yet.”
Thanks to bomb builders and armament Airmen, old, dumb bombs are getting smart.
