The MK-84 is a free-fall, nonguided GP 2,000-pound bomb. The MK 80 series Low Drag General Purpose (LDGP) bombs are used in the majority of bombing operations where maximum blast and explosive effects are desired. LDGP bombs are designed to be aerodynamically streamlined. Their cases are relatively light and approximately 45 percent of their complete weight is explosive. General purpose bombs may use both nose and tail fuzes and conical or retarded tail fins. Normal fuzes are the mechanical M904 (nose) and the M905 (tail). Most of the over 12,000 MK-84s expended during Desert Storm were dropped by Air Force F-15Es, F-16s and F-111Fs; less than 1,000 of the total were dropped by Marine Corps tactical aircraft.
The MK84 AIR is a 2,000 pound bomb modified with a BSU-50/B high drag tail assembly. The "ballute" air bag which deploys from the tail provides a high speed, low altitude delivery capability by quickly slowing the bomb and allowing the aircraft to escape the blast pattern. The tail assembly consists of a low-drag canister unit containing a ballute (combination balloon and parachute), and a release lanyard assembly that opens the canister releasing the ballute. The ballute assembly is made from high strength low porosity nylon fabric. When the bomb is released from the aircraft a lanyard unlatches the back cover which opens, releasing part of the nylon bag/retarder. Air turbulence at the rear of the bomb acts on that portion of the retarder, pulling the remainder out of the housing. Ram air inflation is accomplished through four air inlet ports toward the aft end of the ballute. The weapon can be delivered in the low-drag mode (canister remains closed after release) or in the high drag mode. The pilot may select either a high drag or low drag configuration depending on mission requirements.
The MK-80 series was developed in the 1950s in response to the need for bombs producing less aerodynamic drag. All MK-80 series bombs are similar in construction. MK-80 series bombs are cylindrical in shape and are equipped with conical fins or retarders for external high-speed carriage. They are fitted for both nose and tail fuzes to ensure reliability and produce effects of blast, cratering, or fragmentation. During Desert Storm the MK-80 series of bombs were dropped from literally every fixed-wing aircraft that supported the ground offensive. The bombs were used against a wide variety of targets, including artillery, trucks, bunkers, Scuds, surface-to-air missile sites, antiaircraft artillery sites, early warning radars, and supply points.
MK-84 Insensitive Munitions (IM)
The original MK-84 (2,000 pound) Insensitive Munitions (IM) Technology effort was initiated in response to Office of Secretary of Defense (OSD) disapproval of the FY00/01 MK-84 bomb procurement. In order to meet the DoD requirements for weapons to conform to IM criteria, OSD allowed the FY00/01 buy to proceed if the Air Force formulated and funded a program to provide future GP bombs that would meet the IM criteria. The plan was approved and funded by the Air Force Secretariat in FY01. Program execution is an AAC/WMG and AFRL/MN effort. The plan focused on the only GP munition planned to be procured (MK-84) and based on a single explosive technology, AFX-645, developed in the 1990s for the MK-82. It provided the promise of meeting the IM requirement while maintaining the weapon's current lethality. Due to a DoD wide TNT shortage and possible MK-82 (500 pound) requirements, the IM program was restructured to explore other explosive technologies (non-TNT) and possible bomb case modifications. In February 2002, AFRL/MNME proposed a restructured program to the Secretariat and it was approved. Subsequently, there are two concurrent efforts to meet the IM requirements of MIL-STD-2105B: a new insensitive high explosive fill being developed by AFRL/MNME, and MK-84 bomb case design modifications managed by AAC/WMG. Together, they will provide a system level solution to the IM requirements.
The Key Performance Parameters of the MK-84 IM Technology Program follow: Threshold Requirements:
- Equal or better operational performance than the current MK-84 bomb filled with Tritonal.
- Equal or better IM response than the Navy's BLU-117 (MK-84 filled with PBXN-109).
- Maintain form, fit and function with current MK-84 fuzes, guidance packages, and tail kits.
- Preserve the current MK-84 bomb mass properties, thereby minimizing flight recertification.
The Government intends to award one or more contracts for Concept Technology and Development (CTD) with options for System Development and Demonstration (SDD). To achieve IM compliance with the MK-84, the contributions from both a less sensitive high explosive fill and bomb case modifications must be considered. The Air Force Research Laboratory is currently developing insensitive high explosive fills suitable for insertion into the modified MK-84 bomb case. The offeror(s) will be responsible for developing and delivering improved MK-84 bomb cases for testing.
For the CTD effort, the offeror(s) will design, produce and deliver prototypes to McAlester Army Ammunition Plant to be filled with PBXN-109. The Government will supply the MK-84 cases to be modified and the explosive fill PBXN-109. McAlester will fill the prototypes and Air Force SEEK EAGLE Office (AFSEO) team will perform mass properties inspections. The Government will ship the prototypes to Eglin AFB for test. The offeror(s) will provide engineering support during MIL-STD-2105B and performance testing.
For SDD, the Government will supply current MK-84 cases for contractor modification and the new insensitive high explosive fill developed by AFRL/MN. The prototypes will be filled at McAlester with the new fill and the mass properties inspected by AFSEO. The Government will ship the prototypes to Eglin AFB for full IM qualification, Hazard Classification, and performance tests. The end result will be a change to the MK-84 drawing package.
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