Global Security.org
The W78 warhead, used on the Minuteman III, had seven flight tests (of the eight planned) between 1992 and 1996. DOE and the national laboratory officials told us that a flight test with telemetry equipment was not conducted because the Department decided to use the available warhead test slot on the test missile for a nontelemetry DOE test of the W78. Flight tests involve the actual dropping or launching of a weapon from which the nuclear components have been removed. DOE uses specially designed equipment-referred to as telemetry packages-to test the integration and functioning of the weapon's electrical and mechanical subsystems.he IW-1 LEP, after deferral, is slated to recommence in FY 2020, compressing that period slightly, in part to account for the work accomplished in FY 2014 and before. To avoid an unexecutable “ramp" in funding from FY 2020 through FY 2021, additional funding has been added in the FY 2022 through FY 2029 period to provide the nominal funding profile with the required amount of funding in advance of the first production unit.
To provide warhead diversity in the force, some Safety Enhanced Reentry Vehicle (SERV) modified Minuteman missiles would carry the W78 warhead. A number of W78 and W87 warheads will be retained as reliability replacements and surveillance assets to support the responsive force.
Air Force regulations prohibit air transport of nuclear weapons containing conventional high explosives (CHE), (i.e., B53, W62, W78) unless ground transport is not feasible. Air transport of CHE weapons requires approval by the Secretary of the Military Department or the Commander of the Unified or Specified Command or their designated representatives.In 2013, the Air Force plans to initiate a study, called the Ground Based Strategic Deterrent analysis of alternatives (hereafter “Minuteman III follow-on study"), to identify the best approach to upgrade or replace the Minuteman III. The Joint Requirements Oversight Council approved the Air Force’s initial capabilities document in August 2012, and since that time the Air Force drafted a plan for conducting the Minuteman III followon study.
https://www.globalsecurity.org/wmd/systems/w78.htm
