Programmed Depot Maintenance: A major milestone in Minuteman III sustainment

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HILL AIR FORCE BASE, Utah — Since the first Minuteman I came on alert during the Cuban Missile Crisis in 1962, Minuteman intercontinental ballistic missiles have been the cornerstone of America’s nuclear deterrent force. Designed for a 10-year life, the Minuteman III is still going strong after more than 45 years as the ground-based leg of the U.S. Strategic Triad, one of the two legs the Air Force supports.

Throughout Minuteman history, the Air Force has applied a “fly-to fail” methodology, focusing on alert rate over preventive maintenance, to sustain the robust, reliable and redundant ICBMs (I, II and III). However, keeping 450 launch facilities and 45 launch control centers viable through the current missile’s projected end-of-life in the 2030s has required a fundamental shift in ICBM sustainment strategy, one firmly grounded in reliability centered maintenance.

The journey to reliability centered maintenance began with the development of programmed depot maintenance, a first for Minuteman. The four-year effort to achieve PDM was recently realized, with the first launch facility to have completed PDM returning to alert status in late May. This event marked a significant point in the history of ICBMs and is the culmination of exhaustive efforts by hundreds of professionals in the nuclear enterprise to apply a sound life-cycle management approach to ICBM sustainment and provide the warfighter with the most capable assets possible.

For the first time in its history, the Minuteman III weapon system is aligned with the standard Air Force process of PDM, planned through the aircraft missile requirements process and funded through centralized asset management. This approach enables predictable resource demands, with an ability to accurately forecast parts and commodity requirements while simultaneously supporting critical industrial capacities in both the organic depot and private sectors.

“The entirety of the Minuteman III weapon system is included in the execution of the reliability based maintenance plan,” said John Faulkner, product support manager for the Air Force Nuclear Weapons Center’s ICBM Systems Directorate at Hill AFB.

The Minuteman III PDM effort targets four major areas through an eight-year cycle: launch facility, launch control center, solid-rocket booster (stages 1, 2 and 3), and liquid-propellant propulsion system rocket engine. Within the launch facilities and launch control centers, there are a variety of components targeted to ensure the readiness and health of the site, including shock isolators, various launcher closure components, overpressure-protecting blast valves and blast doors, and environmental control system components. Booster PDM refurbishes the flight controls for each stage and PDM for the propulsion system rocket engine replaces the axial engine actuators and other wear components.

Programming Maintenance

Programmed depot maintenance is a dynamic activity; it adapts to changing environments and is based upon engineering assessments.

“The weapon system tells us what it needs and consequently PDM will continue to grow and include subsystems and components identified in failure and condition analyses,” Faulkner said.

The fiscal year 2017 marked the start of and its first year has 38 combined tasks scheduled for the launch facility and launch control center. The task count grows to 41 in 2018 and 42 in 2019. The long-range projection for tasks shows 58 by Fiscal Year 2022. Review of PDM tasks is a continuous part of the process, and tasks will be added or removed as necessary.

Air Force Global Strike Command and Air Force Materiel Command seamlessly team throughout the process, from clearly defining requirements and establishing funding parameters to managing the execution of PDM at the wings. AFGSC’s missile wings configure and prepare the site for PDM while AFMC depot field teams from the 309th Missile Maintenance Group complete the PDM tasks. The two commands share a common set of metrics and continuously interact to improve the process.

Pivotal to the progress and success of the PDM initiative are the efforts of the supply chain professionals of the 748th Supply Chain Management Group and the Defense Logistics Agency. Jointly, these teammates devised unique methodologies for supplying depot field teams at each missile wing with the materiel needed to successfully refurbish launch facilities and launch control centers. Maintenance teams now have all needed parts in one build set, marking an extraordinary advancement in supply effectiveness and efficiency, according to Faulkner.

Predicting Health

Central to the shift in ICBM sustainment philosophy towards a reliability centered maintenance approach is the predictive health measure.

The predictive health measure is “a quantitative, predictive force health metric by launch facility/launch control center ‘tail number.’ Its central objective is calculating each launch facility’s or launch control center’s relative health within the standard sustainment life cycle as defined by the eight-year programmed depot maintenance interval,” said Frank Adams, logistics management specialist, ICBM Systems Directorate.

This metric is unique because it informs the missile wing how best to apply limited resources to yield the healthiest combat force. The predictive health measure is a game changer, providing a standardized, holistic assessment of Minuteman III health more precisely and more comprehensively than legacy metrics, according to Adams.

Building a Legacy

“We have come a long way since I joined the Minuteman III team in 2013. We have built the program from the ground up and are on target to reach full operational capability in FY 19,” said Richard Cummings, the directorate’s PDM manager for launch facilities and launch control centers.

Full operational capability will produce refurbished assets at an annual rate of 57 launch facilities, six launch control centers, 69 boosters, and up to 96 propulsion system rocket engines.

The shift to comprehensive reliability centered maintenance and adoption of a PDM program will be a lasting legacy for the ICBM enterprise. Programmed depot maintenance is now built into modification programs and support equipment acquisitions. Most importantly, the Minuteman III replacement, the Ground Based Strategic Deterrent, will be fielded with these maintenance approaches already in place.

According to Faulkner, GBSD will take the maintenance baton into the future with a solid sustainment strategy, providing the nation with another half-century of nuclear deterrent capability.