24-Oct-2019 Source: US Army
Recent guidance from the U.S. Army Aviation and Missile Command breathes additional life into several dynamic components of the Black Hawk helicopter, ultimately improving readiness for the workhorse of Army aviation.
An AMCOM safety message dated Sept. 9, updated the time to change out or retire more than 20 parts, increasing component time for aircraft in the fleet.
As the Army aviation airworthiness authority, AMCOM’s Commander, Maj. Gen. Todd Royar, said the new guidance is one of the ways the organization is reducing maintenance time for aircraft.
“Extending the lifecycle of multiple components reduces down time and directly impacts units and their missions,” Royar said. “We have an obligation to help commanders in the field decrease maintenance time,” Royar said. “Minimizing maintenance time so commanders can maximize their options is our obligation.”
For commanders, extended component life means an increased ability to engage in critical aircraft missions, from troop insertion and extraction to support for natural disasters.
“Extended component life not only improves system availability to the users, but it also reduces maintenance and system’s lifecycle cost for the bill payers” said Col. Calvin J. Lane, Utility Helicopter Project Manager for Program Executive Office Aviation.
Sikorsky’s UH-60 twin-engine, medium-lift utility helicopter entered Army service in 1979. Since that time, the Army’s Black Hawk has undergone many modifications. Today, it serves in several roles, including basic transport, air assault and medevac.
The U.S. Navy, Air Force and several foreign countries also fly variations of the aircraft. The safety message affects most aircraft in the UH-60 fleet, including those in all military branches and foreign markets.
The new guidance stems from a collaborative effort between Sikorsky, Program Executive Office – Aviation, and Army Combat Capabilities Development Command’s Aviation and Missile Center, said AMCOM’s Aviation Branch Maintenance Officer, Chief Warrant Officer 5 Michael Cavaco.
“This effort reduces the maintenance burden in the field and improves safety and reliability,” Cavaco said. “Improved data collection and coordination with the original equipment manufacturer is part of our continuous improvement process.”
Initial longevity projections for components on all aircraft begin with an abundance of caution. Reviewing those projections is a continuous process, said AMCOM Safety Director Pat Vittitow.
“Sometimes we see something in the field and we get new data or a process changes. A number of factors can alter the original set point,” Vittitow said. “Original equipment manufacturers also make many recommendations that come from part-life trend analyses.”
Careful evaluation and due diligence is conducted before bringing any recommended changes to the commander, Vittitow explained. “A good deal of parts and a good deal of data must be considered.”
Extending the life of several parts produces a secondary benefit, explained Tod Glidewell, an AMCOM aviation analyst.
“When you take something apart, you risk unintended damage during the maintenance process,” Glidewell said. “Eliminating unnecessary maintenance reduces undue stress on the aircraft.”
Glidewell said the Condition-Based Maintenance process, which examines how different components degrade during operation, also helped inform this latest guidance.
“The science and the system came together to give us high confidence in extending the repair and retirement time for specific parts,” Glidewell said.
Sikorsky’s analysis reviewed the fatigue life on certain parts, using both laboratory analysis, as well as monitoring systems on test aircraft, said George Prosnik, a member of the UH-60 System Safety and Product Quality Team at Combat Capabilities Development Command’s Aviation and Missile Center.
“Testing measured the stress loads and other variables to determine the strengths and weakness of the dynamic and structural components,” Prosnik said. “Improvements in structural and material analysis since the dynamic components were originally designed in the 1970s, as well as data from the flight-hour usage spectrum of the aircraft since they were built, were additional factors in driving the increase for these components’ hours.”
As a life-cycle management command charged with sustaining aviation systems, AMCOM also looks at how extending aircraft components will impact the supply chain.
“Anytime you can extend the life of parts, the burden on supply chain is reduced,” Cavaco said. “If we can keep more parts on the shelf, it builds supply-chain depth and, ultimately, readiness.”