It’s well accepted that Health and Usage Monitoring System (HUMS) technology delivers safety, readiness and other operational benefits for military helicopter operators. It does this by monitoring the health of vibrating and spinning parts and recording the operational context of events so that flight and maintenance crews can analyze trends and perform condition-based maintenance.
The economic benefit HUMS brings to the table is also very significant, according to cost and benefit analysis done by the University of South Carolina’s Condition-Based Maintenance Center and Department of Mechanical Engineering. The study, done in cooperation with the South Carolina Army National Guard (SCARNG), was conducted over an eight-year period beginning when the first HUMS was installed and continuing until the entire SCARNG fleet of AH-64 and UH-60 helicopters was fielded in 2007.
The study looked at the cost savings in parts cost, operational support, the increase in mission capability rates, the decrease in scheduled and unscheduled maintenance and the increase in total flight time.
Researchers concluded that the use of HUMS resulted in savings in parts cost and operation support of $2.1 million. Much of this savings can be attributed to a reduction in the number of hours devoted to maintenance test flights as maintenance crews became familiar with the HUMS-enabled Vibration Management Enhancement Program (VMEP). The study team calculated per-aircraft savings due to maintenance test flight reductions for just rotor track and balance to be $121,000 per aircraft over the eight-year study period. Using their calculations, the system yields a 100 percent return on investment in four years on savings from these test flights alone.
In addition, the SCARNG experienced a 75 percent reduction in unscheduled maintenance, a key indicator of mission readiness. According to the study, unscheduled replacements were reduced to less than 4 percent of total maintenance actions. Annual savings from parts usage was $75,000 per aircraft.
The study also measured non-tangible benefits of the HUMS implementation through the use of surveys and focus group sessions with flight and maintenance crews. Feedback from these SCARNG members who actually use the system daily showed marked improvement in safety, sense of safety, performance, mission, morale and other critical factors. For example, sense of safety improved by 30 percent, ease of troubleshooting improved by 32 percent and confidence was up 20 percent, the crews told researchers.
On the subject of safety, HUMS is credited with preventing several potential accidents. After an AH-64 accident in which no one was injured, Army Engineering analyzed HUMS data and identified three other aircraft with the same tail-rotor bearing issue that caused the accident. Bearings on those aircraft were replaced before they could cause another accident. The problem with the bearings might not have been identified and addressed as quickly and efficiently without data from the HUMS.
Honeywell Aerospace is a leading global provider of HUMS technology. Various versions of Honeywell’s system are flying on a wide range of U.S. military helicopters including the U.S. Army CH-47D and CH-47G Chinook, AH-64D Apache, OH-58D Kiowa, MH-60M Black Hawk, and the U.S. Coast Guard MH-60T Jayhawk. Honeywell has delivered more than 1,500 HUMS shipsets for use on military rotary-wing aircraft.
You can view our HUMS infographic.