Operations & Mainenance: HUMS on Board

By By James T. McKenna | October 1, 2006

Health and usage monitoring system, or HUMS . It is one of those operational and safety technological developments that has become a four-letter word for many helicopter operators and aircraft manufacturers.

In polite conversation, they use words like “toys” and “smoke and mirrors” to describe the systems that have been billed as cure-alls for reducing maintenance problems and operating costs. The reason is that too often the systems sold have failed to fulfill such promises. Add to that the fact that many of the systems offered cost hundreds of thousands of dollars and carry with them nearly as pricey data-analysis contracts.

Three years ago, that was costing Bell Helicopter a significant number of sales. It was relying on commercial vendors selling HUMS as add-on kits for helicopters, and that approach was not working.


At the time, international oil and gas companies, led by Shell, began insisting that aircraft flying their workers to offshore platforms have on board a number of safety features, including HUMS . An engineer at Bell named Joe Wendelsdorf was charged with reversing those sales losses.

Shell is “the big guy on the block when it comes to HUMS ,” Wendelsdorf said. In a meeting on the subject, he said, one Shell official said the following about a HUMS that had been pitched to one of the companies from which the energy company contracts helicopter services:

“Hey, we don’t know what it does, the operator doesn’t know what it does, and we’re not sure the guy who made it knows what it does.” The Shell official then told Wendelsdorf that if Bell was going to offer that HUMS for its aircraft, “don’t even bother.” Still, Shell wanted a reasonably priced and effective HUMS on all aircraft flying its crews. Wendelsdorf had to find an answer. He turned to the U.S. Army.

For 15 years or more, Bell had been working with the Army to develop rotor track-and-balance systems. “We’ve had cooperative research agreements with the Army dating back six years on development” of HUMS -like device, too. “So we pulled that out, presented it to Shell and said, “What do you think of this?’” Comparing it to the other systems that were available, Wendelsdorf said, it turned out to be the lowest cost, lowest weight and an approvable system by Bell’s target customer.

“They said, ‘That will work.’”

What Bell showed Shell was a system based on products developed by a San Diego company called Intelligent Automation Corp. That company had refined its aviation diagnostic technology working as prime contractor with the U.S. Army and the South Carolina Army National Guard for the Vibration Management Enhancement Program to develop a digitally integrated, embedded health management system for Army rotorcraft. Vibration Management Enhancement Program today is installed on every Army helicopter model, according to the company, and is a primary Army source of information for the Office of the Secretary of Defense’s Condition-Based Maintenance-Plus Initiative.

Bell took Intelligent Automation’s system, built around its IA C 1209 Modern Signal Processing Unit, and ran through it taped data from an old test it had conducted running a damaged gear to failure. “It clearly showed the gear beginning to fail well before it actually failed,” said Wendelsdorf. “So that said, ‘OK, their diagnostics are pretty good.’”

The diagnostics also are based in part on the RADS system that is Bell’s standard for rotor track-and-balance system, “so we knew it could” do the “day-to-day maintenance kind of stuff” customers needed such systems for, he said.

Today, Bell is offering the Intelligent Automation HUMS on all its new 412s. Its affiliate, Aeronautical Accessories, holds a supplemental type certificate to install the system as a kit on that aircraft. About a year after approval of the ST C, 22 Intelligent Automation HUMS have been installed and roughly another 20 are in the pipeline. While the biggest demand for the system is from operators serving the oil and gas industry, the first Intelligent Automation HUMS was installed on a corporate 412, Wendelsdorf said, and aeromedical operators are showing interest.

The HUMS is paired with the IA C 1047 Intelligent Machinery Diagnostic System Web-based server, which allows Bell to monitor the condition of HUMS equipped aircraft around the world and alert operators to latent maintenance faults before there are any obvious signs of a pending failure. “Customers anywhere in the world automatically upload data to a central server, which Bell has access to, and we can review the data and make maintenance- action recommendations to them basically anywhere,” Wendelsdorf said.

Bell’s use of Intelligent Automation’s products is just a drop in the bucket compared to the Army’s use.

The IA C 1209 signal-processing unit is installed on more than 180 Boeing AH-64 Apaches, Sikorsky UH-60 Black Hawks, and Boeing CH-47 Chinooks. The IA C 1047 has been in operation with the U.S. Army for four years, supporting those aircraft.

One unit, the 3rd Aviation Regiment (Attack Reconnaissance) of the Army’s 3rd Aviation Brigade reported a 10- percent readiness improvement using a condition-based maintenance approach enabled by the IA C 1209.

In their after-action report, the unit said, “As a medium to spearhead the initiative for condition-based maintenance in U.S. Army aviation,” the Vibration Management Enhancement Program “has provided the battalion the capability to conduct smarter and more efficient maintenance. The effects of this newly acquired capability were increased safety, increased troubleshooting and diagnosis ability, decreased maintenance cost, and decreased aircraft downtime, which all led to maximized combat power generation.”

Condition-based maintenance is a major initiative of Maj. Gen James Pillsbury, commander of the Army’s Aviation and Missile Life-Cycle Management Command. He has said he sees it as critical to bringing aircraft operating costs under greater control and helping Army aviation survive in an increasingly restrictive budgetary environment.

As a result of the demonstrated performance of the Intelligent Automation products, according to the company, the U.S. Army granted airworthiness releases, or “maintenance credits,” for its aircraft equipped with the IAC 1209 health and usage monitoring system (HUMS ) units. Releases have been granted to eliminate the main-rotor swashplate inspection on the AH-64 (saving about 7.5 maintenance manhours and about 6 hr aircraft downtime) and the APU clutch v ibr a t ion che c k and extend mount inspection (saving 28 hr maintenance man hours and 9 hr aircraft downtime.

Othe releases extended the time between overhauls (TBO) on the Apache’s aft and forward hanger bearings by 10 percent each.

On the UH-60 Black Hawk, the Army issued an airworthiness release that eliminated the engine output drive shaft 120-hr inspection (saving more than three manhours and about 2 hr aircraft downtime. It also issued one that raised the TBO on the Black Hawk’s oil cooler fan by 20 percent.

In August, Intelligent Automation received a contract from the Army’s Apache project office for 72 more IA C 1209 Modern Signal Processing Unit HUMS , at about $35,000 a unit. The Army also has approved the system for installation on all 750 of its Apaches.

“It’s gotten to the point on” Apache gearboxes that the Army can detect latent failures early enough and act in response “that they don’t have the catastrophic failures on those gearboxes,” said Jeff Goodrich, a cofounder of Intelligent Automation and its CEO . He explained that by catastrophic, he doesn’t mean that an aircraft crashes. Rather, he said, the system helps Army maintainers prevent gearbox failures from “chipping out” the unit.

“Once it chips out, that component is damaged beyond repair,” Goodrich said. ”So we’re able to tell them very, very early on, ‘Hey, there’s a bearing problem, go fix the bearing problem,’ which saves that component. There are numerous examples of problems like that, where you can tell them very early, ‘Hey, there’s going to be a problem with your engine drive shaft,’ so it doesn’t tear the engine out, or a hanger bearing so it doesn’t tear up a shaft.”

Goodrich said the turning point in the Army’s acceptance of Intelligent Automation’s products may have been an Apache deployed to Kosovo several years ago. The Intelligent Automation system indicated a problem with the swashplate bearing. The Army’s manual inspection procedures produced no signs of a fault. Maintainers elected to look closer and found the bearing was disintegrating. “What that moment said was we could find a very subtle fault they didn’t know about,” he said. “The manual inspection procedures did not work and it was potentially very much a safety of flight issue.”

Intelligent Automation was founded in 1999 by a team of engineers, scientists, and managers committed to producing affordable, easy-to-use systems that predict and diagnose aircraft mechanical faults. The team has several advanced technology efforts under way in the fixed-wing, shipboard, industrial, water security, and advanced information systems markets, as well as the rotorcraft industry. Intelligent Automation’s advanced biomonitoring system, which uses fish as sensors, is used to protect the water supplies for New York City, Washington, San Francisco, and the U.S. Army.

Intelligent Automation has grown by over 30 percent a year through research and development contracts and product development. The company reported revenue of $9.5 million in 2005 and projects that will rise to $12 million this year. It claims to be one of the world’s leading suppliers of helicopter and turbine engine diagnostic products. Headquartered in San Diego, it has a manufacturing plant in Columbia, S.C. and an engineering support site in Huntsville, Ala., near the U.S. Army’s Redstone Arsenal.

Goodrich said Intelligent Automation’s products have won acceptance in the U.S. Army “because people were working in Korea on Black Hawks and they found oil cooler bearing problems. It happened because the 3rd of the Third went over to Iraq and experienced the rotor track-and-balance and all the other component fault finds and they claimed a 10-percent readiness improvement.”

Those successes began to build a word-of-mouth case among Army maintenance officers, he said, that said, “Hey, not only was the vision right that General Pillsbury has but the vision is real,” Goodrich said. “We can really do this. We can really solve problems.”

Bill Lawler, another co-founder and the company’s vice president of sales and marketing, pointed to what he said is a key difference with other HUMS offerings: Intelligent Automation makes all its data available to the customer.

“Everything we collect is available on the Web site. It’s all been validated by third parties. We don’t claim any proprietary magic,” he said. “If we say, ‘I want you to change that gearbox,’ and you’re a manager, you’re going to say, ‘Tell me exactly what you’ve got and why I’m going to make a potentially very expensive decision.’ You want to be right.

“The other guys go, ‘Well, the answer’s B,’” Lawler said. “Why is it B? ‘Well, cause I say so.’”

Col. Lee Eisner, assistant adjutant general of the South Carolina Army National Guard and a long-time advocate of the Intelligent Automation system, said that is among its key advantages. “It’s designed so that the 10-Level mechanic just coming out of school can look at the system and use it,” he said. “It’s not designed for a guy to have a Ph.D.”

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