EXECUTIVE SUMMARY
There is an increasing desire for the implementation of condition based maintenance programs to replace the traditional hour based maintenance on Military rotor wing aircraft. There are several advantages and disadvantages to this type of maintenance. The purpose of this paper is to discuss both and the affect that they play in regards to the organizational behavior of a business. There are distinct advantages in regards to cost when we talk about condition based maintenance. Replacing a part only when it is likely to fail saves the cost of replacement at a possible earlier time like in a phase based program, or catching a part that might have failed prior to the required hour inspection or replacement time. But this new technology comes with a cost. A cost, not only monetary, but also within the organizational behavior of a corporation or organization such as the military. When we talk about Managing change and stress, we have to talk about the external forces of change effecting these technological advancements. The technology of condition based maintenance is justified through the savings it generates through the maintenance program but what cost will it have on the people working on these aircraft? Will there be a reduction in jobs? This concern can start trouble, rumors, and decreased production from employees that normally work hard. What effect will it have on the organizational design? Will there be an increase or decrease in managerial roles? Will there be an increased perception of reliability or confidence of the aircraft from the crews that are responsible to fly them on missions? These are all questions that the answers directly affect the organizational behavior of an organization.
BODY
Phase Maintenance inspections are currently what’s being used to determine if components need to be replaced. There are several hour required inspections for the UH-60 Blackhawk. First is a PMD or “Preventative Maintenance Daily”, these checks take place at the end of the day after the helicopter is done flying or every seven days if the helicopter hasn’t been flying. Second is the PMS or “Preventative maintenance services” are required to be done every 40 flight hours, consuming about 15 to 20 man hours and can be accomplished in one day with two maintainers. Third is the120 flight hour inspection which takes two to three days and checks for critical vibrations of the engine high speed shafts, tail rotor and cooling fan. Lastly is the PMI or Phase Maintenance Inspection which is accomplished every 360 flight hours. There are also smaller inspections like gearbox oil samples taken on an hour requirement to determine the health of the gearboxes, 30 day engine wash to minimize coking and maintain engine performance, 90 day corrosion check.
Nearly all components are replaced when they are found to show signs of wear, fatigue, or cracks indicating impending failure of the component. These are usually detected by maintenance personnel during scheduled inspections or found when the helicopter does not perform correctly. Other components are replaced based on a manufacturer’s predicted failure time, or Time Between Overhaul (TBO). As you can see the traditional Phase maintenance program is extremely in-depth and costly for the continued operation of advanced aircraft such as the UH-60 Blackhawk. With all this required maintenance are the maintenance crews and supervisors that are required to ensure proper implementation of the Phase maintenance program along with quality control to ensure that the work is being completed correctly.
There are two significant draw backs with this maintenance system. One is that TBO’s are projected failure times established by engineers based on science but not perfect. An example of this happened several years ago at my facility. We had am AH-64D taxing in after a flight, when the rotor system at 100% RPMR fell forward into the cockpit, taking the life of the front seat pilot and permanently disabling the back seat pilot. At the conclusion of the safety investigation, it was found that the metal in the main mast failed and the rotor system fell forward. This mast was found to have 15,000 flight hours on it and was the oldest in the Army inventory. With that said, the manufacturer had determined a life expectancy of 30,000 flight hours. The second downfall is regarding the effects on mission readiness. If an aircraft reaches its 250 hour inspection point, it is pulled off the flight line, cowlings and panels removed, and sometimes the component itself is removed from the airframe to complete the procedure, creating a high demand on maintenance personnel and artificially inflating the number of man-hours expended.
Now we think about CBM “Condition Based Maintenance”, where you can fix or replace a part before it fails and the ability to determine how much more running time you have on a component before it fails completely. In 2002 BF Goodrich developed a CBM system called IVHMS or Integrated Vehicle Heath Management System. This system consists of numerous sensors located throughout the aircraft, (RDC) remote data concentrator, (CDU) cockpit display unit, (DTU) Data Storage and Transfer Unit, a central processing unit all connected with fiber optic cable. IVHMS provides monitoring and diagnostic capabilities for rotor track and balance, engine health monitoring, gearbox and drivetrain health monitoring, and structural usage and fatigue tracking for the lifetime of the component. Essentially improving operational readiness and safety by identifying components before they fail.
So is CBM worth the cost? The simple answer is yes with considerations. CBM is not and automatic system where everything works exact without errors. The system is at its infancy and currently enhances the visibility and predictability of future maintenance requirements beyond just the Phase maintenance. With that said, it will not replace phase maintenance or TBO’s but instead gives maintenance crews the ability to better track the usage of critical components. According to research taken during a deployment of the 4-101 (equipped with IVHMS), they decisively outperformed their sister battalion with an overall increase of 2070 flight hours. This significant accomplishment equated to a 10.2 percent flight hour improvement for the CBM equipped unit over the course of the deployment. The IVHMS equipped unit clearly illustrated an overall improvement in reducing maintenance downtime on the airframes throughout the deployment. 4-101 also showed an overall decrease in 172 non mission capable hours for maintenance or an equivalent drop of 6.9% NMCM time. Marc P. Geguzis, MAJ, USA,(2009).
MAJ Geguzis explains in his study that the unit lost an aircraft in April of 2007, After reviewing the data from IVHMS it was found that the static mast bearings on the tail rotor exhibited an above average frequency level and were accompanied by a warm temperature reading. Even though the findings were not in the critical range, an investigation took place into the static mast bearings of the entire fleet. The investigation found that there was another aircraft exhibiting even higher frequency and temperatures. As a result the aircraft was immediately grounded and the entire swashplate assembly replaced. The swashplate assembly was sent to depot level maintenance where it was discovered to have significant corrosion, indicating a possible impending failure. It was estimated to have 5-10 hours to complete failure. This is an example of how phase maintenance would not have detected the problem but CBM could identify the warning signs of another possible failure and save the lives of an entire crew.
CONCLUSION

In conclusion, both Conditions Based Maintenance and Phase Based Maintenance have their advantages and disadvantages when it comes to an organization’s budget, but also has a tremendous impact on organizational behavior of the personnel. If the personnel feel like they will be doing less time consuming work, there will be an increased fear of losing their jobs. And if the flight crew sees that there are going to be less all day inspections and replacing assemblies on a pre-determined time scale, they might feel less confident in the aircraft. That’s why it’s so important that the leadership does a thorough analysis of each program and takes the time to educate the maintenance personnel and flight crews about the advantages each program brings to their organization. This training will both educate the personnel about how their new plan will affect the organization and it will diminish any fears the personnel might have about their specific jobs inspiring them to continue to work hard and strive for promotions from within the organization. The bottom line is that new technology doesn’t diminish the need for maintenance personnel, nor should it diminish the flight crew’s confidence in their aircraft, it just prompts them to shift their focus into other areas.
Reference:
Goodrich Corporation, Integrated Vehicle Health Management Systems (IVHMS). Retreved from www.goodrich.com
MARC P. GAGUZIS, MAJ, USA , (2009), EFFECTIVENESS OF CONDITION BASED MAINTENANCE IN ARMY AVIATION.
Mark W Davis, Sikorsky Aircraft Corporation, Stratford, CT & Brian D Larder, Smiths Aerospace,Southampton, UK, HUMS Condition Based Maintenance Credit Validation
Kreitner, R., and Kinicki, A., (2010). Organizational behavior 9th ed. New York, NY:McGraw-Hill Irwin.
TM 1-1520-BLACKHAWK. Digital Maintenance Technical Manual with limited distribution.