Customized Dynamic Balancing ( CDB )

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Since the inception of the AH-64 fleet, the Apache Program Manager’s (PM) Office has encountered a number of challenges. These challenges include logistics and operational readiness, safety of flight, airworthiness and numerous others inherent in the operation and support of a major aircraft program.

Perhaps the most significant challenge has been the burden placed on fleet readiness and maintenance operations and logistics from the excessive wear and subsequent premature failure of aircraft dynamic components. These components include the main transmission accessory gearbox, intermediate gearbox (IGB), tail rotor gearbox, auxiliary power unit (APU) power take-off (PTO) clutch, and main and tail rotor blades. In addition, issues concerning structural damage to the aircraft, such as cracking in the 2L stringers and 530 and 545 bulkheads exist. The latter issue resulted in an elastomeric vertical stabilizer mounting modification work order (MWO) at a significant cost in terms of dollars, aircraft readiness, and aircrew combat readiness.

The common theme to solving these dynamic component concerns is the requirement to perform new special maintenance inspections and subsequently replace components. The impact on the aviation budget is significant when taking into consideration reduced reliability, decreased combat-ready aircraft, increased cost of maintenance and man-hours, and numerous other factors. Apache users worldwide have borne the cost of dynamic components failing long before their scheduled time before overhaul (TBO).

Shake’d Technologies, Inc., provide a unique solution that addresses the root cause of these systemic dynamic component failures on the AH-64 Apache Helicopter and the associated reduction in component useful life. CDB goes far beyond passively monitoring aircraft vibrations. CDB discerns the root cause of a particular platform's vibration related issues and provides a dynamic solution to significantly reduce high frequency resonant vibrations. This process uses CDB computer vibration analysis tools to gather requisite vibration information from instrumented drive train components. The CDB AH-64 computer analyzes this data and creates an “aircraft vibration profile" to determine the specific solution for the individual aircraft.

The critical challenge facing the Apache program is to reduce O&S costs while maintaining a high level of safety. The two most notable benefits listed above are the major impact CDB has on reducing both O&S costs and collateral damage. Through the implementation of CDB, components will last longer, thereby reducing hourly operating costs. Both O&S costs and issues affecting safety of flight are reduced to the point of having a negligible impact on flight operations.

CDB demonstrates the cost savings as the dynamic component mean time between failures significantly improves. Every additional hour a dynamic component remains in service, the closer it approaches TBO and the lower the O&S cost to the Apache program. A reduction in unscheduled maintenance tasks from dynamic component wear and failure will result in fewer instances of indirect maintenance issues where related components are damaged during the maintenance process. This benefit will continue to deliver cost avoidance and accumulated savings over the life of each airframe.

Another significant benefit is the increase in operational readiness rates. With an effective CDB plan in place, operational readiness rates may improve by as much as 15 percent. The vast areas of operations and continued surge in operational tempo around the globe require a higher density of aircraft to support full-spectrum combat operations. The increase in readiness provided by AH64 - CDB would allow commanders to more effectively employ aircraft in support of multiple-based operations and additional full-spectrum operations.

AH-64 CDB also provides intangible results that are significant but difficult to measure. Some intangible considerations include—
• Increased crew confidence in the aircraft
• Reduced crew fatigue
• Enhanced logistical planning through predictive analysis
• Cost avoidance in repair parts for Target Acquisition and Designation System/Pilot Night Vision System (TADS/PNVS) and other avionics systems components
• Enhanced aircraft performance

CDB solution provides added value beyond the considerations listed above. Fewer dynamic components carried on the prescribed load list, reduced common hardware, and reduced consumable materials will affect the overall logistics footprint. In addition, CDB complements Condition Based Maintenance (CBM) through predictive analysis.

Data collected from instrumented components revealed a high level of harmonic resonant frequency vibration between numerous dynamic components. This finding proved the existence of unacceptable vibration levels in drive train components and adjacent aircraft structures. Understanding the destructive nature of harmonic resonance, the engineers drew a logical conclusion between harmonic resonance and material failure, structural cracks, and limited useful life of dynamic components.