“The Bell 429 is the first helicopter to have a maintenance program designed under MSG-3,” Neil Marshall, program director for the Bell 429 project, told AIN. “We had a working group composed of Bell Helicopter specialists, lead mechanics from customers, representatives from the FAA, Transport Canada and EASA giving input into the design. The first time the group met it had a clean sheet of paper with respect to the 429’s design. It was able to steer the direction of the design to make the aircraft more maintenance friendly, cost effective and efficient to operate.”
According to Marshall, the 429’s design routes systems and locates access panels to make it easier to maintain. “As a result you don’t have to remove the interior during inspections,” he said.
What makes the Bell 429 MSG-3 relationship so unusual is the maintenance steering group (MSG) concept was developed by and for the airline industry. The goal of MSG was and is to change the mindset that essentially everything on the aircraft has to be overhauled or replaced at set intervals to a defined engineering logic that determines the most appropriate scheduled maintenance task and interval for an aircraft’s major components and structure.
Three fundamental concepts are core to MSG-3: hard time limits, on-condition and condition monitoring. Hard time limits are the more conventional method of doing maintenance in that specific intervals are determined for a given part or unit. On-condition refers to repetitive inspections to determine if the condition of a given unit is acceptable or requires maintenance. Condition monitoring is for items that do not require specific time limits or on-condition maintenance. One of the major improvements of MSG-3 is MSG-2 did not differentiate between maintenance being done for safety reasons and that being done for economic reasons, Marshall said.
“The 429 design goal is to be able to quickly and easily find everything you need to maintain the aircraft in a safe manner, but also to set up inspection periods that minimize down time to make it more cost effective and reliable to operate,” Marshall said. “The 429 MSG-3 group meets annually and as the program matures over time the information we gain will roll back into the program to the benefit of the operator. For instance, we may find we’ve underestimated the life of a component and that can be taken into account in the future.”
Coincidentally, after Bell adopted the MSG-3 process to the development of the 429, EASA determined it would make MSG-3 a requirement in the development of all new aircraft, making Bell the pioneer in the helicopter industry. The next helicopter to be designed using MSG-3 is the Eurocopter EC175.
Marshall said the Bell 429 MSG-3 group’s experience brought to light how some facets of the system don’t apply to helicopters. Bell is now working with EASA to come up with a tailored approach for the rotorcraft industry. “It is all about producing a safer product for the marketplace and making the aircraft more efficient and effective to operate,” he said.