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«Spring 2023

Major CL300 Mid-Life Inspection Delivered Squawk-Free

The Workscope

  • 7500-landing inspection
  • 192-month airframe inspection
  • 192-month landing gear inspection
  • 30 Service Bulletins
  • Engine R&R
  • Complete new interior
  • Complete new paint
  • Ku band avionics upgrade

Nearly 800 CL300 aircraft are flying today, with many approaching their 7500-landing inspection milestone. It is the most comprehensive inspection for the CL300, where all panels are removed, many parts replaced, and the entire airframe inspected. It is a significant undertaking.


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Duncan Aviation began preparing for the 7500-landing inspection years before any customers requested it. Adam Lauderback, Senior Airframe Service Sales Rep, spent weeks poring over the requirements, identifying essential tooling, and determining what in-house backshops would be called on to help. He worked with planning teams, Project Managers, and Team Leaders. This in-depth planning turned into flow charts, timelines, and milestones. The result was the most accurate and detailed quote possible.

“I don’t think there is anything left to quote,” says Adam. “We are doing everything there is to do on a CL300. There’s nothing left.”

Duncan Aviation’s Nondestructive Testing team plays a major role. With $500,000 in new standards and probes, there are very few areas of the CL300 that NDT Master Tech (Level II) Rachel Baldwin will not touch.

When Duncan Aviation secured a customer commitment on July 8, 2022, and the workscope was finalized, Airframe Team Leader Nick Lovell and his team started their rigorous planning and preparation. Months ahead of the aircraft’s arrival, they spent hundreds of hours planning, ordering parts, reading the tasks, and acquiring tooling.

Lead Technician Jake Hefner printed and read more than 700 pages of task cards, grouping and prioritizing them for efficiency and determining what milestones were necessary to hit and when.

All the planning made Project Manager Bill Collins confident in the upcoming work. “There was so much planning and communication that even if the technicians faced an unexpected or unknown issue, I knew they could pivot and continue to move forward. They are that good.”

“Preparation for this inspection was no different from others,” says Nick. “It’s just larger.”


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When the aircraft arrived on August 24, 2022, in Lincoln, Nebraska, so did a third-party consultant whose expertise is in organizing and managing service providers, suppliers, logistics, and details that lead to successful deliveries.

Because this was Duncan Aviation’s first time performing a 7500-landing inspection, our CL300 customer hired the consultant to observe the process to identify efficiencies, processes, or communication improvements. They were there only to offer a word of advice toward improvement, nothing more.

Before coming to Duncan Aviation, the consultant expected to encounter a small MRO with an attached FBO. On the first day, he found that Nick’s team had already put in several hours removing panels and parts and was preparing to remove the horizontal stabilizer. He watched as everyone moved forward quickly and confidently.

Behind each panel removed, Rachel conducted the long list of NDT inspection tasks. Every day for two months, she crawled, reached, and stretched into tight spots she had never accessed before, leaving no area left untouched.

“Signing off on the last task (the wing inspection) was a great relief,” she says. She also set her sights on getting started on a second CL300 scheduled to arrive just a few weeks later for its 7500-landing. “I have a roadmap and directions to follow, with known expectations. I may do a few things differently and in a different order, but everything did go smoothly and to plan.”

It didn’t take a week of being at Duncan Aviation for the consultant to conclude that everyone was skilled in their craft and knew what they were doing.

“They are professionals with an impressive facility and a long list of in-house capabilities that includes everything from batteries, landing gear, and component repairs, to paint and interior refurbishments. Integrating these capabilities is a big benefit over sending out parts to be serviced by third-party vendors.”

He also observed how everyone worked with great humility and remarked, “If there was a delay in one area, it was felt throughout the project. But together, they reorganized the plan to keep progress moving forward and further delays to a minimum. The professionalism at Duncan Aviation is on a different level.”

He reported to the CL300 customer that they made the right decision to go to Duncan Aviation for their 7500-landing inspection.


The test flight crew knew the CL300 they were to fly had been dismantled down to the wings and put back together. While still on the ground, they thoroughly combed the maintenance records to test and retest everything. After two hours of this scrutiny, they felt satisfied and comfortable taking off. They flew squawk-free and reported only one minor interior issue.

Despite missing the delivery date due to parts delays, everyone was pleased with how smoothly the project went. “Our biggest challenge was getting parts,” says Nick. “I have no doubt we would have hit the original out-date if it weren’t for parts issues. Parts are already on order for the next one.”

The next 7500-landing inspection arrived in Lincoln on January 31st of this year, and Duncan Aviation has seven more scheduled through 2024 and into 2025.

Call now if you are flying one of the 800 CL300s approaching this major mid-life inspection. It’s the right decision.