AAI On Non-Destructive Testing In Challenger Landing Gear Overhaul

One thing we say over and over again about landing gear overhaul: your landing gear is arguably one of the most important components of your aircraft. It absorbs impact more than any other part, provides a suspension system, and facilitates braking and steering of the aircraft while on the ground.

Landing gear inspection is a critical part of maintaining the safety and reliability of the Challenger series aircraft. At AAI, we have certain specifications and processes we follow when inspecting Challenger landing gear, with a particular focus on the Main Landing Gear (MLG). In this blog article, we’re going to dive into these processes and talk more about our non-destructive testing services with landing gear specifically, and we’ll share a little more about our commitment to safety and quality.

What Makes Challenger Landing Gear Unique?

Challenger landing gear consists of several parts, including the nose landing gear, nose landing gear drag braces, nose landing gear retract actuators, main landing gear, main landing gear side stay actuators, brake assemblies, and wheel assemblies. 

There is a main gear and a nose gear; the main landing gear supports most of the aircraft’s weight and is located under the wings/fuselage. The nose landing gear is at the front and provides steering. Generally lighter and built without brakes, the nose landing gear uses a shock strut to absorb impact during taxiing and landing. Some common wear points on Challenger aircraft landing gear include the shock struts, bushings and bearings, tires and wheels, brakes, hydraulic lines and fittings, and actuators. 

The Role Of Non-Destructive Testing In Overhaul

Non-destructive testing (NDT) is a way to detect and evaluate flaws in materials. In the aviation industry, NDT is crucial for a lot of reasons: safety, cost-efficiency, compliance, and preventative maintenance. Landing gear inspection is a critical part of maintaining the safety and reliability of the Challenger Series aircraft. Below is an overview of the specifications and processes we follow when inspecting Challenger landing gear, with a particular focus on the Main Landing Gear (MLG). 

Thoroughness Goes Beyond Visual & Dimensional Inspection

While visual and dimensional inspections are essential, they are only the starting point. During a typical landing gear overhaul, we employ non-destructive testing (NDT) techniques on more than 100 individual subcomponents of the MLG alone. These methods are imperative for identifying cracks and defects that are not visible to the naked eye.

Landing gear components are subjected to extreme loads, constant wear, and repeated stress during every takeoff and landing. Because of this, even the smallest undetected flaw can develop into a serious issue over time. Our responsibility during overhaul is to identify these cracks and potential failures before the gear is returned to service. 

Magnetic Particle Inspection (MPI) 

For components made from ferromagnetic materials—such as steel or iron—we utilize Magnetic Particle Inspection (MPI). Typical parts inspected using MPI include bolts, pins, axles, trailing arms, and other high-load structural components. 

MPI is a non-destructive testing method designed to detect surface and near-surface defects in magnetic materials. The process begins by magnetizing the part using either an alternating current (AC) or direct current (DC). When a defect such as a crack, seam, or inclusion is present, it disrupts the magnetic field and creates a leakage field at the surface. Fine magnetic particles, applied as either a dry powder or wet suspension, are attracted to these leakage fields and accumulate to form a visible indication of the defect. 

This technique is highly effective for identifying flaws that could otherwise go unnoticed during standard inspections. 

Fluorescent Penetrant Inspection (FPI) 

For non-magnetic materials such as aluminum and bronze, we use Fluorescent Penetrant Inspection (FPI). Components commonly inspected with FPI include housings, brackets, bushings, sleeves, and spacers. 

FPI is a non-destructive testing method used to detect surface-breaking defects in metals. The process involves applying a fluorescent liquid penetrant to a thoroughly cleaned surface and allowing it time to seep into any cracks or discontinuities. Excess penetrant is then removed, and a developer is applied to draw the penetrant back out of the defects. Under ultraviolet (UV) light, these indications fluoresce, making even fine cracks clearly visible. 

FPI is highly sensitive and widely used in aerospace applications. However, it is important to note that it can only detect defects that are open to the surface. 

Our Commitment To Safety & Quality 

By combining visual inspection, dimensional checks, and advanced NDT methods such as MPI and FPI, we ensure that Challenger Series landing gear meets the highest standards of safety and reliability. These inspection processes are not just best practices—they are essential steps in extending component life and protecting aircraft, crew, and passengers. 

AAI Can Help You With Your NDT Needs

Non-destructive testing in aviation, specifically for your Challenger series aircraft landing gear, is important because it helps ensure safety, quality, and reliability of the aircraft parts you’re using in your aircraft. AAI understands that keeping your passengers and crew safe is your number one priority, which is why we make it our number one priority. 

Uncertified, untested parts are all over the internet, but do you really want to risk your safety for convenience?  

We’ll help you avoid the delays and headaches and instead get certified, safe, and tested aircraft accessories so that you can fix your aircraft and get back to flying. 

Give us a call today: (770) 703-4316 or contact us here.