How Airlines Can Ensure Quality Control When Buying Used Landing Gear

Author: gatelesis

The aviation industry heavily relies on the safety and reliability of aircraft systems & components, particularly for landing gear. As airlines increasingly seek cost-effective solutions for maintaining their fleets, the procurement of used landing gear has become a common area of attention due to its substantially higher overall cost on the aircraft relevant to other systems. No different than those other systems though, ensuring quality control during the acquisition of used landing gear is paramount to maintaining safety standards and operational efficiency.

1. Landing Gear History and Certification

Landing gear consists predominantly of life-limited parts, which means that their operational lifespan is finite and must be carefully monitored due to fatigue over time. To ensure quality control in this space, airlines must establish a comprehensive “back-to-birth” records for every component of the landing gear. These records include detailed documentation of all previous overhauls, repairs, modifications, and shop visits. Additionally, documentation of where the aircraft has flown is essential to assess before purchasing it.

The back-to-birth documentation serves several crucial functions.

Primarily, it provides a clear record of the landing gear’s service history, which is essential for assessing its current condition and predicting its future performance.

Next, it allows airlines to verify that the landing gear complies with maintenance & regulatory standards set forth by the manufacturer, as well as aviation authorities such as the FAA & EASA.

2. Key Elements of Documentation

When conducting a back-to-birth review, airlines should focus on several key elements:

Original Manufacturer’s Documentation: This includes the initial specifications, manufacturing details, and any warranties associated with the landing gear.
Maintenance Records: Detailed logs of maintenance performed on the landing gear, including dates, types of services, and the personnel who conducted the work.
Inspection Reports: Documentation from previous inspections, highlighting any issues found and the corrective actions taken.
Overhaul Records: Information regarding any overhauls the landing gear has undergone, including the extent of the work performed and the parts replaced.
Service Bulletins & Airworthiness Directives: Compliance with any mandatory service bulletins or airworthiness directives issued by the manufacturer or regulatory authorities.

During the documentation review, airlines should be vigilant for red flags that may indicate potential issues with the landing gear. These include gaps in maintenance records, incomplete documentation, or indications that the landing gear has been subjected to harsh operating conditions. For instance, landing gear that has operated in regions with extreme environmental conditions, such as high humidity, salty coastal air, desert heat, or sub-zero temperatures – may suffer from hidden structural degradation not common in more friendly environments. This makes it essential to review maintenance records and to understand the geographic & operational history of the aircraft to assess potential exposure to corrosive or damaging environments during flight and aircraft-on-ground (“AOG”) time.

3. Physical Inspection

Once the documentation for the part has been thoroughly reviewed, the next step is in ensuring quality control: conducting a physical inspection of the landing gear. This inspection is diagnostic for identifying any visible damage or signs of wear that may not be clear in the documentation or have incurred during transportation post sale.

Both sellers and vendors should develop comprehensive checklists to guide the physical inspection process. This checklist should include the following components:

Inspection: Inspect the landing gear for any obvious signs of damage, such as cracks, dents, corrosion or wiring issues. Pay close attention to critical areas such as the main struts, wheels, and brake assemblies.
Component Completeness: Ensure that all required components are present with the landing gear. This includes not only the main gear but also any associated parts, such as bolts, nuts, wiring harnesses, and hydraulic lines, which can be easily overlooked.
Condition of Loose Parts: The landing gear often comes with numerous loose parts that are critical for its assembly and operation. Airlines should ensure that these parts are accounted for and in good condition.

The timing of the physical inspection is also crucial. If the landing gear is purchased as unserviceable, the inspection should occur as close to the removal from the aircraft as possible. This timing minimizes the risk of damage occurring during the removal process and ensures that the condition of the landing gear reflects its operational state.

4. Functional Testing

In addition to a thorough physical inspection, airlines must conduct functional testing of the landing gear to verify its operational capabilities. The level and detail of this testing should be determined based on the age and service history of the landing gear.

Functional testing typically includes:

Load Testing: This involves applying loads to the landing gear to assess its ability to withstand operational stress. The testing should simulate real-world conditions to ensure the gear can perform safely during takeoff, landing, and taxiing. Pay close attention here to levels of nitrogen and hydraulic fluid in the cylinders overall.
Operational Checks: Airlines should conduct operational checks to ensure that all components of the landing gear function correctly. This includes swing testing, solenoid checks and position indicator checks, as well as testing hydraulic systems, dampeners, brakes, and steering mechanisms.
Comparison of Industry Standards: The results of functional testing should be compared against industry standards and manufacturer specifications to ensure compliance.

3.1 Adjusting Testing Based on Age

The level of detail required for functional testing may differ based on the age of the landing gear. For instance, a landing gear that was overhauled recently may require less detailed testing than one that has not been serviced in many years. Airlines should develop a criteria for determining the appropriate level of testing based on the landing gear, service history, and condition.

3.2 Non-Destructive Testing (NDT)

In addition to conventional mechanical and hydraulic tests, NDT plays a critical role in the functional assessment of used landing gear. NDT methods enable the detection of internal and surface-level defects without compromising the integrity of the component. This form of testing is indispensable. Common NDT techniques applied to landing gear include:

Ultrasonic Testing (UT): Used for detecting internal flaws and estimating defect size and location. It is effective in assessing forgings, welds, and structural fittings of landing gear legs.
Eddy Current Testing (ET): Particularly suitable for identifying surface and near-surface cracks caused by fatigue or corrosion, especially around fastener holes and wheel hubs.

Magnetic Particle Inspection (MPI): Effective for detecting surface and subsurface discontinuities in steels and ferromagnetic components like cylinders, axles, bogey beams, torque links, struts and bolts.
Liquid Penetrant Testing (LPT): Used to find surface-breaking cracks on non-porous materials, such as aluminum, particularly useful during initial inspections or to confirm suspected flaws.
Visual/Optical Inspection: Includes tools such as borescopes and magnifying lenses for internal visual inspection, especially in inaccessible zones.

The use of these methods ensures a high level of reliability and safety. Importantly, around 70 to 80% of NDT practices in commercial aviation are performed on the airframe and landing gear, underscoring its significance in the maintenance realm.

4. Supplier / Airline Reliability

Another critical aspect of quality control when buying used landing gear is evaluating the reliability of the distribution suppliers, MROs, and the airlines that previously owned, repaired, or operated the gear. Airlines ought to be selective in choosing which maintenance, repair, and overhaul shops to work with, and particularly should conduct thorough due diligence on the operational history of the apparatus.

4.1 How to Assess MRO Shops

Reputation: Research the reputation of the MRO shop within the industry. They should look for reviews, recommendations, and any history of regulatory compliance issues.
Certifications: Ensure that the MRO shop holds current and relevant certifications from recognized aviation regulatory authorities, such as the FAA, EASA, and other equivalent local national regulatory agencies. These certifications are not merely formalities – they serve as evidence that the MRO facility operates in compliance with stringent safety, quality, and procedural standards. Certified shops are regularly audited and must maintain robust quality management systems, documented training protocols, calibrated tooling, audit reports, and traceable maintenance processes. Working with a certified MRO with their latest audit reports significantly reduces the risk of improper repairs or undocumented modifications, thereby safeguarding the airworthiness of the landing gear and ensuring regulatory compliance throughout the part’s lifecycle.

Past Performance: Review the shop’s history of providing landing gear services, including the quality of their work, turnaround time, and any issues reported by previous clients or audits.

How to Evaluate Previous Operators

The operational history of the airline that previously operated the landing gear is also critical. Factors to consider include:

Flight Hours: An airline with a high number of flight hours may indicate that the landing gear has experienced significant wear and tear in a shorter amount of time.
Operating Environment: Airlines operating in harsh environments, such as those with extreme weather conditions or high levels of salt in the air, may subject landing gear to further stress.
Maintenance Culture: Assess the maintenance culture of the airline. Airlines with a strong focus on proactive maintenance practices are more likely to have well-maintained equipment.

5. Packaging

Finally, the packaging of used landing gear is a crucial factor in ensuring quality control during transportation. Given the hefty nature of landing gear, proper packaging is essential to prevent damage during transit.

5.1 Packaging Best Practices Worth Following

Use OEM Packaging: Whenever possible, airlines should utilize original equipment manufacturer packaging that stands designed specifically for that landing gear. This equipment is engineered to provide optimal protection during transportation.
Custom Crating: If OEM packaging is not available, airlines should utilize custom crating that meets international shipping standards such as ATA 300. The crate should be designed to securely hold the landing gear and prevent movement during transit. Additionally, consider adding small things like a clear window on the crating wall to avoid mishaps.
Inspection of Packaging: Before shipping, airlines should inspect the packaging to ensure it has structural integrity and can withstand the rigors of transport. Any signs of wear or damage to the packaging should be addressed before shipment. Additionally, a checklist agreed on between buyer and seller should be checked before and after packaging.

5.2 Training and Checklists

To further mitigate the risk of damage during transport, airlines should implement training programs for personnel handling the packaging and shipping process. In addition, checklists should be put in place to ensure that all necessary precautions are taken before and after shipment. This proactive approach can significantly reduce the likelihood of damage occurring during transit and help correctly identify any damages during shipment vs original product.

5.3 Key Practices for Outbound Inspection

Proper packaging not only protects the physical integrity of landing gear components during shipment but also ensures documentation traceability and regulatory compliance. For example, according to GA Telesis’ outbound inspection procedures, checks and documentation are intense and involve multiple stages of verification before a component is cleared for shipment.

Dual Inspector System: Two separate quality control inspectors perform and verify different portions of the outbound inspection to reduce human error and enforce accountability.
Document Verification: Prior to shipment, the part is matched against customer purchase orders, and key information such as part number, configuration, serial number, condition, and certificate validity is validated. Required documents include the Authorized Release Certificate, trace documentation, and any maintenance records linked to the part’s lifecycle.
Digital Logging and Uploads: All relevant documentation, including the final split of the Maintenance Release Certificate, is digitized and uploaded to the shipper for record in the internal system. Additionally, the Maintenance Release Certificate Tracking Log is updated to maintain traceability.
Visual and Physical Checks: Parts are examined for the presence of safety wires, plugs, warranty seals, and any required hardware. Photographic evidence is captured to document the condition prior to shipment.
Packaging Protocols: Items are placed in color-coded containers and folders corresponding to shipment priority, ensuring standardized handling. All documents are enclosed in labeled envelopes for traceability, and the shipment is only released once it passes a final QC status change in the system.

Ensure Quality Control of Used Landing Gear with GA Telesis

Ensuring quality control when purchasing used landing gear is a multifaceted process that requires careful attention to detail. GA Telesis helps airlines establish a comprehensive back-to-birth history for the landing gear, conduct thorough physical inspections, perform functional testing, evaluate supplier and airline reliability, and implement best practices for packaging.

Airlines can minimize risks associated with sourcing pre-owned landing gear from GA Telesis and maintain the trustworthiness of their fleets by following these processes. Quality control remains significant in the procurement of used components and will remain a critical focus when seeking operational optimization while safeguarding safety standards as aviation continues to advance. GA Telesis has supported landing gear since its inception, deploying best practices in all areas of operation, overhaul, and repair, as well as distribution.

GA Telesis’ state-of-the-art MRO shops and Landing Gear Services make it an easy choice for airlines to subsidize the risk of purchasing standard components. GA Telesis’ integration of rigorous outbound inspection procedures into the packaging workflow reflects the industry’s emphasis on safeguarding component quality beyond the inspection hangar – extending into logistics and customer delivery. To learn more and see how we can support your operations, contact GA Telesis MRO Services Landing Gear today!