When it comes to aircraft maintenance, most owners and technicians focus their inspections on the obvious: wing structures, fuselage surfaces, control systems, and primary engine components. 

But some of the most critical weld points lie in places that don’t get the attention they deserve. Unfortunately, they’re often only discovered when something goes wrong.

Aircraft weld inspection is more than just a regulatory requirement. It's a vital step in preserving airworthiness, reducing long-term repair costs, and preventing dangerous in-flight failures. 

While major welds are regularly inspected, several secondary components are often overlooked. This can lead to preventable fatigue cracks, performance loss, or even mechanical failure.

This blog explores the aircraft parts most commonly missed during weld inspections. It also outlines why they matter and explains how a certified aerospace welding service provider can ensure structural integrity through proper evaluation and documentation.

Why Aircraft Weld Inspection Is Essential For Airworthiness

Routine inspection of aircraft welds is a vital part of any maintenance or overhaul plan. Every weld in an aircraft plays a role in absorbing stress, distributing loads, or containing pressure, especially in engine mounts, exhaust systems, and other high-temperature or vibration-prone areas.

Over time, these welds can degrade due to:

• Metal fatigue from repetitive stress cycles
  
• Heat cycling and thermal expansion
  
• Vibration from engines, propellers, and airflow
  
• Corrosion from humidity or exhaust gases
  

A missed flaw, even a hairline crack, can propagate quickly under load. Weld inspections performed by a certified aviation welding technician ensure that even subtle signs of fatigue are caught early and resolved before becoming safety hazards.

Critical Weld Areas That Are Often Overlooked During Inspection

Even the most experienced technicians can overlook certain weld points if they’re not easily visible or not included in standard maintenance checklists. These components may appear structurally sound on the surface but hide underlying stress damage or corrosion.

Let’s explore which parts need more attention during aircraft weld inspection and why.

Firewall Attachments And Engine Mount Brackets

One of the most fatigue-prone areas in an aircraft is the firewall assembly. Constant exposure to heat, vibration, and engine torque makes it a prime location for weld failure.

Welds securing engine mount brackets or support tabs near the firewall can develop microcracks or stress fatigue, especially in older aircraft or those exposed to aggressive environments. These cracks are often hard to spot visually and may require dye penetrant or borescope inspection to confirm.

Turbocharger Mounts And Exhaust Supports

Turbocharged aircraft experience intense heat fluctuations and mechanical load on their mounting hardware. Turbo mounts and exhaust supports, especially those welded to the firewall or engine bay structure, are frequently under-inspected.

A small crack in these mounts can lead to vibrations, misalignment, or complete turbo detachment, which can cascade into broader engine damage. A qualified aerospace welding service will test these components under load conditions and use non-destructive testing (NDT) to ensure their reliability.

Carburetor Air Boxes And Intake Plenums

The carburetor air box is more than just an airflow passage, it’s a welded, pressurized structure that handles vibration and load cycling during every flight. Cracks along seams or weld joints are common, particularly in air boxes made from thin aluminum or stainless steel.

Because these units are partially hidden beneath the engine or cowling, they often receive minimal inspection. A small failure here can affect the fuel-air mixture, engine efficiency, or airflow balance.

Tail Cone Braces And Aft Fuselage Support Welds

Aircraft tail sections take a surprising amount of stress, especially during takeoff, landing, and turbulent flight. Welded support structures in the tail cone or aft fuselage areas often get ignored because they aren’t visible unless disassembled.

If not checked regularly, fatigue cracks can grow unnoticed in welds connecting horizontal stabilizers, tail strike skids, or bracing arms, especially in aircraft frequently operating from rough strips.

Exhaust Risers, Mufflers, And Slip Joints

The exhaust system is subjected to intense thermal expansion, contraction, vibration, and exposure to corrosive gases. Welds in mufflers, risers, and slip joints often degrade internally long before any visible signs appear.

Because some weld cracks in these areas form on the interior wall, proper aircraft weld inspection involves borescope evaluation and purge welding during repairs to prevent oxidation. A professional aviation welding technician will recognize failure patterns and apply precision TIG welding to restore part integrity.

How Certified Aerospace Welding Services Ensure Accurate Inspection

Professional aerospace welding shops don’t rely on guesswork. Their inspections combine hands-on expertise, advanced diagnostic tools, and certified processes to evaluate weld conditions and compliance.

Here’s what sets them apart:

• Non-Destructive Testing (NDT): Methods like dye penetrant inspection, magnetic particle testing, or borescope evaluation identify subsurface cracks that aren’t visible to the naked eye.
  
• Weld Traceability: Each inspected part is logged with supporting documentation to meet Transport Canada or FAA compliance standards.
  
• Material-Specific Analysis: A skilled aviation welding technician understands how different materials, titanium, stainless steel, chromoly, respond to stress and fatigue, allowing for better diagnostics.
  
• Repair-Ready Fabrication: If a weld defect is found, the same certified shop can repair or rebuild the part using approved procedures.
  

Working with a certified aerospace welding service ensures inspections are thorough, repeatable, and backed by documentation suitable for maintenance logs and airworthiness reviews.

Risks Of Skipping Or Rushing Aircraft Weld Inspections

Neglecting secondary weld points is not just an oversight, it’s a risk that can have serious consequences.

A missed crack or distorted weld can lead to:

• Unexpected part failure in flight
  
• Engine performance issues or misalignment
  
• Cabin pressurization problems or exhaust leaks
  
• Failed maintenance audits or regulatory penalties
  
• Increased long-term costs due to neglected fatigue damage
  

Aircraft owners, operators, and AMEs must include these overlooked parts in every inspection cycle and consult with certified technicians when in doubt.

Best Practices For Maintaining Welded Aircraft Parts

To stay compliant, reduce downtime, and ensure safety, here are recommended practices:

• Inspect overlooked parts annually or after every 100 flight hours, especially for bush planes, floatplanes, or aerobatic aircraft.
  
• Document each weld inspection with traceable records, including NDT results if available.
  
• Use certified aerospace welding providers for both inspection and repair. Their welders follow Transport Canada-approved procedures and maintain material traceability.
  
• Be proactive, not reactive. If a part “looks fine,” but hasn’t been inspected recently, schedule it.

About Us

Acorn Welding is Canada’s leading aircraft welding and manufacturing facility. Specializing in engine mounts, exhaust systems, carburetor air boxes, and structural aircraft components, we provide Transport Canada and FAA-approved repair and fabrication services for both legacy and modern aircraft. 

Our team of certified aviation welding technicians ensures every part meets or exceeds airworthiness standards. 

For professional weld inspections, repairs, or custom part fabrication, contact us today.