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Aircraft undergoing major repair at Penn Air Repair

Major Repair or Alteration (Form 337)

Need a major aircraft repair or modification? Penn Air Repair specializes in major repairs and alterations, complete with properly prepared FAA Form 337 documentation to ensure your aircraft remains airworthy and compliant.

Aviation Services

What is a Major Repair or Alteration (Form 337)?

Penn Air Repair at KPTW Heritage Field Pottstown PA - GH repairing aircraft wing

Certain types of aircraft repairs and modifications are classified as 'major' by the FAA. These require completion of Form 337 — a legal document that describes the work performed and confirms that it was completed to FAA standards. Our team at Penn Air Repair has the experience and expertise to perform these repairs properly and handle all required paperwork for you.

When is Form 337 Required?

Form 337 must be filed when performing major repairs or alterations that can affect the aircraft’s structural integrity, performance, flight characteristics, or compliance with airworthiness standards. Some examples include:

Structural Repairs

Repairs to wings, fuselage, empennage, or other primary structures.

Avionics Upgrades

Installation of modern avionics systems that alter original equipment.

Landing Gear Modifications

Conversions from fixed to retractable gear, or other major gear alterations.

Engine Changes

Upgrades to higher horsepower engines or conversions from one model to another.

Penn Air Repair Pennsylvania - Technician at work on aircraft
Penn Air Repair at KPTW Heritage Field Pottstown PA - Proactive aircraft maintenance

Why Choose Penn Air Repair for Major Repairs & Form 337?

Our FAA-certified team has the experience to complete major repairs and modifications to the highest standards, with full compliance to FAA documentation and regulations.

FAA Certified Repair

All work performed by FAA-certified technicians and IAs.

Proper Documentation

Accurate and complete Form 337 preparation and filing.

Custom Solutions

We work with you to find the right solution for your aircraft and needs.

Commitment to Quality

Your safety and airworthiness are our top priorities.

Need a Major Repair or Alteration?

Contact Penn Air Repair today to discuss your project. Our team will guide you through the process and ensure your aircraft remains compliant, safe, and ready to fly.

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