Understanding FAR 91.213: Inoperative Equipment and MELs

The Federal Aviation Regulations (FARs) are the backbone of aviation safety and compliance in the United States. Among these, FAR 91.213 is a critical regulation for pilots and aircraft operators, as it outlines the procedures for handling inoperative instruments and equipment. This blog post breaks down FAR 91.213, explaining its purpose, key components, and practical implications for general aviation operations under Part 91.

What is FAR 91.213?

FAR 91.213, titled “Inoperative Instruments and Equipment,” provides guidance on whether an aircraft can be operated with inoperative equipment. It applies to operations conducted under 14 CFR Part 91, which covers general operating and flight rules for non-commercial flights. The regulation ensures that aircraft remain safe to fly even when certain equipment is not functioning, provided specific conditions are met.

The rule is particularly important because it addresses scenarios where pilots discover inoperative equipment during preflight inspections or maintenance checks. It helps determine whether the flight can proceed legally and safely, either by using a Minimum Equipment List (MEL) or following specific procedures for aircraft without an MEL.

Key Components of FAR 91.213

FAR 91.213 is divided into two main pathways for addressing inoperative equipment, depending on whether the aircraft has an approved MEL.

1. Aircraft with an MEL

A Minimum Equipment List (MEL) is a document approved by the FAA that specifies which instruments and equipment can be inoperative while still allowing the aircraft to be flown safely. For aircraft with an MEL, FAR 91.213(a) outlines the following:

  • MEL as the Guiding Document: If an aircraft has an approved MEL, pilots must follow its provisions. The MEL lists specific equipment that can be inoperative, along with any associated operational limitations or maintenance procedures.
  • Deferral of Maintenance: Inoperative equipment listed in the MEL can often be deferred for repair, provided the operator complies with the MEL’s conditions (e.g., placarding the equipment as inoperative, following specific procedures, or adhering to time limits for repairs).
  • Prohibited Operations: If the inoperative equipment is not listed in the MEL or the conditions cannot be met, the aircraft cannot be operated until the equipment is repaired.

For example, an MEL might allow a multi-engine aircraft to fly with one autopilot inoperative, provided certain weather minimums are met or additional crew procedures are followed.

2. Aircraft without an MEL

For aircraft without an MEL, FAR 91.213(d) provides a decision-making process to determine if the aircraft can be flown with inoperative equipment. This applies to most general aviation aircraft, such as small single-engine planes. The process involves checking the following:

  1. Required Equipment Lists:

    • VFR Day Type Certification: Review the aircraft’s type certificate data sheet (TCDS) or equipment list to ensure the inoperative item is not required for the aircraft’s original certification.
    • FAR 91.205 Requirements: For day VFR operations, FAR 91.205(b) lists required instruments and equipment (e.g., airspeed indicator, altimeter, magnetic direction indicator). For night VFR or IFR, additional items from FAR 91.205(c) or (d) apply (e.g., position lights for night, or an attitude indicator for IFR).
    • Other FAR Requirements: Check other regulations (e.g., FAR 91.207 for ELTs or FAR 91.215 for transponders) to ensure the inoperative item is not mandated.

  2. Safety Assessment:

    • The pilot must determine that the inoperative equipment does not constitute a hazard to the safe operation of the aircraft for the planned flight. This includes considering the type of operation (VFR or IFR), weather, and other factors.

  3. Placarding and Maintenance:

    • The inoperative equipment must be placarded as “INOP” to alert the crew.
    • The equipment must be removed, deactivated, or inspected by a qualified person to confirm it’s safe for flight.

For example, if a small aircraft’s landing light is inoperative, the pilot might determine it’s not required for day VFR operations under FAR 91.205(b). They would placard the light as “INOP” and ensure it poses no safety risk.

Practical Implications for Pilots

Understanding FAR 91.213 is essential for pilots to make informed decisions during preflight planning. Here are some practical tips:

  • Know Your Aircraft: Check whether your aircraft has an MEL. If it does, always consult it first when discovering inoperative equipment. MELs are specific to the aircraft’s make, model, and serial number.
  • Use a Checklist for Non-MEL Aircraft: For aircraft without an MEL, create a systematic approach to evaluate inoperative equipment using FAR 91.213(d). Cross-reference the aircraft’s equipment list, FAR 91.205, and other applicable regulations.
  • Document Compliance: Ensure inoperative equipment is properly placarded and documented in the aircraft’s maintenance logs. This is critical for regulatory compliance and safety.
  • Exercise Caution: Even if the regulation allows flight with inoperative equipment, pilots must assess whether it’s prudent based on the flight’s conditions (e.g., weather, terrain, or night operations).

Why FAR 91.213 Matters

FAR 91.213 strikes a balance between operational flexibility and safety. It allows pilots and operators to manage minor equipment issues without grounding aircraft unnecessarily, while ensuring that critical systems remain functional. Misinterpreting or ignoring this regulation can lead to unsafe operations or regulatory violations, so pilots must be diligent in applying it correctly.

Conclusion

FAR 91.213 is a cornerstone of safe aircraft operations under Part 91. Whether using an MEL or following the decision-making process for non-MEL aircraft, pilots must carefully evaluate inoperative equipment to ensure compliance and safety. By understanding the regulation and applying it systematically, pilots can make informed decisions that keep their flights legal and secure.

For more details, consult the full text of FAR 91.213 on the FAA’s website or discuss specific scenarios with a certified flight instructor or aviation maintenance professional.

Disclaimer: This blog post is for informational purposes only and does not constitute legal or operational advice. Always consult the FAA regulations and a qualified aviation professional for specific guidance.