Operating an aircraft with inoperative instruments or systems can feel like navigating a minefield of regulations. However, the FAA provides clear guidelines to ensure safety while allowing for reasonable operational flexibility. Understanding these rules, particularly FAR 91.213, is crucial for every pilot and aircraft owner. At The Aero Center, we specialize in single-engine and twin-piston aircraft maintenance, and we’re here to help you navigate these complexities, ensuring your aircraft remains airworthy and minimizing downtime.
NAVIGATING FAR 91.213: YOUR GUIDE TO INOPERATIVE EQUIPMENT
FAR 91.213 is the cornerstone regulation governing operations with inoperative instruments and equipment. It outlines the conditions under which an aircraft can still be legally and safely flown despite a malfunction. This regulation acknowledges that not every inoperative component grounds an aircraft, provided certain criteria are met and safety is not compromised.
The core principle here is consistency. Pilots and maintenance personnel must consistently apply these regulations to ensure compliance and, more importantly, safety. Deviating from these established procedures can lead to serious consequences.
THE MINIMUM EQUIPMENT LIST (MEL)
For many aircraft, especially those in commercial operations or complex general aviation, a Minimum Equipment List (MEL) is the primary document for handling inoperative equipment. An MEL is an FAA-approved document specific to a particular aircraft by serial and registration number. It’s derived from a Master Minimum Equipment List (MMEL), which is developed by the aircraft manufacturer and approved by the FAA.
The MEL specifies which instruments and equipment may be inoperative under certain conditions and for how long, without affecting the aircraft’s airworthiness. It also outlines any operational procedures or maintenance actions required when an item is inoperative. For example, an MEL might state that a specific navigation instrument can be inoperative if an alternative means of navigation is available and certain placard and maintenance procedures are followed.
Using an MEL requires adherence to its provisions. Once an aircraft has an approved MEL, you must use it for deferring inoperative equipment; you cannot revert to the more general provisions of FAR 91.213(d). This commitment to a specific, approved plan is an example of the consistency principle in action, reinforcing safe and predictable operations.
WHEN AN MEL ISN’T PRESENT: PART 91.213(D)
For many general aviation aircraft, particularly non-turbine-powered airplanes with a maximum certified takeoff weight of 12,500 pounds or less, an approved MEL may not exist. In these cases, FAR 91.213(d) provides the pathway for operating with inoperative equipment. This section outlines a four-step decision-making process:
- Is the inoperative instrument or equipment part of the VFR-day type certification instruments and equipment prescribed in the applicable airworthiness regulations? Your aircraft’s Type Certificate Data Sheet (TCDS) and the original airworthiness regulations will tell you what was required for basic VFR flight. If the inoperative item is required for VFR-day certification, you generally cannot fly.
- Is the inoperative instrument or equipment indicated as required on the aircraft’s equipment list or Kinds of Operations Equipment List for the kind of flight operation being conducted? These lists, often found in your Pilot’s Operating Handbook (POH), specify what equipment is installed and what’s required for certain types of operations (e.g., IFR, night flight). If the inoperative item is required for your intended flight, you cannot fly.
- Is the inoperative instrument or equipment required by FAR 91.205 or any other rule of Part 91 for the specific kind of flight operation being conducted? FAR 91.205 lists the minimum instruments and equipment required for VFR day, VFR night, and IFR flight. Other Part 91 rules may also mandate specific equipment. If the inoperative item is required by any of these regulations for your planned flight, you cannot fly.
- Is the inoperative instrument or equipment required to be operational by an Airworthiness Directive (AD)? ADs are mandatory compliance documents issued by the FAA to address unsafe conditions. If an AD mandates the operability of the failed item, you cannot fly until the AD is complied with.
If the answer to all four of these questions is “no,” then you may be able to fly. However, there’s one more crucial step: The inoperative instrument or equipment must either be removed from the aircraft, placarded, and the maintenance recorded, or deactivated and placarded “Inoperative.” If deactivation involves maintenance, it must be performed and recorded by appropriately certificated personnel.
Finally, and most importantly, a pilot certificated and appropriately rated under Part 61, or a person certificated and appropriately rated to perform maintenance on the aircraft, must determine that the inoperative instrument or equipment does not constitute a hazard to the aircraft. This critical safety assessment leverages the authority and expertise of experienced aviation professionals. It’s not just about meeting regulatory checkboxes; it’s about making a sound judgment based on aviation knowledge and experience.
THE IMPORTANCE OF EXPERT MAINTENANCE
While pilots can make the initial determination for some inoperative items under 91.213(d), the deactivation or removal often constitutes maintenance that must be performed by a qualified aviation mechanic. This is where The Aero Center’s expertise becomes invaluable. Our team of experienced mechanics is proficient in diagnosing issues, applying proper deferral procedures, and ensuring your aircraft remains in a condition for safe operation.
We understand that time is money in aviation. An aircraft on the ground is not generating revenue or providing its intended utility. That’s why The Aero Center prides itself on being the only 24/7 maintenance center in California, Arizona, and Nevada. Our commitment to round-the-clock service means we can respond to your maintenance needs swiftly, minimizing airplane downtime and getting you back in the air faster. Our clients consistently praise our rapid response and efficient service, a testament to the social proof of our dedication and capabilities.
BEYOND THE REGULATIONS: ENSURING SAFETY
Beyond the letter of the law, the spirit of these regulations is all about safety. Just because you can fly with an inoperative item doesn’t always mean you should. Pilots must exercise sound judgment and consider the cumulative effect of multiple inoperative items. Even if individually permissible, a combination of failures could create an unsafe situation.
At The Aero Center, we not only ensure compliance with FAA regulations, but we also prioritize your safety. Our mechanics are trained to identify potential risks and advise on the best course of action, whether that’s a quick repair or a more comprehensive maintenance solution. Our authority in the field of aircraft maintenance is built on years of experience and a deep understanding of aircraft systems and regulations.
FOOTNOTES
- Federal Aviation Administration. 14 CFR Part 91.213 – Inoperative instruments and equipment.
- National Business Aviation Association. Inoperative Instruments & Equipment.
- Federal Aviation Administration. Advisory Circular 91-67 – Minimum Equipment Requirements for General Aviation Operations Under FAR Part 91.
- Flight Training Central. Can you fly with inoperative instruments?
The Aero Center is located at William J. Fox Airfield KWJF | Lancaster, CA. Contact us at 209.885.6950 for questions or appointments.