FAR 91.213 Preflight Action: What Every Pilot Student Needs to Know About Inoperative Equipment

FAR 91.213 defines how a pilot must handle inoperative equipment during preflight and determines whether an aircraft is safe and legal to operate. The regulation allows flight only when the equipment does not violate FAR 91.205, Airworthiness Directives (AD), type certification, or operational requirements. A pilot must follow one of two paths whether using a Minimum Equipment List (MEL) if available or applying the four-step test when no MEL exists. This structured process ensures compliance with FAA regulations and supports a consistent safety assessment before flight.

If no MEL applies, the pilot evaluates the equipment through four checks: required equipment under §91.205, AD compliance, VFR-day type certificate, and KOEL. If any step fails, the aircraft is grounded. If all steps pass, the pilot must deactivate, placard, and document the equipment. The pilot then determines if the aircraft remains safe. The pilot holds final authority for the go/no-go decision. Using tools like a pre-tabbed FAR/AIM improves accuracy and ensures decisions are based on regulation, not guesswork.

What Is FAR 91.213?

FAR 91.213 is an FAA regulation under 14 CFR Part 91 that addresses whether an aircraft may take off if the inoperative equipment does not violate required equipment standards, Airworthiness Directives (ADs), or other regulatory requirements. This regulation provides two structured methods for aircraft evaluation: using the Minimum Equipment List (MEL) or applying the four-step test when no MEL exists. 

Prior to dictating whether an aircraft can legally take off, FAR 91.213 also places responsibility on the pilot to verify that the aircraft remains safe and compliant. This includes confirming the equipment is not required under FAR 91.205 and ensuring all regulatory conditions are met before flight. Together, FAR 91.205 defines required equipment, while FAR 91.213 governs how to proceed when that equipment becomes inoperative. This relationship creates a complete preflight safety assessment system in which the pilot evaluates equipment, confirms compliance, and makes the final go/no-go decision.

Can You Fly with Inoperative Equipment? How §91.213 Gives You Two Ways to Find Out

Yes, you can fly with inoperative equipment only if the aircraft meets one of two approved methods defined in FAR 91.213, including using a Minimum Equipment List (MEL) or a four-step test in which the pilot evaluates required equipment, Airworthiness Directives, certification requirements, and operational needs. In both cases, the pilot must assess the situation, verify compliance, and make the final go/no-go decision based on safety protocols.

No MEL on Your Aircraft? Use the Four-Step Test

If an aircraft does not have an MEL, the pilot must follow the four-step test under FAR 91.213(d) to determine if flight with inoperative equipment is legal and safe. This process requires the pilot to evaluate the equipment against regulatory and operational requirements, including FAR 91.205, Airworthiness Directives (AD), the VFR-day type certificate, and the Kinds of Operations Equipment List (KOEL). The pilot must apply each step in sequence and must confirm that the equipment is not required at any level before proceeding with the flight.

4-step test under FAR 91.213 if you do not have MEL on your aircraft is:

Step 1: Is the Equipment Required by §91.205?

The first check is FAR 91.205, which serves as the fundamental checklist for required instruments and equipment. This regulation outlines the bare minimums for different types of flight, such as VFR Day (ATOMATO FLAMES) or VFR Night (FLAPS). If your broken item is required by this rule for your intended flight, for example, a fuel gauge for a VFR day hop, you have a legal implication that prevents takeoff. Understanding this relationship is critical for safety, as these items are essential for basic situational awareness and aircraft control.

Step 2: Is the Equipment Required by an Airworthiness Directive?

Next, you must verify if the inoperative item is mandated by an Airworthiness Directive (AD). ADs are legally enforceable rules issued by the FAA to correct unsafe conditions in a specific product. If an AD requires a certain piece of equipment to be functional for the aircraft to remain in regulatory compliance, you cannot fly with it broken. Non-compliance with ADs is a serious safety violation and automatically renders the aircraft unairworthy.

Step 3:  Is the Equipment Required by the VFR-day type certificate?

Every aircraft is issued a VFR-day type certificate during the certification process, which specifies the equipment the manufacturer must include for the plane to be legal. You can find this information in the Type Certificate Data Sheet (TCDS). If the broken item was a required part of the original design for VFR flight, the aircraft does not meet its certification standards. It is the pilot’s responsibility to ensure that the aircraft's configuration complies with these original legal requirements.

Step 4: Is the Equipment Required for the Operations Listed in the KOL?

Finally, check KOEL located in your Pilot’s Operating Handbook (POH). The KOEL is a table that specifies the required equipment for different types of flight operations, such as IFR, night, or flight into known icing. While an item might not be required by the FAA for a VFR day flight, the manufacturer may have determined it is necessary for the safe operation of that specific aircraft model. This step is a vital part of the pilot decision-making process, ensuring that all system-specific safety requirements are met.

Does Your Aircraft Have an MEL? Start Here

An aircraft’s Minimum Equipment List (MEL) is not required for all operations, but it becomes mandatory when approved by the FAA. While commercial aircraft use an MEL, many Part 91 aircraft rely on FAR 91.213(d) instead. If an MEL exists, it becomes the controlling authority for inoperative equipment, and the four-step test does not apply. The pilot must confirm this by checking onboard documentation, including an FAA-issued Letter of Authorization (LOA). Since the MEL is aircraft-specific, it defines what equipment may be inoperative while maintaining airworthiness compliance.

1. What Is a Minimum Equipment List (MEL)?

A Minimum Equipment List (MEL) is an FAA-approved, operator-specific document that allows an aircraft to operate with certain inoperative equipment under defined conditions while maintaining safety. It is derived from the Master Minimum Equipment List (MMEL), which outlines which items may be inoperative, along with required maintenance (M) and operational (O) procedures and repair intervals. By translating these standards to a specific aircraft, the MEL provides a clear framework for compliance, helping the pilot determine when flight is legal and what actions are required to maintain airworthiness.

2. How to Use an MEL?

To use an MEL, start by locating the inoperative equipment, verifying the required number of units, reviewing limitations, completing operational procedures, ensuring proper documentation, and making a final determination of safety and legality. Following these steps ensures proper use of an MEL while staying compliant with FAA regulations and maintaining aircraft airworthiness.

Step 1: Locate the Equipment

Find the inoperative item in the MEL, typically organized by ATA chapter or system category.

Step 2: Check Installed vs. Required

Review the number of units installed and the number required for the flight to determine whether the operation is permitted.

Step 3: Review MEL Conditions

Read all limitations, notes, and conditions attached to that item to understand operational restrictions.

Step 4: Identify Required Procedures

Follow any listed “O” (Operational) procedures, such as adjusting cockpit settings, and “M” (Maintenance) procedures, such as pulling and collaring a circuit breaker.

Step 5: Verify Completion and Documentation

Ensure all required actions are completed and properly documented before flight.

Step 6: Make the Final Decision

Confirm compliance and determine if the aircraft is safe and legal to operate.

3. When the MEL Says No-Go?

The MEL indicates a no-go when an inoperative item is not listed, when required operational (O) or maintenance (M) procedures cannot be completed, or when the repair interval (Categories A–D) has expired. It also prohibits dispatch if the defect affects safety, exceeds flight manual limitations, or violates Airworthiness Directives (ADs). In these situations, the aircraft is not compliant and must be grounded until corrective action is taken. 

For example, if a required navigation light fails and the MEL requires it for night operations, or if a circuit breaker cannot be properly collared as specified, the aircraft cannot be flown. In each case, the pilot must coordinate maintenance to restore compliance before returning the aircraft to service.

What Happens If It Fails Any Step?

If an aircraft fails any part of the four-step test or the MEL evaluation process, it is not compliant with FAR 91.213 and cannot be legally operated. Under FAA regulations, there is no partial credit in safety compliance, meaning that if the broken equipment is required by §91.205, an Airworthiness Directive, the Type Certificate, or the KOEL, the flight cannot legally depart. The primary consequence of failure at each step is a mandatory No-Go decision. 

Attempting to fly despite a failed step carries severe safety implications. If repair is not immediately possible, the pilot may obtain a Special Flight Permit (Ferry Permit) from the FSDO to reposition the aircraft for maintenance. Until then, the aircraft must remain grounded, as compliance requires acknowledging that flying is neither safe nor legal.

You Passed the Four-Step Test: What’s Next?

If the aircraft passes all steps under FAR 91.213, the pilot may proceed only after completing specific post-test procedures. Passing the test confirms the equipment is not required, but the aircraft must still be configured to remain safe, legal, and compliant. The pilot must deactivate, placard, and document the inoperative equipment, then confirm the aircraft remains airworthy. These actions form a complete preflight safety assessment and ensure compliance with FAA regulations.

Deactivate the Equipment

Deactivating inoperative equipment is a critical safety procedure designed to prevent the faulty item from causing further issues, such as electrical shorts or interference with functional avionics. Legal requirements dictate that the equipment must be rendered inoperative and, if possible, disconnected from its power source. This usually involves pulling the specific circuit breaker and securing it with a collar or zip-tie so it cannot be accidentally reset. In some cases, a mechanic may need to physically remove the item. Proper deactivation ensures there is no impact on flight safety from equipment, satisfying FAA compliance by isolating the failure.

Placard It "INOPERATIVE"

Once the item is dead, you must placard inoperative equipment to provide clear communication in the cockpit. The FAA requires a visible label, usually a simple sticker or piece of tape that clearly states INOPERATIVE or INOP on or near the instrument. This serves as a constant reminder to the flight crew that the data from that gauge or the switch's function is unavailable. Beyond legal obligations, placarding is a vital safety requirement, for example, in an emergency, you do not want to accidentally rely on a failed instrument. This is a standard part of maintenance procedures that keeps all crew members on the same page regarding the aircraft's status.

Document It

You must record the discrepancy in the aircraft logbooks and maintenance records, detailing exactly what is inoperative, that it has been deactivated, and that it has been placarded in compliance with FAR 91.213. This creates a paper trail of the pilot's and maintenance crew's responsibilities, ensuring the next person to fly the plane knows exactly what happened. The legal and safety importance of this cannot be overstated, as if the plane is ramp-checked and the logbook does not match the cockpit placards, you are in violation of FAA regulations.

Determine safe by a mechanic or pilot

Even if the paperwork is perfect, the Pilot in Command must determine if the aircraft is truly safe to fly in its current condition. While a mechanic’s responsibility is to verify the aircraft's technical airworthiness, the pilot has the ultimate authority to decide whether the missing equipment poses an unacceptable risk for the specific mission. If you are flying into a busy terminal area and your only broken item is a non-required second radio, you might be fine, but if that radio failure indicates a larger brewing electrical issue, a no-go is the only smart move.

Inoperative Equipment Flow Chart

The inoperative equipment flow chart is a structured decision tool that helps a pilot apply FAR 91.213 step by step during preflight action. It provides a clear yes/no path for determining airworthiness by guiding the pilot through either the MEL or the four-step test, ensuring that all regulatory and operational requirements are checked before flight.

To use the chart, begin by identifying the inoperative item and determining whether an MEL applies. If the answer is Yes, follow the MEL branch, and if No, proceed to the Four-Step Test. As the pilot moves through each step, the chart prompts verification against §91.205, Airworthiness Directives (ADs), and the KOEL. The final stage directs the pilot to complete deactivation, placarding, and a final safety determination, ensuring the decision is both legally compliant and operationally safe.

Checkride Oral Exam Tips: How Examiners Test §91.213

Examiners expect a clear, structured answer that starts with identifying whether the aircraft has an MEL. If no MEL applies, the pilot should state that the four-step test under §91.213(d) applies and walk through it logically. The key is demonstrating that decisions are based on verified data, not memory. The pilot should reference the POH for KOEL and the FAR/AIM for §91.205, showing the ability to locate and apply regulations. A complete answer also includes an explanation of post-test actions, such as deactivation and placarding, which confirms both regulatory knowledge and practical decision-making readiness.

Common Oral Questions

1. Walk me through what you'd do if you found an item INOP on preflight

Identify the equipment, check for an MEL, apply the four-step test if no MEL exists, then deactivate, placard, document, and determine if the aircraft is safe for flight.

2. What's the difference between §91.205 and §91.213?

FAR 91.205 defines required equipment for flight, while FAR 91.213 explains how to operate with inoperative equipment.

3. What are the consequences of flying with inoperative equipment that is not listed in an MEL?

The flight becomes illegal, the aircraft is not airworthy, and the pilot risks enforcement action.

4. How can you determine if the equipment can still be operated legally?

Use the MEL or complete the four-step test and verify compliance at each step.

5. If you find that a piece of equipment is not required for the flight type but is inoperative, what would your next steps be?

Deactivate the equipment, placard it “INOPERATIVE,” document it, and confirm the aircraft is safe.

6. If the aircraft has an inoperative item that affects night flight but is not required by the type certificate, what actions would you take?

Check the KOEL and planned operation; if required for night flight, do not conduct the flight under those conditions.

Common Student Mistakes to Avoid

Common student mistakes when applying FAR 91.213 during preflight include confusing §91.205 with §91.213, assuming verbal approval is sufficient, and misunderstanding who makes the final go/no-go decision, all of which result from skipping steps or misinterpreting regulatory requirements. A pilot must follow a structured evaluation process, verify compliance at each step, and base decisions on FAA regulations rather than assumptions, as avoiding these errors improves both checkride performance and real-world flight safety by ensuring every decision is safe, legal, and properly justified.

3 common student mistakes to avoid when applying FAR 91.213 during preflight are:

1. Confusing §91.205 with §91.213

A common error is assuming that if an item is not on the §91.205 list (such as ATOMATO FLAMES), it is automatically okay to fly. Students often forget that §91.205 lists only the items required for basic flight types. FAR 91.213 is the how-to guide for everything else that is broken. Confusing the two can lead to significant legal implications, such as flying with an item required by a Type Certificate or an Airworthiness Directive, even if it is not mentioned in 91.205. Always remember 91.205 tells you what is required, while 91.213 tells you how to handle what is broken.

2. Assuming a mechanic's verbal OK is enough

Many students believe that if a mechanic looks at a broken landing light and says, "You are good to go," they are legally covered. This is a dangerous misconception. While a mechanic is an expert on the mechanic’s role (maintenance), the pilot’s responsibility is to ensure the aircraft is legally airworthy before the wheels leave the ground. FAA regulations require the physical act of deactivating and placarding, followed by a logbook entry. A verbal all clear does not satisfy the legal requirement for documentation, and flying without that paper trail makes the aircraft unairworthy.

3. Forgetting the pilot, not the mechanic, makes the final go/no-go call.

The most critical mistake is surrendering your pilot’s authority to someone else. Even if a mechanic has deactivated, placarded, and logged an item, and even if the regulations technically allow the flight, the final decision-making process rests solely with the pilot. Just because it is legal to fly does not always mean it is safe. For example, flying with an inoperative fuel gauge might be legal under certain narrow conditions, but as the PIC, you must decide if that risk is acceptable for your specific flight. Never let anyone else, a mechanic, instructor, or dispatcher, make the final safety call for you.

Final Approach: Know FAR 91.213 Before You Leave the Ground

Mastering FAR 91.213 is a key aspect of pilot responsibility and applies to every preflight involving inoperative equipment. The regulation provides a clear framework for balancing safety and legal compliance by using either a Minimum Equipment List (MEL) or the four-step test, ensuring that each flight meets FAA airworthiness standards. By following these structured methods, pilots can evaluate equipment, verify compliance, and make a confident go-or-no-go decision.

During preflight or under examiner scrutiny, speed and accuracy are critical. Tools like a pre-tabbed FAR/AIM allow the pilot to quickly reference regulations such as 91.205 and 91.213, eliminating guesswork and reducing reliance on memory. This ensures that every decision is based on verified regulatory guidance, allowing the pilot to maintain compliance, safety, and confidence before leaving the ground.