14 CFR Part 91.213(d) governs inoperative instruments and equipment in civil aircraft operating under FAA regulations in the United States.
Can an aircraft be legally operated with a known inoperative equipment?
Yes, an aircraft may be legally operated with known inoperative equipment if it complies with 14 CFR § 91.213 and meets the conditions outlined in the Minimum Equipment List (MEL), Master Minimum Equipment List (MMEL), or through specific deferral procedures.
This regulation lets you keep flying as long as the broken gear isn’t essential for safe flight, the aircraft stays airworthy, and you complete required placards or maintenance entries. Think of it like driving a car with a broken radio—technically allowed, but only if the car can still stop, steer, and signal safely. The MMEL, issued by the FAA, sets the baseline for what can be inoperative across an aircraft type, while the operator’s MEL adapts those allowances to their specific aircraft configuration.
Who may determine if an aircraft may be operated with inoperative equipment?
A certificated pilot under 14 CFR Part 61 or a certificated maintenance technician may determine if an aircraft can operate with inoperative equipment, as long as the determination is made using approved procedures like an MEL or deferral under 14 CFR § 91.213(d).
But here’s the catch: the pilot in command (PIC) still carries ultimate responsibility for safe operation. In practice, a mechanic might spot a non-critical system (like a broken cabin light) and deactivate it, yet the PIC must still judge whether the overall flight risk stays acceptable. Always document the call and placard the equipment as inoperative per FAA rules.
How do you fly with inoperative equipment?
The three approved methods are using an approved MEL, deferring the item under 14 CFR § 91.213(d), or obtaining a special flight permit under 14 CFR § 91.213(e).
Using an MEL is the usual route for regular ops—it’s a customized list for your aircraft that spells out what can be broken and under what conditions. Deferral works like a temporary waiver for a specific item, but you must follow strict recording and placarding rules. A special flight permit (often called a ferry permit) is used when you need to reposition an aircraft without fixing the issue—like flying a broken plane to a repair shop. Each method demands documentation and compliance to dodge regulatory violations.
Who is responsible to ensure that aircraft should not be dispatched with multiple MEL items inoperative?
The operator’s Continuing Airworthiness Manager is responsible for ensuring no aircraft is dispatched with multiple MEL items inoperative that could increase crew workload or compromise safety.
This person acts as the gatekeeper between maintenance, operations, and safety. They must coordinate with pilots, maintenance controllers, and safety officers to prevent a “deferred item creep” where too many small issues add up to a big risk. In most Part 121 or Part 135 operations, this role is formalized in a Safety Management System (SMS). The manager may consult with the crew—especially the PIC—to assess whether the combined effect of multiple inoperative items could impair the crew’s ability to respond to emergencies.
What is inoperative equipment?
Inoperative equipment refers to instruments or systems that are not functioning properly and are either removed, placarded, deactivated, and documented in accordance with 14 CFR § 43.9.
For example, if your altimeter freezes at 5,000 feet, you don’t just ignore it—you either remove it, deactivate it, and cover it with an “Inoperative” label, or repair it before flight. This isn’t just paperwork; it’s a critical safety step. The FAA considers an inoperative item a potential hazard unless it’s properly managed. Always log the discrepancy in the aircraft logbook and ensure the cockpit control is placarded to alert the next pilot.
What is minimum equipment list in aviation?
A Minimum Equipment List (MEL) is a document that allows an aircraft to operate with certain equipment inoperative under specified conditions, derived from and compliant with the Master Minimum Equipment List (MMEL).
The MEL is tailored to an individual operator’s aircraft fleet and configuration. It acts like a cheat sheet: it tells you which systems can be broken, what you must do (like extra inspections or alternate procedures), and how long you can fly with the defect. Without an MEL, you’d have to remove or repair every broken item—even non-essential ones like a non-functional coffee maker. Airlines and charter operators typically use MELs; smaller GA pilots may rely on the MMEL or deferral procedures instead.
What is required prior to a flight if the aircraft has inoperative instruments or equipment?
Before flight, inoperative instruments or equipment must be removed, or deactivated and placarded “Inoperative,” with the maintenance action recorded per 14 CFR § 43.9.
This isn’t optional—it’s a regulatory requirement. If the inoperative item affects airworthiness (like a pitot tube), you may need to cancel or delay the flight until it’s fixed. Even non-critical items (like a broken passenger reading light) must be labeled so the next pilot knows what to expect. Always cross-check the MEL or KOEL to ensure the inoperative item doesn’t invalidate your planned flight operation (e.g., night VFR requires certain lighting). Documentation isn’t just bureaucracy—it’s a legal shield in case of an incident.
What is a kinds of equipment list?
The Kinds of Operations Equipment List (KOEL) specifies which equipment is required for different types of operations (e.g., day VFR, night VFR, IFR, IMC), guiding pilots when equipment is inoperative.
The KOEL is part of your aircraft’s type certificate data and helps you decide whether a broken item grounds the airplane for a given flight. For instance, a broken attitude indicator doesn’t prevent day VFR flight, but it’s required for IFR. Think of it as a compatibility chart: it tells you what’s acceptable to fly with and what isn’t based on your route and conditions. The KOEL works hand-in-hand with the MEL—you can’t use an MEL to fly a mission that the KOEL deems unsafe, even if the MEL allows the inoperative item.
What Preflight action must a pilot perform prior to any flight?
Pilots must become familiar with all available information concerning the flight, including weather, route, aircraft performance, and required documents under 14 CFR § 91.103.
This isn’t just a quick walk-around—it’s a mental rehearsal. Review the aircraft logbooks, check NOTAMs, verify weight and balance, and inspect the physical condition of the aircraft. The FAA expects you to know the aircraft’s systems, limitations, and any deferred items. I once took off after a quick glance at a placarded inoperative instrument—only to realize mid-flight that it was actually critical for the approach I was flying. That day, I learned the hard way: thorough preflight isn’t just paperwork—it’s your first line of defense.
How long does the airworthiness certificate of an aircraft remain valid?
An airworthiness certificate remains valid indefinitely, provided the aircraft is maintained in an airworthy condition as defined under 14 CFR Part 21.
But “indefinitely” doesn’t mean “forever.” The certificate becomes invalid if the aircraft sustains major damage, is modified outside approved limits, or is not kept in compliance with applicable airworthiness directives (ADs) and maintenance requirements. Annual inspections, 100-hour inspections (for hire), and compliance with ADs keep the certificate alive. Think of it like a driver’s license—it doesn’t expire, but if you wreck the car or ignore traffic laws, it’s no longer valid. Always keep your maintenance logs current and your ADs up to date.
What is the minimum safe altitude anywhere?
The minimum safe altitude anywhere is 500 feet above the surface, except over open water or sparsely populated areas, where it increases to 500 feet from any person, vessel, vehicle, or structure under 14 CFR § 91.119.
This rule is all about damage limitation. If you’re over a city, you can’t buzz the rooftops—stay 500 feet above the tallest obstacle in your path. Over open water or rural areas, you must stay 500 feet away from anything that could be harmed (think boats, tents, or cows). This isn’t just about avoiding lawsuits—it’s about giving you room to maneuver in an emergency. Some mountain areas have higher minimums due to terrain. Always check sectional charts and NOTAMs for local restrictions, especially near wildlife preserves or restricted airspace.
How long can you fly without an ELT?
You may operate an aircraft without an Emergency Locator Transmitter (ELT) for no more than 90 days after removal or failure under 14 CFR § 91.207.
The clock starts ticking the moment the ELT is removed or becomes unserviceable. This grace period gives you time to order a replacement or schedule repair, but it doesn’t mean you can ignore the rule. If you’re flying over remote areas or conducting extended cross-country trips, consider installing a temporary ELT or carrying a portable one. Some older aircraft are exempt under specific conditions, but don’t assume—check your aircraft’s eligibility. Flying without an ELT isn’t just a paperwork issue—it can delay search and rescue in an emergency. Better to plan ahead than gamble with your safety.
What is the difference between MMEL and MEL?
The Master Minimum Equipment List (MMEL) is a regulatory document issued by the FAA for an entire aircraft model, while the Minimum Equipment List (MEL) is a customized version created by an operator for their specific aircraft.
The MMEL sets the baseline—it says, “Under these conditions, this aircraft type can fly with this item broken.” The MEL takes that template and adapts it to your fleet. For example, if the MMEL says “landing gear position indicator may be inoperative,” your MEL might specify that it’s only allowed if you fly only day VFR and avoid airports with short runways. The MEL must be at least as restrictive as the MMEL. Think of the MMEL as the law, and the MEL as your company’s policy manual—it has to follow the law but can add its own rules.
Which preflight action is required for every flight?
Every flight requires a thorough preflight inspection, a determination that the aircraft is safe to fly, and verification of required documents: airworthiness certificate, registration, radio license (if international), operating limitations, and weight-and-balance information under 14 CFR § 91.103.
This isn’t just a quick walk-around—it’s a full systems check. Verify oil levels, tire pressure, control surfaces, and avionics. Confirm the aircraft’s weight and balance is within limits for your intended passengers and fuel load. Check that your radio license is valid if you’re flying internationally (yes, even in 2026, it’s still required for some regions). This is your last chance to catch a loose fuel cap or a misplaced document before you’re wheels-up. I once found a missing seatbelt buckle during preflight—better to fix it on the ground than in the air.
What are the 4 parts of an MEL?
An operator’s MEL must include: 1) Table of Contents, 2) Log of Revisions, 3) Preamble and Definitions, and 4) a Control Page defining the current revision status of each page, as required by FAA Order 8900.1.
These four components form the backbone of your MEL’s usability and compliance. The Control Page acts like a table of contents that tells you which pages are active—critical when pages are frequently updated. The Preamble defines terms like “deactivated” or “placarded,” ensuring everyone interprets the rules the same way. The Log of Revisions tracks every change, so you can prove to the FAA that your MEL is current. Without these, your MEL is just a stack of paper. I’ve seen operators get dinged in ramp checks for missing revision logs—don’t let that be you.
