Inoperative Equipment 91.213: What to Check

This guide focuses on a small, nonturbine airplane with a standard U.S. airworthiness certificate operating under Part 91. It teaches the decision framework, not how to disconnect or repair a system. Begin with the airworthiness requirements hub for the relationship between aircraft documents, maintenance status and present condition.

Which 91.213 path applies before takeoff?

Identify the applicable path before deciding what a failed item permits you to do.

The FAA's AC 91-67A explains acceptable compliance methods. It is guidance; the regulation supplies the requirements. The FAA catalog lists this October 16, 2023 revision as active.

When can an airplane use the path without an approved MEL?

Paragraph (d) is available only to the aircraft and operations it describes, outside the approved-MEL operations identified in paragraphs (a) and (c).

91.213(d)(1) distinguishes aircraft types and whether a Master Minimum Equipment List has been developed. A small nonturbine trainer can fit that framework, but “Part 91” alone does not make every aircraft eligible. Do not extend this guide to a turbine airplane or assume a special certificate has the same operating limitations.

An MMEL is a master basis for an MEL; an MEL and its authorization apply to the specific aircraft/operation. A KOEL, or Kinds of Operations Equipment List, identifies equipment requirements for kinds of operation. These names describe different documents. Neither an equipment list nor a web-downloaded MMEL automatically authorizes dispatch with a failed item. AC 91-67A explains the distinctions and the approved-MEL process.

This sequence summarizes the ordinary paragraph (d) study path after eligibility is established. Approved-MEL operations and special flight permits require their own applicable conditions.

Which four required-equipment questions must you answer?

For the paragraph (d) path, the failed item must not be required by any of the four sources in 91.213(d)(2).

Check the airplane's VFR-day type-certification requirements, then its equipment list and KOEL for the intended kind of flight. Use the applicable aircraft-specific material, rather than assuming another airplane of the same general model has identical equipment. 91.9 separately requires compliance with operating limitations.

Next, check 91.205 and every other applicable Part 91 equipment rule. Day/night, VFR/IFR and the intended operation can change the answer. Airspace also matters: 91.215 and 91.225 have distinct transponder and ADS-B Out requirements and authorization provisions. Do not assume that a VFR flight makes installed avionics irrelevant.

Finally, check applicable airworthiness directives. An item required to work by an AD fails the ordinary paragraph (d) screen; 39.7 makes noncompliance with an applicable AD a violation. An owner's reassurance does not replace that review.

Any required-item finding blocks ordinary deferral under paragraph (d). Passing these four screens still leaves disposition, records, hazard and overall airworthiness to resolve.

What is the difference between removal and deactivation?

The rule offers different disposition paths, each with its own placarding and record conditions.

Under 91.213(d)(3), removal requires placarding the cockpit control and recording the maintenance under 43.9. The alternative is deactivation with an “Inoperative” placard; if deactivation involves maintenance, Part 43 governs both the work and its recording.

A switch position does not, by itself, prove that the equipment has been acceptably deactivated. AC 91-67A discusses deactivation and related system effects. Resolve the actual method with appropriately authorized maintenance personnel; this guide deliberately gives no circuit-breaker, wiring or disconnection procedure.

43.3 controls who may perform maintenance and preventive maintenance. Being the pilot does not authorize every removal or deactivation task. A no-hazard determination and authority to perform maintenance are also different questions.

The two branches summarize 91.213(d)(3), not instructions for performing the work. Both still require the qualified no-hazard determination in paragraph (d)(4).

Who makes the no-hazard determination?

The determination must come from a certificated, appropriately rated Part 61 pilot or a person certificated and appropriately rated to perform maintenance on the aircraft.

That is the qualification in 91.213(d)(4). It is an additional requirement after the required-equipment and disposition conditions, rather than permission to ignore an item those earlier checks require.

Consider the failure's effect on other systems, workload, expected weather, night conditions and available alternatives. AC 91-67A's operational guidance discusses these factors. A second failure can change the analysis even when each item seemed manageable alone. For a student, uncertainty is a reason to involve the instructor and authorized maintenance personnel before treating a discrepancy as resolved.

The PIC's responsibility under 91.7 remains. A permitted deferral does not establish that the aircraft is in condition for safe flight under the actual conditions.

What should the records and continuing review show?

The evidence should explain what failed, what was done and what remains limited or unresolved.

For maintenance covered by 43.9, the entry includes the work description, completion date and appropriate identifying/approval information. Its approval concerns the work performed. Do not treat a student-written discrepancy note or a loose placard as a substitute for a required maintenance entry.

Deferral is not a reason to forget the item. 91.405(c) requires an item permitted to be inoperative by 91.213(d)(2) to be repaired, replaced, removed or inspected at the next required inspection. It does not say every such item may simply be ignored until an arbitrary universal deadline.

What if the item is required or the failure is hazardous?

Do not use the ordinary paragraph (d) path to take off while one of its conditions is unmet.

Repair, a valid applicable MEL provision, a different permitted operation, or a separately issued special flight permit may be relevant, depending on the case. Each requires its own complete review. Paragraph (e) refers to 21.197 and 21.199; a special flight permit concerns an aircraft capable of safe flight for an authorized purpose, not normal unrestricted use. Never infer permission merely from the intended destination being a repair shop.

Check yourself

Frequently asked questions

Is a KOEL the same as an MEL?

No. A KOEL helps identify equipment required for a kind of operation. An approved MEL and its authorization provide a conditional operating path for the aircraft; the document names are not interchangeable.

Does “not in 91.205” mean I can fly with it broken?

No. Certification requirements, the equipment list/KOEL, other applicable Part 91 rules and ADs still matter, followed by disposition and hazard checks for the paragraph (d) path.

Is an “Inoperative” placard enough?

No. It addresses one condition. Eligibility, required-equipment checks, proper removal/deactivation, applicable maintenance records and the qualified hazard determination must also be resolved.

Does 91.213 replace emergency procedures for an airborne failure?

No. This article addresses the pre-takeoff decision. An airborne malfunction requires the aircraft's applicable procedures and the PIC's continuing safe-flight assessment; do not turn a ground deferral summary into an emergency checklist.

Sources and review

Last reviewed November 3, 2026. Current FAA/eCFR provisions were checked for this draft. Use the actual aircraft's approved information and the linked rules for detailed applicability.

• 91.213: operating paths, four required-equipment sources, disposition and hazard determination.
• FAA AC 91-67A, particularly Chapter 4 and document definitions; active FAA catalog entry. This describes acceptable methods and is not a replacement for the rule.
• 91.205, 91.215, 91.225, 91.9 and 39.7: operational equipment, limitations and AD context.
• 43.3, 43.9, 91.405 and 91.7: authority, records, continuing maintenance and safe condition; 21.197 and 21.199: special flight permits.

What should you study next?

Return to the airworthiness requirements hub, compare aircraft inspection requirements, and connect equipment applicability with airspace classes.

Practice airworthiness and inoperative-equipment concepts on FirstSolo.ai. Explain the evidence for each condition before deciding what follows. FirstSolo.ai is solely a study tool and does not issue FAA endorsements.