14 CFR 91.213 Inoperative Equipment: How Flight Schools Decide When a Broken Item Grounds the Airplane

A school's 172 came back at lunch with the heading indicator tumbling. The chief instructor put the airplane onto the schedule for the 1430 instrument lesson anyway. The dispatcher asked whether the airplane was airworthy with the directional gyro inoperative. The chief said yes for a VFR dual, no for the IFR lesson. The dispatcher had no written guidance to verify either call. The lesson was rescheduled, and the rule conversation should have happened when the squawk was written, not when the next student walked through the door.

14 CFR 91.213 is the rule that decides whether a broken item grounds a Part 91 airplane. It is the most consequential paragraph the flight school operates under and the one most often answered by feel. Schools that make the call cleanly run on a written framework the dispatcher and the chief instructor read the same way.

What 91.213 Actually Says

14 CFR 91.213 splits operations into two universes. The first is an airplane with an FAA-approved minimum equipment list. The MEL becomes the operative document, and the operator follows what it says about the inoperative item. The second is everybody else: an airplane without an MEL, which is where almost every primary trainer lives.

For airplanes without an MEL, 91.213(d) is the entire game. It allows a flight with an inoperative item only when four conditions are met. The item is not part of the day VFR equipment in 14 CFR 91.205. It is not required by the kinds of operations equipment list or the airplane's equipment list. It is not required by an airworthiness directive. It is not required for the specific kind of flight being conducted that day. If all four are clear, the operator can defer the item by removing or deactivating it, placarding it inoperative, and having a qualified person determine the deferral creates no hazard.

The Four Required Lists

The first test, 14 CFR 91.205, is the one schools handle most reliably because the list is short and printed everywhere. It names the equipment required for day VFR, then layers on what is added for night VFR, day IFR, and night IFR. The airspeed indicator, altimeter, magnetic compass, tachometer, oil pressure gauge, fuel quantity indicators, ELT, and seatbelts are the day VFR core. Any of those broken grounds the airplane.

The second test is the airplane's equipment list, which lives in the type certificate data sheet and the POH. Some equipment installed at certification is marked required and some is not. The required ones cannot be deferred under 91.213(d). The school's mechanic should be able to produce that list for every fleet aircraft so the chief instructor is not guessing whether the rotating beacon is required.

The third test is the kinds of operations equipment list, or KOEL, found in the POH for most modern airframes. It maps equipment against the operations the airplane is approved for. A vacuum pump might be optional for day VFR and required for IFR. Schools running 172s of a vintage that predates the KOEL have nothing equivalent in the POH, and the chief instructor has to make the day-VFR-versus-IFR determination from the underlying rules instead. That is the call the dispatcher in the opening scene needed and did not have.

The fourth test is the AD list. Some airworthiness directives mandate a specific piece of equipment as a condition of continued airworthiness. An AD that requires a working low-fuel warning light is not in 91.205, not in the equipment list, and not in the KOEL, and it still grounds the airplane until the light is fixed. Tracking that connection is the discipline covered in our AD tracking guide: the AD status sheet is what makes the 91.213(d) call accurate, not a hunch.

The Kind of Operation Filter

The piece schools most often miss is the fourth condition in 91.213(d): the item must not be required for the specific kind of flight being conducted. An airplane legal for day VFR with a tumbling directional gyro is not legal for instrument training that afternoon. The aircraft did not change. The kind of flight did.

A working dispatch policy treats this as two questions. First: is the airplane airworthy at all today. Second: is it airworthy for the specific lesson on the schedule. A 172 with an inoperative position light is fine for the 1000 dual that lands before sunset. The same airplane is not fine for the 1900 dual that requires operable navigation lights under 14 CFR 91.209. Same airplane, two answers, and the second one has to come from somebody who looked at the booking.

Deferring the Item Correctly

When all four tests clear, 91.213(d)(2) requires the item to be removed or deactivated and placarded inoperative, and a pilot or appropriate maintenance personnel to determine the item does not constitute a hazard. The deactivation is a maintenance action. Pulling a breaker and writing INOP on a placard is the version most schools use for something like a cabin reading light. Anything more invasive runs through the mechanic.

The hazard determination is the part that gets compressed. The intent of the rule is that somebody qualified actually thought about whether the missing item could cascade into a problem during the planned flight. A deactivated alternator is not a hazard on a day VFR flight that can land in 30 minutes if the master quits. The same deactivated alternator is a hazard on a four-hour cross-country. The thinking has to happen, and it has to be documented.

The Maintenance Record Is Where This Lives

The deferral is a maintenance action in the same sense an oil change is. It belongs in the aircraft logbook with the date, the aircraft time, the item deferred, the method of deactivation, the placard installed, and the signature of the person making the deferral. Without that entry, the next mechanic to open the cowling has no record of who decided what.

The same record-keeping discipline that makes squawk tracking reliable applies here. A deferral is a closed-loop squawk: the item is open, but the operational status was determined and recorded. The maintenance record carries the state.

Make the Dispatch System Honor the Status

A deferred item that is not visible at the booking is going to release an airplane on a flight it is not legal for. The schedule does not know the directional gyro is placarded INOP. The dispatcher might. The instructor probably does not. By the time anyone notices, the flight is in the run-up.

The fix is to surface the deferral on the aircraft record the dispatcher uses, alongside the inspection clocks and the open squawks, and to tag each deferral with the kinds of operation it removes the airplane from. An airplane with a placarded vacuum pump becomes unbookable for IFR lessons. This is the same logic that governs the rest of aircraft availability: the airworthiness call is part of the booking decision, not a side document the front desk consults when something feels off.

A modern flight school management platform like HangarOS treats deferred items as structured fields on the aircraft record, with the affected kinds of operation as flags the booking engine reads before releasing the airplane. The system blocks the IFR booking automatically.

Where Schools Get Caught

The recurring failures are the ones the rule does not catch. A pilot writes up a broken landing light at the end of a day VFR flight, the front desk pulls a placard from the drawer, somebody hand-letters INOP, and nobody writes it in the logbook. Three weeks later the same airplane goes out on a night cross-country, and the legal exposure is not the burned-out bulb. It is the missing logbook entry.

The other failure is kinds-of-operation drift. An airplane gets deferred for a vacuum pump in May, the placard goes up, the maintenance entry is clean, and by August the dispatcher has forgotten the airplane is not approved for IFR. The schedule offers it, the instructor takes it, and a real instrument lesson happens in an airplane already deferred out of that operation. The rule was followed at the deferral and abandoned at the booking.

A 91.213 call that ends in the logbook and on the schedule in the same shape is the call that holds across the year. The school working that way does not relitigate the rule every time something breaks.