Airworthiness Requirements

Two conditions, both required: the aircraft conforms to its type certificate — including STCs and applicable ADs — and it is in condition for safe operation.

• The owner or operator is primarily responsible for maintaining the aircraft in airworthy condition, including compliance with Part 39 (91.403(a))
• The PIC is responsible for determining the aircraft is in condition for safe flight, and must discontinue the flight when an unairworthy mechanical, electrical, or structural condition occurs (91.7)

Teaching point that sticks: 91.7 makes airworthiness a preflight determination by the pilot every single flight. A fresh annual is evidence, not a verdict.

• Airworthiness certificate — appropriate and current, bearing the aircraft's registration number, and displayed at the cabin or cockpit entrance so it is legible to passengers or crew (91.203(a)(1), (b))
• Registration certificate — an effective U.S. registration certificate issued to the owner (91.203(a)(2))
• Radio station license — only for international operations (FCC, not FAA)
• Operating limitations — the AFM/POH, placards, markings, and any STC supplements (91.9)
• Weight and balance data — current equipment list and W&B

Expiration: the airworthiness certificate does not expire as long as inspections are current, the aircraft conforms to type design, and registration is valid. A Certificate of Aircraft Registration issued under 47.31 expires seven years after the last day of the month in which it is issued, and is renewed by application during the six months preceding that expiration date (47.40).

Don't let a student recite the mnemonic and stop. Send them to the airframe, engine, and propeller logbooks to find and read the actual entries — that is the correlation-level skill 91.7 will demand of them alone.

Yes, if it is used to carry any person other than a crewmember for hire, or if a person gives flight instruction for hire in an aircraft that person provides (91.409(b)).

The trigger attaches to the use of the aircraft, not to today's leg. Two nuances worth teaching:

• The 10-hour overfly is allowed only while en route to reach a place where the inspection can be done, and the excess time must be included in computing the next 100 hours (91.409(b)) — it is a borrowing, not a bonus.
• If the student owns the airplane and hires you as the instructor, you are not providing the aircraft, so the 100-hour is not triggered by 91.409(b). The annual still is.

An annual satisfies a 100-hour; a 100-hour never satisfies an annual, and it counts as an annual only if performed by a person authorized to do annuals and entered as an "annual" in the records (91.409(a)).

An AD is a regulation issued under 14 CFR part 39 requiring correction of an unsafe condition in a product — a condition that exists because of a design defect, maintenance, or other causes, and is likely to exist or develop in other products of the same type design (PHAK ch. 9).

Compliance is mandatory and recorded in the applicable maintenance log. ADs come in two categories: those of an emergency nature requiring immediate compliance prior to further flight, and those of a less urgent nature requiring compliance within a specified period (PHAK ch. 9).

Relief is narrow, and teach the boundary precisely:

• You may not put AD-required equipment on an MEL unless the AD itself provides otherwise (91.213(b)(2)), and an AD-required item stops the 91.213(d) ladder cold (91.213(d)(2)(iv))
• There is no provision to overfly the maximum hour requirement of a recurring AD unless the overfly is specifically written into the AD (PHAK ch. 9)
• The one path outside 91.213 is a special flight permit: "notwithstanding any other provision of this section," an aircraft with inoperable instruments or equipment may be operated under a permit issued under 21.197 and 21.199 (91.213(e))

A SAIB — Special Airworthiness Information Bulletin — is FAA-issued and non-regulatory: the FAA looked at a condition and decided it doesn't warrant an AD. Compliance is voluntary, as with a manufacturer's service bulletin. Either can be the precursor to an AD.

First, the aircraft must be one of the 91.213(d)(1) classes. Where no MMEL has been developed: rotorcraft, non-turbine-powered airplane, glider, lighter-than-air, powered parachute, or weight-shift-control. Where an MMEL has been developed: only small rotorcraft, small non-turbine-powered airplane, glider, or lighter-than-air. A training ASEL qualifies either way.

Then the item may be inoperative only if it is not:

1. Part of the VFR-day type certification instruments and equipment
2. Indicated as required on the aircraft's equipment list or on the KOEL for the kind of operation being conducted
3. Required by 91.205 or any other rule of Part 91 for this specific kind of flight
4. Required to be operational by an airworthiness directive

Then: remove it — cockpit control placarded, maintenance recorded per 43.9 — or deactivate it and placard it INOPERATIVE; and a pilot or certificated mechanic determines the inoperative item does not constitute a hazard to the aircraft (91.213(d)).

An FAA-approved, aircraft-specific list of equipment that may be inoperative. You cannot download one. 91.213(a) requires:

• An approved MEL exists for that aircraft
• A letter of authorization from the responsible Flight Standards office, obtained by written request of the airworthiness certificate holder, carried in the aircraft
• The MEL and the LOA together constitute a supplemental type certificate
• The aircraft records available to the pilot include an entry describing the inoperative equipment
• The aircraft is operated under all conditions and limitations in the MEL and the LOA

Operators under subpart K or Parts 121, 125, or 135 who have an MEL must use it (91.213(c)). Most light trainers have no MEL, which is why 91.213(d) is the path your students will actually walk.

Three categories (91.213(b)): type-certification-required and essential equipment, anything an airworthiness directive requires to be operable, and anything required for specific operations by Part 91.

Teach it as the answer to the question students actually ask — "if the MEL is the approved list, can anything be on it?" The three exclusions are the reason the answer is no, and they're worth teaching in the reverse order the reg lists them, because that's the order of a student's reasoning:

1. Part 91 requirements come first. If 91.205 wants it for tonight's flight, no list relieves you of it
2. An AD outranks the MEL. ADs are law; the MEL is an approval issued to an operator
3. Type certification is the floor. Equipment the airplane was certificated with, and needs for safe operation in all conditions, was never eligible to be relieved

The instructional payoff isn't the list, it's the principle underneath it: an MEL relieves you of equipment the airplane can safely fly without, and nothing else. A student who has that principle reconstructs the three categories; a student who memorized three bullets loses one under pressure. Ask them to justify each exclusion rather than recite it — that's the difference between rote and understanding on this item.

Night VFR is everything in 91.205(b) plus six additions — teach it that way, as a delta, not as a second list to memorize:

• Approved position lights
• An approved aviation red or aviation white anticollision light system on all U.S.-registered civil aircraft. If a light of the system fails, you may continue to a stop where repairs or replacement can be made — a real relief clause students never know exists
• One electric landing light, but only if the aircraft is operated for hire — the item most often gotten wrong in both directions
• An adequate source of electrical energy for all installed electrical and radio equipment
• One spare set of fuses, or three spare fuses of each kind required, accessible to the pilot in flight

Two instructor points. First, the day-VFR anticollision requirement in 91.205(b)(11) is limited to small airplanes certificated under Part 23 after March 11, 1996; at night 91.205(c)(3) applies to all U.S.-registered civil aircraft, so an older airplane can be legal by day and not by night on the same item. Second, this is where the KOEL and 91.213(d) ladder come alive: the item you legally placarded for the morning lesson may ground the night dual, and that is the cleanest scenario you can hand a student.

The Kinds of Operations Equipment List lives in the AFM/POH. It is the manufacturer's table of what must be installed and operative for each kind of operation — day VFR, night VFR, day IFR, night IFR, sometimes flight into known icing.

The distinction to teach: the MEL is FAA-approved, aircraft-specific, and relieves — it permits dispatch with items inoperative. The KOEL restricts, and it is a mandatory gate inside 91.213(d)(2)(ii) even when no MEL exists. Most light airplanes have a KOEL and no MEL, so the KOEL is the page your student will actually open.

Who: except for holders of a sport pilot certificate, the holder of a pilot certificate issued under Part 61 may perform preventive maintenance on any aircraft owned or operated by that pilot which is not used under Part 121, 129, or 135. Sport pilots are not shut out entirely — a sport pilot certificate holder may perform preventive maintenance on an aircraft owned or operated by that pilot and issued a special airworthiness certificate in the light-sport category (43.3(g)).

The ownership clause is the one that bites at a flight school: a renter neither owns nor operates the airplane, so the privilege isn't there. Whether a student pilot certificate counts as "a pilot certificate issued under part 61" for 43.3(g) is not settled by any FAA source cited here — if an owner-student asks, send them to the FSDO or an A&P rather than answering from inference.

What: the operations listed in 14 CFR part 43, appendix A — servicing landing gear tires and wheel bearings, replenishing hydraulic fluid, changing oil, replacing safety wire and cotter keys, replacing spark plugs, changing batteries, simple fabric patches (PHAK ch. 9).

Record: an entry with the description of the work, date of completion, and the signature, certificate number, and kind of certificate held by the person approving the work (43.9(a)). Undocumented preventive maintenance leaves the airplane unairworthy on paper. That last sentence is the whole lesson.

A special flight permit — a ferry permit — is a form of special airworthiness certificate issued for an aircraft that does not currently meet applicable airworthiness requirements but is capable of safe flight, to move it to a place where repairs or inspection can be performed. 91.213(e) lets you operate under one notwithstanding the rest of 91.213; the permit itself is issued under 21.197 and 21.199 (PHAK ch. 9, 91.213(e)).

Path: contact the FSDO; the permit is issued by the FAA or by a DAR. The permit specifies the route and conditions — commonly day VFR, no passengers, minimum crew — and is carried as the aircraft's airworthiness certificate. Aircraft carrying a special flight permit are exempt from the 91.409(a) and (b) inspection requirements (91.409(c)(1)).

Teach the scope honestly: the permit is what lets you legally move an airplane that is out of annual, out of 100-hour, or grounded by an AD to the shop — 91.213(e) applies "notwithstanding any other provision of this section." What it does not do is make the airplane airworthy. Before it is issued, an FAA inspector may personally inspect the aircraft or require an A&P or repair station to inspect it for safety on the intended flight, and that inspection is recorded in the aircraft records (PHAK ch. 9).

Standard airworthiness certificates are issued for normal, utility, acrobatic, commuter, and transport category aircraft, plus manned free balloons and special classes (PHAK ch. 3).

Special airworthiness certificates are pink, and are issued for primary, restricted, and limited category aircraft and light sport aircraft, and also as provisional certificates, special flight permits, and for experimental aircraft (PHAK ch. 3, ch. 9).

The operating limitations attached to a special certificate are part of the certificate. That matters directly to you: aircraft with a light-sport, experimental, or provisional special airworthiness certificate are exempt from the 91.409 annual and 100-hour requirements and follow their own inspection programs (91.409(c)(1)), and restricted-category aircraft carry limitations tied to the special purpose for which they were certificated. Read the limitations before you accept the airplane for a lesson.

Make the student work the ladder aloud — don't answer it for them.

• Is it 91.205 equipment? Not for day VFR. The items of 91.205(b) that bear on a piston trainer: airspeed indicator, altimeter, magnetic direction indicator, tachometer for each engine, oil pressure gauge, oil temperature gauge for air-cooled engines, manifold pressure gauge for altitude engines, fuel quantity for each tank, gear position indicator if retractable, anticollision lights for small airplanes certificated under Part 23 after March 11, 1996, safety belts, shoulder harnesses per the manufacture dates in 91.205(b)(14), and an ELT if required by 91.207 (b)(15). (The full list also carries a temperature gauge for each liquid-cooled engine and over-water flotation gear for hire.) No attitude indicator anywhere in it.
• Is it VFR-day type certification equipment? Check the TCDS and equipment list — this is the step students skip.
• Is it on the KOEL for this kind of operation? For a day VFR lesson, likely not; for the night dual next week, likely yes.
• AD? Check.
• If it clears all four: deactivate, placard INOPERATIVE, log per 43.9, and someone determines it is not a hazard.

Then the instructor question: this lesson includes basic attitude instrument work under the hood. The airplane may be legal and the lesson is not flyable as briefed. That is the distinction — airworthy for the flight versus equipped for the lesson — and it is a much better teaching moment than the placard.

Naming errors precisely is the instructional skill being tested. "You didn't check the KOEL" teaches; "be more careful" doesn't.

The Type Certificate Data Sheet is generated when the FAA issues a Type Certificate and specifies the important design and operational characteristics of the aircraft, engine, or propeller (PHAK ch. 3). It is public and available from the FAA.

You need it because 91.213(d)(2)(i) turns on VFR-day type certification equipment, and the TCDS plus the aircraft equipment list are the only way to answer that question for an airplane you didn't grow up in. It's also where you confirm engine and propeller models, fuel grade, and required placards when a school adds an unfamiliar airplane to the line — which is exactly when a student will ask you something you can't answer from memory.

Three separate records: airframe, engine, and propeller. Inspections and AD compliance are signed off in the applicable log, and recurring ADs carry a next-due date or interval you should be able to find and read out loud.

For the oral, be ready to open the actual logs and point to: the most recent annual (and 100-hour if the aircraft is used for instruction for hire), the AD compliance list with recurring items and next-due, the ELT battery replacement date legibly marked on the transmitter and entered in the maintenance record (91.207(c)(2)), the transponder and altimeter/static checks, and the current W&B and equipment list.

• 100-hour attaches when you give flight instruction for hire in an aircraft you provide (91.409(b)).
• The ELT requirement of 91.207(a) does not apply to aircraft engaged in training operations conducted entirely within a 50-NM radius of the airport where the local flight operations began (91.207(f)(3)) — a favorite examiner question, and a bad habit to build, since the exception evaporates the moment the lesson becomes a cross-country.
• An ELT may be temporarily removed for inspection, repair, modification, or replacement for up to 90 days, provided the records contain an entry with the date of initial removal, make, model, serial number, and reason, and a placard in view of the pilot reads "ELT not installed" (91.207(f)(10)).
• Preventive maintenance stays available for a school trainer flown under Part 91, since the exclusion is for aircraft used under Parts 121, 129, and 135 (43.3(g)) — but the aircraft must be owned or operated by the pilot doing the work, which a renter is not.

Three minutes, spoken by the student, not by you:

1. Show me the airplane is airworthy today. Airworthiness certificate displayed and legible, registration effective, operating limitations aboard, current W&B — then the inspection status from the logs or the school's status board, with the actual dates read aloud.
2. Show me nothing is placarded that matters for this flight. Walk the placards; for each, state which of the four 91.213(d)(2) gates it passed.
3. Tell me your discontinue criteria. 91.7(b) requires the PIC to discontinue the flight when an unairworthy condition occurs. What would make them turn around, and where would they land?

Item 3 is the one instructors skip. A student who has never rehearsed "what would make me stop" will press on with a rough magneto because the school is expecting the airplane back.