Glossary
Aviation Operations Glossary
51 terms explained with real-world operational context.
A
Aircraft Group
A grouping of similar aircraft types that share a common checkout. For example, all Cessna 172S models at a school might be in one group.
Aircraft Utilization
The percentage of available hours that an aircraft actually flies. Calculated as actual flight hours divided by total available hours in a period.
Airworthiness
The condition of an aircraft meeting all requirements for safe flight, including current inspections, resolved squawks, and AD compliance.
Airworthiness Directive (AD)
A legally binding order issued by the FAA requiring inspection, modification, or replacement of an aircraft component. Non-compliance renders the aircraft unairworthy.
Annual Inspection
A comprehensive inspection required every 12 calendar months by FAR 91.409(a). Unlike the 100-hour inspection, the annual has no overfly allowance — the aircraft is grounded on the expiration date.
AVIATES
A mnemonic for the required inspections and checks that keep an aircraft airworthy: Annual inspection, VOR check (for IFR), Inspections (100-hour), Airworthiness Directives, Transponder check, ELT inspection, and Static system check.
B
Block Time
Prepaid flight time purchased at a discounted rate. A student buys a block of hours (e.g., 10 or 20 hours) upfront and draws down the balance as they fly.
Booking
A scheduled reservation for an aircraft, optionally with an instructor. Bookings have a type (dual, solo, rental, maintenance, ground), a time slot, and assigned resources.
Booking Type
The category of a scheduled reservation: dual (with instructor), solo (student alone), rental (certificated pilot), maintenance (aircraft out of service), ground (classroom/sim), or discovery (intro flight).
C
Cancellation Policy
The school's rules governing when and how a booked flight can be canceled, including minimum notice requirements and any associated fees or deposit forfeitures.
Checkout
A proficiency evaluation that qualifies a pilot to fly a specific aircraft type at a particular flight school. Typically involves a flight with an instructor and may include an oral quiz.
Checkride
A practical test conducted by an FAA Designated Pilot Examiner (DPE) for the issuance of a pilot certificate or rating. Consists of an oral exam and a flight test.
Currency
The state of meeting recency requirements to exercise specific privileges. Checkout currency means a pilot has flown enough recent flights in an aircraft type to remain qualified.
D
Discovery Flight
An introductory flight lesson for someone who has never flown before. Typically 30-60 minutes, offered at a fixed price, and designed to give the prospective student a taste of flying.
Dispatch
The process of assigning and releasing aircraft and instructors for scheduled flights. Includes verifying aircraft airworthiness, pilot qualifications, and weather conditions.
Double Booking
When the same aircraft or instructor is scheduled for overlapping time slots. A critical scheduling error that wastes time and frustrates students.
DPE (Designated Pilot Examiner)
An FAA-designated individual authorized to conduct practical tests (checkrides) for pilot certificates and ratings. DPEs charge their own fees and maintain their own schedules.
Dry Rate
An aircraft rental rate that does not include fuel. The renter pays for fuel separately, either by reimbursing the school or fueling the aircraft directly.
Dual Instruction
A flight with both a student and an instructor on board. The instructor is the pilot in command (PIC) or is providing instruction to the PIC. Dual flights do not require the student to have a checkout.
E
ELT Inspection
Emergency Locator Transmitter inspection required by FAR 91.207. The ELT must be inspected every 12 calendar months, and the battery must be replaced when 50% of its useful life has expired or after 1 cumulative hour of use.
Exclusion Constraint
A database-level mechanism (PostgreSQL btree_gist) that makes overlapping bookings for the same resource physically impossible. Unlike application-level checks, exclusion constraints cannot be bypassed by race conditions or concurrent requests.
F
Fleet Management
The practice of managing all aspects of an aircraft fleet: maintenance scheduling, utilization tracking, cost allocation, insurance, and operational status across multiple airframes.
Flight Review
A review required by FAR 61.56 every 24 calendar months to maintain pilot-in-command privileges. Consists of at least 1 hour of ground and 1 hour of flight training with a CFI.
Flight School
An organization that provides flight training, operating under Part 61 (flexible curriculum) or Part 141 (FAA-approved structured curriculum). May also be called a flight training organization (FTO) or approved training organization (ATO).
I
IFR (Instrument Flight Rules)
A set of regulations and procedures for flying when visibility is reduced, relying on cockpit instruments rather than visual references. An instrument rating is required to fly under IFR.
Instructor (CFI)
A Certified Flight Instructor authorized to provide flight training. CFIs hold certificates with ratings that determine what instruction they can give — CFI for single-engine, CFII for instrument, MEI for multi-engine.
M
Maintenance Event
A recorded maintenance action — inspection, repair, or component replacement — with the date, tach time, and description of work performed.
MEL (Minimum Equipment List)
A document that permits an aircraft to be operated with certain equipment inoperative, under specific conditions. Not available to Part 91 operators (they use the KOEL — Kinds of Operations Equipment List — or FAR 91.213).
P
Part 141
Title 14 CFR Part 141 — the FAA regulation for certificated pilot schools with FAA-approved training curricula. Requires structured syllabi, stage checks, and FSDO oversight.
Part 61
Title 14 CFR Part 61 — the FAA regulation governing pilot certification under a flexible, non-structured training framework. Most small flight schools operate under Part 61.
Postflight
The process after a flight that includes recording tach/Hobbs times, filing any squawks, and completing billing. The counterpart to preflight.
Preflight Inspection
A visual and physical inspection of an aircraft performed by the pilot before every flight, as required by FAR 91.103. Checks the aircraft's condition and readiness for flight.
Prepaid Account
A student account funded in advance, typically through block time purchases. Flights are billed against the prepaid balance rather than invoiced after the fact.
S
Solo Flight
A flight where a student pilot is the sole occupant of the aircraft. Requires appropriate endorsements and, at most schools, a current checkout in the aircraft type.
Squawk
A reported discrepancy or mechanical issue with an aircraft. Pilots and mechanics file squawks to document problems that need attention.
Stage Check
A proficiency evaluation at specific milestones in a training program, typically conducted by a different instructor than the student's primary CFI. Required at Part 141 schools.
Static System Check
A biennial inspection of the pitot-static system required by FAR 91.411 for IFR flight. Ensures accurate altitude, airspeed, and vertical speed indications.
STC (Supplemental Type Certificate)
An FAA approval for a modification to an existing aircraft type design. STCs authorize specific alterations like avionics upgrades, engine swaps, or structural changes.
T
Tach Time
Engine time measured by the tachometer, calibrated so one tach hour equals one hour at cruise RPM (typically 2,400 RPM). At idle, the tach accumulates slower than real time. At full power, slightly faster.
TBO (Time Between Overhaul)
The manufacturer's recommended engine operating time before a major overhaul. Not legally binding for Part 91 operations but strongly followed by most schools and insurance companies.
Time in Service
Per FAR 1.1, the time from the moment an aircraft leaves the surface of the earth until it touches the surface again. This is the official reference for 100-hour inspection intervals.
Training Progress
A student's advancement through a training syllabus toward a certificate or rating. Measured by completed lessons, stage checks passed, flight hours logged, and milestones reached.
Transponder Check
A biennial (every 24 calendar months) inspection required by FAR 91.413 for aircraft operating in controlled airspace. Ensures the transponder and altitude encoder report accurately.