Private Aviation Glossary

Block time is the elapsed time from when an aircraft pushes back from its parking spot at origin to when it's parked at destination — engine start to engine shutdown. Private jet charter (including empty legs) is billed on block time, not on flight time in the air.

An empty leg flight is a one-way private jet flight sold at a discount because the aircraft has to fly without passengers to its next paid booking. Empty legs are typically priced 25–80% below retail charter, with the discount widening as the departure window narrows.

The Federal Excise Tax (FET) is a 7.5% federal tax on the price of domestic commercial air transportation, including private jet charter and empty leg flights. The tax is collected by the operator and remitted to the IRS; it appears on every empty-leg booking confirmation.

A one-way charter is a private jet booking that flies in only one direction. Empty legs are the most common form, but operators also quote on-demand one-way charters at retail pricing when no positioning inventory matches the customer's date and route.

Positioning cost is the operator's expense of flying an aircraft empty to or from a paid charter — fuel, crew duty, landing and ramp fees, handling. This is the cost empty-leg pricing recovers when an operator sells the positioning segment to a passenger.

The domestic segment fee is a per-passenger, per-segment IRS tax on domestic commercial air transportation. The fee is small ($5.20 per passenger per segment as of 2024) but adds up on multi-leg charter trips with multiple passengers.

Cabin class is the industry segmentation of private jets by interior size, range, and operating cost. SkyAccess uses six classes: turboprop, light jet, midsize, super midsize, heavy jet, and ultra-long-range. Empty-leg pricing varies sharply between classes.

A dead leg is a private jet flight segment with no paying passengers — the aircraft is repositioning to or from a paid booking. Operators sell dead legs at 25–80% off retail to recover the trip's fixed costs.

A deadhead flight is a non-revenue positioning flight where the aircraft (and often the crew) flies without paying passengers to be in position for the next paid booking. Operators sell deadhead seats as empty legs at 25–80% off retail.

Deadhead pay is the compensation a flight crew receives for repositioning flights with no paying passengers. Under FAA Part 135 duty-time rules, deadhead time counts as on-duty time even when no revenue is flying — the crew is compensated and the time counts against their duty-day limits.

An FBO (Fixed-Base Operator) is a private aviation terminal at an airport that provides fuel, hangar, ground handling, and passenger services to private jets — including every empty leg flight. FBOs are where private jet passengers actually arrive and depart; they don't use the commercial terminal.

A ferry flight is a non-revenue private aircraft flight used to move the airplane between bases, to maintenance, or to a delivery destination. Customer-facing ferry flights are typically sold as empty legs at 25–80% off retail.

IFR (Instrument Flight Rules) is the FAA regulatory framework for flying primarily by reference to cockpit instruments rather than outside visual references. Every Part 135 charter — including every empty leg — operates under IFR by default, with crews trained and current for IFR flight.

MTOW (Maximum Takeoff Weight) is the FAA-certified weight at which an aircraft can safely take off, including aircraft, fuel, crew, passengers, and baggage. It's the hard ceiling that drives passenger and baggage limits on every empty leg booking.

A repositioning flight is a non-revenue flight that moves a private aircraft from one airport to another to be in position for its next paid booking. When opened for sale to passengers, it becomes an empty leg priced 25–80% below retail charter.

ARGUS is a private safety-audit firm that rates Part 135 charter operators on three tiers (Gold, Gold Plus, Platinum). An ARGUS rating is a voluntary third-party signal that the operator has passed an independent audit of pilot qualifications, safety management, and operational history.

IS-BAO is an internationally-recognized business aviation safety standard administered by IBAC (the International Business Aviation Council). Operators register at one of three stages (1, 2, 3); higher stages confirm a more mature safety management system.

Operational control is the FAA-mandated authority over the go/no-go decision on a flight. Under Part 135, the certificate holder (the operator) must retain operational control — not the broker, not the customer, not the aircraft owner. This is the defining legal line between legal charter and illegal "gray" charter.

A Part 135 operator is an FAA-certificated company authorized to fly paying passengers on private (non-scheduled) charter aircraft under 14 CFR Part 135. Every legitimate private jet charter — including every empty leg — is operated under a Part 135 certificate.

Part 91 of the FAA regulations governs non-commercial flight operations — private owners flying their own aircraft, corporate flight departments flying company aircraft, recreational pilots. Aircraft on Part 91 cannot be chartered for hire; doing so anyway is illegal "gray" charter.

Part 91 Subpart K ("Part 91K") is the FAA regulation governing fractional aircraft ownership programs. It's a subset of Part 91 (non-commercial) that adds program-specific crew currency, maintenance, and operational-control requirements.

Wyvern is a private safety-audit firm that rates Part 135 charter operators on two main tiers (Registered, Wingman). Wyvern is the second-largest third-party charter safety auditor in the US after ARGUS; ratings are voluntary and reviewed annually.

A charter broker is an intermediary who arranges private jet flights between customers and Part 135 operators without operating any aircraft themselves. Brokers earn a margin on the operator's quote; marketplaces like SkyAccess remove that intermediary by surfacing operator inventory directly.

Fractional jet ownership programs sell shares of an aircraft to multiple owners, who each get an annual flight allowance and pay a monthly management fee. Programs like NetJets, Flexjet, and PlaneSense compete with empty legs by trading higher predictability for higher cost.

A jet card is a prepaid private jet program where members buy a fixed number of flight hours at a locked-in hourly rate and aircraft category. Empty-leg marketplaces and jet cards are competing products: cards trade liquidity for price certainty.