PJS Aviation Glossary: Aircraft Terms to Know

PJS Aviation Glossary: Aircraft Terms to Know

We know that sometimes aviation lingo can seem like a foreign language, especially to those not very familiar with the industry. We’re hoping the brief glossary with the aviation terms below can help clear up some confusion for you when you charter your next trip.

Ad Hoc Charter

An ad hoc chartered flight is any flight that is chartered for a specific purpose on a per-trip basis.

Duty Time

A pilot’s duty time is the time spent “on duty” operating, or assisting in the operation of an aircraft. The FAA has mandated specific limits on the amount of duty time a pilot may accrue before crew rest is required.

Empty Leg

An empty leg is the portion of a chartered flight where the plane is flying without passengers. This usually occurs when the aircraft needs to reposition itself or return to its home base. (Sometimes called a “deadhead.”)


An FBO, or fixed-base operator, is an independent business operating on location at an airport and proving aviation services, like fueling the aircraft. These businesses are what are commonly thought of as private jet terminals at smaller non-commercial airports.


An RJ is a common abbreviation for a regional jet. A regional jet is a type of short to medium range aircraft, typically carrying 40–50 passengers.

Contingency Plan

A contingency plan is a plan that takes several possible future events into account. As it relates to private aviation, this would mean having a backup plan in the event of a delay resulting from bad weather, aircraft maintenance, and other deviations from the “ideal” flight plan.


The acronym for Extended Range Twin Operations, as defined by the FAA. This is a rule that dictates how long a twin-engined aircraft may fly on a single-engine to the nearest suitable landing strip or airport.

Tail Number

A tail number is the airplane’s registration number and is used for identification in a similar way that a car’s license plate number is used. It is typically possible to identify an aircraft’s country of origin by the first letter of its tail number. In the United States, that letter is an “N.”

Part 91

The part 91 flight is any non-revenue generating flight. This can include a flight where the owner of the plane is flying or an empty leg where the aircraft is repositioning. FAA duty time regulations do not apply during part 91 flights.

Check back here often as we’ll be adding more terms to our Aviation Glossary in the near future!