The private aviation glossary
104 terms explained in plain English — from ACMI to wet lease.
A
ACMI ownership
ACMI stands for Aircraft, Crew, Maintenance and Insurance, the four things the lessor provides in a full wet lease; the lessee pays for fuel, handling, navigation charges, catering and taxes. The structure is common in the airline world and increasingly in business aviation when an operator needs extra lift for a season or a fleet gap, or when a large-cabin aircraft or bizliner is chartered for a tour or government mission. ACMI contracts are quoted as an hourly rate with a minimum monthly utilisation, so the customer carries the risk of not flying enough hours. For a traveller booking a single trip it is not a relevant product; for owners and operators it is a way to monetise idle aircraft.
Aircraft management ownership
Aircraft management is outsourcing the running of your jet to a specialist company that employs and trains the crew, schedules maintenance, arranges hangarage and insurance, handles trip planning and regulatory compliance, and usually offers to place the aircraft on its charter certificate to earn revenue when you are not using it. Fees run from about $8,000 to $25,000 a month plus pass-through costs, with the manager often taking 10–20% of charter revenue. Good management turns ownership into something close to a jet card experience; bad management hides mark-ups in fuel, maintenance and crew costs. Audit rights and transparent invoicing are the terms to negotiate.
D
Dry lease ownership
A dry lease hands over the aircraft only: the lessee supplies its own crew, maintenance oversight, insurance and operational control, and is responsible for the flight from a regulatory point of view. It is the normal structure for financing an aircraft through a bank or lessor, for companies sharing an aircraft between related entities, and for owners who want to fly under Part 91 with their own pilots. Dry leases are legitimate and common, but they are also the vehicle most often abused in illegal charter schemes, where a broker 'leases' the aircraft to a passenger for a single trip while secretly providing the pilots. Regulators look hard at who really controls the flight.
E
Engine program (MSP / CorporateCare / JSSI) ownership
An engine programme is a pay-by-the-hour maintenance contract that covers scheduled and often unscheduled engine work in exchange for a fixed fee per flight hour, typically $250–$1,200 per engine hour depending on type. Honeywell's MSP, Rolls-Royce CorporateCare, Pratt & Whitney's ESP and independent provider JSSI are the best known. Owners like them because they turn a $1–3 million overhaul into a predictable monthly cost, and buyers like them because an enrolled aircraft comes with a funded reserve rather than a looming bill. Coverage is transferable on sale, and a jet that is 'not on programme' typically sells for a discount that reflects the engines' accrued maintenance exposure.
Escrow ownership
Escrow in an aircraft transaction is a neutral third party, usually a title company in Oklahoma City for N-registered aircraft because of its proximity to the FAA registry, that holds the deposit, the purchase funds and the signed documents until every condition of the sale is met. The deposit, typically 5–10% of the price, becomes non-refundable once the buyer accepts the aircraft after the pre-buy inspection. At closing the escrow agent confirms clear title, files the bill of sale and registration application, releases funds to the seller and any lienholder, and records the new owner. International deals may use escrow agents in the buyer's jurisdiction alongside Cape Town Convention registrations.
F
H
Hangarage ownership
Hangarage is the cost of keeping an aircraft indoors, protected from sun, hail, snow and bird damage, rather than parked on the ramp. It is one of the larger fixed costs of ownership: from around $3,000 a month for a light jet at a regional US airport to $15,000–$30,000 a month for a large-cabin jet at Teterboro, Van Nuys, London Luton or Dubai. Space is scarce at the popular business airports, waiting lists are common, and transient hangarage for a visiting aircraft can cost $1,000 or more a night, a charge that may appear on your charter invoice if the crew hangar the jet at a cold-weather destination.
Hot section inspection ownership
A hot section inspection is a mid-life check on a turbine engine's combustor and turbine, the parts exposed to the highest temperatures, carried out roughly halfway between overhauls, often at 1,750–3,500 hours depending on the engine. Blades, vanes and liners are inspected for cracks and erosion and replaced as needed; the cost runs from about $150,000 to over $500,000 per engine. For buyers, the time since the last hot section and the hours to the next one are core valuation items, and an aircraft with both engines close to an inspection should be priced accordingly. Engine programmes such as MSP or CorporateCare cover hot sections, which is much of their value.
O
Owner-charter revenue ownership
Owner-charter revenue is the income an owner earns by allowing a management company to charter the aircraft to third parties when the owner is not flying. Typical arrangements pay the owner 80–90% of the hourly charter rate less direct operating costs, which in practice leaves a contribution of $1,000–$3,000 per hour toward fixed costs. Two to three hundred charter hours a year can offset a meaningful share of crew salaries, hangarage and insurance, but it will not make a jet profitable, and it adds cycles, wear and scheduling friction. Owners who need the aircraft at short notice or care about a pristine cabin often decide the revenue is not worth it.
P
Pre-buy inspection ownership
A pre-buy inspection is the independent technical examination a buyer commissions before completing an aircraft purchase, ideally at a maintenance facility of the buyer's choosing rather than the seller's. It covers records review, corrosion and structural checks, engine borescopes, avionics function, compliance with airworthiness directives and often a test flight, and it takes one to three weeks at a cost of $15,000–$100,000 depending on aircraft size. The findings feed into the purchase agreement: airworthiness defects are usually the seller's responsibility to fix, cosmetic and non-airworthiness items are negotiated. Skipping the pre-buy to win a competitive deal is the most common expensive mistake in aircraft buying.
T
TBO (time between overhauls) ownership
TBO is the manufacturer's recommended interval, in flight hours or cycles, between complete engine overhauls, at which the engine is stripped, inspected and rebuilt with new life-limited parts. Business jet turbofans typically have TBOs of 3,500–8,000 hours and some modern engines are 'on condition' with no fixed limit. An overhaul costs from around $500,000 for a small engine to several million for a large one, so the hours remaining to TBO drive a used aircraft's price. Part 135 operators must follow TBO limits; private Part 91 owners have more latitude but their aircraft are then harder to put on a charter certificate.
Title search ownership
A title search establishes who legally owns an aircraft and whether any liens, mortgages, tax claims or unpaid maintenance charges are attached to it. For US aircraft it means searching the FAA registry in Oklahoma City and the International Registry created by the Cape Town Convention; other registries have their own procedures and some, particularly for older aircraft that have changed country several times, are patchy. A clean title report and, ideally, title insurance protect the buyer from a previous owner's creditor turning up years later. It is inexpensive relative to the aircraft price and should be ordered before the deposit goes hard.
W
Wet lease ownership
In a wet lease the lessor provides the aircraft together with crew, and usually maintenance and insurance, so the lessor keeps operational control and the lessee simply buys capacity. In practice a wet lease of a business jet is functionally a charter, and in most jurisdictions the provider must hold an AOC or Part 135 certificate to do it. The term matters because 'wet' and 'dry' decide who is legally responsible for the safety of the flight. If someone offers you a jet plus pilots without a commercial certificate and calls it a dry lease, the label is wrong and the flight may be illegal.