A wet lease is an aircraft leasing arrangement in which one airline or operator supplies another airline with an aircraft and the services required to operate it. It is commonly known as an ACMI lease because the package includes Aircraft, Crew, Maintenance and Insurance.
The company providing the aircraft is called the lessor, while the airline using the additional capacity is the lessee. ACMI leasing allows an airline to increase or replace capacity without sourcing an aircraft, qualified crew, maintenance support and insurance separately.
What Does ACMI Mean?
ACMI stands for the four principal components supplied by the lessor:
- Aircraft: An airworthy aircraft suitable for the agreed routes and operation.
- Crew: Normally the required flight and cabin crew, subject to the contract and applicable regulations.
- Maintenance: The technical support and maintenance needed to keep the aircraft serviceable and airworthy.
- Insurance: The aircraft and operational insurance specified in the agreement.
The precise division of responsibilities must always be defined in the contract.
How Does an ACMI Lease Work?
Under a typical ACMI lease, the lessor operates the aircraft under its own Air Operator Certificate and retains operational control. The lessor provides the aircraft, crews it, manages its maintenance and arranges the agreed insurance coverage.
The lessee usually determines how the capacity will be used within its commercial programme. This may include selecting routes and schedules, marketing the flights and selling passenger seats or cargo capacity.
Flight numbers, aircraft branding, onboard service and other commercial details depend on the agreement and relevant regulatory approvals.
What Is Usually Excluded from an ACMI Lease?
ACMI does not automatically include every cost associated with the operation. The lessee commonly remains responsible for expenses such as:
- Aviation fuel
- Airport and navigation charges
- Ground handling
- Aircraft parking
- Catering and passenger services
- Security and local operating charges
- Crew accommodation or positioning costs where specified
The exact allocation varies between contracts, so every cost and responsibility should be agreed before the operation begins.
When Do Airlines Use Wet Lease Aircraft?
Airlines and operators may use wet lease aircraft for several operational reasons:
- Seasonal peaks or temporary increases in demand
- Aircraft-on-ground disruption and maintenance cover
- Delayed aircraft deliveries
- New route launches
- Shortages of qualified crew
- Replacement of unavailable fleet capacity
- Passenger or cargo programmes requiring additional lift
- Longer-term capacity while fleet plans are being developed
An ACMI arrangement can provide a practical solution when additional capacity is required more quickly than an airline could obtain and prepare an aircraft independently.
How Long Does an ACMI Lease Last?
There is no single standard duration. An ACMI lease may cover a short operational requirement, a complete season or a longer multi-year programme.
The appropriate period depends on aircraft availability, regulatory approvals, crew planning, anticipated block hours and the commercial needs of both parties.
Benefits of ACMI Leasing
The principal benefits can include:
- Faster access to operational aircraft capacity
- Aircraft, crew and technical support supplied as one package
- Flexibility to respond to seasonal or unexpected demand
- Reduced disruption when an aircraft becomes unavailable
- The ability to test or launch routes without immediately adding permanent fleet capacity
- Access to aircraft types not currently present in the airline’s fleet
Before entering an agreement, both parties should confirm matters such as operational approvals, route permissions, aircraft configuration, minimum guaranteed block hours, positioning costs, maintenance planning, insurance limits and service standards.
Is an ACMI Lease the Same as a Charter?
They are related but are not necessarily the same commercial arrangement.
A charter commonly involves purchasing a particular flight or series of flights. An ACMI lease provides operational aircraft capacity for the lessee’s programme, often across an agreed schedule and period. The contractual structure, operational responsibilities and commercial control can therefore be different.
What Is the Difference Between an ACMI Lease and a Dry Lease?
An ACMI or wet lease provides the aircraft together with crew, maintenance and insurance. A dry lease generally supplies only the aircraft, leaving the lessee responsible for operating it under its own approvals and arranging crew, maintenance and insurance.
Read our complete guide to wet lease vs dry lease for a detailed comparison.
Information Needed to Source ACMI Aircraft
To assess a requirement efficiently, airlines and operators should normally provide:
- Preferred aircraft type and configuration
- Passenger or cargo requirement
- Planned base and operating routes
- Required start date and lease duration
- Expected monthly block hours
- Average flight duration or cycle ratio
- Registration, age or jurisdictional restrictions
- Required regulatory approvals
- Any specific operational or onboard-service requirements
Providing complete information helps determine which aircraft and operators may be suitable.
Request ACMI Aircraft
ACMI Lease helps airlines and operators identify aircraft capacity suited to their operational requirements. Availability, commercial terms and deployment schedules remain subject to confirmation with the relevant operator.
Send us your ACMI requirement with the aircraft type, proposed start date, operating region and expected duration.
Frequently Asked Questions
Is ACMI the same as a wet lease?
The terms are commonly used interchangeably in commercial aviation. ACMI describes the four main elements supplied by the lessor: aircraft, crew, maintenance and insurance.
Who operates the aircraft?
The lessor normally operates the aircraft under its own Air Operator Certificate and retains operational control, subject to the agreement and applicable regulations.
Does an ACMI lease include fuel?
Fuel is normally paid for by the lessee, although the final allocation of costs is determined by the contract.
Can ACMI aircraft be used for cargo operations?
Yes. ACMI leasing is used for both passenger and cargo operations, subject to aircraft availability, configuration and regulatory approval.
How quickly can an ACMI operation begin?
Timing depends on aircraft and crew availability, contractual preparation, operating permissions and regulatory approvals. Complete operational information should be supplied as early as possible.