Wet Lease

A wet lease (or ACMI lease — Aircraft, Crew, Maintenance, and Insurance) is an arrangement in which an airline leases an aircraft from another operator complete with flight crew, maintenance support, and insurance coverage. The lessee airline provides fuel, pays airport fees, handles ground operations, and sells the tickets under its own brand.

Wet leases are used for:

• Seasonal demand: Adding capacity during peak travel periods
• Aircraft replacement: Covering for aircraft in heavy maintenance
• New route launches: Testing demand before committing to fleet acquisition
• Emergency capacity: Replacing aircraft after incidents or groundings

The opposite is a dry lease, where only the aircraft is provided — the lessee supplies its own crew, maintenance, and insurance. Dry leases are the standard model for airline fleet financing through lessors like AerCap, SMBC Aviation Capital, and Air Lease Corporation.

Regulatory considerations for wet leases include operational oversight (which authority supervises safety?), crew licensing recognition, and competition law implications.