Abstract: In case of international air crash damage occurred during the operation of the leased aircraft, an injured claimant may seek liability of the aircraft lessor for air crash damages on the grounds of convenience in litigation or for higher punitive damages, or for fruitless claims against the air carrier. The 1929 Warsaw Convention and the 1999 Montreal Convention do not exclude the liability of any other subject except the air carrier and the five jurisdictions of the international air crash damages litigation, leaving space and path for the victim to claim the lessor operating the aircraft. The ambiguity of the definition of aircraft owner in the 1952 Rome Convention makes it highly likely that the lessor of wet or dry leased aircraft will be "deemed" or "presumed" to be an air operator and be subject to claims. In the practice of aviation litigation, there are many difficulties and obstacles in the recourse against aircraft lessor to assume the liability for damages caused by international air crash, such as the secrecy of the object of recourse, the differences in legislation of various countries, and the recourse to exclude liability under relevant international aviation convention. Although it is not easy to claim in the practice of aviation legislation and judicial precedents, the liability for air crash damages of aircraft lessor already existed, and the basis of the claimant's right of recourse is often manifested as the negligent entrustment liability, product liability or vicarious liability. Therefore, the aircraft lessor must attach great importance to the risk of liability for air crash. Effective precautions can be taken by perfecting the liability clause of the lease agreement, the liability insurance clause, the airworthiness liability allocation clause, and by strengthening the monitoring of the operation of the leased aircraft.