HANOI, VIETNAM — An aviation industry organization has issued a warning concerning Vietnam's adherence to international aircraft leasing standards, following a dispute over the repossession of four planes. This development raises concerns about the financing costs for future aircraft deliveries.

Vietnam, one of the fastest-growing air travel markets globally, has hundreds of aircraft on order and relies on air transport for 5% of its GDP, as reported by the International Air Transport Association.

The UK-based Aviation Working Group, which monitors financing regulations on behalf of aircraft manufacturers and lessors, added Vietnam to a watchlist after a Hanoi court hindered an attempt to seize aircraft over an alleged rental payment default. The involved airline was not identified, but the warning update on the organization's website included a link to a file named "Update No. 1 re VietJet".

VietJet, one of Asia's largest low-cost carriers, has not commented on the matter, nor have other Vietnamese airlines. VietJet operates Airbus aircraft and has ordered 186 jets from the European company, including 114 A320neo models yet to be delivered, as well as 200 Boeing 737 MAX aircraft that have not been delivered.

Under the Cape Town Convention (CTC), a treaty to which Vietnam is a party, airlines can obtain better financing rates if their countries facilitate aircraft repossession by lessors in cases of missed payments. The treaty enables aircraft de-registration, or removal from the host country's registry, upon a lawful lessor request, followed by placement on an international register, allowing the owner to fly the aircraft away.

The AWG reported that an unnamed lessor requested this action between November and January, supported by an English court order with jurisdiction over the lease contract. Vietnam's regulator agreed to de-register the aircraft, but a Hanoi court reversed that decision in February after a lawsuit from an airline shareholder. The AWG bulletin stated that the lessor's request and the Hanoi court's unfavorable ruling "are material developments that implicate CTC compliance in Vietnam."