David Learmount/London

An international "regulatory nightmare" has been resolved by a new International Civil Aviation Organisation (ICAO) protocol on cross-border aircraft leasing.

The protocol, Article 83 bis, clears the state of the aircraft's registration to agree transfer of the responsibility for the aircraft's safety oversight to the state of the airline or organisation which operated the aircraft.

Article 83 bis was drawn up as long ago as 1978, but remained unratified until the necessary minimum 98 ICAO member states voted for it.

The protocol was approved by the ICAO Assembly in June 1996, although formal notification of the change started to be distributed only in August.

Some states say that they have not yet received it, and two major international airliner-leasing companies contacted by Flight Inter- national claim that they are not aware of its ratification.

The leasing companies say that the new system should be clearer and less bureaucratic, allowing for agreed transfer, rather than delegation, of oversight responsibility.

The UK Department of Transport says that it welcomes the Article. "It allows states to take full responsibility for [the safety oversight of] aircraft leased by their airlines," it says.

Former US Federal Aviation Administration chief, Adm James Busey, speaking in 1990, described the new protocol's importance. He said at the time: "We must be concerned about how-we can maintain an effective system for monitoring the safety of aircraft operations and maintenance of [for example] aircraft that are owned by a company in one country, operated on lease by a company in another country, maintained by someone else and, possibly, flown by crews from a fourth country?"

Source: Flight International