The automated undercarriage systems on a Boeing Dreamliner, a new high-tech jumbo jet, entirely failed to work during the landing approach of a domestic Japanese flight carrying 250 passengers yesterday morning.
The news follows a similar incident last week on a more conventional Boeing jet, in which a plane on a flight to Warsaw was forced to land on its belly.
In today's problem, the automated landing gear did not operate, but the pilot was able to lower the landing gear manually - using gravity - and landed on the plane's second approach to the runway.
It was the first serious operational problem for the new Dreamliner aircraft, which has been in commercial use for only one week. The planes were sold to airlines partly on the basis of their advanced automated systems.
The Dreamliners have an all-electronic cockpit, and an aircraft-wide computer network that links the flight deck to all of the control systems as well as providing real time data to air control staff on the ground. Many of the safety systems, including the brakes, are electronically controlled, with some traditional hydraulic systems taken out.
The pilot of today's All Nippon Airways flight 651 was warned by on-board monitoring systems, on his approach to Okayama airport, that the landing gear had failed to engage. It is understood that the monitoring screens may have identified a problem with the systems controlling undercarriage hydraulic valves.
Boeing deferred comment to All Nippon Airways, which had not provided more detail at the time of writing on why the automated systems failed to work or how the problem will be prevented in the future.
In 2008, the US Federal Aviation Administration warned that the Dreamliner could be vulnerable to hacking, because of the way critical flight systems are linked with those used by passengers. They said the problems were "critical to the safety and maintenance" of the aircraft.