European aircraft safety regulators are not ruling out the possibility of issuing an airworthiness directive (AD) after the stunning revelation from Japan that seat maker Koito Industries falsified test results on as many as 150,000 seats used by 32 carriers.

The European Aviation Safety Agency (EASA) withdrew production organisation approval for Koito in September 2009 after it was "no longer convinced that Koito was exchanging accurate information with its customers", says a spokesman for the agency.

This effectively prohibited Airbus from delivering aircraft equipped with Koito seats.

But in an interview with ATI today, the EASA spokesman said: "I am not excluding an airworthiness directive on this. The agency for its part at this stage cannot confirm the precise scale of the issue. Neither can it, with any degree of certainty, say to what extent safety is negatively affected. I can, however, say that on evidence we have from the Japan Civil Aviation Bureau (JCAB), three things are affected - 16g, 9g [test data] and flammability [data]."

He adds: "The scale of the issue would be visible in an airworthiness directive, if and when we publish one."

An EASA statement issued this week says the evidence from the JCAB relates to "irregularities in the design and production of Koito seats manufactured in Japan and installed in a number of aircraft types".

Airbus confirms that 130 aircraft or just over 2% of the worldwide Airbus fleet are equipped with Koito seats.

The European airframer is understood to be working on an operators information telex (OIT) concerning the Koito seat problem.

But with shipment of new Koito seats ordered stopped by Japan's transport ministry, operators are already starting to feel an impact.

Kioto seating table

Delivery to Thai Airways International of five new Airbus A330-300s has been delayed, as has the delivery to Singapore Airlines (SIA) of an 11th Airbus A380.

Koito is supplying the business class seats on SIA's A380s and the first class seats on the carrier's Boeing 777-300s, which are being retrofitted.

However, Koito could have fabricated test results on as many as 1,000 aircraft in the world fleet, according to reports from Japan that cite the country's transport ministry. As such, Boeing customers may face a much greater exposure than Airbus customers, in light of the European airframer's revelation that 130 Airbus aircraft are fitted with Koito seats.

Japan's All Nippon Airways has already delayed the launch of its new Boeing 777-300ER service - and its new "Inspiration of Japan' interior - on the New York-Narita route due to a delay in premium economy seats supplied by Koito.

A Boeing spokeswoman says the airframer learned of the Koito situation a year ago. "We worked with our customers at that time to rectify it. When the same issue cropped up again last fall, we sent a team to Koito to help them with their quality management system. Our engineering tests determined that it is not a safety of flight issue, so we notified our customers individually," she says, adding that Boeing is not "able to name them [customers] individually".

The Boeing spokeswoman says the Koito issue applies to all classes of seats - first, business, premium-economy and economy. "We have not yet issued an operator message," she notes.

Koito seats are one of the seat options in the 787 catalogue. Last week, Mark Larson, gallery technical manager at Boeing's 787 Dreamliner gallery, told ATI that Koito is currently under review for offerability, but that the airframer is still working with the Japanese firm.

For its part, the US FAA says is aware of the Koito situation and is "in touch with the Japanese civil aviation authorities about it".

"We're reviewing the situation and haven't made any decisions yet [on whether to issue an AD]. In general when one civil aviation authority issues an AD, generally the other follows suit in some way," says an FAA spokeswoman.

Source: Air Transport Intelligence news