Boeing 737 operators must provide a status report to the airframer on wing slat parts linked to igniting a catastrophic fire on a China Airlines 737-800 in August.

The loss of that aircraft also has pushed Boeing to fast-track a review of all of the company's airliner models to find out if others can be affected by the same problem. The CAL 737-800 was destroyed by loose parts, including a washer and nut attached to the wing slat-track's downstop, that were pinned against the slat can after landing.

As the slat-track retracted, the parts punctured the slat can, causing a fuel leak that started a raging fire. No one was injured as the crew evacuated all passengers before the aircraft fire grew out of control.

Some Boeing models are automatically excluded from the review. The designs of the 747 and DC-series aircraft do not include slat cans, which are extended into the wing fuel tanks.

However, the focus of the investigation remains on the 737-series aircraft due to the fire and at least one other airline in Japan that has publicly reported missing slat-track components. The status report is required by 20 September.

Boeing is still investigating whether the problem of the missing or loose components are caused by a design flaw, assembly errors or maintenance lapses. "The bottom line is it doesn't matter if it's maintenance," the company says. "This can't happen again."

Source: Flight International