Washington

BOEING and the Federal Aviation Administration (FAA) confirmed on Sunday that they are reviewing a wiring issue that could potentially cause a short circuit on the grounded 737 MAX.

Boeing spokesman Gordon Johndroe said the United States planemaker "identified this issue as part of that rigorous process, and we are working with the FAA to perform the appropriate analysis. It would be premature to speculate as to whether this analysis will lead to any design changes".

The New York Times reported that Boeing is reviewing whether two bundles of wiring are too close together, which could lead to a short circuit and potentially result in a crash if pilots did not respond appropriately.

The FAA said in a statement on Sunday that the agency and company "are analysing certain findings from a recent review of the proposed modifications to the Boeing 737 MAX". The agency added that it will "ensure that all safety-related issues identified during this process are addressed".

Boeing is working to design separating the wiring bundles if necessary, and conducting extensive analysis to establish if the electrical fault could occur in a real-world scenario, a company official said.

Officials said the FAA had directed Boeing to complete an audit in December. The wiring issue could push back the return of the MAX, the officials added. Reuters has reported previously that the FAA is unlikely to approve the plane until at least February and might not until March or later. The FAA flagged the wiring issue as potentially "catastrophic". It is possible other protections like shielding, insulation and circuit breakers could prevent the short circuit, a company official said.

Boeing will halt production of the 737 MAX this month following the March grounding of its best-selling plane, after two crashes killed 346 people in five months. Last month, Boeing's board fired chief executive Dennis Muilenburg after repeatedly failing to contain the fallout from the crashes that tarnished its reputation with airlines and regulators.

The crisis has cost Boeing US$9 billion, and has hurt suppliers and airlines. Boeing is struggling to mend relations with the US and international regulators it needs to win over to get the jet back in the air.

Separately, US and European regulators are expected to return to Iowa this week to review a software documentation audit of the 737 MAX that was not completed last year, officials said Sunday. REUTERS