WHAT ARE INVESTIGATORS
LOOKING INTO?
Safety experts said the investigation will focus
on why the fan blades snapped — whether
mistakes were made in manufacturing or
maintenance or if problems were missed
during inspections — and whether blade
inspections need to be done differently or
more often. They will compare Saturday’s
incident with similar ones in December in
Japan and in 2018 on another United flight
to Hawaii.
Investigators will also look at why the
cowling, which covers the front of the engine,
broke off along with other parts. Photos
showed a large gash in the fairing, a piece of
composite material that makes planes more
aerodynamic by smoothing out joints where
the body meets the wings.
“That was a substantial hit,” said John Goglia,
a former member of the National
Transportation Safety Board, which is
investigating Saturday’s incident. “If that
had hit the wing, things might have been
different because the wing is full of fuel” and
the broken engine was still on fire.
Sumwalt said, however, that “there was no
structural damage” to the plane.
Another concern: The engine remained on
fire even after pilots presumably shut off its
fuel supply. That could indicate a fuel leak,
said Todd Curtis, a former Boeing engineer
and now a safety consultant.