sidewall

There, Boeing mechanics and quality inspectors complete the cabin interior — adding wiring, insulation, sidewalls, seats, galley and lavatories.

To access each door plug, mechanics removed two rows of seats and the sidewall.

Other photos show part of the passenger cabin sidewall around the hole was torn off, exposing insulation material.

Otherwise, the hole is sealed with a plug, and from the inside it is covered by a sidewall.

A statement by governing body the FIA said Pirelli had noticed "a separation in the sidewall" when they checked tyres on Friday.