WASHINGTON (AP) — Federal safety officials are requiring inspections of cockpit seats on Boeing 787 Dreamliners after one of the jets went into a dive when the captain’s seat lurched forward without warning and disconnected the plane’s autopilot system.

Boeing also has stopped test flights of a new version of its 777 jetliner after discovering a damaged structural part between the engine and the rest of the plane. The new model has not yet been approved by regulators.

The Federal Aviation Administration said in an order scheduled to be published Wednesday that it will require operators of 787s to inspect both pilot seats for missing or cracked caps that cover a switch used to move the seats.

During a March flight by Chile-based Latam Airlines, the captain’s seat moved forward and hit a switch that disconnected the autopilot system. The plane, flying from Australia to New Zealand, rapidly dropped about 400 feet (120 meters) before the co-pilot regained control, according to a preliminary report by Chilean authorities. Several dozen passengers were injured, according to news reports.

Within days of the incident, Boeing recommended that airlines look at the cockpit seats on 787s for loose caps on the switches and told them how to turn off power to the motorized seats.

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The FAA said it has received four other reports from Boeing of cockpit seats moving when not intended to, including one in June.

The FAA said its safety order will affect 158 planes registered in the United States.

Separately, the FAA published a final rule requiring airlines to inspect inlets around ducts in engine anti-ice systems on 787s for signs of heat damage. The agency proposed the rule in February after a report of damage to “multiple” engine inlets caused by missing or “degraded” seals around the ducts.

Boeing identified the inlet issue in bulletins sent to airlines last year.

Meanwhile, Boeing suffered a setback in its effort to win FAA certification of the 777-9, a new, long-range addition to its lineup of 777 jets. The plane might be most noteworthy for its folding wingtips, which would allow the larger model to fit at airport gates designed for other 777s.

Boeing said Tuesday it has stopped flights after one of four test planes was found to have cracks on a part called a thrust link that helps balance load between the engines and the aircraft. The issue surfaced after a test flight returned to Hawaii.

“During scheduled maintenance, we identified a component that did not perform as designed,” Boeing said in a statement. “Our team is replacing the part and capturing any learnings from the component and will resume flight testing when ready.”

Boeing said there are four thrust links on each 777-9 — two on each engine for redundancy. The company said the component is new to the 777-9 and is not used on existing 777s or other planes.

Boeing, which is based in Arlington, Virginia, said it was keeping the FAA and airlines informed about the issue.

The problem with the component was first reported by The Air Current.