Shares of Boeing (BA) - Get Report dipped Tuesday after federal transportation regulators ordered the aerospace giant to make design changes on all new 737 NG jets while retrofitting older ones following a fatal 2018 accident.

Boeing's stock traded as low as $361.61 after the decision by the National Transportation Safety Board, which requires the jet maker to redesign the "fan cowl structure" on all new and existing 737 Next Generation planes.  In recent trading, shares were off $1.64, or 0.44% to $367.82.

The NTSB's order follows a review of the April, 2018 accident in which a passenger on a Southwest Airlines flight from New York to Dallas was killed after a broken fan blade caused an engine to blow apart.

Bits of metal from the explosion shattered a window and depressurized the cabin, sucking  43-year-old bank vice president and mother of two Jennifer Riordan partly out of the plane before her fellow passengers were able to pull her back in.

"This accident demonstrates that a fan blade can fail and release differently than that observed during engine certification testing and accounted for in airframe structural analyses," said NTSB Chairman Robert Sumwalt, in a statement. "It is important to go beyond routine examination of fan blades."

The NTSB's order shifted Boeing's stock price into reverse, wiping out gains made earlier in the day after news of broke of a pair of big orders for Boeing jets, including the 737 Max, currently grounded after crashes that killed hundreds in Ethiopia earlier this year and in Indonesia last year.

Emirates airlines President Tim Clark said Tuesday in an interview the air carrier is considering finalizing a deal to buy 40 new Boeing 787 Dreamliners.

Meanwhile, Boeing also booked $3.6 billion in orders for its new 737 Max jet at the Dubai Airshow, with the company estimating the model will finally return to service next month.