美国联邦调查局 (FBI) 正在调查波音 737 Max 9 门塞螺栓缺失问题，这可能是针对乘客的犯罪行为。 FBI investigates Boeing over missing bolts on 737 Max 9 door plug, potential crime against passengers.

一月份一架波音 737 Max 9 的门塞被炸断后，美国联邦调查局 (FBI) 正在调查波音公司。 The FBI is investigating Boeing after a door plug blew off a Boeing 737 Max 9 in January. 此前，美国国家运输安全委员会进行了初步调查，发现这架飞机在离开波音工厂时没有配备固定门塞所需的螺栓。 This follows a preliminary investigation by the National Transportation Safety Board that found the jet left Boeing's factory without the necessary bolts to secure the door plug. 航班上的乘客已收到联邦调查局的信件，称他们可能是犯罪行为的受害者。 Passengers on the flight have received letters from the FBI stating they may be victims of a crime. 联邦调查局的调查以及司法部的调查可能会导致对波音公司的指控，并加强对该公司行为的审查。 The FBI's investigation, alongside the DOJ's probe, could lead to charges against Boeing and increased scrutiny of the company's conduct.