2023年6月，有飞机反应右侧反推AFT COWL UPPER SKIN上面一颗紧固件丢失，机队首起。需注意检查。
此类事件一事一议，波音给了胶带封堵，50CY或10天的期限。
Boeing has eviewed the Ref/A message and conirms it is structuraly acceptable to temporarily speed tape the missing fastener area and to continue revenue service for a period of 50 Flight Cycles or 10 days, whichever occurs first. Inspect the condition of the local area and speed tape daily e-apply speed tape as necessary and report back to Boeing any structural condition changes。
但，搜到过外部航司的一些个例，波音相对是比较谨慎，可以用其他材料的钉进行封堵，并保留30天。
Boeing has reviewed the Ref/A/ message and does not approve of dispatching the airplane with an open hole at the identified location. If the fastener per Boeing drawing are not available to install during this urgent AOG condition, then Boeing approves of using any CRES or titanium fastener to fill the hole for a maximum of 30 days until permanent repair can be completed.