推迟该决定的原因如下： 该决定原定于上个月宣布，但由于去年 10 月印度尼西亚雅加达附近狮航坠机事件导致 189 人死亡，人们担心 MAX 8000 系列喷气式飞机存在安全隐患，因此推迟了该决定。 然而，尽管波音公司承诺提供更新的防失速警告系统并进行额外的模拟，但美国联邦航空管理局（FAA）尚未发布官方文件，证明新的警告系统可以充分保护乘客免受潜在的灾难性生命损失风险。 Instead, in response to continuing uncertainty, some American airlines, including Southwest Airlines, recently filed lawsuits against Boeing Company Limited Partnership, alleging fraudulent concealing and violation of product warranty liability。 Meanwhile, other global majors in the civil aviation market have already begun phasing out the MAX 8000 family models based on rising safety concerns since early this January。 On February 1, in a brief statement released via email to Reuters, Boeing Co。 Spokesman Paul Bergman stated that the Chicago headquartered corporation "continues to engage constructively with government regulatory authorities, including the U。S。 Department of Transportation," while referring queries regarding the timing of when to expect approval to return the jets to active status to the FAA。" 您能否根据文字材料总结一下波音737 MAX飞机延迟宣布返航的原因，并解释一下目前美国航空公司起诉波音的法律纠纷？