pilot investigation

例句：

1. 1. The pilot investigation revealed that the accident was due to human error.
   飞行员调查发现，事故是由于人为失误造成的。
2. 2. The company conducted a pilot investigation to test the new product's effectiveness.
   公司进行了一次试点调查，以测试新产品的有效性。
3. 3.The pilot investigation helped us identify the root cause of the problem.
   试点调查帮助我们找到了问题的根源。