Definition of self-certification in English:

1The practice of giving information about oneself or one's company in a formal statement rather than being obliged to ask a third party to do so.

飞机安全检测自我证明的可行性。

1. 1.1 The practice, for the purpose of claiming sick pay, by which an employee rather than a doctor declares in writing that an absence was due to illness.
   （为得到病假工资雇员自己写的）病假证明
   evidence of ill health must be authenticated; self-certification will not be accepted