Pilots are not expected to be superhuman beings, and it must therefore be accepted that they will make mistakes, some of which may have disastrous consequences. If it can be proven that the error equates with negligence in the pursuance of their duties, then they may be subjected to the full force of the Law. However, because pilot error is a multifactorial phenomenon, which is imperfectly understood, the initiation of legal proceedings may be difficult. If a penalty is to be imposed, the law demands a degree of proof which may be greater than that demanded by some investigating authorities, before implementing the appellation 'pilot error'.