First off a few reminders on the definition of the word “probable”:
- likely to occur or prove true: He foresaw a probable business loss. He is the probable writer of the article.
- having more evidence for than against, or evidence that inclines the mind to belief but leaves some room for doubt.
- affording ground for belief.
After extensive inspection of the accident site, airplane remains and other verifiable factual information the “probable cause” is stated (refer to above definition). The NTSB does not state absolute cause as the is often unknown or provable possibilities that cannot be substantiated.