Airplane crashes provide an excellent opportunity for failure analysis. IMHO its kind of a decent fit, but the final report will be a better fit.
https://news.ycombinator.com/newsguidelines.html
What to Submit On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.
Off-Topic: Most stories about politics, or crime, or sports, unless they're evidence of some interesting new phenomenon. Videos of pratfalls or disasters, or cute animal pictures. If they'd cover it on TV news, it's probably off-topic.