Not entirely true, Boomer. If you're a third party, it may be illegal if there's an expectation of privacy, or depending on the state you're in.
If it's a conversation *YOU* are personally involved in, then in most cases, one-party consent is sufficient.
The only states I know of requiring all parties to consent to recording are CA, CT, FL, IL, MA, MI, MR, MT, NV, NH, PA and DC.
There's case law to support whistleblower style recording, provided that it's not being done for illegal or tortious purposes (e.g. blackmail), and there's no implied privacy. I suspect being out on a hangar floor or around an aircraft doesn't imply privacy by any measure.
In NY, People v. Kirsh, 176 A.D.2d. 652 (N.Y. App. Div. 1991): "A party to the conversation may surreptitiously record a conversation. In addition, those who talk in the presence of a non-participating third party may have no expectation of privacy with respect to statements overheard by the third party. "
http://scholar.google.com/scholar_case?case=17426927963481556111&q=People+v.+Kirsh,+176+A.D.2d.+652&hl=en&as_sdt=40002
You also have People vs. Gibson, which is perhaps more relevant:
http://scholar.google.com/scholar_case?case=13011672042630503915&q=People+v.+Gibson,+23+NY2d+618+-+NY:+Court+of+Appeals+1969&hl=en&as_sdt=40002&as_vis=1