Generally speaking, we do not engage in any kind of tracking of our visitors (or mass surveillance of anyone, for that matter). As an organization, we do not put cookies in your browser, but our hosting service may do so for their nefarious reasons; talk to them if you are worried about this.
If you email us, we will then have your email address and whatever other personal information you chose to provide. We archive all email. We do not use the email addresses we thus collect to do mass mailings or other types of targeted advertising. We may, however, use the contact information you provided to contact you, individually. We always love to hear from people who love airplanes like we do, and we are interested in photographs that you might have.
If you buy our books, Amazon may collect (pardon, not "may", but "will") some information about you. There is no avoiding this, and again, talk to them if you are worried. If you really, truly want to buy a book from us but don't want to deal with Amazon, email us and we'll see what we can do.
The European Union's new privacy regulation, called "General Data Protection Regulation", went into effect on 2018-05-25, and there has been a lot of hoopla about that. We are not quite sure if (or how much) GDPR rules even apply to us, but if they do, we are not aware of any reason why we would not be compliant; most importantly, the paragraph above about email states our purpose of collecting data. If you want to know more about the GDPR, please go and read the EU Web site about it.