I was deported from and banned for life from the USA. I have been traveling through South America seeing different countries. I'm currently living in Peru and want to travel to Europe. One way to travel would be flying through US airspace, to Canada.
My main question is: can I pass through US airspace on my way to Canada as part of a flight to Germany?
Are there are other alternatives to travel from Peru to Europe while avoiding North America all together?
The airline will collect Secure Flight information when checking you in, but there is no restriction preventing you from flying over US airspace just because you're inadmissible to the US.
So you'll be fine - you just need the documents for transiting Canada and entering Germany.
Flying over USA airspace is not a problem. What is a problem is that Canada, like the USA but unlike many other countries, requires you to have a transit visa in advance. Peru is not on the list of visa-exempt countries. The Canadian authorities may know that you were deported and banned from the United States, and if so, I think your chances of getting the Canadian visa are reduced. You should apply in advance, and as other answers mention, you should be prepared to book instead through airports where you will not have this problem.
You cannot land in the US (does not matter if it is only a transit). However, I am not seeing any issues with getting a flight to Canada. You need to have in the mind that you will need to land in Canada. So, maybe, you will need a Visa+ for that.
Could you go to Europe avoiding US or Canada?
Yes, you can... You could go to Brazil and get a flight to Portugal, for example.
Personally I would fly direct from Guatemala to Madrid. Or From San Pedro Sula to Barcelona. Or from Panama to Amsterdam. I'm from the UK and can fly to the US without a visa, but due to bad mannered people in the US airports I now avoid flying through the US whenever possible. I'd rather invest my money in countries who treat me nicely. On the Spanish route I have never had any hassle from anyone. It's worth the extra cost.
Airlines you want to look at include KLM, Iberia, Air Europa, British Airways.
I've never had any difficulties in Canada and the people are friendly, but they can be quite strict and it adds an extra complication to your trip. As far as airspace is concerned it doesn't matter about the US at all. The Canadians have a deal with the US to manage those flights. Probably easiest to avoid US and Canada