I'm not sure if you were asked to remove your Aira device at security in the US. This may be something to bring up with staff when checking in, and again in line since electronics need to be scanned and you want to ensure your device remains undamaged.
Regarding Canada only:
Sadly, Canada currently only has 3 provinces with Accessibility Laws (British Columbia, Ontario, and Nova Scotia). Canada is set to introduce the new law this spring. Despite us being behind the times, this does not mean you will not receive assistance at travel points.
This government site on Accessible Travel claims that all transportation systems are opening up accessibility. (www.otc-cta.gc.ca)
Canada's transportation system is open to all. More and more, the companies that move people across Canada are finding ways to meet the needs of travellers with disabilities.
If you're not sure who handles what, give us a call at 1-888-222-2592 or by TTY at 1-800-669-5575. Or send us an e-mail at firstname.lastname@example.org. We'll point you in the right direction.
On the Finding Information link on the Accessible Travel page:
The Personnel Training for the Assistance of Persons with Disabilities Regulations require transportation companies to train their employees and contracted personnel on how to provide services to persons with disabilities.
The standards should be respected everywhere, but they are not a service guarantee. Your best approach is to ask your transportation company for details about how it will meet your needs.
This site also suggests getting in touch 48 hrs in advance with any transportation companies about any needs or assistance (early seating, travelling with/without support person, etc). According to Air Canada and West Jet require 48 hrs notice and to confirm when you check in. Via Rail merely says to approach staff.
The Canadian Air Transport Security Authority (CATSA) site further supports Jim MacKenzie's experience: (www.catsa.gc.ca)
Visually impaired passengers
If you would like assistance, please inform the screening officer when you arrive at the checkpoint. Upon request, supervisors at major Canadian airports are available to provide you with verbal and physical guidance through all steps in the screening process.
Visually impaired passengers and their service animals can pass through the walk-through metal detector either separately or together. Or, you can choose to bypass the walk-through metal detector and use alternate screening options, such as the use of a hand-held metal detector, a full body scanner or physical search.
Though not relevant since you're flying in, I went a bit further to see if the Canada Border Services Agency has special services and zilch. Other than a TTY phone number, I could not find anything.