Airlines (or with ground services) and Airports are working together to look after the passengers. However, in some countries, they have different responsibilities and follow different regulations.
Here is the list of the countries that takes care of disabled passengers at the airports: –
Asia – Either airport nor ground service is looking after passengers at these airports (except Thailand). Foreign airlines use ground services to look after passengers in these airports.
Australia and New Zealand – Local airlines look after passengers whereas foreign airlines use ground services to look after passengers at the airports.
Africa – No information can be found.
Europe – Most airports look after their passengers at their airports.
Middle East – Either airline nor airport looks after passengers at the airports.
North America – Local airlines look after passengers whereas foreign airlines use ground services to look after passengers at the airports.
South America – Different airports look after passengers at their airports.
You do not have to worry about calling the airports or ground services for the special assistance requests. It is best to inform the airlines 48 hours before your travel starts. They will organise your services and accommodate your needs at the airport. However, they cannot guarantee that they would be able to help you because they may not have enough staff or properly trained staff to assist the type of disabilities that you may have.
Bonus: Some airports provide the lounge room and check-in room for the passengers with specific needs. They provide them with free wifi, water, toys and magazines to read.
Inflight Disability Information 