More older people are travelling by air, as prices have got cheaper, and more routes have become available. It is generally illegal for you to be refused a flight because of disability, or mobility problems, in the European Union (or for flights on EU airlines arriving in the EU).
If you need any help at the airport of on a flight you should let the airline know when booking, or at least 48 hours before the flight. The humidity, pressure and low oxygen levels in planes can all be difficult for some older people. There is also a risk of deep vein thrombosis on longer flights (over about four hours). It is good to get advice from your doctor before flying if you have any health conditions which may worry you.
Air travel is far worse for the environment than other forms of travel.