Madam, – As a student in the early 1960s, I was lucky enough to get a summer vacation job working in Aer Lingus. In those days Dublin Airport was a hub before the term was even invented. The quickest and most convenient access to the United States from many regional UK airports was through Dublin with the short-haul, cross-channel Aer Lingus routes, operated by modestly-sized turbo-prop aircraft, acting as feeders for the company’s transatlantic services to New York and Boston. The announcement of the launch of the “Aer Lingus Regional” franchise (Business Today, January 27th) seems to suggest that it’s back to the future for our national flag-carrier airline. So what happened in the intervening half century? – Yours, etc,