Sir - In the comment "Bad promises" (Flight International, 19-25 March), concerns were rightly expressed about the growing restrictions which operators of Chapter 2 aircraft are facing within Europe.

The term "airport system" is defined in the Market Access Regulation, and the Annex to the Regulation provides that Heathrow, Gatwick and Stansted constitute the London airport system.

THOMAS SCHMID

Harbottle & Lewis

London, UK

Source: Flight International