I am not surprised that Boeing is wavering on the Sonic Cruiser (Flight International, 12-18 November). What surely matters to prospective managers is total journey time which, with increasing airport congestion, is scarcely affected by a modest increase in maximum speed. Higher speeds come with serious penalties, as is clear from similar attempts on motorways and railways.

Fuel shortages and sharp increases in fuel prices will likely have a profound affect on travel patterns.

Anthony Phillips Salisbury, UK

Source: Flight International