§ Mr. Ridley
The CAA tell me that when the Boeing 747 was first granted a certificate of airworthiness with 10 main emergency exits, it met the requirements that a fall load of 550 passengers could be evacuated in not more than 90 seconds using only half the total number of exits. The blocked overwing exits displayed lower exit rates than the other emergency exits in the test. The aircraft with currently approved United Kingdom layouts of up to 440 seats allows for the increase in capacity following the blocking of the two overwing exits, and therefore also meets the requirements. The CAA thus has no regulatory basis for requiring another evacuation test.