 This conversion involved structurally "reinforcing" the aircraft — including strengthening the cabin floor and the wing roots – as they were expected to perform many more takeoffs and landings after entering service with Dan-Air (compared with their original role at BOAC).It also involved replacing internal doors with curtains as a weight-saving measure.Subsequently, acquired, larger Comet series 4B and 4C aircraft underwent similar structural modifications to enable them to carry up to 119 passengers before entering service with sister airline Dan-Air.