An aft centreline lift was vulnerable to bombs aimed near a carrier's centre of mass as the ship moved forward beneath the attack. The broad lift opening made this a recurring problem for the Illustrious class. Deck-edge lifts offered a proposed remedy, along with more internal space and greater freedom to operate larger aircraft. That preference for a different lift arrangement leaves room for the armoured hangar itself to remain a sound design choice. British experience of losing aircraft to North Sea and North Atlantic conditions helps explain the more enclosed arrangement they adopted.
Notable Point · 35:20-37:19
Why deck-edge lifts appealed despite Britain's exposed seas
The case for deck-edge lifts combined reduced lift vulnerability with more usable internal space, while British sea conditions helped shape the original choice.