LONDON— Airbus SE, the world’s biggest plane maker, said it would likely miss its key delivery target this year after the company’s chief executive warned that supply-chain woes were still at least six months away from normalizing. The European manufacturer said on Tuesday that due to a “complex operating environment,” Airbus’s previously forecast goal of achieving around 700 deliveries this year is now “out of reach.” Such a miss is rare in the commercial jet-making business, where annual deliveries offer bragging rights between Airbus and rival Boeing but also go directly into cash flow: Much of a plane’s cost is only paid for after delivery.