Complex sentence: Once it had to reduce speed for landing, however, it was doomed; there was too little lift on the right wing to enable stable flight, and the aircraft banked sharply to the right with very little chance of recovery.
Split into simpler sentences: Once it had to reduce speed for landing, however, the amount of lift on the right wing was insufficient to enable stable flight, so a safe landing was going to be very difficult to achieve. The aircraft then banked sharply to the right with very little chance of recovery.