Complex sentence: Neither aircraft reached its destination before the surrender of France in 1940, and the "Béarn" instead sought harbor in Martinique, too obsolete to participate in naval operations of the Free French fleet.
Split into simpler sentences: Neither aircraft reached its destination before the surrender of France in 1940, and the "Béarn" instead sought harbor in Martinique. She was, however, too obsolete to participate in the naval operations of the Free French fleet.