A bi-directional entry vestibule for a passenger aircraft provides passenger access to overhead rest cabins and lower-lobe rest cabins (e.g., on a lower cargo deck) via separate enclosed chambers incorporating ascending and descending staircases respectively. The ascent and descent chambers may be accessed from the main passenger cabin via access doors (one door or separate doors); the ascending and descending access doors may be on opposing sides of the aircraft (e.g., accessible from port-side and starboard-side aisles) or adjacent to each other and accessible via the same aisle. The ascent chamber may include a further transitional space transitioning into an overhead corridor-based cabin, the transitional space including a crew station comprising a fold-down jump seat, communications equipment, and emergency supply storage.