Rate of depressurization is the key. When cabin pressure is lost abruptly due to a breach, the air inside the pressurized cabin is forced out to the much lower outside pressure, creating a rapid, violent outward flow. This swift, forceful release is what “explosive decompression” describes. It’s characterized by a sudden rush of air, loud release, and a rapid drop in cabin altitude, posing immediate hazards like hypoxia and potential barotrauma. The other terms don’t fit because they imply slower, more gradual or irregular leakage, whereas an air rush is the hallmark of explosive decompression.

When a pilot becomes incapacitated, the immediate aim is to ensure the flight deck has immediate, capable support. The best action is to have one cabin crew member stay in the flight deck to provide assistance as requested by the Captain. This keeps a trained assistant right where critical decisions are made, allowing the Captain to direct any needed tasks—radio communications, checklist use, or medical coordination—without losing cockpit control. The remaining crew can focus on other priorities, such as calling for medical help, notifying the CSM, and looking after passengers. Administering first aid, while important, is not the primary action in this moment unless the Captain directs it. Restraining a crew member is situational and not the default response. Notifying the CSM and Captain ASAP is essential, but it’s part of the broader need to ensure cockpit SAMPLEsupport is present and ready to respond to the Captain’s requests.

When a fire or hot smoke is present in a confined space, your immediate safety hinges on avoiding heat and toxic gases, which rise toward the ceiling. Staying low places you in the air with more breathable, cooler air and reduces exposure to the heat and smoke that are moving upward. In a HOT lavatory door situation, this low position helps you assess the scene, protect your airway, and wait for qualified personnel to handle the fire. Opening the door fully or rushing in would bring in more oxygen, feeding the flames and exposing you to extreme heat and potentially sudden flare-ups in a small space. Pushing the door and rushing in is thus unsafe. Simply calling for help is not the first action you should take; getting low and preserving your safety is the priority, while alerting crew or using the established call system should follow as you remain safe and ready to assist as directed.

When a passenger is suspected of a medical emergency inflight, the first priority is to quickly assess their condition to decide the level of care needed. This starts with checking responsiveness—talk to them, tap them if needed, and see if they respond. At the same time you assess breathing to determine if they are breathing normally. If trained, you also check for a pulse to gauge circulation. This trio—responsiveness, breathing, and circulation—helps you decide whether the person is conscious and stable or if they may need life‑saving measures right away. Once you have this initial picture, you should call for medical advice from the cockpit or via the ground medical support service, so a professional can guide the next steps. While waiting for guidance, provide basic first aid within your training: ensure the airway is open, assist with breathing or CPR if needed, control any bleeding, and administer oxygen if available and you are trained to do so. You continue to monitor the passenger closely and reassess as the situation evolves. Diagnosing the condition or prescribing treatment isn’t within the scope of onboard responders, and delaying contact with medical professionals can waste precious time. Focusing only on consciousness misses potential problems with breathing or circulation, and simply handing off to ground crew without guidance isn’t appropriate in an emergency.