Don the oxygen mask first when a CABIN ALTITUDE HI alert sounds on a SkyWest ERJ.

CABIN ALTITUDE HI: Why the First Move Is Wearing Your Oxygen Mask

If you’re flying SkyWest ERJ and you ever see a “CABIN ALTITUDE HI” warning, your training kicks in fast. This isn’t a test of nerves; it’s a real-time safety signal that asks you to prioritize your own oxygen first so you can think clearly and manage the situation effectively. So, what’s the right first move? Don oxygen mask 100%. Then you do the other important tasks. Let me explain what that looks like in the cockpit and why this sequence matters so much.

The moment the warning lights up: oxygen comes first

Let’s start with the obvious question: why is wearing the oxygen mask the top priority? Because a drop in cabin pressure depletes the air we breathe. Hypoxia—insufficient oxygen reaching the brain and other organs—can creep in fast. It isn’t dramatic in the moment for everyone, but it’s real and it’s dangerous. Decisions have to be made with a clear head, and that starts with protecting your own oxygen supply.

Think about it this way: if you start fumbling for steps while your brain is signaling, “I don’t have enough oxygen,” you can lose situational awareness. That’s a dangerous combination in a cockpit. Donning the mask at 100% oxygen right away ensures your thinking stays sharp, your hands stay steady, and your ability to follow through on the emergency plan remains intact. In short, you’re buying mental bandwidth for the job at hand.

What the sequence looks like in real life

Here’s how the response typically unfolds in a SkyWest ERJ scenario, with the “CABIN ALTITUDE HI” cue in mind. The steps aren’t a rigid order carved in stone; they’re a practical flow that prioritizes safety and clarity.

1. Don the oxygen mask

• Do it immediately, to full 100%. This is the anchor move. You may notice other crew members performing the same action; it’s a shared safety rhythm that keeps the crew aligned.

• If you’re wearing a headset or microphone, you can calm your voice and still communicate, but don’t delay the mask for chatter. The mask does the heavy lifting for your physiology, and your brain will thank you for it.

2. Notify the cabin crew

• Once you’re oxygenated, loop in the cabin crew. They’ll start their own procedures for passengers and coordinate with you on altitude targets and descent needs.

• Communication remains essential after you protect yourself. It helps everyone in the airplane stay coordinated and reduces the chance of panicked or conflicting actions.

3. Begin a controlled descent to a safe altitude

• Lowering the cabin to a breathable altitude is the goal, but do this as a controlled descent, not a frantic dive. The air is safer lower down, and passengers can be managed more smoothly.

• Your mask is still on during the descent because you’re still operating in an environment where the air isn’t optimal. The mask isn’t a one-and-done step; it’s part of a sustained safety routine until the crew stabilizes the cabin.

4. Communicate with ATC as needed

• As you descend and stabilize, air traffic control will want to know your intentions and your situation. Clear, concise radio calls help keep everyone on the same page and ensure you get priority handling if needed.

Why this order isn’t just about rules on a checklist

You might wonder, “Couldn’t we call ATC first or alert the cabin crew before suiting up?” The answer is that cognitive function matters first. When oxygen isn’t flowing to your brain, your memory, attention, and decision-making degrade. The other actions—alerting the crew, coordinating a descent, and talking to ATC—will all be safer and more effective once you’re protected.

This isn’t a dry sequence, either. It mirrors how real-world situations unfold: you neutralize the most immediate risk, then you manage the evolving emergency with a calm, thinking mind. It’s a rhythm that training modules in CQ (Cockpit Qualification) and KV (Knowledge Validation) gently reinforce, so you react naturally under pressure.

Bringing CQ and KV realism into the cockpit

CQ and KV aren’t just about knowing a bunch of numbers or memorizing steps; they’re about cultivating a mindset. The “CABIN ALTITUDE HI” scenario is a prime example of why the first action matters. It’s less about cramming rules and more about training your reflex to protect your own safety so you can protect others.

In practice, you’ll encounter realistic cues, layered tasks, and time pressure. The goal is for you to internalize a trusted sequence: protect yourself, then help others. That mental model becomes second nature, which reduces hesitation and improves outcomes when real alarms flash on the panel.

A few cheat-sheet ideas that often help in KV scenarios

• Keep oxygen first: Your most important tool is your own safety. Don’t skip the mask to address something else.

• Verify, then act: A quick confirm of the mask flow and the crew’s readiness buys you confidence to proceed with the descent and passenger management.

• Use a consistent cadence: Speak in clear phrases, not frantic bursts. A steady rhythm helps both you and your crew.

• Remember the family of actions: Once you’re protected, you can focus on the descent, passengers, and air traffic coordination with a clearer head.

Common myths and clarifications

• Myth: You should descend immediately before wearing a mask. Reality: The immediate step is to don the mask. Descending is important, but it comes after you’re oxygenated.

• Myth: You should alert ATC before you secure yourself. Reality: Coordinating with ATC is essential, but your priority is you—your oxygen mask first, then the rest.

• Myth: The cabin crew can handle passengers while you fix the flight. Reality: Collaborative action is the point. You and the crew work in tandem to manage the cabin and the flight deck safely.

A quieter note on the human side

Emotions show up in emergencies, and that’s natural. The key is not to let them drive decisions. When you feel the pressure rise, you can acknowledge it with a quick breath, a steady voice, and a focus on the next right action. That blend of human steadiness and technical fidelity is what KV-style scenarios are designed to cultivate: a calm, capable response under stress.

Real-world takeaways for pilots and watchers alike

• The first move is practical, immediate protection for yourself. Without oxygen, your cognitive toolkit shrinks, and that makes the rest harder.

• The sequence that follows—notify the crew, descend responsibly, communicate with ATC—becomes a shared, coordinated response when everyone understands the same priorities.

• KV and CQ training aren’t about memorizing a single line of steps; they’re about building an instinctive workflow that you can adapt to the specifics of a situation while staying safe.

If you’re new to SkyWest ERJ operations or revisiting these concepts, think of this ordering as a fundamental rhythm rather than a rigid script. You’re not just memorizing a list; you’re learning a reliable way to keep yourself and others safe when the cabin altitude warnings flash. And that reliability isn’t a nice-to-have—it’s the core of safe, professional aviation.

Key takeaways to hold on to

• The first action when CABIN ALTITUDE HI appears is to don the oxygen mask at 100%.

• Oxygen protection buys you the cognitive space you need to execute the rest of the emergency plan.

• After securing your own safety, you notify the cabin crew, begin a controlled descent, and coordinate with ATC.

• KV scenarios and CQ training are about building a practical, human-centered response that you can rely on in real life.

A final thought as you move through your KV and CQ learning journey

This isn’t about acing a single question. It’s about cultivating a trusted approach to cockpit emergencies. The more you internalize the “mask first, then the rest” principle, the quicker you’ll translate knowledge into action when it matters most. And when that moment arrives, you’ll have the mental clarity and steadiness to guide your crew and passengers to safety.

If you’d like, we can walk through a few more real-world analogies or tailor a quick, readable briefing that helps you remember this sequence in a calm, confident way. After all, in the air, the smallest clarity can make the biggest difference.