When all red VASI lights appear during descent, ascend immediately to regain the glide path.

Let me set a scene. You’re descending toward a familiar airstrip, the cockpit hums with routine, and your eyes catch a sudden splash of color on the approach indicator: all red lights on the VASI. The moment feels like a buzzer-beater in a game you’ve played a hundred times before. What should you do? The quick answer is simple, and crucial: ascend immediately. But there’s more to it than a reflex. Understanding why helps you keep calm when the lights start telling you something you don’t want to hear.

What the VASI is, and how it guides you

VASI stands for Visual Approach Slope Indicator. It’s the airport’s little helper, a row of lights that peeks into your cockpit and whispers, “Your glide path is good, or it isn’t.” In practice, you’re looking for a mix of red and white lights that tell you whether you’re on the correct descent path for a safe landing. If you’re perfectly on the ideal slope, you’ll see a specific color pattern—often a combination that signals you’re aligned. If you’re too high or too low, the color changes.

Now, the scenario in question uses a stark signal: all red lights. It’s not a cue to press ahead or pretend the problem isn’t there. It’s a warning. In the VASI system, all-red means you’re below the desired glide slope. In plain terms: you’re too low and that can put you on a collision course with terrain, obstacles, or the runway itself if you don’t correct your path. The visual cue is telling you to back off the landing approach, reset your altitude, and rejoin the proper descent profile.

Why “all red” is a serious signal

Think of glide slope as your descent roadmap. When you’re too low, you’re a step closer to an unwanted encounter with the ground or something sticking up near the approach path. It’s not just uncomfortable; it’s risky. The moment you see all red, the sensible move is to pivot—gently but decisively—to climb. No, you aren’t giving up on landing. You’re giving yourself the space to land safely, with the runway in proper view and the approach path restored.

Let’s be honest for a moment: pilots aren’t machines. When you’re in the heat of descent, light cues can surge through your mind with competing priorities—speed, configuration, air traffic, weather, and that tiny voice asking, “Are we going to be on time?” The VASI alert cuts through the noise. It’s a simple, honest signal: you’re too low. The best response is a controlled climb to regain the correct glide slope and then re-intercept the path to the runway.

What to do in the cockpit when you see all red

Here’s the thing: you don’t chase a landing when the lights tell you you’re too low. You pause the descent, climb to a safe altitude, and re-establish the slope. In practice, that means a smooth, coordinated action sequence rather than a panic pull-up or an abrupt halt in spacing.

A practical, reader-friendly checklist

• Don’t chase the lights. If all red shows up, stop descending and start climbing.

• Initiate a gentle climb. Increase pitch to arrest the descent, then adjust power to maintain safe airspeed. The exact numbers depend on your airplane and configuration, but the idea is to recover altitude smoothly without overshooting or compromising speed.

• Re-check your glide slope. Once you’re back above the problematic band, re-establish the proper VASI or ILS guidance if you’re using it. You want a clean intercept, not a last-minute scramble.

• Cross-check instruments. Confirm your altitude with the altimeter and verify your vertical speed indicator (VSI). If you’re in an instrument environment or your visibility is limited, rely on instruments to guide the climb back to a safe altitude.

• Communicate and coordinate. If you’re in controlled airspace, let ATC know you’re climbing to a safe altitude and re-intercepting the approach. Clear comms reduce confusion for everyone on the field.

• Rejoin the approach with a plan. After you’re back on, reassess your airspeed, configuration, and flaps as you prepare to re-enter the glide path. Don’t rush the re-intercept; a smooth, stable approach beats a hurried one every time.

What not to do (the tempting traps to avoid)

• Don’t try to “make up” the descent by pushing the nose down further after all-red appears. That’s exactly how you get into terrain or an obstacle conflict.

• Don’t assume you’ll fix the problem with power alone. Power helps, but it won’t fix a glide path error if you stay too low.

• Don’t ignore the signal and press on because the runway is near. The runway can wait; a safe approach can’t.

Connecting the dots: glide slope, safety, and calm decision-making

There’s a neat analogy that helps many students, and it sticks if you picture a highway ramp. If you’re coming down to land, you want to hit that ramp at the right angle and speed so you can roll smoothly onto the runway. If the ramp is just a bit too steep, you don’t floor it; you ease off and re-align. The VASI is that ramp indicator in the sky. All-red is a warning light, not a dare to push harder. Ascend, reset, and re-enter at the correct angle.

A moment to breathe: the human side of a technical cue

Let’s be real: the cockpit can feel like a pressure cooker. The more seasoned you get, the more you’ll notice that the best pilots aren’t the ones who never encounter trouble—they’re the ones who recognize trouble quickly and respond calmly. That’s the core skill here: reading the cue, not dancing around it. The all-red signal is simple, almost graphic in its clarity. It’s your cue to step back, climb, and come back to the approach with a clean slate.

A few mindful tips to embed in your flying habit

• Visualize your glide slope during the approach. A mental checklist helps you stay prepared for cues like color changes, even if visibility is limited.

• Practice smooth, controlled transitions between descent and climb. Rough corrections can unsettle the aircraft and the crew.

• Use your instruments as your safety net. If the visual cue conflicts with what your instruments say, trust the instruments and verify visually later.

• Keep a clear head. If you’re fatigued or stressed, you’re more prone to overreact. A measured response is safer than a rushed one.

• Remember the purpose of VASI: it’s a guide, not a single point of truth. The goal is a stable, affirmative approach that keeps you safely above the terrain during the final moments.

A quick aside for broader context

VASI, PAPI, and other approach slope indicators exist because pilots need reliable, redundant cues in a world where weather, visibility, and terrain can throw curveballs. The idea isn’t to memorize a rulebook and recite it at the wrong moment; it’s to internalize a mindset: when the cue says “too low,” lift your head, re-check your path, and rejoin the runway with a plan that keeps you, your crew, and everyone on the ground out of harm’s way. That mindset—that readiness to respond with a safe, deliberate action—stays useful whether you’re flying a light trainer or a high-performance airframe.

Bringing it all home

So, what should you do if you see all red lights on a VASI during descent? Ascend immediately. It’s the safest course because it halts a potentially dangerous situation in its tracks, buys you time to re-establish the proper glide slope, and preserves the runway’s safe approach path. The action is straightforward, but its proper execution—smoothly raising the nose, adjusting power, and re-intercepting the slope—defines a skilled, disciplined pilot.

If you’re ever tempted to second-guess that instinct, pause and breathe. The VASI isn’t a drama queen; it’s a practical tool designed to keep you and the people on the ground out of trouble. When it lights up all red, the conversation in the cockpit is short and honest: climb, re-align, and give yourself a clean shot at a stable, safe landing.

In the end, flight safety is about good habits, steady hands, and listening to the cues the sky gives you. The all-red warning on a VASI is a tiny siren in the cockpit—a reminder that, sometimes, the smartest move is the simplest one: climb and rejoin the path to a safe, successful landing.