How the Black Hole Effect Deceives Pilots, and How You Can Defend Against It

It’s night, you’re on the approach, you can see the landing site perfectly, the aircraft is serviceable, and the weather is great.

But without realising it, you start flying too low, in fact: dangerously shallow.

Welcome to the black hole effect.

I’ve been spoilt for years by flying with night vision goggles. Now that I’m flying offshore, I definitely miss flying with those!

Flying a helicopter at night without them can be a very different world.

This is where the black hole effect has claimed quite a few lives.

So:

🔸 What exactly is the black hole effect?

🔸 Why does it make us fly too low?

🔸 And how can we defend against it?

Let’s take a look 👀

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👀 What is the Black Hole Effect?

Imagine you’re on approach at night.

You can see your landing site ahead: a helipad, runway, ship or offshore installation.

But between you and it:

Almost nothing.

No streetlights. No buildings. No terrain features. Not even a discernible horizon.

Just… black!

During a daylight approach, we use far more of our peripheral vision than we realise.

The ground, buildings and terrain provide a constant stream of visual information about our height, speed and flight path.

Take those cues away and something strange can happen:

You can perceive yourself as being higher or steeper than you actually are.

So what do you do when an approach looks too high?

You lower the flight path ⬇️

Except you weren’t actually too high in the first place…

And now you really are too low.

That’s the black hole effect: a visual illusion that can lead you into landing (or crashing) short of the landing area.

And unfortunately, this isn’t just theory.

💥 When the Black Hole Effect Turns Into an Accident

Accident investigators have encountered exactly this problem in the real world.

Take a look at these recent examples:

1️⃣ Sikorsky S-76C+ – Tofino, Canada,

A Helijet S-76 was conducting a night VFR medevac approach to a temporary helipad at an unlit airport.

The TSB says the airport environment “met the accepted definition of a black hole”: water and terrain around the airport had no cultural lighting, while the temporary helipad appeared essentially as an isolated point of light.

On short final, airspeed reduced, a high rate of descent developed and control was lost.

The helicopter descended to approximately 3 ft above the beach (67 ft below the elevation of the airport) before the pilots recovered it.

They subsequently landed, and at least no one was injured. 

The TSB’s findings include that the crew conducted the flight without sufficient lighting to maintain adequate visual reference and that the operator’s SOPs provided little guidance on “black-hole approach and landing procedures.” 

Of course this can happen offshore as well, which comes with other threats as we discussed recently:

What can we Learn From the Morecambe Bay Dauphin Crash?

2️⃣ King Air – Louisiana

In 2016, a Beechcraft 65-A90-1 was making a visual approach into Slidell, Louisiana.

Again, the runway itself was visible.

But ahead of it was dark marshland with very little cultural lighting.

The aircraft descended too low and struck an 80-foot power-transmission tower around 0.6 NM from the runway.

Both people onboard were killed.

The NTSB found the circumstances consistent with the pilot experiencing a black-hole illusion, contributing to an approach that was too low for the distance remaining.

Different aircraft. Different operations.

But… the same fundamental problem:

You can see exactly where you want to land, while losing the visual information you need to judge whether you’re actually going to make it there.

So, how do we stop ourselves falling for it?

🛡️ 5 Ways to Avoid the Black Hole Trap

As with any illusion, there are some straightforward things we can help ourselves with:

1️⃣ Recognise the setup itself, not the illusion

This might be the biggest one.

Don’t wait until you feel the illusion happening.

You probably won’t.

Instead, recognise the ingredients beforehand: a dark night, little cultural lighting, featureless terrain or water, no horizon and an isolated illuminated landing site.

If the ingredients are there, assume your eyes might lie to you.

2️⃣ Trust numbers over instinct

Here’s the tricky thing:

The correct approach might look (and feel) wrong.

That’s why objective references matter.

Defined profiles, vertical guidance, distance, altitude, rate of descent, radar altitude, whatever is available and relevant to your specific operation.

If the numbers say you’re where you should be but your eyes are telling you otherwise, remember which one is vulnerable to an optical illusion.

3️⃣ Define what “unstable” means beforehand

Halfway down the approach is a terrible time to start negotiating with yourself.

Maybe we’re a little low…

It still looks okay…

Let’s continue and see…

Instead, know your gates before you get there.

➡️ At this distance, where should we be?

➡️ What rate of descent are we expecting?

➡️ What would trigger a go-around?

Objective limits make subjective visual impressions much less powerful.

4️⃣ Use the other pilot

This is where good monitoring really shines.

If the PF is looking outside and building a visual picture, the PM can protect the flight path with something that’s way harder to get confused by:

The numbers.

Height. Speed. Rate of descent. Distance. Flight-path deviation.

Whatever matters for that particular approach.

The important bit is that both pilots don’t simply get sucked into staring at the same inviting patch of lights.

5️⃣ If it doesn’t add up, go around

Finally, don’t keep descending in the hope that a strange visual picture will eventually start making sense.

If the approach becomes unstable, the numbers don’t match your expectations or the visual references aren’t good enough:

Go around.

Create some space. Reset. Try again using a different technique (or don’t continue at all).

Seeing the landing site doesn’t necessarily mean you have enough information to reach it safely.

💭 The Takeaway

I think the black hole effect is a brilliant example of something that makes aviation so interesting:

Seeing isn’t always believing.

We spend our lives looking outside and using visual information to fly.

But take away the horizon, terrain and peripheral cues, leave one inviting patch of lights in front of us, and suddenly that incredibly capable visual system can start giving us the wrong answer.

We feel too high, so we descend.

And without realising it, we create the very problem we were trying to fix.

Try to recognise when the conditions are right for one, back up our eyes with objective information, monitor each other and be willing to go around when the picture doesn’t add up.