How much gold to cause a plane to tilt?

Fascinating story by Ng Kok Song about shipping gold back from London to Singapore.  

Apparently there was so much gold that it caused the plane to tilt.

When I heard this, I almost choked on my water.

Because for that to happen, there must be a lot of gold.

I asked ChatGPT to estimate exactly how much for me:

I heard this story: Once we were shifting the gold back from london to singapore. Everything was laid out nicely. But then the passengers disembarked. Once they did, the plane tilted. So we had to call the passengers back to be seated so that we can first unload the gold. How much gold was there, give your best estimate

ChatGPT:

That’s a fascinating story — and it does sound like one of those aviation logistics anecdotes where weight and balance come into play. Let’s try to reason through an estimate step by step.

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1. Aircraft balance considerations

On large passenger jets, the weight distribution is crucial. Cargo (including gold) is loaded in the hold, typically below the cabin. If the aircraft’s center of gravity shifts too far aft (tail-heavy) once passengers disembark, the nose can lift and the plane can “tail-tip.” This actually happens sometimes even without gold — e.g., if aft cargo is heavy and passengers exit before forward cargo is unloaded.

So, the gold must have been a very substantial weight, positioned aft.

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2. Weight of passengers vs gold

• A full widebody aircraft might have ~200–300 passengers.

• Average passenger + luggage weight = ~100 kg.

• Total = maybe 20–30 tonnes for all passengers combined.

For the story to happen, the gold’s weight must be comparable to or larger than the passenger weight, because passengers had to sit down to counterbalance it.

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3. How much gold could that be in tonnes?

• Gold is very dense: 1 m³ ≈ 19.3 tonnes.

• Central banks ship gold in 400 oz “Good Delivery” bars (~12.4 kg each).

• 1 tonne = ~80 bars.

If unloading required passengers to stay seated, I’d estimate at least 5–15 tonnes of gold, maybe more. That’s a few cubic feet at most (gold is compact).

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4. Cross-check with historical precedent

Singapore’s gold reserves today are around 200+ tonnes (worth >US$16 billion at 2025 prices). If the story is about a reserve transfer from London, it likely wasn’t the entire stock, but a tranche. Historical records suggest shipments of tens of tonnes were typical when repatriating gold.

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✅ Best estimate:
The shipment was likely on the order of 10–20 tonnes of gold — enough to outweigh hundreds of passengers and affect aircraft balance.

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Would you like me to run a more detailed aircraft balance calculation (e.g., assuming a 747 or DC-10, cargo hold positions, passenger weights) to tighten the estimate further?

I followed up with:

How much is that in $

ChatGPT:

Let’s put numbers to it.

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1. Gold price today (2025)

• As of September 2025, gold trades around USD 2,400 per troy ounce (≈ 31.1 g).

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2. Weight conversions

• 1 tonne = 1,000 kg = 1,000,000 g.

• 1 troy ounce = 31.103 g.

• So, 1 tonne of gold ≈ 32,150 troy ounces.

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3. Value per tonne

$$32,150 \,\text{oz} \times 2,400 \,\$/\text{oz} = 77,160,000 \,\$$$

≈ USD 77 million per tonne.

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4. Value of 10–20 tonnes

• 10 tonnes ≈ 770 million USD.

• 20 tonnes ≈ 1.54 billion USD.

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✅ So if the plane carried 10–20 tonnes, that shipment was worth roughly USD 0.8–1.5 billion at today’s prices.

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If this plane got hijacked, I can't imagine what will happen 🤯