Tejas Water Drip Sparks Online Confusion, Engineers Clarify It’s Normal, Not a Leak

A short video from the Dubai Air Show 2025 triggered a wave of online speculation after viewers noticed water dripping from the Indian Air Force’s LCA Tejas fighter. Some social-media users — including several self-styled “aviation experts” — rushed to claim the aircraft had suffered an oil leak, even suggesting that IAF ground crew used gift bags to plug it.

But as aviation engineers confirmed, nothing could be further from the truth. The drip was not oil, not fuel, and not a malfunction — it was simply condensed water draining from the aircraft’s Environmental Control System (ECS), a perfectly normal occurrence for any modern fighter jet on the ground.

Condensation, Not Leakage — The Science Behind It

Fighter jets use bleed air tapped from the engine compressor to supply the cockpit with breathable, conditioned air. This bleed air is extremely hot, often above 200°C. To make it suitable for the pilot, the ECS rapidly cools and dehumidifies this air through heat exchangers and air cycle machines.

This cooling process creates exactly the same effect as an air-conditioner at home:

• Hot air cools rapidly

• Moisture in the air condenses

• Liquid water forms

• Excess water drains out through designated vents

That is all the video showed: condensed water dripping from the ECS drain port.

In the warm, humid climate of Dubai, condensation forms even faster. Engineers say the amount of water can increase depending on temperature, humidity, and how long the ECS has been running on the ground.

Every modern fighter — whether Rafale, F-16, F/A-18, Eurofighter, Gripen, or Mirage — produces the same effect. Anyone familiar with flight lines has seen the same small puddles beneath aircraft after landing or during static display. It is so normal that technicians barely glance at it.

Why the Bag Was Placed Under the Jet

At the event venue, the IAF crew placed a bag under the drain point simply to collect the water so it wouldn’t drip onto the exhibition floor or create a puddle where visitors walked. This is standard practice at many international shows.

There was no attempt to “plug a leak,” and the bag had nothing to do with maintenance or a technical fault.

A Simple Case of Misinterpretation

Despite clear engineering explanations, a few commentators — including Pakistan’s ISPR-aligned social-media accounts — circulated claims of “oil leakage,” pointing at the clear liquid under the aircraft. But oil leaks look entirely different:

• Aviation oil is dark, slick, sticky

• Fuel evaporates quickly and smells distinct

• Water is clear and odorless

In this case, high-resolution images show that the drip was transparent water, consistent with ECS condensation, not hydraulic fluid or engine oil.

Engineering Literacy Gap Fuels Misinformation

Experts noted that such misunderstandings are common because many viewers assume any liquid near an aircraft must indicate a malfunction. The opposite is true:
Condensed water drainage is a sign that the ECS is functioning exactly as designed.

Aircraft technicians emphasize:

• It is normal to see water dripping after landing

• It is normal during air shows when aircraft run APU or ECS for hours

• It is normal in humid climates like Dubai

The science is routine — but online speculation often isn’t.

Tejas Continues to Impress Despite the Noise

Meanwhile, Tejas continued its flying displays confidently, showcasing its agility, precise control, and reliable GE F404 engine performance. Crowds at the air show seemed far more impressed by its sharp turns and compact design than by the misinterpreted condensation drip.

Inside the hangars, on the flight line, and in the briefing rooms, the aircraft went about its duties normally — its ECS still humming, still cooling, still producing harmless condensation.

The controversy around the LCA Tejas’ “drip” at the Dubai Air Show 2025 highlights a broad challenge: misinformation thrives where technical knowledge is limited. What some called a leak was simple condensation — the same phenomenon behind droplets forming under an air conditioner.

No malfunction. No oil leak. No safety issue. Just physics at work.

And perhaps a reminder that modern aviation deserves more understanding than knee-jerk speculation.