In-flight Wi-Fi has a reputation for being slow, expensive and unreliable. All three have real technical causes, and knowing them explains why the experience varies so much between airlines and even between two flights on the same aircraft.
Two ways to get a signal to a moving aircraft
Air-to-ground systems point antennas on the aircraft at cell towers on the surface, aimed upward. They are relatively cheap and work well over land with good tower coverage, and not at all over oceans, which is most long-haul flying.
Satellite systems connect upward instead, and until recently that meant geostationary satellites roughly 36,000 kilometres away. That distance imposes a delay no equipment can remove, which is why older in-flight internet handles email adequately and video calls badly. Newer low-earth-orbit constellations fly a few hundred kilometres up, cutting the round trip dramatically and making interactive use realistic.
Why it still feels slow
- Capacity is shared. One connection serves the whole cabin. Three hundred passengers on a link sized for a fraction of that will be slow regardless of technology.
- Airlines shape traffic deliberately. Video streaming is commonly throttled or blocked to protect messaging and browsing for everyone else.
- Coverage gaps exist. Polar routes and some ocean regions have thinner satellite coverage, and service degrades or drops.
- Handovers interrupt. Moving at speed between satellites or ground cells causes brief losses of connection.
Why the pricing is strange
Airlines pay for equipment, installation, the weight penalty of carrying it, and bandwidth. The aircraft must be taken out of service for fitting, which is expensive in itself. Those costs are recovered in different ways: free messaging with paid browsing, free access for premium cabins or loyalty members, or a flat charge per flight.
Free Wi-Fi across a whole fleet is a marketing decision funded from elsewhere, which is why it tends to appear on airlines competing hardest for frequent business travellers.
Getting the best out of it
Download what you need before boarding, since streaming is the thing most likely to be restricted. Connect early: performance degrades as more of the cabin joins. Expect messaging and email to work well and large uploads to fail. If you buy access, check whether it covers one device or several, and whether it persists across a connecting flight.
Common questions
Why is it worse than my home broadband? Because a single shared link serves hundreds of people while moving at speed, which is a fundamentally harder problem.
Can I make video calls? Technically possible on newer low-orbit systems, though many airlines block voice and video calls for cabin-noise reasons rather than technical ones.
Does it work over the ocean? Satellite systems do. Air-to-ground systems do not, which is why coverage maps matter more than advertised speeds.
Is airline Wi-Fi secure? Treat it as any public network. Use HTTPS sites, and a VPN if you are handling anything sensitive.
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