If it really saves 50% of the aircraft weight, it's crazy that long haul airplanes today are even allowed to have windows.
Maybe you could reduce the weight of just the frame of the fuselage by 50%, but I bet you'd save at most 2-3% of the total takeoff weight, once you include fuel, wings, tail, engines, gear, cabin, baggage, people, cockpit, etc.
Edited: I looked into this more deeply and found the following: https://aerospace-europe.eu/media/books/CEAS2015_211.pdf
It claims a total possible weight reduction on an A320 from 2155kg to 1560kg, or 600kg off the fuselage (plus an additional 150kg elsewhere for a total savings of 750kg). An A320 weighs 42,000kg empty and 78,000kg at takeoff. 2155kg is probably the weight of the fuselage frame sections containing the windows - makes sense that you could save 50% off that piece.
That's a reduction of 1% or so off the takeoff weight.
Also, note that cargo planes are already windowless. I couldn't find a good example of a plane that has both freight and passenger versions that are otherwise identical.
It's always sad when physics gets in the way of aesthetics...
Does this seem odd? The fuselage only accounts for 5% of the empty weight of the plane. I checked your sources and that's what I see too, but it still sounds low. Where does the rest of the weight go? The engines weigh about 4600 kg total. Seats weigh 35 kg x 200 or about 7000 kg. That leaves 28,000 kg. Wings? Landing gear?
The operating empty weight (OEW) is the sum of the manufacturer's empty weight (MEW), standard items (SI), and operator items (OI).
Basically the whole plane, interior outfit and crew needed for full operations, excluding the actual fuel and payload.
An A320 carries around 25,000 L of fuel.[0] Jet fuel weighs ~0.81 kg/L (it varies by temperature).[1][2]
25,000 L * 0.81 kg/L = 20,250 kg = 44,550 lbs.
[0] https://en.wikipedia.org/wiki/Airbus_A320_family
[1] https://en.wikipedia.org/wiki/Jet_fuel
[2] https://aviation.stackexchange.com/questions/48785/how-is-fu...
Also Windows play a role in emergencies: "that sides on fire, let's open the other escape door"
That seems extremely hypothetical and optimistic. If your large passenger plane is on fire you're probably already dead.
I think the types of things they would be looking for are flap deployment, icing, damage to the wing, gear deployment (though there is usually a window in the floor for this), etc.
There's a great YouTube channel called Mentour Pilot that covers a lot of stuff like this, but I can't find his video that discusses visual inspections.
https://www.youtube.com/channel/UCwpHKudUkP5tNgmMdexB3ow/fea...
It's also one of the requirements for starts and landings, along with "make sure your seat back and folding trays are in their full upright position".
The 50% lighter just doesn't work any way you spin it. I think this is another example of the journalist not really digging and verifying statements in a subject their knowledge is lacking/non-existent. (Similar to, "wine/chocolate/smoking/x cures cancer new study shows".)
You can't just remove all the fuselage reinforcements even if you remove the windows... Still, observe as mentioned in calculations [0], even the ~1% gain is significant as it accumulates over time.
[0] https://aerospace-europe.eu/media/books/CEAS2015_211.pdf
The fuselage is generally about 20-40% of the entire dry, empty weight of an aircraft (speaking strictly about large transport aircraft). So clearly seeing that kind of reduction in weight isn't really possible strictly from structurally modifying the fuselage (and even major modifications of the entire airframe). If we look at comparing planes with windows (like those operated by passenger airlines) to those without (like those operated by cargo airlines), loose estimates are less than 1% to around 1% weight savings from removing windows alone. Even if you assume massively increased returns on weight savings because of massive changes in airframe design it's probably no where near 50%...
Keep in mind, even incredibly small weight reductions mean huge savings over the lifetime of an aircraft (especially if they are also carried out over an entire fleet).