Solid-State Batteries Take To The Sky

June 17, 2026 by Bryan Cockfield 13 Comments

There always seem to be a handful of revolutionary technologies perpetually out of reach: fusion energy, quantum computers, and full self-driving cars are always in this list, and it seems like there’s also some battery technology which will finally let us fully decouple from fossil fuels in there as well. Although lithium batteries have allowed some ground-based electric transportation, the energy density is still not enough to enable full electrification, especially for things like aircraft. Solid state batteries may be on the verge of changing some of this, though, and a team has recently put them to work in a test aircraft to help make some headway with this novel battery chemistry.

The main contributing factor of these batteries’ improved energy densities is the ability to use a solid lithium anode, which has much higher energy density than the graphite-based anodes in modern liquid electrolyte batteries. Solid state batteries also have improved safety, since the solid electrolyte is generally not flammable and the battery itself is less prone to thermal runaway. The tests in this aircraft, a modified motorized glider, bear this out as well. With a standard lithium ion pack the team was able to harness 250 Wh/kg and with their new solid state battery they managed 410 Wh/kg, which let them fly the craft up to 24,000 feet (7,315 m) with the help of some wing-mounted solar panels.

Of course, a motorized glider is a long way away from battery-powered commercial flights, but tests like this are an important step on the way to de-carbonizing one of the more impactful industries on the planet, as well as hopefully making it less expensive to operate aircraft in the way EVs are generally much cheaper to operate than their internal combustion equivalents. But the limiting factor to adopting solid state batteries isn’t going to be implementation but rather the discovery of a cost effective way to manufacture them at scale. It’s the same reason we haven’t seen mass adoption of things like algae-based biodiesel or economic carbon capture yet.

Failed 3D Printed Part Brings Down Small Plane

December 10, 2025 by Donald Papp 112 Comments

Back in March, a small aircraft in the UK lost engine power while coming in for a landing and crashed. The aircraft was a total loss, but thankfully, the pilot suffered only minor injuries. According to the recently released report by the Air Accidents Investigation Branch, we now know a failed 3D printed part is to blame.

The part in question is a plastic air induction elbow — a curved duct that forms part of the engine’s air intake system. The collapsed part you see in the image above had an air filter attached to its front (towards the left in the image), which had detached and fallen off. Heat from the engine caused the part to soften and collapse, which in turn greatly reduced intake airflow, and therefore available power.

Serious injury was avoided, but the aircraft was destroyed.

While the cause of the incident is evident enough, there are still some unknowns regarding the part itself. The fact that it was 3D printed isn’t an issue. Additive manufacturing is used effectively in the aviation industry all the time, and it seems the owner of the aircraft purchased the part at an airshow in the USA with no reason to believe anything was awry. So what happened?

The part in question is normally made from laminated fiberglass and epoxy, with a glass transition of 84° C. Glass transition is the temperature at which a material begins to soften, and is usually far below the material’s actual melting point.

When a part is heated at or beyond its glass transition, it doesn’t melt but is no longer “solid” in the normal sense, and may not even be able to support its own weight. It’s the reason some folks pack parts in powdered salt to support them before annealing.

The printed part the owner purchased and installed was understood to be made from CF-ABS, or ABS with carbon fiber. ABS has a glass transition of around 100° C, which should have been plenty for this application. However, the investigation tested two samples taken from the failed part and measured the glass temperature at 52.8°C and 54.0°C, respectively. That’s a far cry from what was expected, and led to part failure from the heat of the engine.

The actual composition of the part in question has not been confirmed, but it sure seems likely that whatever it was made from, it wasn’t ABS. The Light Aircraft Association (LAA) plans to circulate an alert to inspectors regarding 3D printed parts, and the possibility they aren’t made from what they claim to be.

A photo of the old mechanical and new digital altimeters

Ben Eater Explains How Aircraft Systems Communicate With The ARINC 429 Protocol

October 14, 2025 by John Elliot V 7 Comments

Over on his YouTube channel the inimitable [Ben Eater] takes a look at an electronic altimeter which replaces an old mechanical altimeter in an airplane.

The old altimeter was entirely mechanical, except for a pair of wires which can power a backlight. Both the old and new altimeters have a dial on the front for calibrating the meter. The electronic altimeter has a connector on the back for integrating with the rest of the airplane. [Ben] notes that this particular electronic altimeter is only a backup in the airplane it is installed in, it’s there for a “second opinion” or in case of emergency.

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The WindRunner unloading a blade, image Radia.

Giant Airplane Goes Long On Specialization

October 3, 2025 by Tyler August 64 Comments

While not everyone agrees on the installation of wind turbines in their proverbial back yards, one thing not up for debate is that there is a drive to build them bigger, and bigger. Big turbines means big blades, and big blades need to be transported… somehow. If air freight is going to stay relevant to the industry, we’re gonna need a bigger airplane.

A startup called Radia has a plan for that plane, and it is a doosie. The “WindRunner” would clock in at a massive 108 meters (354 feet) long, but with a wingspan of just 80 m (262 ft). That’s very, very long, but it might not be the largest airplane, depending how you measure it. Comparing to the 88 m wingspan for the late, lamented An-225 Mriya, you can expect a lower payload capacity, but heavy payloads aren’t the point here. Wind turbine blades really aren’t that heavy. They’re big, or they can be — the WindRunner is designed to fit a single 105 m blade within its long fuselage, or a pair of 90 m blades.

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Making An Ultralight Helicopter

September 8, 2025 by Fenix Guthrie 38 Comments

Ultralight aviation provides an excellent pathway for those who want to fly, but don’t want to get licensed. These quite often cheap and cheerful DIY aircraft often hide some excellent engineering underneath. This is no more true than in [ultralight helicopter’s] four-year-long helicopter build saga!

While most ultralight builds are fixed-wing, a rotocraft can meet all the legal definitions of ultralight aviation. This helicopter is an excellent example of what’s possible with a lot of time and patience. The construction is largely aluminium with some stainless steel on the skids. A 64-horsepower Rotax 582UL engine powers the two-bladed main rotor and tail rotor. The drivetrain features a multi-belt engine coupler and three gearboxes to ensure correct power output to the two rotors.

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What Happens When Lightning Strikes A Plane?

August 5, 2025 by Zoe Skyforest 24 Comments

Lightning is a powerful force, one seemingly capable of great destruction in the right circumstances. It announces itself with a searing flash, followed by a deep rumble heard for miles around.

Intuitively, it might seem like a lightning strike would be disastrous for something like a plane flying at altitude. And yet, while damage is possible, more often than not—a plane will get through a lightning storm unscathed. Let’s explore the physics at play.

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A Compass That Looks To The Stars

December 17, 2024 by Bryan Cockfield 19 Comments

Although a lot of tools have been digitized and consolidated into our smartphones, from cameras, music players, calendars, alarm clocks, flashlights, and of course phones, perhaps none are as useful as the GPS and navigational capabilities. The major weakness here, though, is that this is a single point of failure. If there’s no cell service, if the battery dies, or you find yourself flying a bomber during World War II then you’re going to need another way to navigate, possibly using something like this Astro Compass.

The compass, as its name implies, also doesn’t rely on using the Earth’s magnetic field since that would have been difficult or impossible inside of an airplane. Instead, it can use various celestial bodies to get a heading. But it’s not quite as simple as pointing it at a star and heading off into the wild blue yonder. First you’ll need to know the current time and date and look those up in a companion chart. The chart lists the global hour angle and the declination for a number of celestial bodies which can be put into the compass. From there the latitude is set and the local hour angle is calculated and set, and then the compass is rotated until the object is sighted. After all of that effort, a compass heading will be shown.

For all its complexity, a tool like this can be indispensable in situations where modern technology fails. While it does rely on precise tabulated astrometric data to be on hand, as long as that’s available it’s almost failsafe, especially compared to a modern smartphone. Of course, you’ll also need a fairly accurate way of timekeeping which can be difficult in some situations.

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