The big news story of the week of course has been the wildfires in California, which as of Saturday have burned over 30,000 acres, destroyed 12,000 structures, caused 150,000 people to evacuate, and killed eleven people. Actually, calling them wildfires underplays the situation a bit because there are places where they’ve clearly become firestorms, burning intensely enough to create their own winds, consuming everything in their path in a horrific positive feedback loop. We’ve even seen fire tornados caught on video. We’ve got quite a few connections to the affected area, both personally and professionally, not least of which are all our Supplyframe colleagues in Pasadena, who are under immediate threat from the Eaton fire. We don’t know many details yet, but we’ve heard that some have lost homes. We’ve also got friends at the Jet Propulsion Labs, which closed a few days ago to all but emergency personnel. The fire doesn’t seem to have made it down the mountain yet, but it’s very close as of Saturday noon.
aviation29 Articles
All-Band Receiver Lets You Listen To All The Radio At Once
There are many ways to build a radio receiver, but most have a few things in common, such as oscillators, tuned circuits, detectors, mixers, and amplifiers. Put those together in the right order and you’ve got a receiver ready to tune in whatever you want to listen to. But if you don’t really care about tuning and want to hear everything all at once, that greatly simplifies the job and leaves you with something like this homebrew all-band receiver.
Granted, dispensing with everything but a detector and an audio amplifier will seriously limit any receiver’s capabilities. But that wasn’t really a design concern for [Ido Roseman], who was in search of a simple and unobtrusive way to monitor air traffic control conversations while flying. True, there are commercially available radios that tune the aviation bands, and there are plenty of software-defined radio (SDR) options, but air travel authorities and fellow travelers alike may take a dim view of an antenna sticking out of a pocket.
So [Ido] did a little digging and found a dead-simple circuit that can receive signals from the medium-wave bands up into the VHF range without regard for modulation. The basic circuit is a Schottky diode detector between an antenna and a high-gain audio amplifier driving high-impedance headphones; [Ido] built a variation that also has an LM386 amplifier stage to allow the use of regular earbuds, which along with a simple 3D-printed case aids in the receiver’s stealth.
With only a short piece of wire as an antenna, reception is limited to nearby powerful transmitters, but that makes it suitable for getting at least the pilot side of ATC conversations. It works surprisingly well — [Ido] included a few clips that are perfectly understandable, even if the receiver also captured things like cell phones chirping and what sounds like random sferics. It seems like a fun circuit to play with, although with our luck we’d probably not try to take it on a plane.
Tailwheel Trainer Go-Cart To Avoid Wrecked Planes
Taildraggers remain a popular configuration for small aircraft, but they come with a significant risk during ground handling: ground loops. If the tail gets too far off course, it can swing around completely, often damaging or destroying aircraft if a wing hits the ground. Avoiding ground loops requires good rudder and brake control, and there currently isn’t a good way to learn it without getting into an actual aircraft. [Trent Palmer] is a pilot and who has been thinking about this problem for a few years, so he built a 3-wheeled electric go-cart to help pilots train their ground handling.
The cart is controlled exactly like a taildragger, with a pair of rudder pedals connected to the single steerable via cables, and springs to add some response delay. Independent hydraulic brakes on each main wheel, operated by toe pedals, further simulate the control on many aircraft. The main wheel are controlled with a throttle lever, with a differential to allow them to rotate at different speeds. The cart is unforgiving, and requires constant corrections with the pedals to keep it going straight.[Trent] had few pilot and non-pilot friends try out the cart, and even the experienced tailwheel pilots got into ground loop. It might be bit too sensitive, but everyone agreed that mastering this cart would significantly improve ground handling skills in actual aircraft.
Repairing a damaged aircraft can cost several thousand dollar, so a cheap training tool like this could prove invaluable flight schools and even individual pilots. [Trent] doesn’t have big plans for commercialization, but we wouldn’t be surprised if it goes that way.
Taildraggers are especially popular as bush planes, with many tracing their heritage from the humble Piper J-3 Cub. We’ve seen some extreme extreme modern bush planes, like [Mike Patey]’s Scrappy and Draco builds. Continue reading “Tailwheel Trainer Go-Cart To Avoid Wrecked Planes”
Unlocking The Mystery Of An Aircraft ADI
If you’ve ever seen the cockpit of an airplane, you’ve probably noticed the round ball that shows your attitude, and if you are like us, you’ve wondered exactly how the Attitude Direction Indicator (ADI) works. Well, [msylvain59] is tearing one apart in the video below, so you can satisfy your curiosity in less than 30 minutes.
Like most things on an airplane, it is built solidly and compactly. With the lid open, it reminded us of a tiny CRT oscilloscope, except the CRT is really the ball display. It also has gears, which is something we don’t expect to see in a scope.
A Live Map Display In A 1960s Airliner
We tend take GPS navigation for granted these days, so it’s easy to forget that it became only available in the last few decades. Aviation navigation used to be significantly more challenging, so how was the Hawker Siddeley Trident, a 1960s airliner, fitted with a live updating map display? In a fascinating dive into aviation history the British Airliner Collection has spun up an insightful article on the magic behind these moving map displays.
Without access to satellite navigation or advanced electronics, engineers had to get creative. Enter the Trident’s moving map display, a marvel of ingenuity that predated the GPS systems. Using a combination of Doppler radar and some clever mechanics, pilots could accurately determine their position without relying on any external signals.
The system makes use of four Doppler radar beams, arranged in what was known as the Janus array. This configuration corrected for errors caused by changes in altitude or wind drift, ensuring accurate ground speed readings. The movable antennas mounted under the cabin floor could adjust its orientation to maintain alignment with the actual direction of travel, calculating drift angle precisely. Combined with compass information and flight time from a known start point to to indicate the current position with a pointer on a rolled paper map. The system was well ahead of it’s time, and significantly easier to use and more accurate than the Decca radio navigation system in use at the time.
It’s mind boggling to see the solutions engineers came up with without much of the digital technology we take for granted today. Gyroscopes for inertial navigation, the cavity magnetron for radar and radial engines were all building blocks for modern aviation.
Thanks for the tip [poiuyt]!
Hackaday Links: January 14, 2024
How long does it take a team of rocket scientists to remove two screws? When the screws they’re working on are keeping a priceless sample of asteroid safe, it’s about three months. That’s how long NASA has been working on the OSIRIS-REx sample return canister, which came back to Earth from asteroid Bennu back in September. The container was crammed full of asteroid bits, thanks in part to an overly energetic impact between the sample-collecting boom and Bennu. There was so much stuff that planetary scientists were able to recover about 70 grams of material that was covering the outside of the sealed container; this must have been a boon to the engineers, who got to figure out how to open the jammed cover of the container without anyone breathing down their necks for samples to study. The problem was a pair of stuck fasteners out of the 35 holding the lid on the container; the solution was far more complicated than a spritz of WD-40 and a little bit of heating with an oxy-acetylene torch. Engineers had to design two “clamp-like tools” and test them on a mock-up to make sure they wouldn’t contaminate the sample. We’d love to know more about these tools; trust us, we’ll be looking into this closely. If we find anything, a full article will be forthcoming.
Next-Gen Autopilot Puts A Robot At The Controls
While the concept of automotive “autopilots” are still in their infancy, pretty much any aircraft larger than an ultralight will have some mechanism to at least hold a fixed course and altitude. Typically the autopilot system is built into the airplane’s controls, but this new system replaces the pilot themselves in a manner reminiscent of the movie Airplane.
The robot pilot, known as PIBOT, uses both AI and robotics technology to fly the airplane without altering the aircraft. Unlike a normal autopilot system, this one can be fed the aircraft’s manuals in natural language, understand them, and use that information to fly the airplane. That includes operating any of the aircraft’s cockpit controls, not just the control column and pedal assembly. Supposedly, the autopilot can handle everything from takeoff to landing, and operate capably during heavy turbulence.
The Korea Advanced Institute of Science and Technology (KAIST) research team that built the machine hopes that it will pave the way for more advanced autopilot systems, and although this one has only been tested in simulators so far it shows enormous promise, and even has certain capabilities that go far beyond human pilots’ abilities including the ability to remember a much wider variety of charts. The team also hopes to eventually migrate the technology to the land, especially military vehicles, although we’ve seen how challenging that can be already.