Floppy Disks Still Used To Update 747 Flight Software

August 12, 2020 by Lewin Day 96 Comments

For garden variety daily computing tasks, the floppy disk has thankfully been a thing of the past for quite some time. Slow, limited in storage and easily corrupted, few yearn for the format to return, even if there is some lingering nostalgia for the disks. As it turns out, though, there is still hardware that relies on floppies – namely, the Boeing 747-400, as The Register reports.

The news comes from the work of Pen Test Partners, who recently inspected a 747 being retired as a result of the coronavirus pandemic. The floppy disks are used to load navigational databases which need to be updated regularly, every 28 days. Engineers responsible for loading updates must perform the process manually on the ground.

Efforts have been made in some areas to replace the disks with more modern technology. As Aviation Today covered in 2014, legacy aircraft often require updates involving up to eight floppy disks, leading to slow updates that can cause flight delays. As anyone familiar with the reliability of floppy media knows, it only takes one bad disk to ruin everything. While retrofits are possible, it’s more likely that airlines will simply stick with the technology until the legacy airplanes are retired. Certifying new hardware for flight is a major cost that is difficult to justify when the current system still works.

Floppies continue to cling to relevance, even if for most of us it’s simply as the save icon. We’ve also seen floppies used as an even more inefficient method of data entry. It turns out you can even fit an entire podcast on one, too!

Building And Flying A Helicopter With A Virtual Swashplate

June 25, 2020 by Dan Maloney 33 Comments

They say that drummers make the best helicopter pilots, because to master the controls of rotary-wing aircraft, you really need to be able to do something different with each limb and still have all the motions coordinate with each other. The control complexity is due to the mechanical complexity of the swashplate, which translates control inputs into both collective and cyclical changes in the angle of attack of the rotor blades.

As [Tom Stanton] points out in his latest video, a swashplate isn’t always needed. Multicopters dispense with the need for one by differentially controlling four or more motors to provide roll, pitch, and yaw control. But thanks to a doctoral thesis he found, it’s also possible to control a traditional single-rotor helicopter by substituting flexible rotor hinges and precise motor speed control for the swashplate.

You only need to watch the slow-motion videos to see what’s happening: as the motor speed is varied within a single revolution, the tips of the hinged rotor blades lead and lag the main shaft in controlled sections of the cycle. The hinge is angled, which means the angle of attack of each rotor blade changes during each rotation — exactly what the swashplate normally accomplishes. As you can imagine, modulating the speed of a motor within a single revolution when it’s spinning at 3,000 RPM is no mean feat, and [Tom] goes into some detail on that in a follow-up video on his second channel.

It may not replace quadcopters anytime soon, but we really enjoyed the lesson in rotor-wing flight. [Tom] always does a great job of explaining things, whether it’s the Coandă effect or anti-lock brakes for a bike.

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An Epic Story Of 1980s FPV Flight

March 13, 2020 by Jenny List 8 Comments

A staple of today’s remote-controlled flight is the so-called FPV transmitter, allowing the pilot of a multirotor or other craft to see the world from onboard, as a pilot might do. It’s accessible enough that it can be found on toy multirotors starting at not much more than pocket money prices, and reliable enough that in its better incarnations it can send back high definition video at surprisingly long range.

In case you think of FPV flight as a recent innovation, the video below the break from [Larry Mitschke] should come as a revelation. In 1986 he was a bona-fide rockstar playing in a band, whose radio-controlled flight hobby led him into creating an FPV system for his planes and soaring above the Texas countryside at significant distance from his base while flying it watching a CRT screen.

The video is quite long but extremely watchable, all period footage with his narration here in 2020. We see his earliest experiments with a monochrome security camera and a video sender, and a whole host of upgrades until finally he can fly three miles from base with good quality video. 70 cm amateur TV makes an appearance with a steerable tracking antenna, he even makes a talking compass for when he loses himself. It’s an epic tale of hacking with what seems rudimentary equipment by our standards but was in fact the cutting edge of available video technology at a time when the state of the video art was moving rather fast. This is the work that laid the path for today’s $30 FPV toys, and for flying FPV from space.

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Classic Toy Helicopter Flies Again As DIY Version

February 11, 2020 by Dan Maloney 31 Comments

For many of us who grew up in the 1970s, “VertiBird”, the fly-it-yourself indoor helicopter, was a toy that was begged for often enough that it eventually appeared under the Christmas tree. And more than a few of the fascinating but delicate toys were defunct by Christmas afternoon, victims of the fatal combination of exuberant play and price-point engineering. But now a DIY version of the classic toy flies again, this time with a more robust design.

To be fair to the designers at Mattel, the toy company that marketed VertiBird, the toy was pretty amazing. The plastic helicopter was powered by a motor located in the central base, which rotated a drive rod that ran through a stiff tether. Small springs in the base and at the copter acted as universal joints to transmit power to the rotor. These springs were the weak point in the design, especially the one in the base, often snapping in two.

[Luke J. Barker]’s redesign puts a tiny gear motor in the aircraft rather than in the base, something that wouldn’t have been feasible in the original. To address the problem of getting electrical power from the base to the aircraft, [Luke] eschewed an expensive slip ring and instead used a standard 3.5-mm audio jack and plug. The plug serves as an axle for the main gear in the base that powers the copter’s rotation; sadly, this version doesn’t tilt the aircraft mechanically to control backward and forward flight like the original. A pair of pots with 3D-printed levers control throttle and flight direction through an Arduino; see it in action in the video below.

These pages abound with rotorcraft builds, both helicopters and multirotor. We appreciate all manner of flying machines, but this one really takes us back.

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Robot Hummingbird Imitates Nature

May 12, 2019 by Al Williams 9 Comments

Purdue’s Bio-Robotics lab has been working on a robotic hummingbird and, as you can see in the videos below, have had a lot of success. What’s more, is they’ve shared that success on GitHub. If you want to make a flapping-winged robot, this is definitely where you start.

If you’ve ever watched a hummingbird, you know their flight capability is nothing short of spectacular. The Purdue robot flies in a similar fashion (although on a tether to get both power and control information) and relies on each wing having its own motor. The motors not only propel the wings but also act as sensors. For example, they can detect if a wing is damaged, has made contact with something, or has changed performance due to atmospheric conditions.

In addition to the tethered control system, the hummingbird requires a motion capture sensor external to itself and some machine learning. Researchers note that there is sufficient payload capacity to put batteries onboard and they would also need additional sensors to accomplish totally free flight. It is amazing when you realize that a real hummingbird manages all this with a little bitty brain.

The published code is in Python and is part of three presentations later this month at a technical conference (the IEEE International Conference on Robotics and Automation). If you don’t want to wait on the paper, there’s a post on IEEE Spectrum about the robotic beast, available now and that article contains preprint versions of the papers. The Python code does require a bit to run, so expect a significant flight computer.

The last hummingbird bot we saw was a spy. We’ve also seen robots that were like bees — sort of.

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Gliding Back Home From 60,000ft

April 6, 2019 by Lewin Day 21 Comments

If you want to play around with high altitudes, weather balloons are the way to go. With a bit of latex and some helium, it’s possible to scrape up against the edge of space without having to start your own rocketry program. [Blake] was interested in doing just this, and decided to build a near space glider which could capture the journey.

There are certain challenges involved with this flight regime, which [Blake] worked to overcome. There was significant investment in the right antennas and radio hardware to enable communication and control of the aircraft at vast distances. Batteries were chosen for their ability to work at low temperatures in the high altitude environment, and excess heat from the transmitters was use to keep them warm.

The glider was also fitted with an Ardupilot Mega which would control the gliders’s flight after separation from the lift balloon. [Blake] had some success flying the aircraft at 60,000 feet, but found that due to communications issues, the autopilot was doing a better job. The initial flight was largely a success, with the glider landing just 9 miles off target due to headwinds.

We’ve seen glider builds on other autopilot platforms, too. Video after the break.

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Flying Convenience Not So Convenient

February 23, 2019 by Lewin Day 19 Comments

It’s a situation that plays out every day, all over the world – you walk into work, and there’s a full-scale foam toilet sitting on the bench, demanding to be used in a crackpot project. This time, it happened to be at the [FliteTest] workshop, and naturally, they set about making it fly.

The team at [FliteTest] are well resourced, with a laser cutter being used to quickly produce a set of custom foam board wings. However, after wing failures on their previous projects, this time the team opted for a riveted aluminium wing spar to add strength. A twin-boom tail is used to try to avoid the cistern from interfering with airflow over the elevator, and careful attention is paid to make sure the center of gravity is in the right position for stable flight.

Despite the team’s laudable efforts, the toilet (somewhat unsurprisingly) flies like crap. It just goes to show, you can strap a brushless power system on to just about anything, but aerodynamics will still be standing ready to bring it all crashing down to Earth.

We’ve seen some great builds from [FliteTest] over the years – before the throne, it was an IKEA chair that soared amongst the clouds. Video after the break.

[Thanks to Baldpower for the tip!] Continue reading “Flying Convenience Not So Convenient” →