Saying Farewell To Another B-17 And Its Crew

October 3, 2019 by Maya Posch 91 Comments

The harsh reality of keeping historical airplanes airworthy and flying is that from time to time one will crash. Thus it was that on October 2nd a Boeing B-17 Flying Fortress crash-landed after technical troubles. Incidentally, this is the very same airplane which we covered only a number of days ago. Painted to look like another B-17 of WWII (Nine-o-Nine, variant B-17G-30-BO), this late-model B-17G-85-DL aircraft wasn’t finished in time to join World War II, but instead spent its 74 years being a flying museum to these amazing airplanes.

Details about the cause of the crash are still scarce, but from radio communication between the crew and tower, it’s understood the B-17 was having having issues with the number 4 engine, which was seen sputtering and smoking by a witness. The airplane’s pilots tried to perform an emergency landing at Bradley International Airport, Connecticut, where it had taken off from only moments ago. Unfortunately the aircraft ran off the runway and struck a building, after which it burst into flames. The NTSB has indicated that they have dispatched a team to investigate the crash, and say that a preliminary report is likely two weeks away.

Of the thirteen people on board, seven died, with the remaining six surviving with injuries. One person on the ground was injured as well. The vintage bomber (civilian registration number N93012) has been all but completely destroyed in the fire, with only a section of the wing and tail remaining recognizable.

We feel terrible about such loss of life and hope the injured make a speedy recovery. The loss of yet another B-17 is also tough to swallow, as this leaves just ten airworthy B-17s. How long until we say farewell to this part of our history, with the final flight of a B-17, or its kin?

(Thanks to Pez for this update)

What On Earth Is A Pickle Fork And Why Is It Adding To Boeing’s 737 Woes?

September 30, 2019 by Jenny List 88 Comments

It’s fair to say that 2019 has not been a good year for the aircraft manufacturer Boeing, as its new 737 MAX aircraft has been revealed to contain a software fault that could cause the aircraft to enter a dive and crash. Now stories are circulating of another issue with the 737, some of the so-called “Pickle forks” in the earlier 737NG aircraft have been found to develop cracks.

It’s a concerning story and there are myriad theories surrounding its origin but it should also have a reassuring angle: the painstaking system of maintenance checks that underpins the aviation industry has worked as intended. This problem has been identified before any catastrophic failures have occurred. It’s not the story Boeing needs at the moment, but they and the regulators will no doubt be working hard to produce a new design and ensure that it is fitted to aircraft.

The Role of the Pickle Fork

For those of us who do not work in aviation though it presents a question: what on earth is a pickle fork? The coverage of the story tells us it’s something to do with attaching the wing to the fuselage, but without a handy 737 to open up and take a look at we’re none the wiser.

Fortunately there’s a comprehensive description of one along with a review of wing attachment technologies from Boeing themselves, and it can be found in one of their patents. US9399508B2 is concerned with an active suspension system for wing-fuselage mounts and is a fascinating read in itself, but the part we are concerned with is a description of existing wing fixtures on page 12 of the patent PDF.

A cross-section of the aircraft wing fixing, in which we've highlighted the role of the pickle forks. (Boeing) — A cross-section of the aircraft wing fixing, in which we’ve highlighted the role of the pickle forks. (Boeing)

The pickle fork is an assembly so named because of its resemblance to the kitchen utensil, which attaches firmly to each side of the fuselage and has two prongs that extend below it where they are attached to the wing spar.

For the curious engineer with no aviation experience the question is further answered by the patent’s figure 2, which provides a handy cross-section. The other wing attachment they discuss involves the use of pins, leading to the point of the patented invention. Conventional wing fixings transmit the forces from the wing to the fuselage as a rigid unit, requiring the fuselage to be substantial enough to handle those forces and presenting a problem for designers of larger aircraft. The active suspension system is designed to mitigate this, and we’d be fascinated to hear from any readers in the comments who might be able to tell us more.

We think it’s empowering that a science-minded general public can look more deeply at a component singled out in a news report by digging into the explanation in the Boeing patent. We don’t envy the Boeing engineers in their task as they work to produce a replacement, and we hope to hear of their solution as it appears.

[via Hacker News]

[Header image: AMX Boeing 737 XA-PAM by Jean-Philippe Boulet CC-BY 3.0]

A CIA In 74HCT

September 28, 2019 by Jenny List 14 Comments

If you owned a classic Commodore home computer you might not have known it at the time, but it would have contained a versatile integrated circuit called the MOS6526. This so-called CIA chip, for Complex Interface Adaptor, contained parallel and serial ports, timers, and a time-of-day counter. Like so many similar pieces of classic silicon it’s long out of production, so [Daniel Molina] decided to replicate a modern version of it on a PCB using 74HGT CMOS logic.

The result will be a stack of boards board that appear to be about the size of a 3.5″ floppy disk covered in surface-mount 74 chips, and connected to the CIA socket of the Commodore by a ribbon cable. The base board is the only one completed so far and contains the data direction registers and parallel ports, but the succeding boards will each carry one of the chip’s other functions.

It seems rather odd to use so much silicon to recreate a single chip, but the point is not of course to provide a practical CIA replacement. Instead it’s instructive, it shows us how these interfaces work as well as just how much circuitry is crammed into the chip. It’s no surprise that it’s inspired by the C74 Project, a TTL 6502 processor that we featured last year.

Hackaday Podcast 037: Two Flavors Of Robot Dog, Hacks That Start As Fitness Trackers, Clocks That Wound Themselves, And Helicopter Chainsaws

September 27, 2019 by Mike Szczys No comments

Hackaday Editors Mike Szczys and Elliot Williams take a look at the latest hacks from the past week. We keep seeing awesome stuff and find ourselves wanting to buy cheap welders, thermal camera sensors, and CNC parts. There was a meeting of the dog-shaped robots at ICRA and at least one of them has super-fluid movements. We dish on 3D printed meat, locking up the smartphones, asynchronous C routines, and synchronized clocks.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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A Virtual Tour Of The B-17

September 24, 2019 by Tom Nardi 98 Comments

The Boeing B-17 “Flying Fortress” is arguably the most recognizable aircraft of the Second World War. Made infamous by the daring daylight strategic bombing runs they carried out over Germany, more than 12,000 of these four-engined bombers were produced between 1939 and 1945. Thanks to the plane’s renowned survivability in battle, approximately 60% of them made it through the war and returned home to the United States, only to be rounded up in so-called “boneyards” where they were ultimately cut up and sold as scrap. Today there are fewer than 50 intact Boeing B-17s left in the world, and of those, only 11 remain airworthy.

One of them is Nine-O-Nine, a B-17G built in April 7, 1945. This particular aircraft was built too late to see any combat, although in the 1950s she was fitted with various instruments and exposed to three separate nuclear blasts for research purposes. It’s actually not the real Nine-O-Nine either, the original was scrapped after it completed eighteen bombing runs over Berlin. Without a combat record of its own, this bomber was painted to look like the real Nine-O-Nine in honor of its incredible service record of never losing a crewman.

Since 1986, Nine-O-Nine has been owned by the Collings Foundation, who operate her as a living history exhibit. The bomber flies around the United States with an entourage of similarly iconic WWII aircraft as part of the Wings of Freedom Tour, stopping by various airports and giving the public a chance to climb aboard and see the pinnacle of mid-1940s strategic bombing technology. History buffs with suitably deep pockets can even book a seat on one of the scheduled 30-minute flights that take place at every stop on the Tour.

I was lucky enough to have the The Wings of Freedom Tour pass through my area recently, and couldn’t pass up the opportunity to experience this incredible aircraft first hand. The fact that I’m equal parts a coward and miser kept me from taking a ride aboard the 74 year old Nine-O-Nine, at least for now, but I made sure to take plenty of pictures from inside this lovingly restored B-17G while it was safely on the ground.

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An Arduino Enhances This 7400 CPU

September 22, 2019 by Jenny List 10 Comments

How quickly could you make an entire computer from 74 series logic, from scratch? [Richard Grafton had only 30 days until the UK’s Retro Computer Festival and set out to design and build his Cambridge-1 computer in that time. The result is a machine spread across several breadboards, with neatly placed wiring and unexpectedly an Arduino Micro sitting in the corner. Isn’t the little Italian board a cheat? Not so, he says, because instead of being part of the computer itself it serves as a program loader to make putting software onto the machine from a PC as easy as possible.

The machine itself is simple enough, a 4-bit design with 8-bit data and address busses. There are only 16 instructions, and the clock speed is a relatively pedestrian 40Hz. This does, however, allow the many blinkenlights to show the machine’s state in a more visible manner. There’s a video which we’ve placed below the break, and if you have further questions you might like to look at the GitHub repository.

We like the Cambridge-1, and we see no problem with the Arduino being part of it. It doesn’t take away from the 74-driven nature of the machine. Instead, it enhances the usefulness of the device by facilitating coding on it. We’ve had huge quantities of TTL computers here over the years so it’s difficult to pick one to send you towards, however you may want to consider the 7400 as the original in the series.

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Pictorial Guide To The Unofficial Electronic Badges Of DEF CON 27

September 19, 2019 by Mike Szczys 15 Comments

DEF CON has become the de facto showplace of the #Badgelife movement. It’s a pageant for clever tricks that transform traditional green rectangular circuit boards into something beautiful, unique, and often times hacky.

Today I’ve gathered up about three dozen badge designs seen at DC27. It’s a hint of what you’ll see in the hallways and meetups of the conference. From hot-glue light pipes and smartphone terminal debugging consoles to block printing effects and time of flight sensors, this is a great place to get inspiration if you’re thinking of trying your hand at unofficial badge design.

If you didn’t catch “The Badgies” you’ll want to go back and read that article too as it rounds up the designs I found to be the craziest and most interesting including the Car Hacking Village, Space Force, SecKC, DC503, and Frankenbadge. Do swing by the Hands-On articles for the AND!XOR badge and for [Joe Grand’s] official DC27 badge. There was also a lot of non-badge hardware on display during Hackaday’s Breakfast at DEF CON so check out that article as well.

Enough preamble, let’s get to the badges!

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