Day: September 24, 2019

A Virtual Tour Of The B-17

September 24, 2019 by 97 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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Helicopter Chain Saw

September 24, 2019 by 54 Comments

Among the most dangerous jobs in the United States are timberjack and aircraft pilot. Combining the two wouldn’t sound like a recipe for success, but in fact it makes the job of trimming trees near pipelines and power lines much safer. That’s what this helicopter-suspended chainsaw does. And it definitely doesn’t look safe, either, but here we are.

The saw is equipped with ten two-foot diameter saws and is powered by a 28 horsepower engine which is separate from the helicopter itself. The pilot suspends the saw under the helicopter and travels along the trees in order to make quick work of tree branches that might be growing into rights-of-way. It’s a much safer (and faster) alternative that sending out bucket trucks or climbers to take care of the trees one-by-one.

Tree trimming is an important part of the maintenance of power lines especially which might get overlooked by the more “glamarous” engineering aspects of the power grid. In fact, poor maintentance of vegitation led to one of the largest blackouts in recent history and is a contributing factor in a large number of smaller power outages. We can’t argue with the sentiment around the saw, either.

Asynchronous Routines For C

September 24, 2019 by 35 Comments

[Sandro Magi] noted that the async/await idiom has become more prevalent in programming recently. According to him, he first encountered it in C# but has found examples of it in JavaScript and Rust, too. The idea is simple: allow a function to return but come back later to complete something that takes a long time. Of course, multithreading is one answer to this, but generally, this technique implies more of a coroutine setup where functions cooperate to some degree to get good behavior. [Sandro] took some ideas from the existing protothread library and used it to create a system to get this effect in C and, by extension, C++.

Adding this “library” is as simple as including a header file. All the magic occurs at the preprocessor and compiler. There’s no code to link. The async routines only need two bytes of overhead and — unlike proper threads — don’t need a preallocated private stack.

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