Wednesday, May 13, 2015

Homemade jet engines, then and now

True story: as a fifth-grader, I and a classmate built a rudimentary jet engine for a science fair*.

OK, OK... maybe "rudimentary" is being a little complimentary. And in reality, it was more of a motorjet, which was cutting edge in the late 1930s. But still. A jet. I assume the Parents of the Blog have a picture somewhere, but since I don't have one in hand, I'll just describe it to you.

It was a coffee can with both ends removed.

The beginnings of an engine.

Inside the can was mounted a smaller can--I think it once held tuna. The lid was removed and a hole about 1/3 the diameter was cut in the bottom.

The ignition system.

At one end was a two-stroke model airplane engine with a two-bladed propeller.

This would be the "motor" part of a motorjet.

Inside the tuna can was a wad of steel wool mixed with wood putty--the ignitors. I won't even try to find something to illustrate that. But the point was that after experimenting with a bunch of different flammable things, we discovered this mixture would maintain an open flame in high winds... like those generated by a model airplane engine.

Finally, a tiny hole in the top of the coffee can admitted a tiny straw, which was attached to a can of WD-40. This was the fuel system.

You started up the prop in the front, started spraying fuel, and whoosh: a jet. The tuna can compressed the air inside the coffee can enough that, combined with the heat of WD-40, you actually got a little thrust. We never tested it, but I suspect it would have, say, accelerated a skateboard pretty nicely.

What made me think of this? Well, I saw today that GE just produced a rudimentary jet engine of its own. Except this one was more or less 3D-printed. And it's quite a bit more powerful. Check it out:

It's a really cool application of a technology that is still evolving in interesting ways. Just a couple of years ago, 3D printing was basically something you used to make toys or plastic parts. Now you can, in theory, simply command a computer to make a jet engine.

I think even adjusted for inflation, my production costs were much lower. But measured in skateboard thrust units, GE's version of a cheap jet engine blows mine away.

*Our jet came in second, to a "microwave that cools things down." It was a box with a fan in it.

Tuesday, March 10, 2015

The Danger Zone, as seen from two continents

The Internet has given humanity, for better or worse, the ability to share just about anything with millions of people. Cat memes... dumb jokes... vital economic data... it's all there.

It has also made it immeasurably easier to create and share pieces of cinema that, 15 years ago, simply didn't exist outside of movie trailers. I am of course talking about hype videos. This being an aviation d̶o̶r̶k̶ enthusiast's blog, and the aforementioned d̶o̶r̶k̶ enthusiast being located in Asia this post focuses on fighter jets and China.

First, what does a modern fighter jock's hype video look like? Here's one of the best, from the Navy's VFA-27 Royal Maces squadron, which apparently has Michael Bay on staff:

And here's a version from the other side of the planet, courtesy of the People's Liberation Army Air Force (if the video doesn't show up below, click the preceding link):

-Engine noises
-Stirring music

-Few pilots visible (China)
-No CGI (VFA-27)
-No danceable music (China)
-No colored smoke (VFA-27)
-No weapons fired (China)
-No chess pieces (VFA-27)

The two videos, in all seriousness, have different audiences. The VFA-27 piece isn't meant for wide distribution, other than getting some viral play. It's really aimed at other pilots and d̶o̶r̶k̶s enthusiasts. Showing off, in other words--a favorite pastime of fighter pilots.

The PLAAF video, by contrast, is meant for everyone to see. It's a commercial for the growing airpower might of China... as evidenced by the repeated use of J-31 footage. (And of course also by the inclusion of English in the video.)

Overall, it just illustrates that the need... the need for speed... exists across the globe. And as long as the fight centers around who is better at timing their smash cuts to the music, that's not a bad thing at all.

Sunday, March 8, 2015

Kind of a big deal

Yeah, yeah... you are by now tired of first sentences that go something like, "I know it's been a while since I've posted, but blah blah blah." So we'll just dive right in.

First of all, Kansas won the Big 12 again. This is cool not just because it's incredibly rare for one team to win a power conference 11 times in a row, but also because it sets the stage for a Spinal Tap reference:

Eleven. Exactly. One louder.

Second of all, the conference was exceptionally tough this year; some number crunching indicates it was actually the toughest conference top to bottom. And that means the Big 12 tournament, which starts next week, will be unusually fun to watch. Just about every matchup either puts two ranked teams against each other or involves general bad blood.

I'm sure this, like all memories, has become a bit sepia-toned with age. But I remember getting into a game on an early day of the 1988 Big 8 tournament to watch Oklahoma (I remember because they had Skeeter Henry) play Colorado (I remember because they had, and still have, a buffalo mascot). My dad had gotten tickets. Kemper Arena smelled of sweat and popcorn. And cheering on two teams my 12-year-old self only vaguely cared about with my dad was... awesome.

Sadly, most of the games will be on at an hour that not even an unhappy Baby Blog would care to be awake at. I'll either be watching solo, or on time delay. Either way, I'm sure there will be a stream of text messages that will give me a pretty good idea of how things went. And then it's on to the NCAA tournament.

So here's to some great basketball. This has always been my favorite time of year for sports... even before Kansas' streak started.

Wednesday, December 24, 2014

It's Christmas Eve, babe...

... and as we all know, there is really only one place to be.

It has been a big year for the Blog family, and despite a lot of unpleasant news around the world, I feel like 2014 is ending on a good note. So, yeah: Happy Christmas (or whatever holiday you may celebrate), wherever you are. May your cars be big as bars, and your rivers be gold.

Thursday, December 4, 2014

To the stars, through a̶d̶v̶e̶r̶s̶i̶t̶y̶ budget cuts

A few hours from now, NASA is about to send a brand-new manned spacecraft called Orion into orbit. It's the first time this has happened since 1981, when NASA did this:

I remember watching this with my parents, excited but not fully realizing what a big deal it was (more specifically, I remember holding a plastic model with the vertical stabilizer broken off, sitting on the edge of my parents' bed in front of the TV). I was too young to feel nervous for the two guys strapped into Columbia's cockpit or to feel like there was even any chance of failure. The whole experience got me hooked on space, rockets, and space rockets--much in the same way, I'm sure, that others were mesmerized by Apollo 11.

Over the years, Space Shuttle launches became almost routine, but its first flight was a big moment for NASA. It was, essentially, a brand-new concept. And it was, literally, a manned test flight of a vehicle's maiden trip into space, something the organization had never done before and has never done since.

Indeed, Orion will carry all kinds of things--including a rubber ducky from Sesame Street and a T. rex fossil--but no astronauts. It will blast into high Earth orbit, circle the planet a couple of times, and splash down. The whole exercise will only last a few hours, but it's a huge deal because it marks the first tiny steps of much longer journeys. NASA has its sights set on a manned asteroid landing, and of course eventually Mars.

Neat, right? Everyone these days is focused on space as a source of resources, and that's important. It would be nice to be able to build things without destroying our planet looking for the raw materials. But it's much more important for us as a species to keep exploring, keep looking for questions to answer. Some of what we find might be practically useful, like new technology or materials. Other stuff might be bigger picture, like discovering extraterrestrial organisms. But regardless, it's not healthy for humans to just look around at where we are, shrug, and say, "eh--good enough."

(Orion is also a nice distraction from the awfulness of Ferguson, New York and Cleveland. And I don't just mean the killings or grand jury decisions--the way some have responded to the protests is beyond disheartening.)

So here's to a successful test flight. I hope by the time astronauts are using the craft, perhaps five years from now, Earth will be a better place than it is now, and we'll be well on our way to a new chapter of space exploration... and the Littlest Blog will get to watch astronauts walking on Mars.

Wednesday, October 29, 2014


Halloween is just around the corner, so it's time to look at a terrifying video. I call it "Day of the Looping J-31." Catchy, right?

(hat tip to Alert 5)

But let's be real. Like any horror movie, if you think about it too much, it stops being scary. The J-31 arrived in Zhuhai today, ostensibly in preparation for the airshow there, which starts on Nov. 11. The maneuver above, a half-Cuban 8, isn't particulalry arduous. It does not show off speed, maneuverability, and certainly not stealth--not that the Chinese military would be eager to put any of those things on display.

What I'm trying to say here is that the J-31 has been flying for a while now, but there remains no confirmable indication that, other than looking awesome, it or the larger J-20 can match or exceed the capabilities of other operational stealth aircraft. (Of which, to be fair, there are just two: the F-22 and F-35, with the retired F-117 flying around Nevada for who knows what reason).

What is "under the hood," specifically, remains questionable. Chinese engine technology is no great shakes, hindering not just military programs, but its commercial aviation industry. Less-obvious systems like low-probability-of-intercept radar, which allows a stealthy aircraft to track targets without its radar emissions giving away its position, are also tricky to develop. Without them or a robust airborne warning and control network, which China does not substantially have, a stealth aircraft's air-to-air capabilities are severely limited.

In the end, this video should be taken solely for what it is: neat footage of a neat-looking plane. It's not a milestone, and it's certainly not an indication of a closing technological gap... even with Jason Voorhees in the cockpit.

Wednesday, October 22, 2014

Shades of 1985

It's been a busy month. Mrs. Blog and I now have Little Blog; Hong Kong is (extremely politely) demonstrating in favor of full democracy; and of course the Royals are in the World Series.

I'm still figuring the first two out, but I have some experience with the third one. I was in grade school when the Royals played the Cardinals in 1985. At the time I didn't realize it would be the last time in a long time they would even get into the playoffs.

The aftermath looked a bit like this.

Now, 29 years later, they're back. My perspective this time around is a little different because instead of being a kid surrounded by revelry in my hometown, I'm an adult surrounded by a near-total lack of interest in baseball, 7,500 miles away from home.

My memories are a little sepia-toned, as childhood recollections tend to be. My classmates and I (and our teachers, who were no doubt more interested) watched one of the day games in the cafeteria. There was a parade on TV. George Brett was king of the universe.

I have less personal experience with this team--although I did get to a game last year!--and it's much harder to watch them play live, but it's still cool. They have a great story, of a good regular season and a sparkling (undefeated until today's game against the Giants, booooo) postseason. The style of baseball they play is genuinely interesting, with lots of incremental moves to gain advantage, and disruptive speed. Their bullpen is outstanding. Come to think of it, it's kind of like watching "Major League."

Anyway. Scenes like this are amazing to see, even from afar...

... and I hope that despite the lackluster Game 1, there will be more to come. After all, way back in 1985, when the Earth was still cooling, Kansas City lost its first game against the Cardinals.

And we all know how that turned out.