Just a quick note to let blog readers know that I’m a bit tied up with work right now and too busy to blog. So although you might find a few “Interesting Links” posts as I stumble across interesting things on the Web during my workday, it might be a few more days before you see a full-blown blog post from me. Bear with me; I have lots to say and just need the time to say it.
The media stumbles over a basic aerodynamic aspect of helicopter flight.
I was on Twitter Thursday evening when manp, one of my Twitter friends, tweeted:
So, what is this ‘vortex’ condition with ‘higher than expected temperatures’??? @mlanger any idea?
To be honest, I had no clue what he was talking about. But I Googled “vortex condition with higher than expected temperatures” (don’t you love Google?) and saw an article about the helicopter that went down during the Bin Laden assault in Pakistan. Moments later, manp sent me a link to a Bloomberg article titled “Helicopter Carrying SEALs Downed by Vortex, Not Mechanical Flaw or Gunfire.” The first paragraph read as follows:
A United Technologies Corp. (UTX) Black Hawk helicopter carrying U.S. Navy SEALs to Osama Bin Laden’s hideout was downed by an air vortex caused by unexpectedly warm air and the effect of a high wall surrounding the compound, not mechanical failure or gunfire, according to U.S. officials and a lawmaker.
Whoa. What a mishmash of information. You have to read further into the article where the phenomena they’re trying to explain — vortex ring state — is explained at least two more times by people who actually have a clue what it is. But that first paragraph sure is misleading. It makes it seem as if there was come kind of weird warm air vortex in the compound that brought the helicopter down.
Any vortexes, however, were caused by the helicopter itself. My educated guess of what happened, based on this article and knowledge of helicopter aerodynamics, is this:
As the helicopter was descending inside the 18-foot walls — a descent that was likely nearly vertical — it encountered a setting with power — or vortex ring state — condition. This occurs when the helicopter settles into its own downwash. This may have been made worse by the change in the flow of air due to those 18-foot walls — as suggested in the article. It may also have been made worse by the outside air temperature being warm.
This image from the FAA’s Rotorcraft Flying Handbook helps illustrated what the vortexes are and how they manifest themselves in a hover far above the ground and close to the ground:
As the Rotorcraft Flying Handbook explains:
Vortex ring state describes an aerodynamic condition where a helicopter may be in a vertical descent with up to maximum power applied, and little or no cyclic authority. The term “settling with power” comes from the fact that helicopter keeps settling even though full engine power is applied.
In a normal out-of-ground-effect hover, the helicopter is able to remain stationary by propelling a large mass of air down through the main rotor. Some of the air is recirculated near the tips of the blades, curling up from the bottom of the rotor system and rejoining the air entering the rotor from the top. This phenomenon is common to all airfoils and is known as tip vortices. Tip vortices consume engine power but produce no useful lift. As long as the tip vortices are small, their only effect is a small loss in rotor efficiency. However, when the helicopter begins to descend vertically, it settles into its own downwash, which greatly enlarges the tip vortices. In this vortex ring state, most of the power developed by the engine is wasted in accelerating the air in a doughnut pattern around the rotor.
In addition, the helicopter may descend at a rate that exceeds the normal downward induced-flow rate of the inner blade sections. As a result, the airflow of the inner blade sections is upward relative to the disc. This produces a secondary vortex ring in addition to the normal tip-vortices. The secondary vortex ring is generated about the point on the blade where the airflow changes from up to down. The result is an unsteady turbulent flow over a large area of the disc. Rotor efficiency is lost even though power is still being supplied from the engine.
There are three ways to recover from settling with power once you’re in it:
(They train us to recover from settling with power using a combination of the second two methods, but we always practice at altitude, since you can get a good descent rate going if you’re really into it. Indeed, settling with power is a serious danger during aerial photo missions requiring hovering at high density altitudes or heavy weights.)
So the pilot did the only thing he could: land hard. Fortunately, although his hard landing damaged the helicopter, it didn’t cause injuries to to men on board. They were able to complete their mission and come home safely. And they left a souvenir lawn ornament in Bin Laden’s yard.
I realize that this is a pretty complex topic and it’s probably not reasonable to expect the press to get it right. But I personally believe that all technical content published in the media should be reviewed by an expert — or at least someone knowledgeable — to make sure it’s not misleading or unclear to the layperson who will read it.
manp is a pilot — although not a helicopter pilot — and he couldn’t figure out what they were talking about. I can only imagine how much that opening paragraph confused the average reader.
Use less fuel.
Yesterday, during the brief time I was in the Jeep running errands in town, I caught part of an NPR interview with someone about the current fuel price situation. His take was that the fuel companies are gouging us — they’re obviously charging far more than it costs them to produce and deliver fuel.
My response to that: What the hell do you expect them to do?
As one of my least favorite presidents so accurately quipped years ago, “Americans are addicted to oil.” (That may have been one of the few truthful things he uttered during his eight years reign.)
I agree. We are addicted to oil.
Look at it this way: the oil companies are drug dealers. They hook us on their product by making it relatively affordable — the U.S. still pays far less for gas than Europe and most of the rest of the world. The car companies help the process by selling us vehicles that are impractical for most people but have lots of “style” or “status” — which insecure people apparently need. Cities like Phoenix and Los Angeles further encourage us with their urban sprawl and insufficient mass transit, forcing us to drive to work from our dream homes in distant subdivisions.
So we settle in, like junkies, burning our daily fix of fuel. We drive everywhere in vehicles that are far bigger and more costly to operate than we need: trucks and SUVs instead of more fuel efficient sedans. We live in the ‘burbs and commute, alone in our cars, to our workplaces, which are sometimes thirty miles away or more. We’re too lazy to walk anywhere — we’ll often drive across the street from one shopping center to another.
When we’re good and hooked, the prices start coming up.
Bravo, oil companies! You sure know how to work that bottom line!
In Wickenburg, I’ve been listening to people whining about fuel prices for the past ten years. They never seem to shut the hell up about it.
It’s the same complaint: local filling stations are gouging them on fuel prices. Wickenburg pays at least 10¢ more per gallon than they do in Phoenix. Funny thing is that these complaints are coming from the same people who think nothing of doing their grocery shopping down in Surprise, 35 miles away. So not only are they driving far more than they need to, but they’re likely buying their fuel where it’s cheaper anyway.
Still, they think our government should somehow intervene and cap fuel prices.
That’s the kicker. The same people who are complaining about fuel prices are the ones who voted in Republican congressmen and senators who are pro big business. The ones that are right behind tax breaks and other incentives for the oil companies. And they’re the same people who are saying we need smaller government and less regulation.
Guess what, folks? You can’t have it both ways.
I can’t complain about the fuel companies gouging us — which I agree that they probably are. Why can’t I complain? Because I recognize the right of a business to maximize its profit any way it legally can. If that means charging as much as the market will bear, so be it.
You see, there’s this little economic theory called Supply and Demand. As long as there’s demand for a product the provider of that product can charge as much as it wants — or as much as it can get away with. There comes a point, however, when the amount they charge is just too much and demand falls off. As supplies increase, prices go down.
This is basic economic theory.
So as long as we keep buying fuel, they’ll keep selling it to us at the highest prices they can squeeze out of us.
And I can’t fault them for that. We’ve made it possible for them to gouge us.
But we also have the power to make it stop.
Instead of complaining about it and carrying on like usual, do something about it. Want some ideas? Try these:
These are just a few basic ideas. Surely you can think of more.
And before you start spouting excuses why you can’t do any of these things, why not do a little research to see if you can?
And instead of complaining about the problem, why not be part of the solution?
Remember, the reason they’re gouging us with fuel prices is because they can. We have empowered them. The solution is not government regulation. It’s consumer lifestyle change. When they start to see consumption go down, they’ll know our addiction is faltering. Their logical course of action is to drop prices to get the hook in a little deeper again.
It’s happened before; it’ll happen again. Why not give it a try and see?
Are you as frustrated as I am about Web sites relying on Flash?
I need to share a little rant here.
Until recently, I never realized how many Web sites are built around Flash. I’m not talking about sites that include Flash animations here and there. I’m talking about sites completely contained in a Flash animation.
Like this monstrosity: http://www.stingraysushi.com/
Stingray Sushi is a restaurant. Its site includes a menu, which can only be viewed in that Flash animation.
Now I don’t know about you, but sometimes I look for a restaurant when I’m on the go. I’ll whip out my iPhone or iPad, open the Maps app, and search for restaurant. Or I’ll use the Safari browser to Google a specific restaurant. Either way, my goal is to see the Home page for the restaurant so I can learn more about it and the food it serves before I drive/walk over. To do that, I need to be able to see the Home page or, at least, a menu.
Unfortunately (or perhaps fortunately), I’ll never be able to see the Home page for Stingray Sushi on my iPhone or iPad.
Now you might want to blame Apple for this. After all, it’s Apple that decided that it won’t support Flash.
But I blame the Web developer. Apple mobile devices, including the iPhone and iPad, have been available for nearly four years. Apple is currently the fourth largest seller of mobile phones, with millions of iPhones out in the wild. Apple is also the top seller of tablet computers, with millions of iPads out in the wild. Developers who continue to base entire sites on Flash are basically thumbing their noses at iPhone/iPad users, telling them that they simply aren’t important enough to view the oh-so-valuable Flash content on their Web sites.
I have two words for these developers, and they’re not “thank you.”
So when I reach a site I can’t view on my device — whatever that device is — do you think I’ll visit that business?
Do you think that I’m interested in rewarding a business for the frustration their Flash-based site has generated by actually buying something there?
There are alternatives to Flash. Many alternatives. HTML 5 is one of them. But apparently, Web developers would rather lean on a crutch like Flash than move forward with new, more compatible technology.
Why does this continue to be an issue?
Just say no to Flash.
How many times has something like this happened to you?
By now, most of us who participate in social networking — Twitter, Facebook, Foursquare, etc. — know firsthand how social networking can absolutely destroy productivity. The rest of us with Internet connections can see how having an email client or Web browser open at our desks can seriously reduce productivity. But have you ever stopped to consider how the computer applications we actually use to get our work done hurt our productivity?
For an example of this, I can draw upon something that happened to me last week.
I manage a number of WordPress-based Web sites, including one for N&W Associates, which sells helicopter ground handling solutions. N&W is owned and operated by Walter, who is an older gentleman who builds wheels and tow bars from scratch in his workshop. He’s a very nice man but not exactly computer literate, so I manage every aspect of the site for him. Every once in a while, he sends me some new material for the site and I put it online.
About a month ago, I completed my move of all sites I manage from GoDaddy hosting (good riddance!) to Bluehost. N&W was one of the last sites I moved. After moving it, I tested it and it worked fine.
Last week, Walter sent me an email message asking if I’d add mention of R66 helicopters, since their skid configuration is the same as R44 helicopters, thus making his equipment compatible. No problem, I said. It was an easy fix. His site only has about 6 pages so adding references to the R66 should take about 10 minutes tops. I told him I’d do it right away.
And I did. Or at least I tried to.
Trouble is, when I went to log into WordPress on his site, I couldn’t log in. No error message — instead, the login screen kept reappearing, as if I hadn’t even tried to log in.
For about 10 minutes, I tried multiple password combinations. No luck.
For about 5 minutes, I used FTP software to examine the settings files for a password and tried that password. No luck.
For about 20 minutes, I researched the password problem on WordPress’s Support site.
For another 20 minutes, I tried three different techniques to reset the password. No luck.
For about 20 minutes, I researched the login problem on forums on WordPress’s Support site.
For another 15 minutes, I tried both of the solutions people in the forums claimed would work for them. No luck.
For 10 minutes, I went back to the WordPress support forums using a variety of different search phrases. In one forum post, someone mentioned, in passing, the .htaccess file. A lightbulb went off in my head.
For 5 minutes, I used a text editor to open the .htaccess file I’d created for N&W. There was some code I’d included that would automatically rewrite the site’s URL to www.helicopterwheels.com (in the address bar and site logs) no matter how the domain was reached. I pulled out those four lines of code, saved the file, and tried logging in.
It worked.
For those of you who care about the problem, here are the details. The N&W site can be reached through two domain names: helicopterwheels.com and r22bigwheels.com. When I moved the site, to ensure continuity during the move, I moved it using the r22bigwheels.com domain. That’s the domain that was set up in WordPress’s General settings for the moved site. I used DNS on Bluehost to point both domains to the same folder containing the site files and it worked fine. Trouble is, when I tried to log in as an administrator, WordPress wanted to give me administrative access on R22bigwheels.com but the .htaccess file kept directing it to helicopterwheels.com. I’d created a loop. Once I logged in, I changed General settings to www.helicopterwheels.com, saved them, and restored the lines of code I’d temporarily removed from .htaccess. It worked the way it was supposed to do.
That little fix took another 5 minutes.
So if you add up all the time I spent on this “10-minute” edit, you’ll see that I lost an hour and 40 minutes of my day.
I can’t blame the computer, of course. And I can’t blame WordPress. It was my configuration error that had caused the problem. But placing blame isn’t the point of this post. The point is, we rely on computers to make us more productive and get tasks done quickly and efficiently. But all too often, it’s computer problems that slow us down.
The problem could be something technical like this. Or it could be a computer malfunction, such as a bad hard disk or software bug. Or it could be the simple fact that we don’t know exactly how to perform a task and have to learn how to do it before we can get it done.
I’m not suggesting here that we work without computers. But I am suggesting that we keep in mind that the more we rely on computers, the more we’re setting ourselves up for the possibility of getting less work done.
And I’m also suggesting that we try hard to keep things simple. If I didn’t put that fancy code in N&W’s .htaccess file, I wouldn’t have lost an hour and 40 minutes of my day to troubleshooting.
Got examples of how your computer cost you time? Share them in the comments!
In addition, the helicopter may descend at a rate that exceeds the normal downward induced-flow rate of the inner blade sections. As a result, the airflow of the inner blade sections is upward relative to the disc. This produces a secondary vortex ring in addition to the normal tip-vortices. The secondary vortex ring is generated about the point on the blade where the airflow changes from up to down. The result is an unsteady turbulent flow over a large area of the disc. Rotor efficiency is lost even though power is still being supplied from the engine.