With Wings As Eagles: Craig P. Steffen's Blog

back up more often

2007 February 22 23:42

After 7 months of living here, I finally have a computer set up in the basement to do basic utility things like burn DVDs and back up files:

The thing sitting on top of the tower case is my Sharp MM-20 laptop in its backup/configuration cradle:

When you turn the cradle on, the laptop's hard drive appears to the host computer like a USB storage device. It makes up for the fact that the MM-20 doesn't have an optical drive. During the process of pulling all the files off the laptop to be burned on disks, I was appalled to realized that I haven't really backed up in a year. That's really quite bad, I know better.

The machine I'm using to do the backups was one that I bought just before leaving Champaign, and so I'm running Knoppix on it. Knoppix is a Linux distribution that runs purely off of a CD. IN other words, you can run it on a machine without installing or altering the contents of the hard drives at all. There are things that I like to tweak about an installation and so it's unlikely that I'd ever go entirely to that for my desktop needs, but it comes loaded with almost all the software that you could think of to include, and so it's a really useful tool. When I've had an install fail for some reason, Knoppix enabled me to get back running without having to resort to going to a Windows machine and getting new install media set up. After pulling a year's worth of photos off my laptop hard drive, I burned them to DVD+R disks using their nifty graphical CD burner application:

So, the moral of the story today: back up often, and a Knoppix CD is a really great tool in a pinch...or any other time.

the matrix is everywhere

2007 February 22 09:41

Role-playing game often have complex hierarchies of skills that characters can acquire. Documentation of those skills are often in the form of a "skills matrix", which shows which skills are pre-requisites for others and generally which order they are acquired. I've often thought what a "skills matrix" for FAA pilot ratings would look like. I have posted a first stab at it.

Many of the ratings are not strictly sequential, but I think it's a reasonable representation. I've marked the rating that I'm working on and ratings that I might work on in the future.


2007 February 17 18:25

These are quoted from Federal Aviation Regulations section 1.1:

Category: (1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a broad classification of aircraft. Examples include: airplane; rotorcraft; glider; and lighter-than-air; and (2) As used with respect to the certification of aircraft, means a grouping of aircraft based upon intended use or operating limitations. Examples include: transport, normal, utility, acrobatic, limited, restricted, and provisional.

Class: (1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a classification of aircraft within a category having similar operating characteristics. Examples include: single engine; multiengine; land; water; gyroplane; helicopter; airship; and free balloon; and (2) As used with respect to the certification of aircraft, means a broad grouping of aircraft having similar characteristics of propulsion, flight, or landing. Examples include: airplane; rotorcraft; glider; balloon; landplane; and seaplane.

Regulations, by their nature, are over-precise and overexplanatory. I'm bringing up these two because they are at the core of a lot of FAA regulations, and because there's an inherent contradiction in them. "Airplane" is a category with respect with pilot certification, but a "class" with respect to aircraft. This just one of those things you have to learn to be a pilot.

Starting to study for the FAA written, can you tell? :-)

spins, measures, cuts...paper strips

2007 February 11 08:11

A lot of the pilots that I talk to consider air traffic control an unwelcome intrusion on their flying time. They intellectually understand that airliners need ATC to fly safely, but would just as soon never have to deal with it themselves. Filing flight plans is something that a lot of pilots just don't do because it's not required. So far in my flight training, I have always filed for cross-country's, and I can't see changing that. It's nice to have the thought that someone will come looking for me eventually if I don't show up at my destination.

I think that ATC is kind of a neat idea. I've been studying the communications aspect of ATC for quite some time. However, I was reading Avoiding Common Pilot Errors: An Air Traffic Controller's View and chapter 4 has an interesting discussion of flight progress strips (Wikipedia, howstuffworks, FAA), which are paper strips that controllers use to keep track of information about an aircraft that's on their screen. (They are part informational printout, part note paper, and part legal document. Their use is portrayed, I think fairly authentically, in the movie Pushing Tin.) You can see flight progress strips in use on this page. Note that each strip represents an aircraft in flight. This Isle of Man airport page has an example of how the strips are used to visually indicate where aircraft are located. Luxembourg ATC has a page with lots of photos of progress strips and other related items.

The point the book brings up is that filing a flight plan is how information gets into the air traffic computer system about your flight. If you file a flight plan, controllers in facilities along the way have a computer-printed flight progress strip pre-printed with all your initial information. They only have to note changes to your status or instructions they've given you. If they don't have a printed progress strip, some controller has to tie up a frequency to get the information from you and write it down.

I actually saw progress strips in use when I paid a visit to the Rockford tower in early 2006. The local controller(s) (radio callsign "tower") and ground controller(s) are on the top floor of the tower building with windows on all sides. The approach and departure controllers are on the next floor down, in windowless rooms with big radar displays. I was very amused to observe the hand-off procedure for a departing flight. When the flight was exiting the local controller's area of juristiction, the controller made a radio hand-off, and then dropped the flight progress strip (attached to it's plastic carrier) down a tube which leads to the desk of one of the controllers in the room below. Efficient in use, but crude in implementation.

As far as the book Avoiding Common Pilot Errors: I think it's an interesting read, and I would commend it to anyone who is at all interested in the technical aspects of flying, with the following proviso: It was written in 1989, so a lot of the concepts are conceptually useful, but not specifically. I really wish there was a newer edition.

watch the fine DVD

2007 February 09 07:44

Working on my beetle has been assisted by having several different manuals around, including the Muir book. I discovered another really great resource lately at "Bug Me Video".

The site has a whole series of videos (offered on DVD or VHS) on maintenance and repair of Volkswagens. I currently just have #1, General Maintenance. Since at some point, I need to take work on the brakes of my car, I will probably get the brake video, and probably the ones on wiring too.

It's not that anything in them is particularly profound, but since I've really never working on a car before, it's extremely valuable to me to have seen it done, even on video. It's all well and good to read the description of setting the timing, but seeing it done makes it much more clear, and will be very useful when I go to do it myself.

make sure your connectors are clean and tight

2007 February 07 22:19

I had an annoying and mysterious problem with my Volkswagen that I just solved last weekend. It's one of those things that my theories got very complicated because I hadn't checked the basics.

The symptoms were that the right brake light was significantly brighter than the left and when the brakes were pressed, the speedometer and the front fender lights came on dimly (like the running lights were on but at a low voltage). I tested where voltages were going, first with the bulbs in and then with the bulbs out. I got all kinds of wierd results, and I couldn't figure out anything conclusive.

The bulb for the tail/brake lights has dual filaments:
It's called a 5 and 21 watt bulb. The dimmer filament is for the tail lights, the brighter one is for the brake lights. The base of the bulb looks like this:
There are two studs at the base of the bulb, one for each filament, and the barrel is the common ground. The bulbs fit into a socket that has two contacts at the back, one for each stud:
I think the problem that existed was that one of the studs on the left bulb had become corroded, and so it wasn't making good contact with its contact. The former owner tried to get it to work, and in the process, got the bulb jammed into the socket sort of sideways so that the stud for the tail light was touching both of the contacts. That would mean that the tail lights would work as normal. When the brake light circuit was engergized, the tail light filament lit up (thus creating a dim brake light), and it also transferred some of the current to the running light circuit, lighting up the speedometer light and the fender lights.

The rule that I forgot was when you have an electrical problem, always make sure your connections are clean and tight. I didn't do that, and I ran around looking for wierd things in the wiring. Notice in the photo above of the base of the bulbs, the studs on the bulb on the left are all shiny, but the other bulb is only shiny where it rubs on the contacts. Well, I took some fine grit sandpaper, sanded off the studs on the (formerly non-working) left bulb, and put the bulbs in, and now they work just fine. Both brake lights are now significantly brighter than the tail lights, and the speedometer light and front fender lights don't light up when I push on the brakes.

a long, leisurely drive

2007 February 07 09:15

I picked up the paperback Roving Mars last weekend, and I ended up reading it in less than 24 hours. The book talks about the current two-rover exploration mission to Mars that was launched in the summer of 2003 and reached Mars in early 2004. The mission was conservatively specced for 90 days, but the twin rovers, Spirit and Opportunity, are still going three years later. It's written by Stephen Squyres, the PI for the science part of the mission, who is an astronomy professor at Cornell.

If you're interested in space exploration at all, run, don't walk, and pick up this book. But don't start reading it until you have several hours to dedicate to it. The only drawback of the book is that it was written in late 2005, so the book only covers the first 1/2 of the missions so far. I hope that sometime this year he writes another one with more updates.

There is, apparently, an IMAX film about the rovers that was circulating at the time the book was released. I can't seem to find any reference to it currently, though.


2007 February 06 00:16

Changing the oil. People do it to their cars all the time. It's not rocket science; I ought to be able to do it.

So...this evening, I went to change the oil in the beetle. My first time doing that on any car. I got the oil out fine. Then when I went to put the oil drain plug back in the plate, I stripped it, even though I still wasn't at the specified torque. Argh! So I just ordered a super-duper drain plate, so I should have the car running again by the end of the week.

With the cold weather, I didn't want to leave the crankcase open to the air, so I put in the plate and put in one quart of oil, then closed up the crankcase. The seal around the drain plate seems Ok, but the drain bolt is dripping oil a little:

Now I realize that some people probably assume that all Beetles drip a little all the time...but I'm going to do my best to make mine not do that at all.

of COURSE it's an AND-gate

2007 February 03 06:46

I thought about a game I've not thought about in ages yesterday, called Robot Odyssey. It was a game I had for my Tandy 1000 EX made by the Learning Company. It was a very involved puzzle game where the central theme was circuit logic. You had three (later four) robots (moving boxes) that you wired to do certain things in the game, like retrive objects or push buttons to open doors. I played the game through a couple of times in junior high and high school, and so learning a bunch of basic circuit logic stuff. To the point that when I got to electronics class my junior year at Gustavus, I already knew the basic symbols of circuit logic and the basics of how to use them.

Some links for Robot Odyssey, past and present:

I played this game...well, an apallingly long time ago, during my formative years. It was a lot of fun, and I learned stuff, but I don't think I can underestimate its effect on my personality. It, along with Starflight, were very important in training me to be able to take on long tasks and persevere to the end.

I recently started to get enough furniture in the basement that I can start to set up some of my vintage computers. When I've set up the Tandy, I will see about getting some screen shots of Robot Odyssey.

if you don't know who the sucker is...

2007 February 02 22:31

Bloggers! I'm passing on a request from Neil Gaiman. Please help play a trick on his friend Penn Jillette by following the instructions at the bottom of this post in Neil's blog.

Thanks, and have a great weekend!