I’m still trying to find a way to deal with the problem of assigning Canadian waypoints to their correct province. The first thing I did was grab George Plews Airports In Canada data file, which as well as giving me hundreds of new airports that I didn’t have already, also made sure that all my airports were in the right province. But I’ve still got problems.
Continue reading ‘There’s no such thing as a perfect solution’ »
Archive for the ‘Flying’ Category
My favourite airplane, our club’s Piper Lance, is up for sale on eBay Motors:
Personally I think the reserve is too high, but I think they’re just trying to find out what the market will really bear. It looks like the only bidders so far are dealers bidding less than half what it’s really worth, looking for a totally desperate seller, and we’re not there yet.
But the plane’s annual is due in December, and we were told last year that the engine probably won’t pass another annual, and there just aren’t enough club members willing to pay the surcharge to justify spending the money for an engine and prop overhaul. So this plane is going to get sold, somehow.
So good bye, old friend. I’ll miss your speed, your load capacity, and your outstanding interior room. But mostly I’ll miss the fact that it felt like a good solid honest plane.
Well, it didn’t start off promising because I woke up in the middle of the night with an upset stomach and spasming back muscles. But we got home fairly uneventfully. And I even got to fly a bit of an ILS in IMC. Not well, but I did.
Continue reading ‘Flight home’ »
We flew the Lance to Pittsburgh last night. It was glorious.
Continue reading ‘Through footless halls of air’ »
It’s been a beautiful weekend, so I decided this afternoon to go out and fly a bit just to keep my hand in.
Continue reading ‘First you work, then you play’ »
Is it really too much to ask that when somebody uses the contact email address on a web site to expect that they’ve actually read at least the first page of that web site? I just got an email to the address that is published on the Rochester Flying Club web site that asked a bunch of questions that prove categorically that the sender had not read the first page of the site, specifically the part that says “It is not a flying school, although we welcome student pilots”.
His second question was “Is Rochester Flying Club just a Pilot School, or it is a college too?”. Which part of “It is not a flying school” are you having trouble understanding there, sport? His other questions are just as oriented towards a full time flying school.
One thing that’s unusual, though. Normally I get these sorts of clueless emails from people in India or Pakistan - and indeed I found our club web site linked from an Indian site that claimed to be a list of flying schools in the US, but this time the guy claims to live in Rochester, although from his wording I’m not so sure. “I live in Rochester, NY which is 14 miles away from 1313 Scottsville Rd, Rochester, NY.” Doesn’t that sound like somebody who plugged two addresses into Google in order to provide some fake verisimilitude? Although I have trouble thinking of a part of Rochester that’s 14 miles away from the airport.
I made some changes to my FAA data loader script and ran it. Four days later it had finished running, I discovered a few bugs, and was getting ready to run it again, but I decided to see if I could improve the speed any. I’d already run the perl profiler and discovered that 95% of the time was spent in mysql. So I tried doing an “EXPLAIN” on all the queries. That’s when I discovered that one very common query was doing the dreaded “ALL” query on a 12,000 row table as step 1. Hmmm. That table isn’t even an important one, it was just table joined to the main “waypoint” table to get one field that was semi-useful. The query has a “waypoint.datasource_key = ?” in it, why isn’t it doing that first? “DESCRIBE TABLE waypoint;” showed me the error of my ways - I’d forgotten to put an index on “datasource_key”.
So I created the index and started the script before going to bed. I was astonished to discover that the script was done this morning. According to my Munin graphs, it had only taken about 6 hours to run. 96 hours down to 6 hours. Yeah, that’s a worthwhile optimization.
Discovered while trying to debug my nav data loading scripts: The Hendersonville Airport (0A7) and the “W.N.C. Museum Airport” (8NC9) are only 0.03 nautical miles apart, but they’re separate airports. I’m not sure if they’re the closest two ever, but they’re certainly pretty damn close. As a matter of fact, I think this picture 
from the AirNav.com web site listing for Hendersonville shows both runways, the paved one for Hendersonville and the turf one for the museum. I bet there is a story why they didn’t just build a taxiway between them and call it one airport.
The founder of the flying club is not the sharpest knife in the drawer when it comes to using technology. He just sent an email to the entire club with the subject line “Advertising” and the text “$82,000″ followed by his name and a AOL banner. Now, unlike most of the club, I know he’s involved in trying to sell the club’s Lance, so I have a bare inkling of what he might possibly mean, but even I’m scratching my head wondering what the fuck he’s talking about. I wonder if that’s his asking price or an offer we’ve received or the reserve he’s going to eBay it under or what.
Personally, I think that there’s no way in hell we’ll get $82K for a 1977 Lance with a clapped out engine (2480 hours+) and prop and ancient avionics. But I suppose one can live in hope. Looking at Trade-a-Plane I can see a 1976 Lance with less TTAF (Total Time on Airframe) with only 875 hours on the engine and prop, and they’re asking $80K.
The mission was to get two planes back from Batavia, one of which was the Lance. We tried on Friday and Saturday and Sunday, but the weather didn’t cooperate. The weather was fine today, but only two of us could make it, so we only managed to bring back the Lance.
Continue reading ‘“Anticipated Separation”? I don’t like it.’ »
Ok, the big load job just finished, and it appears I was loading the old FAA data, not the data that became current on Wednesday. Also, it appears I have a bug in the code that loads the runways - the old scripts seemed to have taken “U” or “” for the runway end latitudes and longitudes as null, but the new ones are putting those values in as 0. Oops.
I guess I’ll have to run it again - using nohup this time. See you next week.
I took the Lance over to Batavia for service. It was only supposed to take a couple of hours, and I’d be back at work before 11:00. Of course, it didn’t work out that way.
Continue reading ‘A day well wasted’ »
I made some major changes to the way data gets loaded into my navaid.com waypoint generator database, mostly in the processing of the “combined user data”. Mostly, I wanted to make sure that if “Bob” provides me some data on Canadian airfields that includes communications frequencies but no runway data that it doesn’t wipe out the runway data from the dataset of Ontario airfields that “Alice” provided me last year, but only updates the data that has changed in the overlapping part of those two datasets. Add in the possibility that a waypoint might have changed identifier or been resurveyed so the location has changed a bit, and you can see that there are a lot of possibilities to consider.
Unfortunately, considering all these possibilities is time consuming. I’ve been testing these new scripts with a dataset from one person that covers the entire UK and some nearby locations in varying levels of detail, and another that covers Ireland in great detail, but which is unfortunately no longer being updated because the person who provided it moved. Running both datasets would be an overnight job. But now that I’m satisfied with the results of that, I decided it was time to reload the old DAFIF data though these scripts to get the combined user data exactly the way I want it. But this has caught a couple of bugs in the scripts, one of which only manifested itself after 36 hours or so of running. That one didn’t even give me enough information as to why it failed, so I had to add some “use Carp” and “use Data::Dumper” magic to my scripts and then I re-ran it and found the actual cause after another 36 hour run. I’ve been almost continually running load scripts all week. I’m hoping this run will be it, but I’m not sure.
Since my new home box is so fast, I’m thinking one possibility might be to do the load processing on it, and then just mysqldump it and bring the dump file up to the colo.
Thanks to a post by Skud, I’ve discovered Freebase, which is, as Skud described it, “crack for information nerds”. It appears to be exactly what I was hoping to develop or find for my aviation navigation data project - a flexible structured information agregator, almost like a wiki with user definable fields.
You probably can’t see much of it, because right now it’s in alpha and by invitation only, but so far they’ve imported all of Wikipedia and added some links between then, and people have written some demo applications.
Like many AJAX applications, it has a tendency to get the dreaded “a script on this page is running slowly”, but otherwise it’s pretty nifty.
A couple of months ago I was so happy when my friend Mike took me out flying in his float plane, as I wrote in Rants and Revelations » Splashy fun.
Today, Mike and his flying partner Dave crashed that plane and died.
This sucks.
