October 29, 2005

Back Home






After finishing priming the fusalage this week, today was the big day to move the fusalage back into the house. Took a little wrestling. I've removed the sliding doors enough times now that I have that part of the procedure more or less down pat.

The trick we used this time was to drag it backwards up the slope to the opening and then place my small rivet cart under the rear spar bulkhead area of the fusalage. Then Cathy got the chore of weighing the tail down to lift the nose area so we could remove the gear and scoot it back into the room. Only hitch was we couldn't quite get enough lift to remove the main gear... So, a little mule lifting on my part under the fusalage and voila... We had the gear off.

Once it was back into the room we had to get a little extra lift again with the ol' thighs to get that little extra to insert the gear into their respective tubes. In any event, the fusalage is back in the house for the winter and sitting securely on a pair of steel saw horses.

October 28, 2005

Bush Plane








One of the advantages of being newsletter editor is the opportunity to visit other chapter members' projects, like Dave Bridgham's shop where he is working a bush plane comparable to the Murphy line of bushplanes... Sort of an affordable version of a Beaver.

From the looks of the welded steel fusalage it will be as strong as an ox! Some of the features include use of spades rather than a conventional aerodynamic counter balance on the elevator to avoid the possibility of getting a jammed up elevator condition from twigs etc. in the rough terrain bush planes inhabit.

The floor tube structure of the fusalage is even trussed so this brute can handle some real loads... Dressed bull moose? Anyhow, Dave has a beutiful shop this looks to be a very interesting project to follow for the newsletter.

October 27, 2005

Flight Resources






Had a chance to get together with our EAA Chapter's flight advisor Dino Vlahakis, pictured here with his beutiful Stearman. The irony, the photo is taken at Lebanon Airport (KLEB) in New Hampshire, and Dino is an international captain veteran with time logged flying into Bierut.... aka Bierut, Lebanon.

One of the things we are hoping to take advantage of is Lebanon Airport, because it has a tower, long, and wide, paved runways, and people like Dino in the chapter, who have been through the aircraft birthing process.

Meanwhile, back at the ranch: Put a the crosscoat of primer on the fusalage and when I was finished it was the end of my gallon of Dupont Corlar fleet grade primer. If things go well, we will have the bird back in it's nest for winter tomorrow afternoon or Sunday.

October 26, 2005

Making Power






It took til about 2:30 this afternoon to get power... for 45 minutes then kaput! ...By then I had the fusalage taped off for priming, and I figured, "Phooey on the electric co-op, I'll just run the generator."

About midway through priming, it looked like the local area was back on the grid so I could turn off the generator. Man do those things make a lot of noise!... I'll double check the results Thursday to see if I need any touching up on the priming. Otherwise, I'll let it cure through the weekend and then it back into the nest for winter.

October 25, 2005

Storm System






Cruising along alodining the fusalage, and I kept thinking, "Boy, the Wilma storm system is moving up the coast fast... Gee, that rain looks awful white." Got the fusalage alodined and then about 3:30 pm... ZAP! ...No power for like 23 hours ...Grr!

Oh well, nice opportunity to drink beer and play cards by the light of my ancient anchor light. Lately it seems like if two chipmunks get in a fist fight the power goes off! Come on boys, chainsaws are for clearing trees from around and about them power lines... Seriously, I'm begining to to think those power grid yahoos are just doing chicken and turning the power off. I'll be darned if I could find anything wrong with the power lines in Canaan.

October 24, 2005

Lake RV-7




Fun upside down today scotchbriting the underside of the fusalage. Acid etched the skins. Tried using the sponge and bucket of water routine to clean the skins after etching. Finally threw in the towel... literally... and got the hose out to rinse everything off. Next stop, Alodine, Step B.

October 23, 2005

Heel Hook






One thing I've always hated about working on cars is the issue of working upside down under the dash, etc. with your head held up. Makes for some interesting sore muscles the next morning! As a countebalance device, I found that hooking my foot over the saw horse seemed to eliminate the neck strain while running the drill motor to scotchbrite the fusalage bottom skins on the tail cone.

Hopefully I can finish the initial scotchbriting work on the fusalage tomorrow and then go on to acid etch and alodine the skins for priming. Then maybe we will have the fusalage primered and back home in the back room by November first. We'll see...

October 22, 2005

Prime Finish






I started scotchbriting the fusalage friday, this should take a couple of days work through alodinining the skins. It took about a half day + to prime the other wing and after it cured somewhat I moved it to the house. I had to close off the back room as the solvent evaporation was getting a bit much, and I didn't think my mother in law would appreciate the cheap high her cockatiel was getting off the fumes...

I'll prime, if I can, the fusalage in the garage, sans the paint booth which I disassembled to make for some turn around space, so I could get the Elantra station wagon to pass inspection this year. Boy, with that paint booth out of there the garage is starting to look cavernous. Looks like a lot of rain coming our way, so I'll use the time to work on prepping the skins of the fusalage. If I can get the fusalage primed and back in the house before the snow flies hard we'll declare it a successful season.

October 21, 2005

Wing Prep




Friday we managed to get the wing scotchbrited, acid etched, and alodined in preperation for priming. ...Ya know, the water off the hose is a tad cold this time of year!

October 20, 2005

Heading Home

10-20a



Priming the wing takes a while! ...Like half a day. Starting to migrate the various pieces back into the house for winter. I have worked it out so I can put the wings, fusalage and empenage assembly parts all in the back room and still work on the fusalage innards. That, or the dining room is going to get stuck with the wings again!

But since pretty much all the fabrication and installation on the airframe proper is pretty much done, it's internal wiring and firewall forward on the fusalage. I am going to try to get the fusalage back in there and put it back on it's main gear so I can finish the gear leg details, like the brake lines, in the comfort of the house this winter.

October 19, 2005

Wing Saga






Scoped out putting the wing tip on and decided against it for now, I'll do it during the winter in the house. Finished the platenut detailing for the wing root fairing, and acid etched and alodined the skins. In the evening, Cathy and I finished the grouting on the floor so we could start moving things back in for winter.

On the uNav front, I got the source codes for the stargate computer compiler on my Linux box and now I can run the uNav data through the serial port and have the software do the filtering to product the AHRS results, i.e. the pitch, roll and yaw angles, altitude, speed, latitude and longitude. Now to dig up a laptop, or it's going to look kind of funny with with my Samsung monitor in the back seat of the Oldsmobile for testing!

I figure to run the device in the station wagon I'll have to put it on a cardboard box to keep it away from all the iron! The magnetometers are sensitive, as demonstrated quite easily with a screwdriver placed a few inches from the device.

October 11, 2005

Hard Drive




A simple little power failure, sometime after midnight, just after I had published my EAA Chapter's newsletter, and when the power came back on Linux would not boot and I got a nasty surprise to see the words "Kernel Panic!" as the last words on the monitor.

It took from the wee hours of last Thursday morning until about 3 o'clock yesterday afternoon to get the drive put back together and running again. For those who may run into this little disaster, here's a run down of what seems to have happened and how it got fixed:

Apparently from the power failure the superblock on the drive became corrupted, and accordingly Linux, would not mount it. But it gets a little more complicated. The system under Fedora Core 3 was set up with the Logical Volume Management (LVM2) disk management system. Under this approach the boot sector is on an Ext3 partition and the root "/" and swap partititions are logical volumes in a LVM2 partition. It took a while for that to sink in, particularly after repeated attempts run dumpe2fs to find the backup superblocks failed using the hardware mount points.

After I could not get a rescue disk to mount the drive I took a new 120gb drive and built a Fedora Core 3 system from scratch and dug out the source codes for the file system utilities. After some snooping around I started modifying a hack routine called "findsuper.c" to raw read the device and see what was on it. The boot partition looked fine, when I dumped some of the second partition to disk and looked it with a binary editor I got a nasty surprise when I went to where the superblock on an ext3 system should be. I found the text reference for the LVM partition. The real meanng of my fdisk checks on the disk now dawned me!

I didn't have very good tools for LVM under Core 3 so I bought the book on Core 4 and built a core 4 system from scratch on the 120gb drive. I got a little smarter (this is key!) when I built the core 4 system. I explicitly named the LVM components differently then the Core 4 defaults. This was necessary because if I didn't I never would get Core 4 to see the defective drive's LVM structure because it would have the same identifiers. With this construction I could then use the LVM gui to find the mount point which would now be under /dev/VolGroup00/LogVol00. I also installed Core 3 on a small, otherwise useless 5gb drive. With the little drive for testing I could now mount it's root partition at /dev/VolGroup00/LogVol00 and run dumpe2fs to get a report on the structure of the drive and where the backup superblocks where.

Armed with that info I started dumping sections of the drive to disk for snooping with the binary editor to make sure our understanding of how ext3 was structured jived with reality. Headway there, now it was time to try the bad drive.

Dumpe2fs would not work on the bad drive, but now debugfs would if you mounted it read only and with the catastrophic option (-c) turned on. I though, well, here goes nothing... Lets just run the "ls" command to see if we can read a directory... Voila!... or "Balok" in Lord of the Rings parlance ...We could read the drive root directory. That 5gb drive key to figuring out how to run debugfs and get it to mount the drive. From the little drive I could see that Linux sets the block size at 4096. And from that 5gb drive I got the backup superblock address. The boot sector block size is 1024, the root partition is 4096 and the difference is very important.

Anyhow, you have to run debugfs with both the blocksize and the backup superblock address specified. That done, I was able to start dumping directories onto the new Core 4 drive. After pulling off every key thing I could think of (including the 10+gb flightgear terrain, my nasa shuttle radar altimeter database etc.) I was now ready to take the plunge and run e2fsck on the sick drive to try to repair it. It took a couple of e2fsck runs with different settings and about 5 or six hours but finally, the drive passed systems tests with a clean bill of health and would boot. This email was generated from the system running with the fixed drive.

Gee, now that... That killed a week. I can hopefully go back to looking at the uNav, but first I've got to get some priming done before winter and there is still some firewood to rustle up... The fox picture is of a young one that keeps dropping by for a visit and taking a nap out in the open in the back yard.

October 02, 2005

Communications






Solved my little communications protocol problem to talk and listen to the uNav sensor from a Linux box courtesy of some help from my ISP John Babiarz.

Crossbow doesn't provide datalogging source codes for the uNav so I'm taking the data log code for one of their other navigation sensors to write one from scratch. With that alligator skinned, I've still been pushing to get things primed before winter.

Finished fitting and drilling the wing root fairing. Also double checked the motion limits on the elevator and rudder per Van's specs. With that done, it was time to take the empenage apart and put everything back onto the storage cart. With the wing root fairing drilling completed we next took the temporary pins out and removed the wings. I'll next fit the wing tips to the wings and take the fuel tanks off to test them. If all goes well, I can then prime the wings, put them back on the storage cart, and prep and prime the fusalage.

I want to get the hardware processed before the weather runs out on me. I figure in the dark days of winter I can take my time working on the software/hardware to get the synthetic vision system up and running. I figure I'll test the system using the station wagon initially, then use a laptop to run some tests in a rented Cessna.