Details
Hits: 3017

I got home last night after two weeks on the road doing Enhanced Vision System testing. We had at least three "authorities" pilots on each trip, and we rotated through the left seat. So, I had a fair bit of time riding around in the back of the test aircraft. I took my laptop along, and managed to find a fair bit of time to finish off the Perl script to record flight test data from the Grand Rapids EIS-4000 engine monitor.

Grand Rapids will provide a DOS program to record data, upon request. That program works well, but it only runs in DOS, it writes every parametre to disk once per second, even those that are not connected. My program is a Perl script. The current version runs on Unix-like operating systems, such as Mac OS X and Linux. I had an earlier version of it running under Active State Perl on Windows 2000, so it should be fairly easy to get it working there. It records data at a user-specified rate - the fastest practical rate is about 8 records per second, although there is probably no need to record that quickly. The user can specify which parametres to record, and the label for each parametre. And it records the high-resolution computer time of each data record, which is only really relevant once you are recording from more than one "box".

I'll update the script to run in Active State Perl on Windows, someday. But, if anyone wants the current version, send me an e-mail (khorton01 AT rogers DOT com).

Next, I'll finish the script to record data from the Dynon D-10 EFIS, then the Garmin GNS-430.

Details
Hits: 2532

I've been spending quite a bit of time in Wichita lately, doing Enhanced Vision System testing. We need very specific combinations of ceiling, visibility and type of weather, so we end up doing a lot of running around the country looking for weather. At the start of the program, that was a very hit or miss process, as it was pretty much impossible to keep your eye on the way the weather was evolving once you walked out to the aircraft. We would launch off to one of the coasts based on forecast and actual weather, and invariably the weather we wanted was somewhere unexpected by the time we got there. Very frustrating.

Bombardier installed a WX Worx XM satellite weather system prior to this last test phase. This is the first time I have seen such a real-time weather data link system in action, and I am very, very impressed. We were looking for heavy snow last Friday. Sure enough, a band of heavy snow went through Wichita. But it took so long to get de-iced that the visibility had improved before we could get airborne. The WX Worx display was showing the band of heavy precip on radar, and the 5 minute loop showed it moving towards Topeka. We landed at Kansas City, waited an hour, then took off for Topeka. We got there before the snow did, so we set up in a holding pattern at 5,000 ft at the Final Approach Fix, which was about 5 miles from the runway. We could watch the heavy precip on the radar updates, and sure enough, the snow arrived at the FAF, but there was enough resolution on the display to show that it hadn't arrived at the airport yet, which was only 5 miles away. We watched the snow crawling towards the airport on every 5 minute update. Finally the tower reported that the snow had arrived, just when the WX Worx showed it hitting the airport. Great system!

I will eventually purchase a real time weather system, and right now the XM stuff is the front runner.

Details
Hits: 2194

I've been in Wichita for the last week, and probably won't get home until sometime on the coming weekend. Hopefully this will be my last trip down here until at least March.

I've been flying a lot, but have managed to find a few hours to work on the EIS flight test data program. I now have a working prototype that grabs records at a specified interval, decodes them, adds a timestamp, and writes them to a text file. I want to make it more user friendly, and add a watchdog program that will restart it just in case it ever hangs up. I have never seen a hang up yet, but I want to cover that failure case to ensure I don't land and find I haven't got much data. I'll also move the list of parametres to be recorded, and any special parametre scaling, to a config file, to make it easier for other people to modify for their aircraft.

Details
Hits: 2494

I've been down in Wichita since Monday, and I had a bit of spare time Tuesday evening. I brought my Grand Rapids EIS-4000 engine monitor, a 12v DC adapter to power it, a Keyspan 4-port USB to serial adapter, and a patch cable I made. This allows me to connect the engine monitor up to my laptop the same way it would be in the aircraft. I had messed around trying to record data from the engine monitor several times in the past. I finally figured out how to record the raw, binary data using a terminal program, but I never succeeded in getting clean data using Perl. Almost every record had spurious extra bytes in it, which meant it was useless.

Tuesday I threw out the part of my Perl program that sets the serial port parametres and started over. Success! I recored 20 seconds of data, with every record perfect. I recorded 15 minutes of data on Wednesday and every record (about 11-12 per second) passed the checksum, which means the data is valid.

I have a lot more work to do on this program, but I'm over the major hurdle. I need to write some code to only grab a data record at desired interval (once a second for example), convert it from binary to ASCII, add a time stamp and record it to disk.

Details
Hits: 5062

I was asked an interesting question on the VAF WWW Forum:

Kevin,I'm building an RV-8 also. I was perusing your site the other day when I found your POH. I downloaded it, and then I noticed that you had increased the max T/O wt. to 1900 from 1800. I pondered this and wondered if maybe the MOT would have something to say about it. Obviously you have though this through so I wondered if you could elucidate on this point a little for the unwashed.Thanks, Pete

I decided to look into a higher declared gross weight as I will have a heavish aircraft. I've got an RV-8, with IO-360-A1B6, Hartzell prop and an IFR panel. Van's RV-8A demonstator, with a similar engine and prop, and a VFR panel, has an empty weight of 1127 lb (Ref CAFE APR on the RV-8A). The RV-8 is reputed to be heavier than the -8A, due to those heavy gear legs, and the landing gear boxes. I've also got a Christen inverted oil system and an IFR panel. So, I'm guessing my aircraft will be around 1140-1150 lb empty. I weigh about 210 with flying gear, and I've got a good friend who weighs a fair bit more than I do. Add full fuel for a cross country, a travelling tool kit, etc, and the 1800 lb gross weight just won't cut it.

Pete raises an interesting point on how Transport Canada may view my planned declared gross weight.

Details
Hits: 11398

I thought I had my plan for a standby attitude indicator all figured out. In fact, I would have ordered it by now, except it didn't look like my current travel schedule is compatible with trying it out before the 30 day return with no questions asked expired. So I decided to wait a month or two before ordering.

I was planning on buying an eGyro-2, from PC Flight Systems. The eGyro-3 has gotten good reviews, another RV-8 builder has one flying in his Mooney and he likes it. The eGyro-2 supposedly has the same screen size, in a slightly smaller overall package. PC Flight Systems' web site isn't very well organized, but there is a slightly out of date brochure with a little picture of the eGyro-3. The fact that they either don't have enough energy to keep the web site up-to-date, or make sure the prices are consistent from one part of the site to the next, does make me wonder whether they will be around for the long haul though.

Anyway, that was the plan. But today I saw a reference to a new HSI from Blue Mountain Avionics. I eventually want an HSI, so I went to their web site. I quickly found that it isn't really an HSI - the EFIS/Lite is a multi-function device, with the HSI as one of its functions. It is also a small EFIS, similar to the Dynon EFIS that I have, and an autopilot control head (if you spend a bunch more money for servos). So, for about twice as much money as for the eGyro-2 ($2,800 vs $1,300), I could have an HSI that is also a standby attitude indicator. TSO'd HSIs run around $7,000, if I recall correctly.

If I needed the standby attitude indicator, I would lose the HSI function, but I can follow a track using the GNS 430 screen, so that is no big deal in an emergency. The big thing I lose is the ability to shoot an ILS, if I need the standby attitude indicator displayed. And I lose the having a full time standby indicator to crosscheck the Dynon against. But, if I every need the standby attitude indicator, it would be in a better spot in the panel, as it would be right below the EFIS, rather than way down at the bottom in front of my belly button.

The avionics scene is changing so fast, I can't build my aircraft fast enough to keep ahead of it. Wow. I'm not sure BMA has shipped any units yet, so I need to sit tight for awhile and think about this. I need to measure my panel to confirm that this thing would fit, and see if I should make any wiring provisions now. Hmm.