Spring 2010 · · PAGE 332.
March 27, 2010: The weather was clear on this
Saturday. With all the flying I did last weekend, I did not mind working in the
hangar to fix a minor problem. I noticed the RS-232 serial data from the GPS was
intermittent during the flights last Saturday. I knew the problem was in the plug on
the Garmin data power cable since I had to repair my first data power cable that I use in
my car. Since this one is used on the panel of my airplane, I had to make the
modification so the cable would remain in front of my panel. The older one I
repaired did not have that size restriction. I used a piece of plastic tubing cut
short enough to clear the panel and allow a right angle direction for the cable behind the
GPS when it is secured to the panel. I slipped it on the cable after I had cut all
the wires, stripped and tinned the ends prior to soldering into the pins in the plug.
After that was done, I slipped the short piece of tubing down over the plug, then
filled it with epoxy using a toothpick to be sure not to leave any air pockets. The
original plug from Garmin had hot-melt glue inside its cover to secure the wires. An
air pocket in the hot-melt glue was why the plug would flex slightly when it was removed
from the back of the GPS. The flexing is what finally broke one of the data wires.
I would check the socket occasionally during the epoxy curing process. I found some of the resin leaking down to cover one of the pin sockets. I had to keep cleaning that away with a matching metal pin and some acetone until the epoxy was thicker. Although I did not take a photo of the plug later, I had to trim away part of the tubing on one side to clear the GPS mounting bracket. That allowed a firm fit of the plug in the socket when the GPS is mounted on the panel.
Here is the posting I did in April 2005 on page 163, and a photo showing the first repaired plug I use in the car. I bought a new replacement data power cable that went into the airplane, which has failed after almost five years.
August 16, 2005: I brought home my
electrical components box from Wendell's hangar when I left the paint shop
yesterday. Last night I had to repair my data power cable I use in my car with the
Garmin GPS 296. I used a piece of polyethylene tubing to go around all the wires and
the plastic plug assembly. Unfortunately, I was not able to save the rubber right
angle plug cover and ended up sealing the repaired connections in epoxy inside the tubing.
Here is a close-up of the plug I repaired and an original GPS 296 power plug from
the AC power supply that came with my 296. This failure of the plug taught me how to
properly UNPLUG the cable in the airplane in order to NOT cause similar damage.
( End of Flashback )
March 27, 2010: As I was finishing up the data power cable repair, I plugged in my battery minder/charger to the 12-volt accessory socket on the panel. I noticed the green LED was not glowing. I tapped on the charger to discover the LED connections inside the case were intermittent. The LED presses against the case from the inside with it slightly protruding through the case for easy visibility. Since I had my soldering iron out, I started to take the case apart to repair the cold solder joints. That was when I discovered the four screws holding the charger case together had non-standard screw heads. The screw driver needed to have a triangle for a point, not a flat blade, phillips, or torx. A rusty old phillips with a damaged point was quickly put to the bench grinder on the stone and polished with the Scotchbrite wheel until it would fit the head of the screws.
When I got the power supply case open, a quick touch of the green led confirmed the cold solder joint on one leg. I soldered them both and put the case back together. The green LED will light anytime the unit is connected to AC power. The RED LED only lights up when the unit is charging a battery, not floating the battery in maintenance mode. I plugged the unit into the airplane and flipped the avionics master switch to put a load on the battery to see the charger change modes. When I picked up the charger to look at the RED LED, it was also intermittent. I took the charger apart again and soldered both connections on the RED LED. The second time I reassembled the case and checked the unit, both LED's were solid with no flickering when the charger case was tapped.
This was my day for all things electrical. Wendell had been mowing the grass around the house this week and had some problems with the starter on one of his mowers. I helped him with it when a fully charged battery would not start the engine. The solenoid would click like it would with a low battery voltage. This led me to check the push-on blade connections to the solenoid coil. They turned out to be the problem. Just pulling them off and re-seating them solved his problem with the mower. He was cleaning them when I headed home for the day.
March 28, 2010: The rains came with thunder and lightning near the house this Sunday morning. Then came some brief sunshine, and finally a partly cloudy day after lunch. I went out to get some printer paper at Wal-Mart and stopped by the hangar to check on the curing of the epoxy in my repaired data power cable. Sure enough, it needed one more cleaning of one of the plug sockets. I took care of that and pulled the airplane out of the hangar far enough to get GPS signals. Everything works as it should. The next flight should not have any troubles with the autopilot and Dynon display of winds aloft, etc.
I also checked the repair to the battery charger/minder. When I plugged in the socket to the 12-volt accessory socket, the green light flickered and went out! This was a loose connection at the power plug going into the socket itself. The fuse in the plug was fine, the wire at the crimp location needed to be folded double as it entered the power plug. All is well, the battery will be properly charged as it should be. There is about 21 gallons of fuel remaining in the tanks after last week's flying adventures.
April 3, 2010: I went back to check on the GPS power plug today and found the negative power socket was blocked. I got out a suitable mating pin and a pair of pliers and was able to clear the small amount of cured epoxy that was blocking the way before I tried plugging it into my GPS 296. Then it turned out it would not stay plugged into the GPS. I put three layers of the foam weather strip on the panel behind the GPS power plug and that seemed to help, but not quite. It turned out the mounting bracket had a minor interference fit with the power plug as it exists today. I trimmed a bit of the plastic from the plug and ground off some of the plastic tab from the mount and all appeared to be better. All that remained to do was take a short test flight and determine if I would have a solid data connection when in actual flight conditions from engine vibration, etc.
The weather front that had been closing in on the Chattanooga area passed
without much rain, just a few showers in the morning. The short local test
flight was under very clear conditions with light winds aloft at 2,500 feet MSL from the
southwest. That information came from my Dynon D-10A and the autopilot tracked the
GPS course very well. The flight added 0.3 hours to the Hobbs meter. Here is
the photo before putting the airplane back in the hangar.
April 10, 2010: This Saturday was a good day for flying, but it was not to be. Marty and I had planned another aviation outing to the annual Fly-in at Bonifay, Florida for today. He called me this morning while I was enroute to Folks Field and reported water problems at his home with a broken pipe from the street to the house. I stayed at the field for a while. Wendell came out to make the first pot of coffee and the usual friends started arriving. We talked for a while and I realized I had some chores I could do at home.
I have a business trip that begins on Sunday, April 11th. I am teaching a fiber optic communications seminar in Sioux Falls, South Dakota on Monday and Tuesday. The return home is on Wednesday. This is an airline trip, not an "Enterprise" trip. My airplane stays in the hangar as the weather was unpredictable at the time I had to purchase the airline tickets. The forecast in the Sioux Falls area for this coming Wednesday would not be favorable for flying my airplane back home to Chattanooga. If the weather had been known to be favorable, the cost of AVGAS would have been much less than the airfare, and quicker since I would have flown direct with one fuel stop and no hassles with the airline. There is not one empty seat on any of the six flights that will take me there and back. Sunday the route is CHA, ATL, MSP, FSD. The trip home will be FSD, MSP, MEM, CHA and of course there are the usual layovers at the big airports. It has been a long time since I have been to the airports serving Minneapolis/St. Paul, and Memphis, Tennessee.
April 11, 2010: I am in Sioux Falls at the hotel publishing this update. Only the third airplane departed the terminal at MSP a few minutes late today with a timely arrival at my destination. The airport here is similar to the Chattanooga airport in size and passenger services. These secondary airports have less security delays compared to places like Atlanta for passengers beginning their trips. Changing airplanes in Atlanta is painless by comparison to starting at the Atlanta ticket counter. If I could have flown my airplane today, I would have saved two hours in my travels for this trip by covering less miles, and no air-traffic delays in the air or on the ground. Of course, I would have to bring my own in-flight lunch, but then I usually do that on the scheduled air lines anyway.
I had several encounters today with interesting people. In Chattanooga, I met a guy from Pennsylvania who had a face similar to mine and hair like I had when I was in my early 20's. He also sat next to me on the flight to Atlanta.
There was also this guy who got on my flight in Chattanooga who was in the water "demonstration" business. He described some of their projects like indoor waterfalls and fountains. My hotel here in Sioux Falls has them in the atrium lobby restaurant and bar area. When he got to ATL, his next flight was to Albuquerque to join up with some of his crew before they headed for Singapore.
The guy sitting next to me on the Atlanta to Minneapolis flight was a 29-year old Canadian lawyer practicing in corporate law. His wife does criminal law cases. He was heading for Winnipeg after MSP.
My flight from MSP to FSD had a lady doctor (surgeon) in the seat beside me for the short ride to Sioux Falls.
Each of these folks had some interest in my experiences building and flying my airplane. Showing them my airplane "business" cards gets their attention, then I answer the usual questions -- How did you do that? How long did it take? Is it safe? How fast does it go? What is the price of AVGAS? How do you deal with air traffic and control towers? Where have you flown your airplane?
Such is the life of the wayward RF engineer now doing fiber optics after 38 years of learning my trade in basic cable TV from 1971, to satellite uplinks and downlinks from 1977 to 1989, then finally working for a cable company from 1990-1992. After that, I was selling cable hardware to cable companies, creating a web site like this one in the late 1990's, and on, and on...until today. So it goes... Time for dinner in the hotel restaurant.
April 18, 2010: Sunday
again and the weekly update of the web site. I took two photos during the approach
to the Minneapolis/Saint Paul airport last Sunday April 11. They were both taken
with a polarizing filter on the camera lens. Airliner windows have a layer of
Plexiglas or Lexan that produces a rainbow effect color shift when the light is passed
through a polarizing filter. I have processed both these photos for contrast and the
color shifts have been accentuated by that post processing.
My fiber optic seminar had good participation and interactions from the attendees. All were CATV RF technical folks except for the technical writer who wanted to learn the meanings of the fiber optic "buzz words" in the manuals he was editing for their company.
The weather was not that bad during my stay until Tuesday, April 13th. A cold front was heading in from the west toward Sioux Falls and was bringing high winds forecast for 50 MPH on the ground and a line of rain showers and possibly lightning overnight Tuesday evening, Wednesday morning, the day of my departure. During the short regional jet commuter flight from Sioux Falls to MSP, I looked south and could see the front had passed and was stretched out along a parallel path with our flight toward Minneapolis. There were some clouds at various levels, but VFR flight behind the front was possible. As for trying to find a path through that front to the south and east toward Chattanooga in my airplane -- I was glad I left it home in the hangar. Those overnight 50 MPH winds and possible storm damage if hail had fallen were not worth the risk. I had made the correct decision to fly with the airlines and leave "Enterprise" at home. When I got back to the Chattanooga Airport, I found my car had a yellow coating of pollen from the four days it had been sitting out in the long-term parking lot.
Thursday was still a warm day here in Chattanooga with my day job consisting of normal office hours. Friday was another warm day with a ride up to our Tennessee office to meet up with the boss and the sales manager. I had to use the car air conditioner due to the heat and the pollen in the air.
Saturday morning, April 17th, I went over to the hangar and found nobody there. I called Wendell's cell phone and he answered from the airport at Sanford, Florida preparing to board a flight on Allegiant Air back to Chattanooga. He had been attending the Sun-N-Fun EAA fly-in down in Lakeland, Florida this past week with two friends. They would arrive at the Chattanooga Airport around 1:30 PM.
The weather here on Saturday was influenced by the same cold front I had left
in Minneapolis on Wednesday. It had finally made its way to the Chattanooga area
bringing a few light rain showers and cooler temperatures. There was not enough rain
to wash the pollen off my car. The skies to the south were clear. Above this
area and to the north was a solid overcast. It was a good morning to clean off the
bugs from my last short test flight and get the pollen off the airplane that had blown
into the hangar. This photo had pollen on my soft Viva paper towel I was using to
clean the wings. My hand print is clearly formed by pollen. I also cleaned the
windshield and checked the air in the tires but did not want to go fly in the marginal
conditions outside. The twenty gallons of fuel in the tanks would better serve me in
a future flight.
There is another grass strip fly-in down below Cartersville, Georgia scheduled for next Saturday. The forecast for next weekend currently is predicting a 60% probability of thunder storms for that day.
April 24, 2010: This Saturday was a rain-out in Chattanooga and across most of Georgia. The fly-in I mentioned south of Cartersville was not for me on this day. I have yet to discover if it even happened down at Taylorsville, Georgia. The news last night and this morning was all about the tornadoes that hit in Mississippi and Alabama. Here in Chattanooga, it was just a rain event and some occasional thunder and lightning. I called Wendell Saturday morning as I was heading out to get groceries. He asked for some help on his autopilot which sounds like an intermittent serial data link. His Garmin GPS 396 uses the same data power cable I have in my airplane. I am betting it is the same problem at the power plug behind the GPS. I will be going over to the hangar to check on his problem Sunday afternoon when the weather should be clear, but with gusting winds.
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