I still need float-rigging info

[Lynn Matteson]

Landing gear woes

Now that I've got the plane back in my hangar, I can fly it to local fly-ins, breakfasts, etc., but with a warning from Brian (my flight instructor, mentor, and good friend) that these floats are not the strongest he's ever seen, and that the landing gear is the weak point. I shouldn't be considering them to be as strong as the Grove landing gear that I built the plane with, and I ought to be operating them on hard/smooth runways whenever possible....in other words, cut out some of the turf activity. Well, that's hard to do when my place is turf, and so is his, and so are most of the places I frequent. So I kinda let this advice fall on deaf ears, which mine nearly are, and this will bite me in the ass later on....

So now I've modified my plane, after I've flown it for over 1600 hours and to both coasts of the US, into something that I can't fly to all the places that I used to, can't fly it into lakes, etc., because the training is dependent on Brian's time being available, and I'm getting frustrated.

I should point out here that when I built and installed the floats, that I installed a couple of pressure gauges to show the pressure in the gear retract system...a pressure gauge for the "up" direction, and another for the "down" direction. Because I can't see the actual position of the wheels, I operate the switch (operation is electrical/hydraulic pump) in the chosen direction until I see the pressure gauge max out, telling me that the work is done....all four cylinders are at their maximum extension or retraction, whichever the case may be, and I can release the switch. Right from the start of the project, I had built mechanical indicators for the front wheels to show up or down, but nothing yet for the main wheels. I was relying on the pressure gauges to show position indication of the mains, either up or down...another ass-biter coming up.

Lynn

[Lynn Matteson]

Landing gear woes solved?

Somewhere along the way, Brian suggested that as old as I am, and having flown only one plane (not true, I've flown about six different planes, but no solos in them) that I should look into getting a device to remind me to check gear location. I figured that the gear position is the only thing different about flying this plane now as opposed to wheels only flying. He pointed out: "Isn't your life worth $600?" (approx. cost of a gear position reminder device that calls out wheels down for runway landing, or wheels up for water landing)
I guessed that it was, and ordered one...it'd give me something to do while waiting for the next lesson. So I got the device from Spruce, and it needed info from the gear telling it where the wheels actually were....position switches. So I set about building a small switchbox containing two microswitches, one that would close (complete the circuit to ground) when wheels were up, and one that would close when wheels were down, and I wired them into the plane. I then built a small subpanel ( running out of room on the main instrument panel) and mounted a green light (runway landing) and a blue light (water landing). This worked great! Now instead of watching for the pressure gauges to indicate when the wheels were at their end positions, I had these really cool lights that came on to tell me the same thing...or so I thought.

I got this panel mounted on the plane the day before I left for Oshkosh. Took it up for a flight or two and everything was ginger-peachy. Weather kept me from going until Monday of Oshkosh week, and when I did get going (west from here [southern Michigan], then around Chicago, then north) I had a 10-15 mph headwind until I turned north. I finally got there, stopping once for fuel/**** call, then landed on 27 at OSH, and made the turnoff to head for Seaplane parking. An attendant crossed his arms in front of me and I stopped. "You have smoke coming from your right float" I got out and the right float was dragging on the pavement. A small group had gathered and they lifted the wing while I ran the "'down" switch. The wheel locked into position, I thanked them and taxied off to my eventual parking place.

When I had changed my procedure from watching the gauges max out as an indicator of "locked and loaded", to watching the light come on, I overlooked the fact that the light was indicating that ONE wheel, the left one, (the ONLY one with the switches) was locked, and I still needed to observe the gauge for max pressure...the only true (more on this later) indicator of maximum wheel movement.

More later...gotta go install a bladder tank into a Republic SeaBee.

Lynn

[kmach]

I enjoy reading your adventure. Thankyou for sharing your experiences

[av8rps]

I'm still sitting on the edge of my seat...

[Lynn Matteson]

I'm still sitting on the edge of my seat...

Hang in there, Paul, more adventure on the way.

Prior to Oshkosh

I left out an important part of this journey into "floatdom"....prior to devising and installing the landing gear position indicator, I had made a flight up to Clare Muni airport for a breakfast (they've got the best cheesy potatoes in the land) Leaving there...without the benefit of my GPS, which went belly-up some time ago, I saw a freeway which I thought was the N-S one, I followed it, and ended up going NW-SE towards Saginaw and some Class C airports. When I realized this, I made a correction to go south and get out of their territory. I was getting frazzled by now and tired, and wanted to get home.

When I got home, I saw my hangar-mate waiting for me, and, wanting to make a great landing to impress he and his wife, I brought it down the grass runway and made the smoothest touchdown in the history of the world...for a little bit. Then the plane sort of came to a rather quick stop. I thought I had left the line-lock on for the brakes, but then realized I had landed wheels UP! By this time in the flight, all my brain power was used up, and I had finally done what they say all pilots with re-positionable gear will do eventually, and that is make a wheels-up landing. Well, it didn't take me long to accomplish that feat....probably 30 landings into my re-positionable landing gear career, I had my merit badge. We got the floats raised with planks and wood blocks and lowered the gear and in 15 minutes I was able to taxi to the hangar.

It was at this point that I decided to order the annunciator, and build the position indicating switches, because I couldn't trust my brain to remember to check for the proper position of the gear. Then came the incident at Oshkosh, and the realization that even with an audible reminder (which wasn't functional yet) to check gear position, I still needed to have a mechanical device to show where the wheels were...EVERY wheel, not just the one with the microswitches, and the fronts with their mechanical indicators.

So now I had to devise mechanical indicators for both main wheels...what if a wire broke, or a light bulb failed, or the annunciator (if and when I got it functioning) went belly-up?...so I could see proof positive that all wheels were in the proper position for whatever surface I was going to land on, water or land.

I already had the mechanical indicators for the front wheels, and the ones for the mains weren't that hard to devise, so I set about building them. On the Zenair floats, the mains go down and are locked in place by an over-center mechanism, and I used this feature to make my indicators such that as the links go over center, the indicators are actuated, and this can be seen from the cabin via a rod that sticks up through the skin of the top of the float. So now I had all four wheels showing their positions by mechanical means, as well as the pressure gauges to show when the actuating cylinders were at their extreme positions.

Early on in this business of trying to make a fool-proof method of knowing where the wheels were, I had thought of the pressure-indicating method of wheel position as the end-all in knowing where they were....but what if a log were to become jammed between the mechanism and the float? In this case the gauge would show high pressure, but the cylinder would not have moved the mechanism the entire way to either up or down, and I wouldn't know this and would land with one wheel not in the proper position. So that is why I went with the mechanical position indicators. Now when I land, I operate the up or the down switch, watch the pressure gauge for maximum deflection, then observe the wheel-position indicators for proper position for the intended surface. When I get the annunciator working, I'll have that to remind me that I'm going to land on whatever surface the wheels are presently positioned for, and if my brain is working, the landings will be made with the wheels positioned correctly. Now if I can get some more training, maybe I can actually use these things for what they were intended...landing on water.

Next up...fixing the damage from the Oshkosh incident.

Lynn

[avidflyer]

Lynn, your series of messages reminds me of the 'Cloud Dancer's Alaskan Chronicles' series on the Super Cub dot org website. Hope yours has a happy ending like most of his do. I'm waiting for the next installment. Jim Chuk

[Av8r3400]

What about a simple pair of mirrors on the jury struts?