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What a difference a day makes. Yesterday I was quite bummed out to discover that I would have interference between the main power feeder and the aileron pushrod. And I probably had interference in the same place on the right side, with a different wiring bundle. The main power feeder could be repositioned, as there was a loop at the battery contactor that could provide some slack. But the feeder has bundled with the remote compass wiring bundle, and any slack I could get there was going to require at least two trips way down into the aft fuselage to loosen and retighten the clamps.

Tonight I took a second look at things. Now I'm almost certain that the wiring bundle on the right side will be OK as is. And I realized that while the remote compass wiring was bundled with the main power feeder, it wasn't actually bundled with it in the area where the interference was. So, I wouldn't need to go all the way back in the fuselage to make any slack in that bundle.

I loosened up all the clamps holding the main power feeder, cut all the plastic ties that bundled it with the remote compass wiring, and loosened the power feeder at the battery contactor. Then I was able to gradually work it forward a bit to create some slack in the aileron pushrod area. I drilled a hole for another Adel clamp and secured it clear of where the pushrod will go. I still have to work the feeder straight again along its length, retighten all the clamps and put on new plastic ties, but I'm over the hump. I'm much happier now than I was 24 hours ago.

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I've spend quite a few hours this week securing wiring bundles in the fuselage. I thought they were in reasonably good shape, but a close inspection revealed quite a number of areas where the wiring bundles could move around, or where there was risk of chafing on something. I've had to add quite a few extra clamps, and move some of the already installed clamps. I've found that a few wires had some slack in them, so I've had to chase that wire down the whole length of the bundle, pulling out the slack and moving it to the end of the bundle. Then I cut the wire and shorten it at whatever it connects to.

This evening I finished securing the main power feeder from the aft battery to the forward fuselage, and I thought I had finally finished all this wiring bundle work. Then I noted that both the main power feeder and another wiring bundle go very, very close to where the aileron pushrod will be. I can't tell exactly how high the aileron pushrod will be, so I can't say for sure whether I have a problem or not. I guess I'll let this one sit until I install the wings at the hangar. Hopefully it'll turn out OK. If not, I'll have to do a lot of repositioning of things to create some slack at the aileron pushrod area so I can secure things out of the way. That'll be a very big job.

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It's been two steps forward, and three steps back with the fuel tank leak fixing. Last weekend I put some Proseal inside a corner of the left fuel tank to hopefully fix a leak. It's a week later, the Proseal is cured, so I started a leak check yesterday. It is hard to say for sure, as the level in the manometer goes up and down with the temperature and atmospheric pressure, but there certainly isn't a large leak. I'm hopeful.

But the bad news is that on Thursday Van' Aircraft released Mandatory Service Bulletin (SB) 06-2-23, which "requires" RV owners to open up the fuel tanks to add safety wire to the fuel pickups. It was triggered by a fuel pickup that became undone inside a fuel tank, resulting in fuel starvation and an off-field landing. After Van released the Service Bulletin, another builder reported that the same thing had happened to him, but he was able to glide to an airfield. So, with two known incidents, I agree that it is wise to secure the fuel pickups so they cannot unscrew. I'll have to open both fuel tanks up to do this, so that'll mean yet another round of leak checks. The leak check I'm doing now is still useful, as I need to know whether the repair I did last week is working.

SB 06-2-23 "requires" the owner to remove the fuel pickups, drill a small hole in each securing nut, and to use safety wire to secure the nut after tightening it. This is easy enough to do with the normal fuel pickup, but it is a much bigger job if you have an inverted fuel pickup (as I do in the left wing). The normal fuel pickup is mounted on the access cover on the inboard end of the fuel tank, so you it comes out of the tank with the access cover. But the inverted fuel pickup screws onto to an elbow way up in the very front of the fuel tank. It would be pretty much impossible to get safety wire on it, working through the access cover near the back of the tank. So, Van recommends that the elbow be removed so the safety wiring can be done on the bench. But, this means that you need to somehow scrape off the Proseal that keeps it from leaking around the elbow, then put some new Proseal in place after reinstalling the elbow. That looks like a leak waiting to happen.

I'm planning an alternate means of compliance with the SB. I'm going to spread some Proseal on the nut that secures the inverted fuel pickup to the elbow, after making sure the nut is properly tightened. There is no way that nut will come loose if I put a good layer of Proseal on it and the elbow. The inverted fuel hose I've got now is made from a type of hose that is supposed to be replaced every few years. I'll order a length of Teflon lined flexible hose, as it has a supposedly infinite service life. - I've learned that the Teflon hoses are quite a bit stiffer than conventional hoses, and it is quite possible that they are too stiff to work properly as an inverted fuel pickup. I will not order a Teflon hose for this application.

Update - 28 Feb 06 - Another builder has stepped forward to say that he totaled his RV several years ago after the fuel pickup came undone, so we are up to three known events.

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I spent the week in Seattle, in a Synthetic Vision workshop sponsored by the FAA. Synthetic Vision is a new technology that is just starting to show up in avionics for type-certificated aircraft, and the workshop was an attempt to start getting all the manufacturers and certification authorities on the same page about certification requirements.

Thursday evening I managed to meet up with RV-8A builder Terry Watson. Terry is building a very nice RV-8A, but like me his completion percentage vs time curve looks to be asymptotic. After visiting Terry's project, we went to Paine Field to meet up with Mike Robbins - Mike has a very nice RV-8. And we visited the project of RV-8A builder Marc Drake.

Marc also works on another very interesting aircraft, the R-4360 powered Sea Fury Furias. They are in the midst of adding a second seat, and plan to have the aircraft back together in time for the Reno air races. The Sea Fury looks absolutely huge compared to the RVs, but it has had 28 cylinders and 4,000 hp, so it gets out of its own way without too much trouble.

Yesterday I did some more wiring bundle clean up. A package of misc hardware arrived from Van's while I was in Seattle. So today I attacked some of the little odds and ends that were waiting for parts. The biggest item completed was I put some Proseal inside the fuel tank to hopefully seat the leak I had. Then I Prosealed the access cover back on. I'll give it a week or two to cure, then try a leak check again.

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I updated the software that runs this web site today. I think everything is working properly, but if not, please let me know. Either leave a comment, or e-mail me at: khorton01 AT rogers DOT com.

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I'm in a busy period at work now, with a bunch of travel.

Last weekend Bruce MacKinnon came over to help me finish riveting the flap fairing. Even with his help there were several holes where I had to use blind rivets. Then I did some wiring bundle cleanup under the floor. Last week I spent several days on the road doing some flight testing, and I managed to pick up a cold at the end of the trip. So I was a bit under the weather after I got home and didn't get much done until today.

Today I attacked the wiring bundles in the rear fuselage. I had ran the bundles a long time ago, but I subsequently had to run one more wire, and I had realized that some of the bundles could chafe in some places. Better to prevent the chafing now than have to do a repair back there later.

It is a royal PITA to work in the rear fuselage. It is so cramped back there that you have to figure out which arms you need to have over your head before you get back too far. Once you are far enough in your elbows hit the fuselage before you can get your arm over your head. And of course once you worm your way in, you always find you need one more tool.