Hello WIXers,
We're running late with the maintenance report this week, but tht's mainly because the maintenance is still not over. We've had teams working on the plane straight through since Saturday, and more to follow each day through the week. We're intending to fly this coming Saturday, and we will, too, or know the reason why.
As usual with Hot Stuff, though, the items on the do-list are the least of our worries--always things cropping up. The main idea is to finish with the annual in time to get her signed off and test-hopped.
Saturday's work boiled down to two main efforts: compression check on the right engine, and replacing the main fuel boost pump on the left side. There you see the layout. A few of the boys looked into the balky ground power cart, too.
Machine Shop Gaylon led the compression check effort, assisted mainly by Rich no. 1 and Hot Rod Steve. It takes a while to do 18 cylinders. The helpers rotate the prop to get each cylinder to TDC in turn, then hold the prop stationary while the compressed air is applied. 80 psi goes in, and the pressure held by the cylinder is recorded. We want to see all cylinders within 20% of each other. The engine checked out good to go.
Before the check was over, a group of visitors came by: radio people from local station WFBQ, buddies of Rich no. 1. They've heard the old man telling tales of the old bomber for a while now, and wanted to see the goings-on. They got an eyefull, certainly.
While that was going on, PJ and I were under the left wing, taking care of the boost pump install.
There's PJ, soldering the splices in the wiring harness. Before we could get to that point, we had to go through the heap of old soldering irons on the shelf to figure out which were good. By the time we'd tried three different weak, barely-warm irons, I noticed PJ tinning one with the air of someone who's been there, done that. Turns out that she was a soldering technician for several years. From that instant, the solder splices became her job. Solder them together for a good strong bond, then heat-shrink over the individual wires, more heat-shrink over the pair, RF shielding over the whole package.
We threw away all those bad irons, too. Enough is enough with the worn-out stuff!
There's me, finishing up the install after PJ wrapped up the wiring. The flange bolts take a light torque, no more than 30 in-lbs. It doesn't seem like much, but over-torqueing will make it leak and dribble fuel all over. This is about the third one of these I've installed, and I've not yet had one leak.
Once we were done with the pump, we took off to visit our AI, George, who had a replacement battery for us. While we were at his shop, we got a load of the Waco UPF-7 he's been restoring. It is a thing of beauty. We got there just in time to help him hang the engine. It's going to be at Oshkosh this year, I believe, and it sure is looking like a trophy winner--shiny inside and out, and a feat of craftsmanship.
Of course, I didn't think to take my camera on the errand! Next time I go out, I won't be so forgetful.
While PJ and I were gone, the crew had lunch, courtesy of Rich no. 1, who brought an enormous pizza. I managed to get one little piece on the way out the door, but I figured it'd be consumed by the time I got back. Yep.
Having returned with the battery, we set about moving fuel back into the empty left inboard tank, to leak-check that pump installation.
There's Barnstormer Joe, in the cockpit manipulating the valves. We moved enough fuel to make sure of the pump (no leaks), then called over the fuel truck to put a decent load in there.
We capped off the day with another engine run--just the left engine. It's still running like a peach, as you'd expect.
Sunday's crew came out in the afternoon to address a nagging problem with the left brake. We've changed the seal in that hub three times at least, and each time, it's begun weeping hydraulic fluid before too much time passed again.
We've had a local fabricator of o-rings and the like make up these things for us, but we decided this time to work it up ourselves. Buna rubber stock, oversized by ten thousandths this time.
Long Tall Glen and his EAA buddy Randy taking care of business in the shop, there. They used a spare hub to find the correct circumference, and then it's a steady hand and a careful clean cut. A special CA glue, formulated for the buna, joined the ends together--another use for a steady hand.
And there it is.
We've gone through this particular evolution a dozen times at least--pull the wheel, disassemble the brake stack, pack the bearings, clean the brake segments. Then we can put the new seal in, and hope that this time is the time.
There's PJ with the representative components, one each rotor and stator. The brake stack consists of a dozen of one and eleven of the other--or is it 13 of one and 12 of the other?--and everything must be clean and dry before we reinstall it. Hydraulic fluid dribbling all over it does not make for good braking action!
There's L.T. Glen putting the new seal in. It was a good tight fit, this one was. It has promise. Two days later, still no sign of so much as a molecule of fluid coming out of there.
Then Randy takes each rotor/stator pair and puts them on the hub. The stators have teeth that engage slots in the hub, keeping them stationary. The rotors have teeth that engage slots in the wheel, spinning them with the wheel as it rotates.
And there's the whole thing assembled, just waiting for the wheel and tire. Glen's tightening the nut, which locks all those plates in place. Turn it down as far and hard as you can with hands alone, then back it off one full turn and secure.
While all this was going on, Sideshow Ted was over at the right nacelle, removing the fire bottle. Each engine has two bottles, which can be individually released. This gives us two shots at putting out a fire, if we should ever have one. No. 1 on the right engine needs to be recharged, so Ted was pulling it.
It's infrequent that Ted's schedule lets him come out and work on the plane. He is frequently out working on our ramp shack, though. it was good to see him.
Today's work was more of the same--the right brake hasn't been leaking, but it needed to be pulled, inspected, bearings packed, and reassembled to satisfy the annual. That's been done.
Tomorrow there'll be another crew out, and possibly another engine run with a hope of capturing usable date. We've still got the idle speed, idle mixture, and prop governor to verify and adjust as necessary, plus a couple primer solenoids that need attention.
If we can get this plane in the air _before_ the weekend--a long shot, but potentially do-able--we may be able to get our boys a bit of practice, and potentially their type rides. I'd like to see that! But the main thing is to get the plane into the air safely and back again.
It's coming.
More reports as the maintenance week progresses,
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