If I Can Fix An Airplane...

[MistWolf]

You'd think I'd learn by now. More than one adventure filled project has begun with this very proclamation. "If I can fix an airplane, I can..." say, build an FAL or fix the plumbing of the RV we live in. In the middle of winter. In minus 20 degree weather". Most infamously was, "If I can fix an airplane, I can do the tune-up on the RV engine myself. I think I'll change the oil at the same time." How hard can it be?

I did survive each of the projects I tackled (although the Tune Up Incident put four credit cards in ICU) and I've learned a lot along the way. Keeping that in mind, when the dishwasher quit draining, I said "If I can fix an airplane, I can fix a dishwasher. How hard can it be?" It's a modern appliance and all the parts look like they're plug & play. You know, modular. Like an AR. Or an Apache helicopter. Just loosen up a couple of bolts disconnect the electrical connector and viola!- Out come the parts.

I dug the wet & dry vac out of the basement, sucked out all the water and began disassembling the dishwasher.

Before we go any further, let's take a look at a couple of rules when working a problem on any aircraft. Or any other problem-
1) Start by reading the tech manual
2) Assume nothing
3) Do the easy and obvious fixes first

I'd already removed and cleaned the heavily plugged drain filter, but that didn't fix the problem. Hmm, must be the pump. I disconnected the water & drain lines, disconnected the wiring, removed a solenoid, pulled the pan and removed both pumps. I was certain it was the pump although I could find nothing wrong with it. How much is a pump?

As I sat amid various dishwasher parts, I went online to check prices and during my research I stumbled across a troubleshooting guide for the model dishwasher I have. It narrowed the drainage problem down to three items-
1) Bad pump.
-Checked the pump. No damage to the impellers. Spins freely. Passes continuity check

2) Bad solenoid
- Arm moves freely. Switch clicks when it supposed to. Passes continuity check

3) Clogged drain line
- Oh. Remember the rules about reading the manual, assuming nothing and checking the easy fixes first? Didn't read the manual, assumed the pump was bad and didn't check the drain line. I found a small bit of easily removed plastic blocking the drain line.

Yep. I fix airplanes. I can do this. It can't be that hard...

...Can it?

[Joe in PNG]

Heh. My current DIY tube guitar amp project is on hold because I wanted to save $25. So, I got a 20w Fender style power transformer* to use in a heavily modified Marshall 18w style amp.
And wired up everything according to the Marshall style schematic. Turned it on, and it worked... for about 10 minutes, then the smoke came out of the transformer.

I should have taken a closer look at the Fender 20w schematic. As it turns out, the red & blue wire wasn't supposed to go to ground- it was supposed to go to the bias tap. The red & yellow wire likewise wasn't supposed to go to ground- that was supposed to be cut and capped.

Looks like I'm paying $70 in stupid tax from trying to save $25.


*I have used this style transformer for a previous 18w Marshall style 2019 Bass & Lead circuit successfully, so go hurbis!

[peterb]

I like to think I’m reasonably good at working on bicycles. Just a couple of nights ago I was going to put a quick-link in one of my chains for easier maintenance. Got the chain tool, drove the rivet out, removed the chain, ....and realized there was already a quick-link installed.

Sigh.

[NickA]

I've done the same kind of thing several times, with much simpler projects (I'm not all that handy). Every time, I'm reminded of this scene:

https://youtu.be/AynXoLjYrKc

Sent from my Pixel 3 using Tapatalk

[txdpd]

I’m going to ass-u-me that building an airplane is is like Sara Lee baking a pound cake. These exact ingredients are mixed in this order and baked exactly this long, and we get the same product every single time. Let’s call that science. All that other stuff is like when I cook eggs. Heat up a pan, hot but not too hot, add enough butter, and cook the eggs. I always get cooked eggs but they’re never really the same. It’s more of an art.

[BehindBlueI's]

I like to think I’m reasonably good at working on bicycles. Just a couple of nights ago I was going to put a quick-link in one of my chains for easier maintenance. Got the chain tool, drove the rivet out, removed the chain, ....and realized there was already a quick-link installed.

Sigh.

So it'll be twice as fast to maintenance now!

[trailrunner]

I've often said that since I have an advanced degree in engineering, I should be able to fix this or do that. But the best lesson I've learned in life is a clear understanding of my limitations, i.e., when it's better to hire a professional.

When I bought my gun safe, I really wanted to save the delivery fee and pick it up myself. After all, I had a full-sized truck and a dolly. However, I have some tricky steps to get down into my basement, so I swallowed my pride and paid the delivery fee. The guys who came out were pros and pulled a few tricks that came from experience. If I would have tried to do that myself, I would have given myself a hernia, threw out my back, dropped it on my foot, and have gotten the safe stuck at the bottom of the steps. In the end, it was the best money I ever spent.

[Darth_Uno]

I did all the electrical in our homes for 15+ years, and when something doesn’t work there’s a few things you always check first before taking things apart.

Is the breaker or GFCI tripped
Is it plugged in
Is the bulb burned out

99% of the time it’s one of those. And I get why phone and computer techs want to walk you through the basic troubleshooting every time. I’ve had customers call and say their coffee pot won’t turn on. “Yes sir, before I come out and look, that circuit is ground fault protected. Go ahead and see if you can press the reset button on that outlet.” Them: “The what is what protected?” Easy fix, they just didn’t know what to look for.

OTOH, I can think of a few times I spent a dollar trying to save a dime, so there’s that.

[Doc_Glock]

Looks like I'm paying $70 in stupid tax from trying to save $25

Having paid that tax before, I prefer to label it “educational expense.”

[MistWolf]

I’m going to ass-u-me that building an airplane is is like Sara Lee baking a pound cake. These exact ingredients are mixed in this order and baked exactly this long, and we get the same product every single time. Let’s call that science. All that other stuff is like when I cook eggs. Heat up a pan, hot but not too hot, add enough butter, and cook the eggs. I always get cooked eggs but they’re never really the same. It’s more of an art.

Not even close! There are a lot of components that fall under the "Easy To Install Plug & Play" category, but there are far more that are "Custom Fit and Require Tuning To Your Specific Airframe Because Welcome To Aviation." That's just building new aircraft that have been in production for decades and the engineers should have all the bugs worked out by now. Should.

Things get complicated when the aircraft needs repairs, modifications, updates or rebuilding. Re-skinning the upper fuselage to accomplish a beef up mod designed to prevent the aircraft going all Instant Sun Roof at 30,000 feet is nowhere near "Follow the Instructions Until You Have Cake". Or maybe it is, but withe the understanding that you'll have to make refined flour from grain and have to continually adjust the recipe of each individual cake for altitude density, variations of egg size, oven temperature; have all the measuring cups certified for accuracy, have custom cake pans made to ensure the final dimensions are within tolerance, document every step, ensure no inspection points are missed during the process and have the final cake checked for it's weight and balance when finished. In the end, no two aircraft are exactly alike and the larger and more sophisticated the aircraft, the larger the variance in weight, dimension and even how they feel to the aircrew when they fly.

Sure, there are instructions to building aircraft. There are instructions to maintaining, repairing, modifying and operating aircraft. But they are followed by a set of rules and standard practices that that assemblers, maintainers and operators follow when they encounter a variance. Even so, there can be variances that fall outside those rules and standard practices that require the attention of an engineer (who also have rules and standard practices to follow).

That's just for regular type certificated aircraft. I've also spent time working on old Warbirds (specifically the DeHaviland Vampire & Venom and a couple of old Soviet fighters from the Cold War era) that we have to scrounge, inspect, rebuild and modify parts for and fall under the category of Experimental Aircraft. That's when things get really fuzzy. Often, you have to make the call on a repair or modification with nothing but your interpretation of the general rules and standard practices to go by, knowing that the responsibility for safety of flight of that aircraft falls on your shoulders and yours alone. The life of the pilot is in your hands. It's a big responsibility and I take my job seriously. For all that, I love what I do.

[OlongJohnson]

My grandpa ended up falling severely ill at the end of basic, and they weren't able to put his infantry ass on the Liberty ship to go east. Which was lucky, because the U-boats found that one, everybody went down. Rather than put him through basic a second time, they put him in aircraft mechanic school. He was in the top 1 percent of the class, so they kept him in Nebraska to be an instructor. Eventually, according to the story he told, he was part of a team that took the wreckage of three German fighters and combined it into one (hopefully) flyable plane. No manuals for anything, of course. The base commander took it up for the shakedown. My grandpa's told a lot of stories, many of which involved situations in which it would be reasonable to be scared. The part where the base commander opened the throttles was the only time I ever heard him say he was scared. "...almost peed my pants."

If anything in this story is verifiably factually incorrect, I blame my grandpa.


https://www.youtube.com/watch?v=5Rzao52ndNA

[Joe in PNG]

It's been written that the American theory for WWII mass production was precision & uniformity, per Big Bill Knudson. Every part made for the M1941 Widget was supposed to work in all the other M1941's, according to the plans and specs.

England and the Soviet union treated the plans and specs more as general guidelines and suggestions, and depended on the guy in the factory to hand fit the bits to the other bits. Witness the notorious non-interchangeability of SMLE and PPSh-41 mags.

Even with my clones of classic tube amps, I have:
-The schematic as Marshall (or Sunn, Orange, HiWatt, ect) did it
-The schematic as others cloned it (with lessons learned from years of use- extra fuses, and resistors to prolong tube life)
-The schematic as I modified it
-The layout as I planned it
-The amp as I actually built it, because my suppliers were out of stock on this or that... which reminds me, I really need to re-do the schematic and layout of my new amp before I blow something up again.

[Trooper224]

When I was running a bullseye league one of our shooters, an engineer in the local aircraft industry, asked for my help. He'd purchased a used S&W revolver on the cheap, because it didn't work. He described the problem and the were only one or two possible causes. Neither one of which is a difficult fix. I discussed it with him and told him to bring it in next week and I'd fix it. He started to give me his, "I'm an engineer..." speech that I've heard from engineers, doctors, all kinds of advanced professionals who have more ego than sense. I told him not to try taking it apart, but just wait. Well, the next Monday he walks in with the expected box of revolver parts he couldn't get back together.

[mmc45414]

Got the chain tool, drove the rivet out, removed the chain, ....and realized there was already a quick-link installed.
A few years ago I had a motorcycle that is referred to as a "Motard" conversion, basically a dual sport motorcycle that has the spokes and rims changed out to put shorter sportbike wheels on it. Tons of fun, but the short sidewall tires are a bitch to change out, and part of the struggle is breaking the bead, especially using improvised methods like putting it under a car jack and pushing it down to the center of the rim. After my first tire change on the Motard I decided I deserved to buy myself a proper bead breaker, and set about researching them. You can buy a cheap shop version from Harbor Freight, you can get a simple version that can be packed along on the road and pinched by turning a wrench, you can buy a lightweight titanium version of the portable version so you are not lugging around the heavy one, and of course the portable ones could work in the shop also. So it was a decision matrix of cost, portability and convivence. Since I just changed the tires I had time to contemplate the decision and didn't do anything immediately.

Later I was out in the garage, glanced up, and saw my bead breaker...