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Mooney Service Bulletins


Cruiser

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Despite the best efforts of engineers and designer, sometimes things don't work out the way they were planned.

In aviation, manufacturers has a system in place to correct and/or improve the product when the conditions call for change. Maybe not a huge problem or a major issue but things that definitely need attention. This is called Service Bulletins.

Case in point. Mooney SB M20-286. Models affected are late numbered Js, Ks, Ms, early Rs and most Ss. See the SB for specific serial numbers.

Since the panel was out and we had easy access, I decided to have this service bulletin completed as it was not noted in the aircraft logs. It is not a difficult fix or requires costly parts. It is just hard to get at the parts that need modifications (unless you have the entire panel out) 

This is what we found. It is incredible that these did not cause a much more serious problem! I was shocked when I saw them.

My moral to the story is that the manufacturer probably knows what they are talking about. Follow their advice. 

Anyone with a 28V Mooney that hasn't done this SB yet should think seriously about fixing it.

 

 

IMG_0998.jpg

sbm20-286 Landing_taxi light .pdf

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Mooney was the first manufacturer that I encountered to make all of their service documents available to everyone without cost, it's a great way to encourage compliance.

More are following the lead now.

Clarence

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1 hour ago, orionflt said:

love the LED stuff, I want to replace all the lights with them.

I like my LED landing light! And the LED belly flasher (replaced separately about 3 years apart). If pricing was less ridiculous, I'd replace both wingtip lights and the rear white light. But it's > 1 AMU just for the wingtips, so it ain't gonna happen. They still work . . . unlike my landing ljght, which worked at dusk departure in a wide open area and didn't come on again landing over the trees 3 hours later. My first clue was when I turned base, I couldn't see the ridgeline parallel to the runway a couple hundred yards away. Wingtip recognition lights don't have that failure mode. 

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On 6/16/2017 at 6:51 PM, Cruiser said:

Despite the best efforts of engineers and designer, sometimes things don't work out the way they were planned.

There are three schools of magic.

     One: State a tautology, then ring the changes on its corollaries; that's philosophy.

     Two: Record many facts. Try to find a pattern. Then make a wrong guess at the next fact; that's science.

     Three: Be aware that you live in a malevolent Universe controlled by Murphy's Law, sometimes offset by Brewster's Factor; that's engineering.

 

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Not being familiar with Brewster's factor, Harley, I had to look it up...

Closest I got was...  

"As I understand it, the idea is that every once in a while just the opposite of what you expect will happen, and it won't be frequent enough to predict. So in this case, once in a while you'll be caught off gaurd and nothing will go wrong."

 

Best regards,

-a-

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27 minutes ago, HRM said:

There are three schools of magic.

     One: State a tautology, then ring the changes on its corollaries; that's philosophy.

     Two: Record many facts. Try to find a pattern. Then make a wrong guess at the next fact; that's science.

     Three: Be aware that you live in a malevolent Universe controlled by Murphy's Law, sometimes offset by Brewster's Factor; that's engineering.

 

Quoted from "The number of the beast " by Robert A. Heinlein

The Brewster Factor is thought to relate to Brewsters Law where non-polarized light is reflected back as polarized and internally reflected/refracted at right angles. Brewster's angle is when this occurs. Perhaps suggesting that engineering/design works predictably in most cases expect for certain special conditions.

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At 3 I found a piece of zip cord that someone had affixed a plug to each end. Why? Who knows? My dad taught vocational electronics and had a master electricians license, so perhaps it was some sort of test cord. In any event, I reasoned, preconscious, that the two plugs should be inserted into a duplex outlet. I performed the task and what we now call arc flash resulted. I believe that was the moment I became an EE. Been a great ride ever since...

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11 minutes ago, HRM said:

At 3 I found a piece of zip cord that someone had affixed a plug to each end. Why? Who knows? My dad taught vocational electronics and had a master electricians license, so perhaps it was some sort of test cord. In any event, I reasoned, preconscious, that the two plugs should be inserted into a duplex outlet. I performed the task and what we now call arc flash resulted. I believe that was the moment I became an EE. Been a great ride ever since...

I stuck a resistor in a receptacle when I was 4. Made a nice flash, black smudge on the wall and flew across the room.(The resistor, not me). Going on 27 years as an electrician then elec engineer. i know that story well...

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Just now, milotron said:

I stuck a resistor in a receptacle when I was 4. Made a nice flash, black smudge on the wall and flew across the room.(The resistor, not me). Going on 27 years as an electrician then elec engineer. i know that story well...

I took two watches apart in 2nd grade. Got my BSME, and got paid first to take things apart and fix them (machining new parts as required); now with MSE, I supervise people doing what I used to do, and plan making new things. Just don't make me do any electrical troubleshooting, I can't hold electrons in my hand, move them around and see how they're supposed to go . . . .

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I had the same problem where my taxi light was not turning on.  I ended up buying the kit from Mooney for $300.00 to re-route the wires for both taxi and landing lights.  I consider this a design mistake by Mooney and a fire hazard that deserved more attention (AD?) to correct it.  

 

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