Shadrach

During a VMC cross wind approach, I will sometimes opt to slip into the wind using rudder to hold runway alignment. However, that is not the same thing as skidding the airplane in level flight. Stalling in a slip results in the high wing stalling first. A skidding stall is how a snap roll is initiated.

If you have a wing leveler it sort of complicates the issue because the it will seek to hold the wings level during rudder inputs. Without it, the inside wing would drop naturally due to asymmetric lift caused by the yaw. If the pilot or wing leveler holding wings level while inducing yaw with the rudder, they are necessarily inducing an asymmetrical AOA as the inside wing will require additional up aileron and the outside wing additional down aileron to maintain level flight. Is it teetering on knifes edge? No...not unless done at an unusually low speed. but it's not good airmanship in my opinion. However, in IMC an overloaded/fixated pilot steering solely with their feet could get into trouble with little margin for recovery.

I have used diphenhydramine as a sleep aid. While it certainly helps me sleep, I feel groggy the next morning even though well rested. So much so that I need to be sharp, I would rather deal with minor sleep deprivation over the "hangover". IIRC, there was also a study published not long ago that found chronic diphenhydramine use correlated with dementia.

Though it is not supposed to, it is certainly conceivable that the combination of max RPM/piston speed coupled with full rich, single point of ignition (minimum combustion speed) could precipitate a rough running engine. With much of energy from combustion lagging behind the piston's power stroke and going out the exhaust. A little leaning would likely bring things back to a sufficiently harmonious state. My NA IO360 loses a noticeable amount of power when full rich, max RPM on a single mag. It does not run rough, but EGTs increase significantly. I can get back much of the lost power by leaning a little bit. It would not be a bad idea for folks to experiment with single mag operations at altitude so they are more prepared to diagnose and understand how ignition issues can affect combustion. One of my partners RTB'd and scrubbed a trip because he could not lean the engine upon reaching cruise altitude. It would go rough before peaking on the leanest (#3) or richest (#2) cylinder in spite of a perfect ground run up. He landed, called and told me he had canceled due to mag failure. It was simply a $hitty Champion spark plug on cyl #1 that was failing under load and going of line at about 2200rpm. Had he understood what was happening, he'd have only been delayed an hour.

https://safeskiesparts.com/products/mooney-m20-m20g-bungee-assembly-retracting-lh-rh-p-n-560138-501-0921-462 https://www.texasairsalvage.com/main_view.php?editid1=278797 Both Texas Air Salvage and Safe Skies have bungee assemblies in stock. The assembly from TAS is from an E model but the spring is the same. The safe skies is from a G model. I’d call them both as online inventory isn’t complete. I don’t know who’s searching for you but you’ll have better luck looking for bungee assemblies rather than the compression spring by itself. I found these two in less than a minute.

I’ve known more than one old school instructor that has advocated yawing toward the needle on an ILS. It’s not uncommon. I have also seen the technique used on VFR approaches to make minor corrections for runway alignment. I think it’s poor airmanship and have said as much in the cockpit.

Yes, just like a mag packing it in. Which in my experience causes a very small, almost imperceptible rpm drop for fraction of a second as the governor reacts to the power loss.

Good to know Savvy has identified the misfire. Have they offered theories as to a potential cause?

I don't really track oil consumption to the hour. The utility of the information is greatly over stated as most do not control for all of the different variables. Oil usage varies by oil level. If I topped off in such a way as to start every flight with the sump at max capacity (8qts) my usage would be very different from used some other lower target number. Oil puked out the breather can tell you something about cylinder health, but only at the extreme. Under normal circumstances it is near impossible to determine how much oil departs through the breather vs burned. One can say the same about compression numbers. They don't tell you much until the readings get extreme...and even then, it can be an one time anomaly. I fill to seven quarts when I change the oil and add a quart when it drops below six quarts On average, I add about two quarts between 50 hour oil service intervals. It's usually ready for a third quart when it's time to change the oil. I don't sweat the burn rate, but I do watch for trend changes but it has been consistent throughout the engine's life (to include one OH and an IRAN).

Absolutely. Which illustrates how poorly written/interpreted regulations can bend a straight forward scenario into an ambiguous, confusing and inconsistent reality. At least it contributes to safety...oh wait.

Indeed the gross costs to OPP this piece are significantly less than buying PMA...if you can find one. The question is how has such a scenario occurred. The most obvious answer is low volume and over regulation. However, the manufactures have some responsibility here. If several dozen people have collaborated to fabricate hard to get replacement parts, then the manufacture was obviously asleep at the wheel. We have a commerce section on this board. As far as I can tell, it's not being well utilized by folks with PMA. Seems small producers of STC'd mods are more interested in their potential customer base than the folks with PMA. What stopped Mooney or LASAR from offering a group buy to facilitate an efficient production run?

While that is not pretty, someone placed that blob of RTV there to prevent chafing. Can the group confirm that this is how all J models are routed? Are all of the top leads routed through a single grommet? My F has "2 wire" plates (shown below) that secure the leads where they pass through the rear baffle wall. They are obnoxiously expensive (>$60 Each)

I had a similar experience when my ignition switch rotated clockwise in the panel. The switch indexes (unbeknownst to me) no longer matched the labels in such a way the the "both" was actually "left". Full rich climb performance was diminished, but the engine ran as smooth as ever. Why would your engine miss on a single mag? It's not supposed to.

Agree that you can feel a mag drop off line as I have experienced it a few times. However, none of mine have felt like a "misfire". More a just perceptible rpm drop until the governor responds. Last time it happened neither pax nor copilot picked it up. I felt it and my suspicions were confirmed by an across the board increase in EGTs. I was LOP in cruise at the time. I suspect the symptoms would be diminished in full rich climb. Also, if the effective gap goes to 0 because of heat, wouldn't that cause the mag to drop off completely rather than intermittently? I am not doubting your theory or experience. I am just trying to get my head around the scenario and symptoms.

Well mine are 56 years old and show no signs of corrosion but they are probably steel.

I hadn't thought of that. With regard to you mag theory, I am confused as to how this would manifest as rough running unless both mags are manifesting the symptom at the exact same time. Also, why would it be intermittent?

The red stuff is possibly made up of bits of deteriorated sealant top coat or other debris that have been introduced over years for fueling and or occasional fuel tank services. Unlikely to be rust as there is no ferrous metal in the tank or the sump. Leaning for taxi is a fine habit in general, but do understand that a properly set up IO360 isn't prone to plug fouling with the mixture full rich during taxi nor is it prone to fouling at pattern power settings when full rich. Some pilots like to make complex aircraft operations more complex than needed. If indeed you had a mag or ignition lead dropping out, it is not significant enough for me to find it in your EGT data. Furthermore, the fact that you "feel" the sputter suggests more than mere incomplete combustion of a single plug or mag. It's a constant speed prop, the the load is no greater in climb than in cruise. Engine load is determined by the pilot's desired power setting not the airframe's AOA.

Are you reducing RPM in the climb? Are you leaning in the pattern? I'm sure there are those that will be more skilled than I am at analyzing your data. I am finding it quite challenging differentiate data that signal a potential problem from pilot inputs on mixture MAP and RPM. That being said, it is spark or fuel. I don't see a significant event within the other noise. FF looks good, Fuel Pressure looks good, so the fuel pumps and servo appear to be doing their jobs. EGTs are consistent with good fuel flow and correct ignition timing. Your description reads like a momentary ingestion of water, or perhaps an ignition issue downstream of the mags (short in an ignition lead). If you can see what you believe to be your misfire manifested in the data, can you post a screenshot?

It would be helpful to know what model you’re flying. The master cylinders are located in different locations depending on the model. If it’s a vintage bird, it is likely coming from one of the brake cylinders as Rich stated above. Unlikely you will pump everything overboard but I completely respect the decision to not fly it that way (though I’d personally not worry if ferrying it to 3k plus strip). Did you park it with the brake on?

https://www.chiefaircraft.com/aircraft/flight-instruments/compass-repair-parts/ap-l4vt-housing.html?gclid=EAIaIQobChMIs5fpy-fl_QIV5MiUCR0HpgP-EAQYBCABEgLfTvD_BwE If I were you, I would just upgrade to a SIRS. https://www.aircraftspruce.com/catalog/inpages/sirs_compass2.php

Looks that way. I would miss it in the summer time. I have to believe the designer intentionally positioned it so that it generates max airflow right up the left leg of the pilot’s shorts. I have flown a number of GA aircraft but Mooney is the only make that I have flown with “ball conditioning”.

67 F has one. What’s weird is that most Cs have them but some don’t. Does not seem to track model year. Vented 67 Vented 67 non vented 68 non vented 64

I used 1/2” super soundproofing with adhesive backing to insulate my cabin about 13 years ago. It sticks to aluminum but releases pretty easily (so far). It may have helped quite the noise a bit. I covered every surface and made ceiling inserts our of it. No rattles in the cabin. It seems to have truly helped even out temps in the cabin. The material has not deteriorated since installation. There is still a temp differential from front to back, but I don’t need to cook myself to keep the rear seat pax comfortable.

There are many subjective opinions being rendered here that I don’t think pass the smell test. Let’s take a try a totally different scenario. That I will intentionally make a bit more questionable. Let’s say I have a CAD drawing of a specific tool. It’s known to be accurate because I used it to have a tool duplicated for myself. An acquaintance of mine who has inquired about borrowing the tool learns that I have the CAD drawing. I give them the name of the machine shop that I used and tell them that the shop has drawing number XXX3762 on file. That person and several acquaintances take that information and decide to have several tools made for each of them. They all prepay for the tool, they all know the CAD files was developed from an original tool but they have one person go to the machine shop and make the initial request. Another member of the group calls to check on the fabrication progress. Yet another member picks up the final products and meets the other three in his shop. All of them review the supplied paper work which is in their individual names. All of them analyze the tools for quality and conformity. All of them test the tools for functionality. Is the machine shop a manufacturer or a fabricator? Did the group buy manufactured tools or did the group commission the production of tools with verified data?

It’s a 1979 231 that was last overhauled in 1991. See his first post.