DXB

My C has plenty of previous holes in the firewall that now contain plugs (e.g. that scary fuel containing pressure line removed after install of JPI, vac pump lines after removal of vac system). I bet it would be pretty easy to use that to run a cord through and seal around it with Permatex gasket maker. That conversion of the pilot window looks like more work and is also aesthetically challenged There are also flat power cords that you could close the cabin door over if you want to go that route.

The pilot-A&P is definitely a special kind of resource - the dual background creates efficiencies in communication and troubleshooting. Luckily, there seem to be lots of them out there, including in the Mooney world. I've been lucky enough to have at least 4 such individuals work on my plane in the last 7 years of ownership. The fact that my A&P has ample Mooney hours and flew my plane back to me personally after major engine work at last annual does add some confidence and trust. Also, it should be a standard expectation that the person doing the work will join you on a post maintenance shakeout flight upon request (getting paid for their time of course). I've only gotten a "I don't have time" once - I won't use that person again.

Surefly questions. The lead from the battery to the unit is direct, bypasses the master, and has a low power draw from the battery at all times. It seemed strange that they had a fuse in this lead right next to the battery and not a breaker on the panel for such a critical component, but I now gather that they wanted to minimize the distance between the battery and the fuse to negate the risk of a catastrophic short in that segment of wire. Questions: 1. Anyone know the correct 10amp fuse type for the SIM4N? Oddly it's not specified in any of their literature, and I just failed to get through to their tech support. Specifically anyone know if its supposed to be a fast blow or slow blow fuse? The one that blew for me was a Bussmann 4GC 10A (fast blow) fuse, but I'm wondering if someone put the wrong one in after the last time it blew. 2. Also any idea why it always seems to blow when we work on the right (conventional) mag?? It's now happened twice in that context. Luckily I'm on the ground and discover it after a difficult start followed by a failed left mag check. That's the only time I've had the issue in a couple hundred hours of flying with it. It would suck for it to happen in flight so I'm trying to understand why it blows. 3. It was pointed out to me that we have to carry spares for all fuses in our planes per the regs, and I now vaguely recall this from studying for the PPL, so it's time to start doing this, particularly since the Surefly fuse seems to like to blow. Any other hidden fuses in my '68 M20C that I'm not aware of? The panel is completely redone so some may have been removed. I can't find anything in the service or parts manual about fuses. BTW I already know about the fuse in the hookup for my battery minder.

Not sure, but carb idle mixture has negligible contribution to mixture at WOT so I doubt that caused it. Static WOT rpm of 2650 is pretty normal - governor will typically go to 2700 once you get going and the prop gets unloaded a bit.

I think I've had the liquifying Aeroshell #6 slowly leaking out onto one of my two Hartzell blades for a few years now. I'm just watching it because when I pump Aeroshell #5 into the hub periodically, grease comes out immediately from the opposite fitting with the first or second squirt, so I'm very confident the hub isn't about to run dry. One shouldn't try to flush the old grease out aggressively because the pressure of a grease-packed hub may really trash the seals during operation. Just pump until it comes out the opposite fitting or 5-6 squirts, whichever comes first. I think there is a good Youtube video from Hartzell on this somewhere. However mine is just a subtle sheen visible only on the inner surface of one blade, only just near the hub, and mainly in the hot summer months. That is WAY more grease than I've ever seen coming past my seals, and I'd worry that if it keeps up, you're gonna need a reseal job pretty soon or risk trashing your hub. Since the prop is low time, my worry would be that some ham-handed A&P already aggressively pumped your hub full of grease and thus totally trashed the seals.

So basically no change for 2021 (*fingers crossed for December).

As a new owner, I finally got to move into a T hangar that was quite a bit larger than my diminutive short body Mooney. The previous occupant of that hangar was a Piper Cheyenne, which fit with ease. However, the hangar turned out not to be infinitely vast - I trashed my left elevator the first time I pushed my plane back into it. Remember kids - The flight isn't over until the plane is fully secured in the hangar. You really should be able to log hangar entry and egress as PIC time.

Cheap fast good. One only occasionally encounters anecdotal evidence of this elegant mythical beast in the aviation world. By contrast, there are plenty of ham-handed Sasquatch-like shops out there.

I tend to file the full route to destination and then tend to cancel, or not, once I'm out of the SFRA, depending on circumstances and mood. I've never tried filing IFR to a fix. To be honest, I only do 3-4 departures per year out of the SFRA, usually from KGAI. I think the folks based inside the SFRA get equally comfortable with any flavor of departure. For me, it's easier to just file IFR than refer back to that kneeboard reference.

Ah, that flying b*tt pl*g rears its ugly head again. Kinda the anti-Mooney. I dismiss it solely on aesthetic grounds .

I fly in this area all the time. Whether you go VFR or IFR, they'll put you at whatever altitude they want you at in the NYC and Philly class Bs - in my experience it's not that different on VFR flight following vs. IFR. If you want max discretion, go VFR and stay clear of Bravo airspace until you get near Baltimore / SFRA. Flying in the SFRA is no big deal when VFR. All else being equal, I tend to enter and exit the SFRA IFR just 'cause I'm lazy -I don't want to waste mental energy thinking about SFRA flight plan entering through Wooly gate blah blah blah....

A request: Please post the number of accidents that had fatalities so far this year? I started a thread a while back after tabulating the # lethal accidents annually across the fleet annually since 1961. For the past decade, it was pretty stable at ~7/year when averaged over 5 year increments. Presumably the gradual decrease in size of fleet and hours flown over that period is continuing, so a big spike now would be particularly alarming.

A loud noise triggers a reflex that contracts the tensor tympani muscle, which pulls the ear bone attached to the eardrum (the malleus) inward into the middle ear space, thus tensioning it against the eardrum and thus stabilizing it from large amplitude movements that could damage the inner ear. A similar reflex contracts a second tiny muscle, the stapedius, which attaches to the stapes. The stapes is the last of the 3 little ear bones that connects the eardrum to the inner ear (specifically the cochlea) and makes direct contact with the cochlea via the oval window. The stapedius muscle thus directly prevents the stapes from banging too hard against the oval window of the cochlea, and the tensor tympani does so indirectly. The cochlea contains all those delicate hair cells that get damaged easily from either physical or chemical toxic insults, making us lose our hearing. The fact that these muscle protective mechanisms are evolutionarily conserved across mammals tells us how vulnerable the inner ear really is to loud sound. One can certainly feel some ear pressure from these muscles contracting in response to loud sound. There are also rhythmic spasms that some people can experience for these muscles even in absence of a sound stimulus that can be annoying. I'm not sure these reflexes have anything to do with the "ear suck" and some other types of dysphoria a subset of people experience with ANR - I tend to think not. I suspect those are phantom sensations that arise from aberrant sound processing within the neural circuitry of the auditory cortex of the brain. ANR forces the brain to process a strange new sound profile where the low frequencies just drop out asymmetrically. The central auditory system isn't adapted to process this kind of profile because it looks nothing like sound profiles encountered in the real world, and so the output the auditory cortex gives to your higher brain centers contains some aberrant signals. That's pure conjecture on my part, but there's surprisingly little that's known about the phenomenon it seems. I bet real hearing scientists who study the auditory cortex would have a lot to say about it. I'm not one of them though.

There are definitely times when I've stopped monitoring 121.5 in flight due to these distractions. Since 121.5 serves multiple serious functions and is also monitored by ATC, the constant meowing, LGB, etc. must annoy ATC as much as it annoys me. It probably also interferes with them using it to raise an aircraft on 121.5 from time to time. I gather there is also no recourse if some anonymous person were to abuse another ATC frequency either? If so, it seems strange that rarely happens.

That's actually my point - an ANR headset like your Telex 50D can afford to be comfortable by reducing clamping pressure (without ANR, an over the ear headset has to either be uncomfortably tight or bad at attenuation) - and the set you describe is only 4 oz heavier than a Bose A20 and 2 oz heavier than a lightspeed zulu.

A few misconceptions here.... "If your primary desire is hearing protection don’t get a Bose headset, or any other headset that doesn’t work well with the ANR off, reason is they are very poor passive sets, they rely heavily on the magic of ANR and that’s a great marketing tool. Salesman says just turn it on and see how good it is. Impressive isn’t it?" Don't use it as a passive set. A20s are inferior passive sets because the clamping pressure was reduced relative to over the ear passive sets in order to increase user comfort. Even with the reduced pressure, they provide objectively far superior noise attenuation in the frequency range where there's loud noise in our piston single cockpits. The fact that it facilitates cute salesman tricks is just a side benefit. "Problem is ANR can’t cover all freqs." True but it doesn't need to. The sound profile in our particular cockpits (i.e. turbines = different animal) is heavily biased toward the low frequencies where ANR excels, so it's not a problem. "So if you have a Bose or similar headset, wear the foam plugs under them and turn up the volume. The cheap foamies are actually extremely protective." Foamies are superior to ANR at the high frequencies, but that's not where the dangerous noise is in our cockpits, so the plugs aren't buying you much. The modest passive attenuation of good ANR headsets at high frequencies is more than sufficient for the low levels of sound present in the range of speech and higher. So all the plugs will do for you is force you to turn up the volume so you can hear ATC. Zero sum game at best. "Another way is to get a very good passive headset and add ANR to them, that gives you the best of both worlds, ANR on top of a good passive set really reduces noise." Again, an over the ear headset designed for optimal passive attenuation has a high clamping pressure. In principle, adding ANR to it may give the maximum low to mid frequency attenuation attainable, though foamies remain the gold standard for high frequency. But the added discomfort to the wearer doesn't seem worth it when ANR is so effective already within the sound profile of piston single cockpit noise. In the end there is no single optimal hearing protection strategy - each sound profile brings its own challenges. I'm just addressing the Mooney cockpit here.

That plane looks sweet. Price is high by conventional standards, but who knows in the bonkers current market - it may very well get full price. You can start there and work the price down depending what prebuy turns up. As always, start the inspect with the major deal killers - spar corrosion, steel frame corrosion, copious metal in suction screen and/or filter, evidence of undocumented and/or poorly repaired damage. If you get it, be of a mindset to shell out for an overhaul in the not too distant future - who knows when the time will actually come. And hurry up and finish your PPL so your new Mooney doesn't sit around and rot ! You could train in it also, but that will slow down your license considerably and also require you to find a Mooney-specific CFI who is willing to take you on for primary training.

Yup - I should have added any significant change from baseline (even at "safe" levels) for a given flight condition should warrant close inspection of the entire exhaust, not just the muffler. Also @PT20J makes an important point regarding much more CO at rich mixtures. The graph below is the best I could find to illustrate. Mixture changes obviously have a big impact while ROP, so it's not alarming for the baseline to be higher at takeoff and after GUMPS. Below a stoichiometric mixture, the curve flattens out significantly, but there are still potentially threatening levels of CO produced at even the leanest combustible mixture, so being deep LOP does not assure safety.

Getting back to the original question here before this thread had to shift to correcting misunderstandings of cardiopulmonary physiology. 10ppm in flight in and of itself should be no big deal, though admittedly its impact on hemoglobin oxygen delivery to tissue would increase as altitude goes up in a way that the OSHA standard levels don't fully capture. I originally didn't want a Sensorcon specifically because I didn't want to know about levels that low getting into the cockpit in flight - it provides a meaningless number as a source of stress without detecting real hazard. One could reasonably look for small gaps in the firewall and cabin floor that could be sealed easily based on that information, but those gaps aren't ever likely to become really dangerous. I've changed my opinion a bit after the experience of @AlexLev. He saw very low levels in the cockpit with the heat on, but his baseline with heat off was zero in flight. I told him to blow it off (pun intended?). Investigating further led to him finding a minute hole in his muffler leaking into the heat shroud - that tiny hole could have grown rapidly to become seriously life threatening in a hurry on a cold winter flight. It was a good early catch that was facilitated by the high sensitivity of the Sensorcon. I think the bottom line is that low levels are acceptable in cruise and perhaps inevitable on the ground. However, any increase upon turning on the heat warrants close inspection of the muffler.

This may address @midlifeflyer 's question... I wondered why the superior comfort and high frequency deadening of foam ear canal insert-based headsets haven't been effectively combined with the superior low frequency performance of ANR. I think part of the answer is that effective ANR for low frequency relies in large part on a microphone inside the ear cup to drive the cancelling wave generation algorithm. The insert-based headsets may not have room for such a microphone. There is this Bose earbud-based headset and a couple cheap knockoffs on the market that I suspect use an external microphone to drive ANR, but their performance does not seem suitable for the low frequency-biased noise profiles of our planes. They are marketed for jets exclusively, and I wonder if they're really any better than foam inserts in that environment. https://www.bose.com/en_us/products/headphones/aviation_headsets/proflight-aviation-headset-ii.html#v=proflight_hdst_ii_portable

Yeah I've noticed mine performs much better on LPV approaches in GPSS/HDG mode than ILS in Hi-Trk mode, which is kinda unfortunate.

I'm actually not sure what's back there. The mounting screw was actually pretty long because there is a gap between my panel and the hole for the screw. Once I got a screwdriver to touch the base of that hole, a 180 degree turn toward the course was enough to take away most of my 1500 ft offset. Then it took a bunch of trial and error with small turns in both directions before I figured out how precise it could get. I did the whole thing in GPSS while on a victor airway with the default nav page of my GTN650 measuring crosstrack in real time. I used a 1/32" screwdriver from a cheap set of jeweler screwdrivers like the one below. The black business end of the driver isn't nearly long enough, but the handle is so skinny that it fit into the screw hole in my panel and the one beyond it on the STEC30. I'm not sure a driver with even a slightly fatter handle would have worked. It took some trial and error feeling for the screw hole in the STEC30 head before I got the driver tip in the right place to work. https://www.ebay.com/itm/332853777963?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=332853777963&targetid=1262779892849&device=c&mktype=pla&googleloc=9010328&poi=&campaignid=10459841973&mkgroupid=123050527180&rlsatarget=pla-1262779892849&abcId=2146002&merchantid=116333718&gclid=Cj0KCQjw8p2MBhCiARIsADDUFVF6sDZ7-O_SKSIec3X895TTWaMS0ulyxUYpUEFNXS_jI6i-WjgsQYQaAqCSEALw_wcB BTW I did this over rural North Carolina in smooth air with no airspace or traffic nearby and a quiet radio. Still, the attention required did lead to some loss of situational awareness.

Agree oil on the nose wheel after it sits post flying is NEVER normal and worthy of immediate attention. Some good possible sources are mentioned above. In my case it was a loose mag. If you can’t find the issue clearly, then clean everything up really well, add a little uv dye to the oil, run up on the ground, look with UV flashlight carefully. Still don’t see it? Fly exactly one lap in the pattern (the oil blows everywhere so a prolonged flight will make it hard to find). Look again with UV flashlight. BTW there is not a good approved low cost dye choice I don’t think, but adding a little of this stuff is pretty safe in my estimate. The oil itself has a bit of fluorescent dye in it already so it might work even without adding something. https://www.toolsource.com/leak-detectors-c-1321_1_4/mini-12-led-true-uv-flashlight-and-dye-kit-p-150875.html https://www.amazon.com/ACDelco-10-5045-Multi-Purpose-Fluorescent-Detection/dp/B008I2VPC4/ref=asc_df_B008I2VPC4/?tag=hyprod-20&linkCode=df0&hvadid=312061979255&hvpos=&hvnetw=g&hvrand=7587869341174403223&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9010328&hvtargid=pla-570750857018&psc=1 https://www.harborfreight.com/uv-blacklight-flashlight-63931.html?ccdenc=eyJjb2RlIjoiOTQ2NTQxNTciLCJza3UiOiI2MzkzMSIsImlzIjoiNi43NDI1In0%3D&utm_source=google&utm_medium=cpc&utm_campaign=15142691993&campaignid=15142691993&utm_content=127879545743&adsetid=127879545743&product=63931&store=223&gclid=Cj0KCQjw8p2MBhCiARIsADDUFVESIAqm-wEAIPLVjAww_sinrGIH150QK5Q5w1LCtt8VdT0mRQee58EaAkUAEALw_wcB

Did this adjustment in flight this eve - definitely a win. I did it in calm air at 8000 ft in GPSS MODE. My cross-track error went from 1500 feet right of course to pretty much right on (oscillates 200-400 feet to either side). That’s as good as I could get it though. @Jim Peace’s 500ft error might not be that far off from what’s possible. I thought it might do a better job flying an ILS so I gave it a try - nope - it still acted like a drunken sailor down the localizer course. Oh well, I’m still gonna call it a win

For part 91, just IRAN it via a good shop, not overhaul. Cheaper, fixes everything you need and nothing you don’t. Overhaul means grinding the blades and if they end up thinner than spec (real risk, particularly if overhauled before) then you pay $$ only to trash the prop in the end. BTW a small amount of grease seepage past the seals is not a big deal. Usually its Aeroshell #6 grease, which likes to break down and liquify. If it’s minor, you can just keep an eye on it in this state for a very long time, top it off periodically with a couple squirts of #5 into the hub. If you get it IRAN’d the seals will get addressed. If the prop was IRAN’d or overhauled shortly before going on your plane 2 years ago, it’s probably best just to watch it. But with the AD hub, I’d be inclined to get rid of that painful AD if the prop is gonna come off the plane for service. In that case a different prop altogether may prove the most economical path.