Vance Harral

No, but I think doing so is entirely reasonable for pilots with plenty of interest in avionics (which is most of us). A lot of this has to do with what kind of equipment is in the airplane now, and whether the partners are really interested in just maintaining that exact same capability (and style), vs. staying at some Xth percentile of avionics cache' in the community. The former can be done less expensively, but a lot of pilots would say the latter is the real definition of "maintaining the avionics". Basically, they'll acknowledge they don't need an upgrade every time something breaks, but in the end they can't really stand the thought of flying with yesteryear's panel. As a specific example, you can't get a GNS430 repaired any more, and some people interpret this to mean that if their unit breaks, they "must" at least install in an Avidyne 440 (at considerable cost), because there is "no other option". But there are always other options, e.g. accepting a prolonged period of time without an IFR certified GPS, while hunting around salvage yards for a serviceable old GNS430, the same way one might have to do for a serviceable fuel selector or intake boot or landing gear actuator. If you take the latter attitude, the old GNS430 in your airplane is merely a $3-5K time bomb, not a $10-20K one. You can make similar arguments about autopilots, engine monitors, etc. Heck, we're still maintaining our Brittain autopilot, and we're not the only ones. I understand the concern, and I think there is no way around this risk in certain cases, e.g. a Mooney with a non-WAAS G1000 panel is a major liability due to a combination of integration, and how the STC is held by Mooney. But most of us don't have these corner case panels, certainly not in the vintage birds. What's a little more perilous/expensive/frustrating is how the system can change out from underneath you in ways that are out of your control. When we bought our airplane in 2004, a transponder was a dull gizmo that we didn't think much about, and had no plans to ever upgrade. We didn't set aside separate funds for "transponder maintenance" any more than we did for tires. But we had to shell several thousand dollars out of pocket for a new transponder in 2019 in order to continue legally operating the airplane in the metro area where we live. That was an unexpected cost, essentially a "forced upgrade". One could make the same argument about VOR receivers in the future, or even transponders again (I'm waiting for the powers that be to dictate we must have ADS-B diversity antennas in the US). So putting specific dollars per hour into an avionics kitty is certainly fair, and I wouldn't avoid a partnership that did so. Long story short (too late), I think you should talk with your partners about what it really means to "maintain" avionics, since there's a much wider swath of opinions about it vs. maintaining O-rings, rod ends, brake pads, etc. In general, I'd say a partnership of scroungers doesn't need a separate avionics fund, while a partnership of panel junkies does, even if both partnerships start with exactly the same equipment in the panel. Excellent, this attitude will server a partnership nicely. I don't begrudge those who feel differently, I just wouldn't want to be partners with them. That sounds like a great number to me, as long as everyone understands that some annual inspections uncover discrepancies that must be addressed immediately and vary wildly in cost. Whether to attribute such things to "the annual" vs. "maintenance that was coincidentally performed at the annual" is a regular source of discussion in our partnership. It's always complicated (and kinda fun, actually), but one guideline we use to decide is if we feel the affected component broke or wore out due to use (flight time) or just age (calendar time). In our case, we have separate logical funds for fixed vs. operating expenses, but the fixed expenses include maintenance items in addition to things like hangar rent, insurance, etc. The annual inspection is itself a fixed expense, so it's not a stretch to say that certain things addressed at the annual are fixed expenses as well. A trivial example of this is fuel-cap O-rings, which you might replace on a 1 (rubber) or 5 (fluorosilicone) schedule at the annual, regardless of number of flight hours. Most of the sole owners browsing this thread have quit reading at this point, after rolling their eyes right out of their sockets that anyone in a partnership really agonizes over the bookkeeping of O-rings. But I trudge on... One of the most difficult things to figure out in a partnership is how the partners really feel about "banking" money. Of course you want a kitty, but you need to treat the partners like grownups, and not overdo it. Requiring partners to bank money toward future maintenance expenses reduces the risk of someone coming up short, but it also requires them to pay opportunity costs for things that might never happen. Everyone has (or should have) a limit beyond which they're not willing to give a corporation they're affiliated with an interest-free loan. Even if that corporation is made up of their friends and fellow airplane pilots.

We've run our partnership for 20 years as of 2024, and have tracked this kind of stuff pretty closely, but only the past couple of years are relevant looking forward. Regarding engine/prop reserve, there is no way to set an hourly assessment that ensures the kitty is fat enough to avoid out-of-pocket costs at overhaul time, because you have no way of knowing when the engine will actually need an overhaul. Because of this, we choose to bill an hourly value that tries to approximate the market depreciation on the airplane as more and more time is put on the engine, which presently seems to be about $20-$25 per hour. This is related to the cost of overhaul and recommended TBO, of course, but it's not exactly the same. More importantly, the hourly depreciation is the same regardless of whether the airplane has 600, 800, or 1000 hours on the engine when the new partners buy in. To relate it to your specific question, I'd say $45/hour is much too steep, because the airplane isn't worth $45 less every hour it gets flown. It sounds like you're getting that $45 number by dividing your guess at overhaul cost by (2000-600), such that over the next 1400 hours you'll build up enough reserve to overhaul the engine for no out-of-pocket cost. Again, though, you have no idea when the overhaul will be needed, so that's not a realistic financial model. Instead, all the partners have to share the risk that the engine will need a premature overhaul, and everyone is on the hook for a share of the out-of-pocket cost (they can also share in the windfall if the engine goes well beyond TBO before needing an overhaul). The only way this works is if the hourly rate is based on market depreciation per hour, not the estimated cost of a future overhaul divided by a wild guess at how many hours it will be before that happens. To each their own, but I would not buy into a partnership that required me to pay an "initial reserve" on the engine, unless my buy-in price discounted the value of the airplane by exactly the same amount as the initial reserve. It kinda sounds like you're trying to get the incoming partners to cover some of the cost of the first 600 hours of depreciation, even though you were the only person enjoying the use of the airplane during that time. Regarding non-engine maintenance reserve, ours is currently set at $20/hour, and that's been adequate to cover status-quo upkeep. But we do a lot of owner-assisted maintenance, and we're also pretty formal about the difference between "upkeep" vs. "upgrade". For example, when our vacuum attitude indicator timed out a few years back, everyone paid out of pocket for the G5 installation, we didn't claim that installation of a G5 was just "maintenance" of the vacuum AI. We're not going to "maintain" our UBG-16 engine monitor by installing a GI-275 EIS when it malfunctions, or install a 201 windshield when the stock windshield gets too scratched up, and so on. If you choose to approach things this way, there is really no difference between the maintenance kitty for avionics vs. the maintenance kitty for tires, shock disks, heim joints, and so on. Things are maintained by replacing them with exactly the same thing. Anything different is an upgrade, subject to whatever voting procedures you use for upgrades. You didn't mention fuel costs, and that implies you plan on dry rates. Based on experience, I'd like to suggest you consider wet rates instead, that get adjusted a few times a year as fuel cost varies. I know this sounds like more trouble than a dry rate, but I think what most people miss is that it's simply not possible for every partner to always exactly replace the fuel they use at the end of a flight. Sometimes the fuel pump doesn't work the day you get home, and you're not able to drive back out to the airport the next morning to gas up. Other times one partner might ask another to deliberately leave the airplane down on gas so as to carry more payload, etc. In a wet-rate partnership, partners are simply reimbursed by the LLC for whatever fuel they buy, under any circumstances. In a dry rate partnership, events like the ones I mentioned create debts directly between partners rather than through the LLC, and that can lead to hard feelings. A wet hourly rate does deprive frugal partners of the opportunity to save money by gassing up at cheap airports and/or flying at reduced power, but the actual value of those savings is trivial in the scheme of overall airplane ownership, and in my opinion not worth the stress and risk to the partnership of creating fuel debts between partners. Finally, a word of advice: "add-on" partnerships like the one you're proposing sometimes fail because the previously sole owner never really treats the new partners like equals when it comes to how the airplane is operated. You've got to be at peace with the idea that you're *selling* the airplane, not merely lending it. On day 1 of the partnership, the new partners have a fully equal vote on how much gas to leave in the tanks, whether the airplane gets wiped down after every flight, how the seatbelts are stowed, what oil level to run at, whether the tow bar is left on the nose gear in the hangar or stowed in the baggage compartment, and so on. You need to avoid the feeling that you've got the airplane all figured out, and you'll teach the new partners how to operate it, and that can be pretty difficult. Regarding number of partners, we've had 3 or 4 at various times throughout the partnership, and that has indeed been a magic number for us. But... none of the partners fly overnight trips very often. Maybe 1-2 per year per partner. Obviously 4 partners isn't going to work very well if each partner wants to have the airplane away from its home base 90 days per year. That said, it's also worth noting that many people who buy into a partnership fly less than they planned/hoped, especially if it's their first airplane. I'm unconcerned when new partners approach our partnership stating they're going to fly 100+ hours per year, because I know that historically, most of them fly a little less than that the first year, and even less in the years after that. That knowledge makes it easy to be generous with scheduling. Most people are decent, and aren't going to take advantage in the long run, so you can build a really great partnership by being generous with scheduling and operating policies to your new partners in the early going. You might be a little annoyed that they don't put the airplane away the same way as you, but that seems pretty trivial in the long run when you build a great friendship, and every unexpected cost is split across the partnership rather than borne by you alone. Best of luck with your plans!

@amekler there may not be anything really wrong with yours. The intensity of the display is controlled by a potentiometer. Over time, with vibration of the panel, dirt, etc., this potentiometer can lose slider contact, resulting in the display intensity going to full bright or full dim. Simply wiggling the potentiometer back and forth a bit can often re-establish contact and restore reasonable intensity. We have had exactly the same problem as you, and I was able to resolve in just a few minutes with a small screwdriver. Instructions from the installation/maintenance manual are shown below. Suggest you slide the box out of the panel, tweak the display potentiometer a little, and re-install. It can't hurt, and might help.

I hesitate to say this in public, but after posting and asking questions like this about the oil stains on our gear doors and exhaust tunnels for years, our long-standing mechanic finally said to me one day, "Son, you need to either overhaul the engine, or lower your standards." Certain oil leaks that are benign from a safety perspective, simply cannot be fixed without maintenance that is just as likely to cause serious problems as it is to fix the annoyance of the oil leak. In our case, the main source of the leaking oil is the gasket seal on the oil pan, which is quite long in the tooth. This could definitely be addressed without an engine overhaul, but it would require removing the oil pan, which first requires removing the exhaust, which first requires removing the lower cowl, and so on. All of that could generate more serious problems. A bit of leaking comes from the rubber couplings on our oil drainback tubes, as @Yetti notes. When this first started, we tightened the hose clamps a bit and got it to seal, but eventually the rubber got pretty brittle, and it's more or less impossible to keep it bone dry without replacing the couplings - which maybe can be done without removing exhaust and/or induction tubes, but it's a pain. We have a couple of pushrod tubes that leak chronically at the seal near the cylinder head. The gaskets have been replaced multiple times, but they continue to seep. When we had cork valve cover gaskets, they'd start seeping after a year or two, though that's gotten better with the silicone gaskets. Sometimes seeping oil comes from a blown main seal at the crankshaft. We do check for this, and address it when found. But it's not really a critical airworthiness issue, and the prop has to come off to address it. One time the mechanic who removed the prop showed me how the previous mechanic to remove the prop botched the prop bolt safety wiring on re-installation. We do wash the engine at every annual, inspect for oil seeps at the crankcase seam and cylinder attach bolts, look for cracks in the case, etc. More importantly, we try pretty hard to wipe the oil off after each flight, so that we're starting from a relatively clean state, and can check after the flight to see if the amount of oil on the gear doors and exhaust tunnel is "normal". Bottom line, I've come to accept that while we'd all like a bone-dry engine, the design of the engines we fly isn't really conducive to staying dry through thousands of hours and dozens of years. Most of the Lycoming/Continental engines I see in the shop and on the ramp leak some amount of oil - particularly flight school airplanes and those flown for hire. For better or worse, I've abandoned the dream of a dry engine... at least until overhaul time.

Getting back to the question of ground testing... you should be able to do this using the OBS mode of your GPS. I'm not going to give a blow-by-blow detail of OBS mode here - you can read about it elsewhere - but in short it's the GPS equivalent of a VOR. You select a waypoint on the GPS, and a course relative to that waypoint, and your CDI needle (and the data fed to the navigation system) will indicate your position relative to that course. By selecting different courses, you can make your present position be "on course" or "left of course" or "right of course", without moving the airplane at all. If you enable your autopilot, it should move the control wheel to make a left or right turn accordingly, to intercept the selected course. As others have said, to test roll steering (GPSS), you'll want to have the autopilot in heading mode while you're doing this.

That's one of my favorite tricks, I use (and teach) it all the time.

Each PIC gets to make their own judgement calls, and I don't know anything about you personally, so don't take this the wrong way. That said, most of the unofficial line-up-and-wait I observe at my local non-towered field does essentially nothing to help with spacing. It is instead - intended or not - merely a way for an airplane on the ground to bully their way in front of an aircraft approaching to land, by establishing a dominant position on the runway. Most of the time things works out fine, but on the occasions they don't - which is not that uncommon - the approaching aircraft is forced to go around, while the departing aircraft still gets to depart as desired. There is then sometimes a fight on the radio where the departing aircraft insists the go-around aircraft should have stayed on the approach and that there was plenty of room. Even setting aside the immediate safety implications of the go-around, that makes line-up-and-wait sort of a jerk move by the departing aircraft, that occasionally creates a secondary safety problem while people fight on the radio about what just happened. When people ask me about this in an instructor capacity, I suggest they time how long it takes for them to taxi from the hold short line to the runway center line. Some airports have strange configurations with hold-short lines that are a long way from the actual runway, and it takes 30+ seconds to taxi the distance. I think reasonable people can agree that maybe there is a place for "unofficial LUAW" in that environment. In contrast, at my home airport, a competent pilot can taxi from the hold short line to the runway center line in about 10 seconds. An airplane approaching at 65 knots covers about 1100 feet in 10 seconds. It's my assertion that if you're trying to insert yourself into a slot where an extra 1100 feet of distance is the difference between going and not going, you are probably missing the bigger risk management picture.

A cap that fits the OEM switch in 70s-era Mooneys is this one: https://www.mouser.com/ProductDetail/690-SW53AA2 But... the problem a lot of people run into is that as those switches malfunction over the years, they are often replaced by shops with a switch that is equivalent in function, but not exactly the same, such that the OEM caps don't fit. There's nothing particularly shady about this - the OEM switches can be hard to find, and are often superceded by other parts. They're also "standard electronic parts", and a reasonable interpretation of the rules allows replacement of simple electrical switches with equivalents that are not exactly the same dimensions. So... your best bet is actually to replace the whole switch, along with caps to match. Perhaps with this one: https://www.mouser.com/ProductDetail/690-SA1BV20, which matches the caps above. Doing so is straightforward if you're handy with a soldering iron (and if there's enough of a service loop left in the wiring, otherwise you have to replace the wire or add extensions). I'll leave the legalities of DIY to others to pontificate on. Word of advice about the caps: either buy a whole bunch of them, or have the gumption to place a drop of CA or plastic glue on the cap when you stick it on the shaft. The caps just press fit onto the switch shaft. They're not particularly secure, and they don't stay in place very long in the cockpit environment. When they come off, they often get lost in the seats, carpet, or down in the bowels of the belly. You can guess how I know this, and it's probably the reason your caps are missing in the first place. I went through my whole stash of caps a while back, and gave up - we're back to just stabbing our thumbs on the tiny little shaft.

You're absolutely correct that statistical risk across a population doesn't necessarily map to any particular individual. ... but that's still the way to bet, including on yourself. About 1/3rd of all VFR-into-IMC accidents involve instrument-rated pilots, and about 1/3rd of all landing accidents involve pilots with a Commercial or ATP certificate. There's nothing particularly mysterious about this - pilots with instrument ratings are more willing/likely to fly in marginal VFR conditions, and those with advanced certificates are more likely to fly to challenging runways in challenging conditions.

The advantages of a feathering prop are a tradeoff against complexity, and new potential problems. Even if the feathering mechanism was free and weightless, some designers and owners might still choose against having one in a piston single. In a piston prop twin, single engine service ceiling and - more importantly - controllability, are so severely affected by a windmilling prop that feathering capability is a no-brainer even with the complexity and potential problems it brings. But in a single, the only thing you're buying with a feathering prop is a slight improvement in glide range, in the event of a total engine failure that doesn't affect the ability of the propeller to rotate. Note that feathering in a single doesn't help you at all if the engine is still making partial power (often the case, and in that case you want all the thrust you can get); or if it seizes suddenly enough that you don't get it feathered before rotation stops. In exchange for the benefit of feathering in the small number of cases where it actually helps, you get all the failure modes of the feathering hardware . Those include sticking of the anti-feather shutdown pins, such that the engine feathers on shutdown and is hard on the engine and battery on the subsequent restart; as well as the unlikely-but-catastrophic case of accidentally feathering the propeller in flight at full power, which tends to damage the engine. And because it would be very high risk to practice feathering and securing the only engine in a single-engine airplane in flight, you'll never train to do this "in real life", only in a simulator or on the ground. Most of my multi-engine students have a pretty difficult time getting the feather/secure sequence exactly right on their first "real life" attempt, and I suspect the error rate would be even higher amongst pilots of single-engine feathering propellers, who do not hold a multi-engine rating and regularly train the feathering sequence in multi-engine airplanes. I'm not really arguing that a feathering prop in a piston single is a bad idea. Just that it's not the no-brainer it might seem to be at first glance, even setting aside the large cost and small weight penalties.

Coincidentally, this week's update of the AOPA McSpadden report re-organizes the data in a way that specifically breaks out collisions, including by phase of flight. Here's the fixed wing, non-commercial data for the most recently available full year (2022): https://www.aopa.org/training-and-safety/air-safety-institute/accident-analysis/richard-g-mcspadden-report/mcspadden-report-figure-view/?category=all&year=2022&condition=all&report=true For those who don't want to pore over the charts, here's a quick breakdown of collisions in 2008 vs. 2022, which arguably spans the time period when in-cockpit traffic displays became ubiquitous: landing: 2 nonfatal in 2008, 1 nonfatal in 2022 takeoff and climb: 1 nonfatal in 2008, 1 nonfatal in 2022 maneuvering: 1/2 nonfatal/fatal in 2008, 1 fatal in 2022 descent and approach: 4/2 nonfatal/fatal in 2008, 2 fatal in 2022 enroute: 1 fatal in 2008, 1 fatal in 2022 taxi: 13/1 nonfatal/fatal in 2008, 10/0 nonfatal/fatal collisions in 2022 It's interesting to note that the overwhelming majority of collisions occur while taxiing. It's unclear to me if the landing and takeoff collisions occurred on the runway surface, or just after takeoff/just before landing, but I'm guessing they're probably on the surface, especially given that... ...there is an important note in the data stating that each aircraft involved in a collision is counted separately in the data. e.g. a classic "midair" is reported as two incidents, and any data point showing only one incident involves a collision with something other than another aircraft (probably a tower or cable in the air, probably lights and signs on the ground). So I think - my guess only - that the midair collision concern that traffic displays address, is contained in the fatal maneuvering, descent/approach, and enroute data, where there are an even number of incidents. That's 4 incidents (2 collisions) in 2008, and 2 incidents (1 collision) in 2022. It's debatable whether traffic displays have driven a 50% reduction in midairs, or if the numbers are so small that it's just noise in the data. It would be interesting to create a separate graph for every year to see how things move around. But what's indisputable is that that the average pilot is ten times as likely to kill themselves due to loss of control (the breakout says that in the descent and approach phase, for example, there were 29 fatals in 2008 and 17 fatals in 2022), as they are to die in a midair. I think one should plan their risk management focus appropriately. All this only applies to the average pilot, though - not gods of the sky who would never lose control of a perfectly good airplane. For that latter group, obviously "the other guy" is their biggest risk, and it makes sense for them to focus a lot of attention on midairs, and little on stick and rudder. Up to each of you to decide which group you're in.

Old instrument instructor's axiom: the more ridiculous the hood looks on you, the better it works. Anything that looks like a cool pair of shades is marginal at best. We're jiffyhood fans ourselves, just pull the strap over your headset. Trivial to raise it up at the end of an approach when you "break out".

Sure. A couple of months ago I was asked to assist with recurrent training for a client who was returning to aviation after a long hiatus. Despite the layoff, he was a good stick, and flew the pattern nicely. But only after I took his iPad away. On the first downwind leg, he has his head absolutely buried in the iPad, and was extremely concerned about a couple of other airplanes on or entering the downwind. I s**t you not, he spent more than 50% of the flight time on the entire downwind leg with his head in his lap (I know because I watched his eyes, like I do with all students). Meanwhile, he allowed the airplane to accelerate to over 100 KIAS (this was a 172), climb almost 200' above traffic pattern altitude, and was unable to conduct a stabilized approach. Again, he had no problem maintaining reasonable speeds and altitude profies in the pattern once I took the iPad away. When I asked him about this, he said he felt it was important to get acquainted with the "new technology", and talked about how much safer he felt with it. But no one had ever given him any training on how to use it, and he was stunned to hear me say he was making himself less safe. I did my best to do so politely, using some of the data discussed here. He finished the checkout with another instructor, and it's unclear to me what impact my training had on him. Another: last week I was established on downwind with a student in a specific training scenario (power-off 180 in a significant crosswind), when an airplane from the flight school down the road reported inbound on the VOR-A approach to my home drome. I'm very familiar with the approach. The MDA is 600' AGL, and flown properly, inbound aircraft are established at 600' AGL well before crossing the downwind leg for the runway on a perpendicular course, enroute to a midfield flyover and missed. There is no conflict between the VFR traffic pattern and this approach, when everyone has eyes outside (and augmenting that with ADS-B traffic data is great). But rather than continuing to simply report position, the inbound aircraft identified us by call sign and issued us an instruction to do a 360 to accommodate them. I've had this happen a couple of times, and I'm always incredulous. But that's actually not the relevant part of the story. Doing what they asked would have both compromised my training scenario and created another conflict with an aircraft behind me, so I replied "unable", to which the response was, "we have you on ADS-B, we'll blah, blah, blah", at which point their aircraft blindly maneuvered to head directly toward the location of our downwind-to-base turn, and climb right through the pattern altitude. I presume this is based on what they saw on ADS-B based on their last announcement, but who knows? In any case, they clearly had positional awareness, but not situational awareness. Another example, less interesting but still to the point: traffic is congested enough in our metro area that a "common training frequency" has been established, which all the local flight schools would like pilots to monitor if more than a few miles from any particular airport. I'm unconvinced this is helpful, but I'm not a jerk, so I do monitor it, and do my best to be polite. I routinely get calls to my N number from aircraft that are multiple minutes away from a possible conflict, asking me to "say intentions", and wanting to negotiate separation even greater than what the professionals who staff ATC require. Again, I try not to be a jerk about it, but the minor irritation is that it unnecessarily distracts from training; and the major issue is that I've seen it create bizarre panic on a couple of occasions when more than two aircraft happened to be vaguely in the vicinity of each other, but not anywhere near a real threat. If you've never seen or heard things like this, I respect that. But don't tell me I haven't seen and heard it with my own eyes and ears. There is definitely fixation and distraction going on out there. The bottom line argument in this thread isn't whether ADS-B is "bad", no one is saying it is. The opposing positions are between "Traffic displays are easy to use effectively, never a distraction, and represent a huge safety improvement", vs. "Effectively using a traffic display is complex and can be counterintuitive, and it provides a moderate benefit against a tiny risk, at the possible expense of a small increase in larger risks". In this respect, your comments about airspeed indicators are actually a great conversation piece. We have a finite amount of time to be "heads down" in the cockpit, so what do you think the risk is of taking time away from checking the ASI while in the traffic pattern, in order to look at your traffic display? Yeah, yeah, I'm sure you can do both at the same time - you're an excellent pilot, you can pat your head and rub your tummy, etc. But the accident data is right there in black and white: huge numbers of takeoff and landing accidents, very tiny numbers of midairs, and this hasn't changed since ADS-B became commonplace. As an instructor, should I really be telling other pilots, "I see you're looking at the airspeed indicator a lot, you really should spend more time on your ADS-B display"?

This is a cool picture and certainly shows that the Stanfield stack is busy. But it also illustrates the emotional effect of zoom scale. In this clip from the image above... ... there are four airplanes inbound on the approach to KCGZ, and another two in the vicinity, in addition to the ownship. Sure looks busy. But the distance between the VOR and the airport is 8 nautical miles. The very closet airplanes in this image are about 2nm apart, and the case that is nearest to head-on probably has a closure rate of about 200 knots groundspeed, or about 30 seconds of time at 2nm. Certainly worth paying attention to, and having the depiction on ADS-B is useful. But none of the airplanes in the picture are (yet) in a "near miss" scenario by anyone's definition, even if they were all at the same altitude; and everyone is less close than the traffic pattern at many uncontrolled airports on a Saturday morning. It's also worth noting that while your average GA airplane is about the size of a house, the icons in the depiction suggest a single airplane is about as big as the entire city limits of Casa Grande. My experience working with clients is that these issues of scale/zoom are often poorly understood, leading to inappropriate fixation. For better or worse, this is what I think about every time someone posts an ADS-B depiction of all the airplanes inbound to Airventure being "crazy"; or says something like, "you just don't realize how many airplanes are out there"; or expresses certainty that a threat they saw on ADS-B would have speared them but for their superior situational awareness and valiant maneuvering. Of all the bad things that could happen to the airplanes in this picture - basic loss of control, mechanical failure, etc. - a midair is the lowest risk by far, even given what it looks like on the display. Presumably the pilots in this picture are all working on their instrument skills, and that training results in significantly more risk reduction for them than the risk of the stack itself. To hear some on this thread characterize it, operating in the Stanfield stack or something like it without devoting a significant amount of attention to traffic displays is a death trap; and yet as has been noted, the stack was around for decades before ADS-B traffic became commonplace. That doesn't mean ADS-B traffic is worthless or that pilots shouldn't use it. But the folks saying, "If it saves even one midair it's worth it" are ignoring a crucial part of the calculus, which is, what other risks increase and how much additional maiming and death is caused by fixation on a very small threat, to the exclusion of more significant ones? In a world of finite resources, fixation on shark repellent instead of swimming lessons may be a bad idea, even if it conclusively prevents a single shark attack.

The caveat is that this information can be of limited value unless you're already pretty close to the airport. Seeing the direction and density of pattern traffic at an airport a few minutes away is helpful. Less so when you're 10+ minutes out, because things can change a lot in 10 minutes, at least in some areas of the country. This is especially true in the dense metro area where I teach, hence my sensitivity to it. There are no less than 7 GA fields one could choose to practice pattern work at, within reasonable flying distance of each other, even on a short lesson. I can't tell you how many times I've had an instrument or commercial student say something like, "Hey, it looks too busy at KXXX, let's go do our pattern work at KYYY where it's easier", only to find that in the short time it takes to get to KYYY, that airport has become a beehive while KXXX has gone quiet. Because of this, I no longer base my planning on what traffic appears to be doing on ADS-B at an airport that's more than a few miles away, and that just feeds back into my arrogant opinion that traffic displays should prohibit zooming out more than a few miles. More generally, one of the common mistakes I observe training advanced students is a stubborn assumption that airport conditions won't change between the time they first think about them, and the time they actually get close to the airport. Ironically, this problem gets worse the better the student is at staying ahead of the game. It's admirable to check winds, etc. via ADS-B or ATIS/AWOS when you're 20+ minutes away from an airport, but if you do that, don't forget to spot check them again when you get closer.

Absolutely. The graph you posted shows the accident rate per 100K hours has declined from 5.82 to 4.84 in the last 10 years, a roughly 20% improvement. The fatal rate is also about a 20% improvement. No argument there. But you seem to conclude this is mostly or at least largely a result of improved technology. The accident data doesn't support that at all. The graph that's relevant to this thread is this one: That's for 2022. You can take my word for it (or not) that the graphs for the past 20 years are essentially identical. Midair collisions are in the "other" category. It's difficult to tell how many of these were actually midairs vs. other "others". But it's probably reasonable to estimate that midairs are roughly represented by the fatals. That's 3 in this case, which is about 0.3% of all accidents, and about 2% of fatals, both of which are statistically insignificant. So that 20% reduction in overall accident rate isn't coming from a reduction in midairs due to ADS-B improving threat awareness. I'm sure some of it comes from other technology - onboard weather, better maps and backup instruments in IMC, etc. But it's worth noting that the majority of accidents occur during takeoff and landing (557 out of 965) , and by definition fall into the "loss of control" category (again, collisions are in the "other" category). Technology essentially never helps you avoid a takeoff crash. It can help avoid a landing crash to the extent you might divert somewhere else with better conditions to land in, but I'd wager only a very small number of those landing accidents fall into the, "I wouldn't have tried to land here if only I'd known earlier in the flight that the conditions were challenging" category. I think you're misrepresenting my position . I never said that no one should be allowed to spend money on technology, or that it should be banned/shunned. I said that when you have X amount of dollars and or time to spend it on "safety", upgrading the avionics in your airplane - and demanding others do the same - is almost never the best use of that money and time. Now, there are lots of good reasons for avionics upgrades other than safety. They're fun (I'm an electronics nerd, I really enjoy playing with them); they can make a flight more comfortable; and to the extent they make you feel safer, there is some indirect safety value in that even if you haven't actually changed your direct risk profile. But what gets my hackles up is stuff like this: To the extent this is true of ADS-B, it's at least as true of training with an instructor, and per the data above, arguably much more so. So... the bare minimum training requirement for Part 91 ops is a 1-hour flight review every two years. Is everyone who pursues no additional training beyond that also doing a disservice to themselves and everyone around them? To be clear, my point is no so much to shill that everyone should get more flight instruction, but just to point out the curiosity of the passion around technology - particularly that designed to reduce midair collision risk - vs. the "meh" attitude toward everything else that is much more likely to hurt you, and somewhat more likely to hurt others. Bottom line, if you're going to start throwing around opinions about what you think every other pilot should be investing their time and money on, it better be backed up with data; and mid-air collisions ain't. The fact that one can post an occasional story about a midair where ADS-B might have made a difference doesn't change the risk profile. As tragic as those accidents are, they're still a drop in the bucket vs. the things that actually put us most at risk. Focusing on them is akin to investing a bunch of money in shark repellent for a beach vacation, instead of on swimming lessons.

This is a great question, and I think it's really the crux of the matter. It's certainly the reason why I tend to get my hackles up about this stuff. An aircraft that is "near" certainly presents more risk than one that is "far". But my experience flying with a lot of other pilots is that many of them are unable to appropriately internalize what actually constitutes "near". A comical example of this - but an honest-to-god-true-life-story - is a pilot I flew with whose display showed no threats at a particular time during the flight... so he kept zooming out until he found one (any aircraft looks "near" if you zoom out far enough). Then he got fixated on maneuvering to avoid this wildly distant threat, instead of paying attention to something more important. This resulted in him basically losing control of the aircraft (uncommanded attitude change under the hood) while trying to figure out what direction to turn to avoid an aircraft that was multiple minutes away (and likely was going to turn away from us anyway). That's an extreme example, but I see variants of this quite a lot - pilots who are very concerned about midair collisions, who spend an inordinate amount of time looking at traffic displays trying to analyze threats that are objectively tiny, to the detriment of managing other risks. It turns out there's a pretty narrow range in which traffic displays actually help. If you're 5 seconds from a conflict, they're unhelpful because they tend to indicate bad position data, just like @MikeOH noted above. The delays in the ADS-B network are indeed very small, as the reference posted by @Aaviationist indicates. But that study ignores delays in the display device (maybe a couple of seconds for a Bluetooth-connected iPad which is the most common setup), and delays in the pilot's scanning of said device (maybe very large). At the other end, if you're more than 60 seconds from a conflict, the information just isn't relevant - you don't actually know if there's a threat, and the best course of action is to just keep doing whatever you're already doing. If I had my way, no traffic display would be capable of zooming out beyond a couple of miles. In the narrow range between "too far to care" and "too close to help", ADS-B traffic displays are really helpful when used properly, and all the arguments extolling their virtues make sense. Airplanes in the same traffic pattern or holding stack with you fall into that range, and people pointing that out have a strong argument. But it's worth noting that's also when all your other risks unrelated to traffic go way up. I flew with a pilot earlier this year for an aircraft checkout who was incapable of maintaining pattern altitude and appropriate heading and airspeed on the downwind leg of the traffic pattern, because he was completely heads-down on his iPad, and terrified of a couple of other airplanes trying to work into the pattern. That's just a single anecdote, but again, I fly with a lot of pilots as an instructor, and I see a lot of variations on this basic mismanagement of airmanship. One thing that would help is if the industry could put together an AC on how to effectively use traffic systems. Today, there's just an assumption that the way to use them is "obvious", and that's a lot of what all the arguing is about. One of my fellow flight instructors wrote a great article in the NAFI Mentor magazine about this. I don't have a link, because it requires a subscription. But the gist of it was to define certain ranges to the threat, and appropriate actions to take in response to threats in those ranges. Outside a certain range, no action is warranted and there is no value in paying attention to the threat. Once a threat moves inside a "noticeable" range (30 seconds or so of closure), a single, predictable, course or altitude change may be warranted before visually acquiring the target - especially if that change actually helps you and the threat acquire each other visually. But if the target moves inside a "critical" range, blind maneuvering is as likely to cause a collision as it is to prevent one, and the best action is to maintain course and altitude while working especially hard to visually acquire the threat, perhaps to the extent of paying less attention to your usual fly-the-airplane duties. Only after visual acquisition is maneuvering appropriate inside this range. Everyone is free to disagree with this strategy, and would be even if there was an AC. But @EricJ is asking a really good question: not if ADS-B traffic data is helpful, but when. Especially relative to other risks.

The problem with this kind of thinking is that all of us have finite limitations on the amount of time and money we spend on "safety", and those resources often wind up being misdirected. Consequently, the most important risks aren't mitigated, and the rate of maiming and death stays about the same. Scientifically, this is borne out in accident data. CFIs who enroll in a FIRC every two years get data jammed in our face about it. The rest of the pilot community could benefit from at least a casual look at it. AOPA does a good job with their annual McSpadden report. Here's a link to the data from 2022, which is the most recently compiled year: https://www.aopa.org/training-and-safety/air-safety-institute/accident-analysis/richard-g-mcspadden-report/mcspadden-report-figure-view/?category=all&year=2022&condition=all&report=true Anecdotally, in my neck of the woods, some of the biggest risks to the aviation community are the aircraft with $100K of avionics, flown by pilots with so little recent experience that they can barely keep the greasy side down, and have almost no ability to really grok where other traffic is in the pattern (or the stack, or the airway, or whatever). Imagine how much better things would be if those pilots kept their airplane on the flight line instead of in the avionics shop, flew more often, and spent a few bucks on training with the local CFIs, or even just flying with more experienced friends. But this seems to be a loser of an argument, primarily because humans are terrible at data analysis and risk management. For better or worse, those folks really believe their big avionics upgrade was a great investment in safety, and scoff at others who are less-well-equipped as being "too cheap for aviation". Those pilots aren't going to read the McSpadden report; or even if they do, they think it doesn't apply to them. So yes, I do think "all of the other safety precautions we routinely take to mitigate small risks" are often inappropriate. Not because it's wrong to mitigate all risks, but because we live in the real world where no one has infinite time/money/energy to actually mitigate all risks. If you can't mitigate all the risks, you should focus your time and attention on the biggest ones. That requires the curiosity to actually look at the data, and the humility to accept that you are not somehow a special pilot, whose risks are different than average.

Most of the value in getting an instrument rating comes from developing the ability to easily and precisely control the airplane with less and less cognitive power, such that you have more and more cognitive power to tend to other things: reading charts, programming navigation, obtaining weather, interacting with ATC, scanning for traffic, etc. Pilots who obtain an instrument rating get fairly good at this, at least at the time of their check ride (the skills lapse if you don't use them). These skills certainly make one a better and safer pilot, but there are other ways to develop them without getting an instrument rating of course - mostly just a lot of cross-country flying with flight following. The rating itself may not have much value to any particular individual - especially if they do most of their flying in a part of the country where the weather is not conducive to flying a piston single regardless of having the rating.

Shaw (now Parker Aerospace) made a lot of different fuel caps with a 3" diameter and 120-degree, three-tab locking mechanism. They're not interchangeable from a paperwork standpoint, but one flavor often fits in the hole designed for another... except for maybe the orientation of the tabs/holes. Between honest confusion over part numbers, willful ignorance, and the reality of maintaining aging aircraft, I think there are a lot of airplanes flying around with Shaw caps that are functional, but technically incorrect for the airframe. Incorrect "clocking" of the cap is possibly a clue you've got the wrong flavor of cap on the airplane, but not necessarily. I used to be all pompous about this, and say any airplane with Shaw caps that could not be installed with the tab pointing directly aft, clearly had the wrong caps. But I've never been able to find actual guidance from Shaw/Parker or any airframe manufacturer about the orientation of the tab, just a bunch of people on the internet who say, "I was taught ..." The closest thing I've found to official guidance is that the illustrated parts catalog for some airplanes depict Shaw caps in a particular orientation. But I'm not sure that's really intended to convey there is only one correct way to install the cap. Even if it did, IPCs for different airframes show different orientations.

I used to ask the A&P/IA who did our annual throughout our first 10 years of ownership, about our smoking wing rivets, basically every year. We have a lot of them, but he was completely unconcerned about it, particularly given the ugly cosmetic condition of our airplane. Finally, when I asked one too many times, he said something to the effect of, "Alright Junior, the straight dope is that if it's really bugging you that much, you can re-buck a rivet exactly one time, and it *might* stop the smoking, but no promises". So I gave it a try, and it didn't seem to help. For better or worse, I quit asking about it after that, which was over a decade ago. The fact the wing hasn't come off since then doesn't necessarily mean it's OK to ignore the smoking rivets, but it's a data point. The concept of re-bucking relies on the idea that the original installation didn't work harden the material enough to prevent it from further deformation, i.e. that there is still some "give" left in the rivet. It also assumes the problem is a rivet that was never set correctly in the first place, rather than something else causing the rivet to move. All of that is a crapshoot. If you really want show-plane quality with absolutely no smoking rivets, I think you're in for a long haul of drilling and replacing, and you have to carefully examine each drilled out site to ensure the hole in excellent shape to receive a new rivet (which may not have been true even when it was built at the factory). I've never been able to find official guidance that matches my mechanic's "you can only rebuck once" advice, maybe that was just lore. But if true, it's irritating, since even the best maintenance logs are not going to identify re-bucking of individual rivets, especially given that the factory might have done some re-bucking themselves. So in practice, I think it's essentially impossible to tell in advance if re-bucking is going to correct a smoking rivet or not - you're not necessarily going to have the same good/bad luck someone else had, there is too much variation in circumstance. All you can do is try it.

Just for reference, here's what mine looks like at present (no LASAR cowl closure).

@Ragsf15e's picture exactly matches what our 1976 M20F looks like today. I think the flat head screw with the countersunk washer at the rear of the cowl is OEM; and that the one at the front of the cowl is actually not. I think the one at the front originally matched the other two truss-head screws up there, closer to the prop; but that IAs get nervous about the underlying hole getting ovaled out much larger than the diameter of a #10 screw as the years go by, and go to the flathead/washer arrangement as a "fix". That's just a guess, though. The IPC for this vintage of Mooney doesn't actually detail any of these screws, see attached. Whatever the case, the important thing to understand is that the underlying nut plates are 10-32 threads. Or, at least they are supposed to be. In the early days of our ownership, I was chagrined to find a small number of coarse thread sheet metal screws jammed into places that were clearly supposed to receive machine screws. In most cases, I was able to use a tap to un-bugger the threads of the nut plate to receive the correct screw. This is yet another reason to bring a bin of correct screws to your annual or other maintenance. It's not uncommon for a less experienced or just less patient shop assistant, who gets the lowly work of re-installing cowls and inspection panels, to lose a screw, and in their embarrassment/frustration just jam in whatever random fastener in the shop doesn't immediately fall out and hope you don't notice.

By the way, these are the screws used for the vast majority of the belly and wing inspection panels, avionics access covers, etc. They're 12 cents a piece at Spruce, you can order a lifetime supply for practically nuthin'. Keep a bin of 'em in the hangar for use as needed. Bring that bin to your annual, so you can throw away any screw that's even the slightest bit buggered and replace with new. It goes a long way toward reducing the frustration of the annual R&R'ing-the-screws ritual.

The IPC doesn't do a great job of documenting these screws, I had to figure it out by trial and error. We have a 1976 M20F model, but based on your photos, it appears you have the same arrangement. If so, OEM for the screw at the back corner of the top cowl is an AN507-1032R8 flat head screw, a.k.a. MS24693-S272; along with a size 10 countersunk washer like https://www.aircraftspruce.com/catalog/hapages/nas549washers2.php. Those are cad-plated screws, if you prefer stainless use P/N AN507C-1032R8 a.k.a. MS24693-C272. OEM for the screw at the front of the top cowl is an AN526-1032R8 truss head screw (AN526C-1032R8 if you prefer stainless over cad plated). The holes at the front of the cowl tend to wear larger over time with vibration, and a common mechanic's trick is to replace the OEM truss head screw with the same AN507 flat head screw and countersunk washer as the back corner, to provide more grip. Based on the witness marks in your photo, I'd guess this trick has already been employed on your airplane. Again, my statements are based on a later model F, I'm just hazarding a guess your C is the same. This stuff is not expensive hardware, so it's a cheap experiment to give the parts I suggested a try.