Vance Harral

That is not an O-ring, at least not in the traditional sense. It is a "Stat-o-seal", which is a sort of combined washer and O-ring assembly. You don't buy the O-ring separately, you buy the whole Stat-o-seal assembly. I don't have the specific part number handy, but the guys at LASAR are more likely to be able to help if you ask for it by the right name.

No. I was surprised by this when BasicMed was first pitched, but you can instruct on BasicMed.

No, I don't want that, but I have had to deal with that, and have become proficient in doing so as part of the larger skill of rapid navigator reprogramming. In the scenario you're describing, the fix you've been cleared to - the one that's no longer in your flight plan because you loaded VTF - must have been a fix prior to the FAF, because the FAF is never deleted from the flight plan with VTF, in any version of any navigator software. In other words, it's either an IAF or an IF. It's my position that being asked to reload an approach when you are still approaching an IAF or IF for that approach, is not a crisis, and should be a tool in your tool bag. When fixing the VTF problem, the approach you have to reload is the same approach you've already loaded, just with a different transition. So it's not like you have to select a different airport or a different approach, just a different transition. If you can't do this in the space of a few seconds with a GTN or IFD, or even with an older GNS, then I respectfully submit you could use some more practice. Again, I want to be really clear that I'm not advocating pilots load VTF as a matter of course, contrary to the AIM guidance. What I am saying is that fixing the VTF problem isn't any more difficult or time consuming than fixing other types of problems you're going to run into, regardless of your position on whether you ever load VTF.

I see the old saw of "Don't use VTF" has come up again, and that it's now been codified in the AIM (of which I was unaware, thanks for the link). I don't disagree with the guidance itself, particularly with the older GNS navigators and their etch-a-sketch user interface. The problem I have with the way this guidance is usually phrased, though - including what's now codified in the AIM - is the implication that reprogramming your navigator based on a final set of intercept instructions from ATC, late in the approach game, is somehow "unreasonable" and must be avoided. That it's too high of a workload during that phase of flight, and that you're too likely to screw up if you even try it. Reducing workload is always a good idea, but it's my position that you're always subject to last-minute changes to your approach plan from ATC, and that being nimble enough with your navigator to handle them is a required skill for the proficient IFR pilot. If you're proficient in that way, the "Don't use VTF" guidance becomes moot. If you're not... well, you can avoid the problem where VTF omits points you may be cleared to; but there are similar problems unrelated to VTF that you're not going to handle well. Here's an example: where I fly, it's not uncommon to be told to "expect the GPS 29 approach to KLMO", which you can dutifully load in the recommended manner, selecting either WOLTS or FIPPS as the IAF depending on which direction you're coming from. Roughly half the time, the next ATC instruction - late in the game - is "cleared direct FIMUR, cleared for the approach". FIMUR is an IF, and ATC is permitted to clear you direct to an IF rather than an IAF if the resultant turn to the final approach course is less than 90 degrees. This is becoming more common, as T-shaped and V-shaped GPS approaches see more and more use. To comply with such a clearance, you must push a non-trivial sequence of buttons - again, late in the approach game - even when you "did the right thing" of loading the full approach. Here's another example: say you're approaching KBAZ (New Braunfels, TX) with winds from the northwest. There are equally good approaches to equally good runways 31 and 35. This is an uncontrolled airport, there is no tower/ATIS to tell you which approach(es) are "in use". As the wind moves around and various CTAF reports roll in, the proficient pilot has no issue switching from one of these approaches to another, relatively close to the airport. The un-proficient/less proficient pilot will be reluctant to change the approach they loaded early in the game, even if there is good reason to do so. Sticking to the plan in this manner avoids getting wrapped around the axle of re-programming the navigator, but introduces other risks. For these sorts of reasons, late-in-the-game reprogramming is part of what I teach as a CFII, during the final stage of instrument training and in IPCs. If I'm simulating ATC, I don't care what you load in the navigator (including VTF). But whatever you load, I'm going to give you a late change and see how you handle it. If you load VTF, I'm going to clear you to an approach fix that's no longer in the flight plan. If you load a full approach with an IAF, I'm going to clear you to a different IAF or IF. If I can't reasonably do either of those, I'll just say that "due to wind changes, need to clear you to a different approach". If the pilot has trouble with any of these things, I'll suggest additional training with an iPad trainer or similar, to become more familiar with the navigator. The analogy I use is that of a typist. Sure, you can get by with hunt-and-peck, but professionals know how to touch type. Having said all that, the main reason I give students late-in-the-game navigator programming changes is, I want them to understand the ultimate tool in the tool bag: "Unable, I'll need vectors until I can reprogram my navigator". As with so many things in aviation, I want my students to have plans for what they're going to do if they get into a scenario they hoped to avoid, rather than thinking they can somehow guarantee the scenario won't happen in the first place. In my mind, saying, "I don't allow myself to get into a situation where I have to reprogram the approach", is like saying, "I don't allow myself to get into a situation where I have to land in a strong crosswind". Of course you can make go/no-go decisions that minimize the risk of that, but you can't guarantee the weather at your destination (not even if it's the same as your departure); and we still encourage training for crosswind landings. So it goes with navigator programming, in my opinion.

100% concur. It's especially confusing because it implies the GNS/GTN navigators have some "mode" or "state" they go into, where the approach is "active". That's not the case. An instrument approach - which is just a flight plan with multiple legs - cannot be "active" (or "inactive") in the navigator. Only a leg of a flight plan can be active, and only one leg can be active at any particular time. I teach students that "activate approach" is simply shorthand for "Create a leg from present position, direct to the initial approach fix of the approach that is currently loaded, and make that the active leg in the flight plan" (VTF is a special case of this which substitutes a point out at infinity for present position). Since that's a mouthful, and won't fit on a screen, Garmin invented a shorthand phrase for it - "activate approach". I get that, but would have been much less confusing if they'd chosen "Goto IAF" for full approach and "Goto VTF" for VTF.

That's been my experience as well. I periodically cover other attitude instruments and fly myself or ask my instrument students to fly using just an iPad and a GTX 345 AHRS connection for attitude. What I've observed is that it will keep you upright in a pinch (haven't had the really bad experience PT20J has), but it is "swimmy" - seems to lag a bit, and seems to show small banks when the aircraft is actually level. I've had worse experiences with the AHRS in Stratus/Sentry devices, that so many people seem to be counting on as a backup these days. I continue to find instrument pilots who feel good about having Foreflight and a bluetooth connection to AHRS as a backup solution, but who it turns out have never actually trained with it; so I always cover everything else and ask them to fly that way. In roughly 25% of these scenarios, there is a major glitch. One time it was the device falling off its suction cup mount, which is bad, but presumably fixable. The more disturbing thing is that I've seen a Sentry have a major pitch glitch, even with a good mount. We were flying along, and the indicated pitch began to oscillate between zero and about 15 degrees up, for no explicable reason. I no longer trust these devices as a backup.

The difference in path length is certainly greater at slower speeds, due to the smaller turn radius. But there is a practical limitation: the slower you go, the less steep of a level turn you can maintain without exceeding critical AOA and stalling the airplane. Vs1 in a 172 is 44 KCAS. In a 2G turn, that increases to 44 * 1.4 = 62, so you're probably not going to find a lot of instructors willing to fly a 60-degree banked turn at 70 knots even in a 172. Private pilot "steep" turns are spec'd at 45 degrees, and the steeper commercial pilot turns are typically taught by entering at maneuvering speed to provide margin against an accelerated stall. Those lower bank angles and/or higher speeds increase the turn radius, and therefore decrease the magnitude of the effect we're discussing. To be clear, I'm not saying the simple explanation is wrong and speed differential between inboard and outboard wings never matters; just that several factors affect spiral (in)stability, and in most piston GA scenarios, the speed differential effect is negligible relative to design and loading factors.

Agreed; and while not disputing FlyingDude's math, 50 lbs of differential force (which is likely not at the wing midpoint but further inboard, at least on a Mooney, but I digress...) is on the same order as differential forces due to completely normal asymmetry in passenger and fuel loading. 50 pounds is about 8 gallons of avgas, and is also much less than the weight difference between children, petite adults, and beer-gutted, aging pilots (which I can say, because I am one). Yet none of the differential-speed explanations of overbanking mention it being eliminated/doubled by having an odd number of passengers, or burning an hour of gas out of one tank before rolling into the turn. Whether a piston GA airplane exhibits overbanking in "steep" turns or not, is mostly a function of the airframe design. Things like wing dihedral, keel area, and CG are typically the dominant factors in spiral instability, rather than the differential speed going around the circle. This explains why some airplanes exhibit more or less of it, despite executing the same turn, vs. other airplanes that exhibit less.

This is one of those things that is technically true, but is so overstated as to arguably be false for a typical GA piston aircraft. Consider a Mooney with a 35' wingspan, flying an "aggressive" 60-degree banked turn at 120 knots. The handy calculator at https://calculator.academy/aircraft-turn-radius-calculator/ tells us the radius of the turn is 738 feet. That means the centerline of the aircraft is 738 feet from the centerpoint of the turn. The path traversed by the inboard and outboard wingtips do not differ by the full wingspan, because of the bank angle. Employing some trigonometry, cos(60)=0.5 and therefore the wingtip paths of a 35' wingspan aircraft are only 17.5' feet apart relative to the center of the circle in a 60 degree bank. Specifically, the inboard wingtip traverses a path of 729.25', and the outboard wingtip traverses a path of 746.75'. Circumference of a circle is 2*pi*R, so the circumference of the inboard and outboard wingtip paths are 4582' and 4692', respectively. That's a path difference of 2.3%, therefore the airspeed difference is 2.3% as well. Bear in mind this 2.3% is only the difference at the wing *tips*, not the effective difference across the whole wing, which will be smaller. I don't have a formula handy for that, but across the whole wing we're probably talking about a difference in effective airfoil speed on the order of 1%. So yeah, the outboard wing is moving faster than the inboard wing and generating more lift. But not enough to make any noticeable difference, and certainly not enough to be the primary cause of over-banking tendency in the turn. Extreme cases, like a glider with an enormous wingspan flying very slow and tight in a thermal, experience the airspeed delta effect to a greater degree, but you're not going to get that scenario in a typical Cessna/Piper/Mooney/Bonanza/etc. Overbanking tendency in steep turns is caused by many things, and the airspeed difference between the two wings is almost never the primary cause.

Avemco does not have a blanket policy against insuring an aircraft owned registered to an LLC. I can say this with confidence, because I hold in my hand at this very moment a letter from Avemco addressed to the LLC that owns our partnership airplane, thanking us for insuring our aircraft with Avemco this year, and offering to renew the policy for next year. Either the person you spoke with at Avemco is misinformed, or there is something more to the situation than just the fact your aircraft is registered to an LLC.

Did this have anything to do with one-engine-inoperative flight? In a conventional twin with one dead engine, zero side-slip requires holding the ball slightly off center, see https://www.boldmethod.com/blog/und/how-does-zero-sideslip-work-in-a-multi-engine-aircraft/

I see this advice pretty frequently when people mention being concerned about prop strikes in Mooneys. I'm not inclined to "correct" it, because it's good advice for nosewheel airplanes in general, and it certainly makes a non-trivial difference in a Cessna or other aircraft with an oleo strut on the nose gear. With an oleo strut, the amount of force required at the tail to raise the nose a couple of inches is only a few pounds. In my airplane - an M20F - at rest, the nose gear doughnuts are hardly compressed at all. If I exert significant force on the tail, I might get them to expand an eighth of an inch or so, theoretically gaining an addition eighth inch of prop clearance. But holding full up elevator at normal taxi speeds won't generate enough force at the tail to do so. If I exert tremendous force on the tail, I can of course lift the nose wheel off the ground. But that would only gain ground clearance if I taxi at takeoff speed. So... within our partnership, we tell each other to taxi with full up elevator by all means, because it's good muscle memory. But we also tell each other not to have any illusion that it actually increases ground clearance at the nose and reduces the likelihood of a prop strike. There's just not enough force at the tail exerted by full up elevator at taxi speeds to make any difference. Short and/or mid-bodies may be different, I'd be interested to hear opinions from others on this.

By all accounts, the EI tachs are reliable. Having said that, I'll throw in a couple of minor gripes I have about the one in a flight school airplane I give instruction in. First, no matter how many times I tell myself I'm going to remember to record the tach time before the student turns off the master, I essentially always forget. That requires turning the master back on to get the tach time, which is of course an opportunity to accidentally leave the master switch on. Analog tachometers with a mechanical tach time display don't have this problem. This is a pretty minor gripe, though, and arguably less critical in an airplane you own. Second, the display when mounted on the lower left-side panel in a 172 is essentially useless from the right seat under most conditions. Between the acute angle, and even the slightest amount of sunlight on the instrument, I often can't read either the LCD numbers or the LED lights without leaning over far enough to be a little creepy. This may be particular to the airplane in question, though. In Maurader's picture above, the tach is obviously mounted on the opposite side of the panel from where the pilot sits, and I'm sure he'd mention if the display was an issue for him. Again, these are minor gripes, just throwing them out there for you to consider.

If you find some, make sure they match your particular airframe for length and connecting hardware at the back end. Mooney made different yoke length shafts over the years, and the connecting hardware at the back changed configuration as well. You can't just grab whatever salvage J-style yokes are available, and expect them to drop right in to your older airframe.

I see this argument tossed out a lot, and I'm not really here to change minds. But it's worth pointing out that people who change their oil twice as often have twice as many opportunities to get bit by bad parts and/or maintenance-induced failures: bad seals, bad torque, missed safety wire, stripped threads, etc. Changing your oil more often isn't without its own set of risks, and if unlucky, you could wind up overhauling a lot sooner than you otherwise would have as a result. Just saying "oil and filters are cheap compared to an overhaul" is a naive approach to cost and risk management.

Flew some approaches in real IMC last week in the Denver area. We were asked to ident on the initial ATC callup after switching over from tower, and multiple times on various missed approaches, despite having a discrete code the whole time.

This one isn't small or pixelated, but it's an F model rather than a J, so slightly different cowl and windshield. It would certainly get you started in the short term, though.

I've had this happen numerous times in the dozen-ish years we've had an engine monitor. Sometimes it was a bad probe, but other times it was just a broken thermocouple wire. Mine happens to be an Electronics International system, and EI has changed the connectors they use for thermocouple wires a couple of times. They won't admit it's due to the older connectors being prone to wire breaks at the crimp, but that's almost certainly the reason.

While I understand some people specifically request audio alert systems to be connected to switched inputs like this, I've never been a fan, for exactly the reasons you specify: just too easy to inadvertently turn them off. I'm not an expert on the GMA35 remote audio panel that your GTN 750 is almost certainly connected to, but all modern audio panels have unswitched inputs. These are "always on", and cannot be switched off, which sounds like what you prefer. Modern audio panels all have gain adjustments for inputs, too. Sounds like your installer didn't ask you what behavior you wanted, or test how it worked, before delivering the work to you. Maybe they'll give you a discount on an update to move the LHS connector to an unswitched input, and adjust the gain.

Great photos, @Jpravi8tor, thanks for sharing. I regret to report that my ram air seal is already showing signs of cracking, even though it's only been a couple of years (I think) since the last replacement. We'll need to do it again at the next annual. Fortunately it's not too bad a job.

Our oil sump has been seeping for over a decade, and we've never done anything about it. It does indeed "look" like a lot of work to do so, which is why we've never seriously investigated doing it. But I don't know what's actually entailed. My assumption is that it can't be done without removing the lower cowl and all of the intake and exhaust system, but perhaps there are clever tricks.

Again, advancing the mixture control during a hot start doesn't necessarily introduce a well-controlled amount of fuel into the system. For one thing, the new supply of liquid fuel that must pass through the still-very-hot lines between the divider and the injectors can itself be pre-vaporized (prior to reaching the injector) by the lingering heat. For another, heat from the engine doesn't only soak the lines between the divider and the injectors. Given enough time, it can also soak the lines from the fuel servo to the divider, and the fuel servo itself, such that advancing the mixture doesn't immediately introduce any liquid fuel into the line between the servo and the divider. In a Continental engine, vaporized lines and orifices in the fuel servo can be cooled by running the boost pump with the mixture set in ICO, to circulate cool fuel from the tanks, through the fuel servo and back through the return lines to the tanks. In Lycomings, the design of the Bendix RSA system has no return line, hence running the pump with the mixture in ICO doesn't do anything useful. That's news to me, but makes sense, and I guess limits the amount of fuel that can "percolate" into the cylinders as those lines cook. Thanks for that piece of information, I learned something new. Doesn't seem to make starts after 10-15 minutes of sitting any easier, though.

The difficulty with this method in horizontally opposed engines that have the fuel injector lines running right across the hot cylinders, is that in the classic hot start scenario, the mixture knob isn't really directly controlling the amount of fuel going into the cylinders. The presence of vapor in the fuel lines effectively adds high frequency randomization into the mixture control loop. In any given second, an individual injector line may be delivering liquid fuel or it may be just delivering vapor into the cylinder. So regardless of whether you're modulating the mixture to try to match fuel to a fixed amount of air, or modulating the throttle to try to match air to the fuel being delivered, it's difficult to maintain a combustible mixture because the fuel delivery isn't stable. What we hope for is a scenario in which that fuel/vapor variability in the lines is small enough that it doesn't deviate much, such that slowly increasing the throttle or mixture or whatever gets the engine running. That will be the case if you start just a few minutes after shutting down, or a long time after shutting down. There is a period of time in between when the liquid fuel/vapor variability is large. I never have any trouble getting the engine to fire in this condition, the problem comes a few seconds later with keeping it running. That's when the circus act starts, involving guessing at throttle/mixture settings, running the boost pump, etc.

Due respect to Don, but the only hot start in that video is the first one, which he describes as "kind of a dirty start". Every subsequent start he demonstrates is uninteresting, because the problems that cause hot starts require a couple of minutes or so to develop. Shutting down the engine for 30 seconds and then restarting doesn't give enough time for the problems jaylw314 describes just above to actually develop. Those only occur after the heat from the cylinders has a little while to "cook" the fuel in the lines into vapor. The way I teach it, if you shut down at the pump, fuel up, and restart right away, it's generally not a hot start. If you also need to pee and do it quickly, still not really a hot start. If you get a cup of coffee, chat up the desk staff at the FBO, etc., you're looking at a genuine hot start.

That's a good question, but ours are not particularly close to the cylinder head. We have an E.I. engine monitor also, and the installation manual suggests that the "ideal" location for EGT probes is 1.5" from the exhaust ports. Ours are more like 4" down, because the exhaust already had existing EGT probe holes there for a prior system, and I felt the position wasn't critical enough to warrant welding up the old holes and drilling new ones. Also, we choose to use the P-110-F "fast response" probes, which are arguably more fragile than the P-110-R "robust" probes. That might have something to do with longevity. That said, we've had as many CHT probes fail as EGT probes over the past decade. We also had a lot of trouble with the thermocouple wire cracking at the quick-connectors, back when EI was still using spade-type connects. We used to find a break every few months or so. That problem seems to have mostly resolved with the introduction of the OLC connectors. I was kinda irritated at EI over connectors, because their support reps assured me on multiple occasions that there was not a widespread problem with the spade connectors, and that there must have been something about my installation that was causing them to break. Then they "suddenly" announced the OLC style connectors, but it must have just been coincidence, right?