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Vance Harral

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Vance Harral last won the day on July 23 2021

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    Erie, CO
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    N7028
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    M20F

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  1. Thanks for the point-out, @Marc_B. PM sent to @BageMooney
  2. I have no doubt most shops can overhaul the gyro part of a Brittain TC. Less sure about the shuttle valves and associated roll trim mechanism inside that device, though my guess is it's not complicated machinery. Our Brittain TC requires nearly full right roll trim for the wings to actually stay level, and we've contemplated "doing something" about that for a long time. We've verified rigging (airplane stays wings level in in still air with balanced fuel tanks and PC disabled), and we've also verified good vacuum hold on both the "left" and "right" tubing systems that connect to the TC, via a test rig. So the off-center problem has got to be in the TC itself. Haven't done anything about it because it's not really a serious issue. But the TC hasn't been out of the panel in at least 30 years (per notes from prior owner) and nothing lasts forever. Good to know there is, at least at the moment, a specialty shop that deals in these things.
  3. That used to be an actual requirement, not just something that "could" happen. But in major metropolitan areas, there's so much training traffic in the patterns that it's almost never reasonable to bomb into the key point from a steep spiral that starts way above the pattern; and I'm betting that's one reason it got taken out of the PTS/ACS. I'm sure some examiners ask for it in places where traffic permits. But around these parts, it's effectively off the table - steep spirals and emergency descents are done in the practice area, and power-off 180s are done from a normal downwind, even on the practical test.
  4. Lazy Eights are another maneuver that's weakly specified in the ACS, mostly to accommodate airplanes of varying performance. Because there is no requirement to enter the maneuver at any particular speed, or gain any particular altitude at the highest point, or use any particular bank angle at the apex (ACS just says "approximately" 30 degrees), you can meet the standard with very little pitch and/or bank. A poster on another board once called this variant of the maneuver "Comatose Eights". The argument is that the comatose variant is easiest to fly. But it takes forever, isn't much fun, and I frankly find it hard to teach them that way because the pilot usually cannot get the airplane to continuously change pitch and roll when the total pitch and roll delta is small. What I'd call an "aerobatic" lazy 8 is max speed on entry, whatever pitch gets you near stall speed at the apex, and the max bank angle you're willing to tolerate (in the extreme, it's a 90-degree wingover). That would legally require parachutes, require an actual aerobatic airplane in practice, and probably earn a bust from the examiner even if you were legal due to being grossly in excess of "approximately" 30 degrees at the apex. I think they're easiest to teach in a typical piston single with about 40 degrees of bank at the apex, and that seems to satisfy the examiners around here. Note that if you're doing it right (and being evaluated correctly), nobody is looking at the attitude indicator during the maneuver - you judge "approximately 30 degrees" at the apex by looking outside. The bottom line is that despite the intent of the ACS to take subjective judgement out of the examiner's hands, there is always going to be some degree of interpretation, and this interpretation is most prevalent in the commercial performance maneuvers. Fortunately, most examiners seem to be reasonable about this, and only bust people on things that are clearly stated in the ACS as standards. For the lazy 8s, that's having an exit energy at the 180 point which is within 100' and 10 knots of the entry energy; and - the thing my students tend to have trouble with - continuously changing bank and pitch throughout the maneuver. I spend most of my coaching time pointing out that the pilot has become "stuck" on a fixed pitch and/or bank angle at some point in the maneuver.
  5. Not sure when you did your ride, but the current Commercial Pilot ACS covers this on page A-20, which Marc pasted above. The 2002 version of the PTS has the same selection language, so examiners have had the discretion to evaluate only some of the performance maneuvers for at least 20 years. They are allowed to require all of them, though, maybe that's what your examiner preferred. In practice, it doesn't matter, because you have to be prepared to perform any of the maneuvers. You're not supposed to get advance notice on which ones the examiner has selected for their Plan of Action, and again, they're allowed to require all of them. I suppose every candidate hopes the examiner will only pick their favorites, but at least around here, no examiner ever tips their hand in advance.
  6. One other tip based on the most common mistake my students make. When starting the maneuver - which you will do around 4500' AGL - the geometry is such that the point you are about to spiral around will be almost directly underneath you, and you cannot see it (not even in a high-wing airplane, but especially not in a low wing). If you can see the point you intend to spiral around off your wing as you're about to begin the maneuver, you are much too far away from it laterally. Because of this, I teach students to use a 4-way intersection of some small country roads that extend into the distance, as the point to spiral around. Establish a course over the top of one of the roads while still well away from the intersection. As you come up on the intersection, you'll lose sight of it, but you can use the perpendicular road extending into the distance to know when you're over the top. Roll in to a 45 degree bank at that point. You may still not be able to see the actual intersection at first, but you'll know where it is by the crossroads extending into the distance. As you descend, the actual point will eventually appear off the wingtip.
  7. As others have said, the Commercial Pilot Steep Spiral is a separate maneuver from the Emergency Descent. Don't confuse the two. The Steep Spiral is the commercial maneuver that irritates me the most as an instructor, because the ACS actually provides almost nothing in the way of guidance about how it is supposed to be flown. There is also nothing particularly "steep" about it - the ACS standards do not require any minimum bank or pitch, so you can theoretically perform the maneuver at very shallow angles of each. The only salient point in the commercial pilot ACS about this supposedly "steep" spiral, is that you must complete 3 turns before reaching 1500' AGL. Using optimum turn radius angles of about 45 degrees typically results in a descent of about 800' per turn, and when I start practicing these with new commercial pilot students the first time, they often lose 1000' or more per turn. So you've got to start the maneuver around 4500' AGL. The shallower the bank you use below ~45 degrees, the more altitude you'll lose per turn, and that's really the only thing that forces the turn to be "steep". Again, you could theoretically perform the maneuver with 10 degrees of bank, but you'd need to climb really high to complete 3 turns prior to reaching 1500' AGL. Up here in mile-high country, we have to climb to about 9000' MSL to start the maneuver, which takes a while in a normally-aspirated airplane (even a Mooney). To give us a fighting chance to complete 3 turns by 6500' MSL, I teach the maneuver in the clean configuration, and using minimum sink airspeed, which is slower than best glide. Note that neither the ACS nor the Airplane Flying Handbook actually say to use best glide speed, the ACS says "a specified speed", and the AFH says "gliding speed". I'm not interested in best glide speed because we're not trying to go anywhere, we're staying put over a specific point. And since we have a goal to minimize our altitude loss per turn (again, need to complete 3 turns by 1500' AGL), min sink sink speed is a better way to do that than best glide.
  8. Historically Avemco is a lot more expensive than other carries when you have a lot of experience, but a lot less expensive when you don't. Over the 20 years of our partnership, we have periodically cycled in new, low-time pilots with little/no complex time and/or no instrument rating. In almost every case, we switched to Avemco for a year or two, then back to a traditional broker after the new guy gained more experience.
  9. Availability of overhaul/exchange fuel pumps has been an issue for some time now, I'm not surprised the OP is having problems. We went through this about a year ago with similar results: no overhaul/exchange units to be found anywhere. After a couple of days looking, we gave up and shipped our own unit to Aeromotors for overhaul, and they were able to turn it around relatively quickly. I think the airplane was down a total of less than two weeks. Not a big deal to us, but our airplane is just a hobby toy, we don't use it for business.
  10. The mechanic first tried to drill out the screw, and when that didn't work he simply wrenched the yoke off the shaft, which of course left a big score in the shaft that had to be addressed. No one was there to stop him from ham-fisting it (we don't use that mechanic any more). It was a nightmare, and a perfect example of the unintended consequences of a "mandatory" inspection with thin justification. In a word, no. The yoke shaft type against which the AD was issued doesn't have the set screw at all. It has a roll pin instead, and is a smaller diameter shaft. It's literally not the same thing. Unfortunately for those of us with late-model M20Fs that have the newer yokes and yoke shafts, AD 77-17-04 doesn't exempt our airplanes from the yoke shaft inspection, even though we don't have the parts on which the problem was observed. Those of us who follow the letter of the law are unquestionably performing unnecessary inspections. Those who don't perform the unnecessary inspections aren't following the letter of the law, and may get hassled by future IAs and/or buyers. Pick your poison.
  11. Do you have "late model" rams horn yokes? on your airplane? If so, you're not going to find what you're looking for in the M20F IPC, you have to look in the M20J IPC. The set screw is documented in section 27-30-00, it's an AN565-D416-H4. We applied a very light fingertip "dab" on one side of the threads, similar to what one does with anti-seize when installing spark plugs. It's entirely possible that you used less of the stuff than we did, and that you'll have no trouble later on. But when you start getting into a debate about fractional differences in the amount of thread locker you apply being the difference between damaging a yoke shaft on the next removal, I'd argue it's not worth it. The set screw is not a structural item, and the yoke isn't going to come off the shaft if the set screw is loose and allows some slop. It's just annoying if you're trying to do something like hand-fly a smooth set of lazy 8s.
  12. Neither did we, but in our case the set screw wound up "glued" in so tight that the mechanic who performed the next inspection wound up damaging the yoke shaft trying to remove the yoke to perform the yoke shaft inspection. Talk about irony. Because of this incident, I strongly recommend against using any kind of thread locker on the set screw. Yes, it will loosen up and have to be re-tightened periodically. We keep a specific Allen wrench in one of the seat pockets to do so.
  13. I've never used a paid system like Adlog. But years of doing my own AD research has convinced me that the value in such a service would not be in the nice paperwork they produce. The value is almost entirely in the extent to which they can hunt down ADs issued against "appliances" that may or may not be attached to your aircraft. Anyone care to speak to that? To elaborate, it doesn't take much knowledge or skill to produce a list of ADs against a particular airframe/engine/prop combo, but appliances are insidious. An AD issued against the magnetos in your airplane is not going to show up under "Mooney" or "Lycoming". Neither is one issued against your ADS-B out Tailbeacon, your Saf-Air oil quick drain, and so on. Obviously a vendor cannot provide you with good service in this respect without a lot of input from you, the owner. So there's really no way around the responsibility of understanding what components on your airplane, who manufactured them, and what their serial numbers are, so as to keep an eye out for ADs issued against them that aren't going to show up under "Mooney". Accepting that responsibility seems to me to obviate much of the value of a vendor AD service. People understandably sign up for those services because they want a professional to help them be responsible for ensuring they know about all ADs applicable to their airplane. But I'm not sure those professional services can help much with anything other than the grossly obvious. Frankly, I think you can do about as well just monitoring our community here on Mooneyspace. People were posting about the recent elevator counterweight AD before it even became official. I'm certain those of us here were better informed, sooner, than someone who was waiting on Adlog or similar service to tell them about it. And that's for an airframe AD. We're also a lot more likely to tell you when an AD has been issued against V-band clamps on turbochargers, Garmin autopilots, etc. vs. waiting for a vendor to tell you about it.
  14. For those who don't know, the PROTE setup is not a "chamber" in the sense you might think of. It's simply a "tent", into which abundant quantities of nitrogen are injected, to reduce the available oxygen. There's no question this reduces your O2 saturation - you can see it on an oximeter. As such, you can experience symptoms of hypoxia, and that has value. That said, whether or not nitrogen dilution at ground-level pressure produces exactly the same symptoms as reduced partial pressure at altitude is debated. For example, my wife is a professional research scientist. Her and her colleagues work experiments in an actual altitude chamber a few times a year, as part of their research on pulmonary hypertension, and thus have accumulated dozens of experiences over the years. Occasionally they are asked to assist with experiments involving a nitrogen dilution tent like the PROTE chamber. They all swear that the experience and the symptoms in the tent are not the same as in the chamber. The fact that the people in question are scientists doesn't make this any more "data" than "anecdote". It's not a double-blind study, and I'm sure there is some group reinforcement of beliefs in casual conversations. But it stands to reason that in addition to hypoxia, lowering of pressure can have other effects on sinuses, bowels, etc.; all of which may or may not contribute to feelings of unwellness or euphoria. I've done the PROTE chamber thing, but conversations with my wife have made me curious enough to want to get an actual altitude chamber ride and compare the experiences. She has yet to sneak me into one of her experiments, though.
  15. Magnetic field strength decreases cubically with distance, so interference with the compass is largely a function of distance. Our compass is conventionally mounted on the center windshield post. We have two highly magnetic Steelie Ball mounts sticky-taped to the yokes, which are about 24" away from the compass, and there is no discernible effect on the compass. There is a noticeable effect on the compass if I set my phone with its magsafe case anywhere on the glareshield, though, which is a small part of the reason I prefer a yoke or kneeboard mount down low to a suction cup mount up high.
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