PT20J

The latter. I've known for years that the J trims in cruise with the elevator trailing edge slightly down. I was curious about how the original design trimmed and in another thread C pilots confirmed that short bodies trim with the elevator in trail. Some long body pilots chimed in that their planes trim with the elevator tailing edge slightly up. Let's do a thought experiment (easier than bending metal ). The airplane requires a certain tail down force when trimmed to counteract the airplane's inherent nose down pitching moment. This force is generated by a combination of the incidence of the stabilizer (which sets angle of attack) and the deflection of the elevator (which changes the effective stabilizer camber). The incidence is variable by means of the trim system. The elevator floats at a position where there is a balance of aerodynamic forces and the elevator bungee system. Now, suppose we bend the trailing edge up. This will increase the aerodynamic force tending to lower the trailing edge of the elevator and make it possible to get the elevator to trail the stabilizer. However, there will now be less tail down force (due to the decrease in effective camber) and the nose will pitch down. This can be compensated by changing the incidence of the stabilizer by adjusting the trim. So, what's wrong with that? Well, the trim system can only change the stabilizer incidence by about 6 degrees total. By making the above adjustment, you will remove some amount of nose up trim capability and you will likely run out of trim in the landing configuration. An engineer at Mooney told me years ago that Lopresti noted the elevator misalignment and calculated that the drag penalty was inconsequential and not worth the cost to fix it (which would have required redesigning the empennage to change the fixed incidence of the stabilizer). Evidently, all the engineers that came after him have reached a similar conclusion. Again, the trim drag is primarily the extra induced drag of the wing to carry the tail down force and to a lesser extent, the induced drag created by the tail in generating the tail down force. The parasitic drag from the slight elevator deflection is inconsequential by comparison at the speeds a Mooney flies. Skip

https://www.shell.com/business-customers/aviation/aeroshell/knowledge-centre/technical-talk/techart-18-30071600.html https://www.avweb.com/ownership/leaning-on-the-ground/

I looked at the wiring diagrams for a C-172N and a M20J. If the alternator is generating power, it will hold the battery relay closed even if the battery is dead. This makes sense since you wouldn't want the battery out of the circuit as it acts as a big capacitor to dampen out voltage transients. Skip

Don't mess with the elevator. Short bodies trim with the elevator in trail. Mid bodies trim with the trailing edge deflected down slightly. Long bodies trim with the trailing edge deflected up slightly. This is normal. There are springs in the system that bias the elevator in addition to the incidence change of the stabilizer. The strip on the rear of the elevator increases area -- it's not a trim tab. Trim drag is primarily the extra induced drag from the wing generating extra lift to offset the tail down force. Any slight misalignment of the elevator out of trail is negligible. Skip

Sounds like a good idea, but... The paint will be 2K (paint + hardener). You can get 2K rattle cans, but once you activate it, it will go bad after about a day. And, wear a respirator so isocyanates in the hardener don't wreck your lungs -- it's nasty stuff.

Over the years, I have had the occasion to hand prop a PA28 and a C-172 with dead batteries. Both flew fine and, while I don't remember the exact charging current, it wasn't excessive.

The business term for deciding to serve only the high margin, high priced segment of a market is "skimming the cream." Usually works for a while and then ultimately fails for a variety of reasons. The real problem has been that established manufacturers with legacy designs made the mistake of viewing Cirrus as just another competitor rather than a market disruptor.

TCDS = Type Certificate Data Sheet. It's the specifications that the airplane must meet to be in accordance with it's certification. The Mooney TCDS is 2A3 and can be found on the FAA.gov website. Evidently your airplane was modified by installing a M20J engine/prop combination. In this case there should be some paperwork for this in your airplane file -- look for an STC (Supplemental Type Certificate) which should have the revised specifications. The page of the TCDS for this installation in an M20J is: Note that this has the same pitch settings as you found in the propeller logbook. It is highly unlikely that these settings have been changed since to do so on a McCauley prop requires disassembly and changing spacers. So, if you are near sea level density altitude and perform a static runup with the mixture rich, the prop full hi rpm and full throttle and no wind and you cannot turn at least 2650 rpm with a known accurate tachometer, then either the governor is set too low or the engine isn't putting out rated power. But, I believe you indicated that you can get 2700 rpm in flight which would eliminate the governor and implicate the engine. Skip

It’s whatever is specified in the TCDS.

As Cody said, it is important to know if this is something new or if it's always been that way. The prop pitch stop settings are specified in the TCDS for the airplane and should have been set the last time the prop was in the shop. What prop do you have? Here is the TCDS page for M20E props. If you are unsure of the low pitch setting, you can measure it on the airplane. I did this for the museum DC-3 which is a real PITA requiring a tall ladder. There is a special prop protractor tool made for this whereby you measure the angle at the hub and the angle at the specified blade station and it subtracts the two to give the blade angle, but you could do the same thing with a digital protractor. The easiest way to find the 30" propeller station is to put the prop horizontal and drop a plumb bob from the center of the hub to the ground and then use a steel tape to measure out from that point. Drop a plumb bob along the blade until it hits the 30" point on the tape and mark the blade station. Skip

SBs and SIs on the Mooney site. ADs on the FAA site: https://www.faa.gov/regulations_policies/airworthiness_directives/ Skip

Wow, now I get it: Cirrus won because Mooney screwed up by carrying 8 gallons more gas. Wow.

That’s why I said “with the engine putting out rated power.” If everything is set up right, the rpm at the beginning of the takeoff run is a check on the health of the engine. On the radials that all have superchargers and have takeoff power settings with MAP greater than 30”, field barometric power checks are part of the runup procedure. The drill is to run the power up to a MAP that is the same as the altimeter setting and note that the rpm is within a specified range. In this condition, the prop is on the low pitch stops so the governor is out of the picture. Skip

With engine putting out rated power, static rpm should be a little (maybe 20-50 rpm) less than redline. In this condition, the prop is against the low pitch stops and the governor is out of the picture. As you accelerate the prop drag decreases and it speeds up until the governor holds it at redline. The only effect of the flaps is that the takeoff speed will be higher without flaps. Always check the tachometer accuracy first before messing with the governor. Skip

Agree that is the way to adjust the air switch as it's the test method described in the service manual. I was referring to one reason why the little flapper switch used for clocks is probably not a good choice for the gear safety switch.

Are you sure they were Part 91 flights? There are lots of airports with approaches that don’t even have weather reporting capability. Part 91 flights can use them but commercial flights cannot. Another possibility is that ATC was just reporting the status and giving pilots the option of going somewhere else. Offering the option to cancel makes no sense unless it was VMC.

Service manual (37-12-05) says to set to 4.75 +/- 0.25.

Good advise. I accidentally hit that yoke switch once in very light icing and immediately retracted them again. The left brake didn’t retract fully until I had descended below the freezing level. Pretty scary. I wouldn’t use WD-40 though. The manual warns not to use spray lubricants (I believe that’s because it can get into the clutch and cause slippage) and the solvents can wash the grease off the gears. Skip

I wonder if they will sell parts. Here’ an article with a picture of the switch disassembled. http://www.knr-inc.com/shoptalk-articles/25-shoptalk/93-201901-electric-gear-safety-system Skip

On my ‘78 J that switch was connected to the Davtron clock for recording flight time. Probably difficult to calibrate accurately. Skip

Try this. KFC150 Installation Manual.pdf

The procedure is written assuming legacy navigation aids. The IAF is an NDB so ADF is required. However, if you have an IFR GPS, you can use it as a substitute for the ADF. https://www.aopa.org/advocacy/advocacy-briefs/air-traffic-services-brief-use-of-gps-in-lieu-of-dme-adf

Well, you have your answer(s) ranging from “no sweat” to “you’re gonna die.” That’s the Mooney mystique. Truth is all similarly certified GA airplanes stall at 61 kts or less and all can easily land on a 2000 foot runway if flown precisely. The long span flaps and short gear make the Mooney more sensitive to ground effect than others and this increases float if you are a bit fast, so in that respect they are a bit less forgiving. The Cirrus has the highest stall speed of any comparable airplane and I used to fly in and out of KPAO which is a bit less than 2500’ and it never felt short. Skip

Winner for correct explanation in fewest words.

Vacuum regulator is on cockpit side the firewall, on the pilot’s side. Make sure you check everything else before messing with the regulator. Biggest problems are filters that haven’t been changed and old deteriorating hoses - sometimes they delaminate and the inside collapses but they look OK from the outside. I get 4.75” with a new Tempest pump at sea level. About 4.5“ at 10,000’. A little rise if I turn the backup pump on. Skip