PT20J

I know this is frustrating. The manufacturers of replacement primary instruments are bound by what the airframe manufacturers specified as limitations. Everyone that was at Mooney when they set 6 psi max is dead or gone: who knows why they specified that. Maybe the original boost pump put out a bit less. With old analog gauges, we didn't pay so much attention to such things, but now red lights flash and make us nervous. I know; I'm not immune. It's a mismatch between equipment designed 60 years ago when close was good enough and modern digital technology.

If it were mine, I'd leave well enough alone. You only get the high indication with the boost pump on and it's only slightly high. Fuel flow, not pressure is what keeps the engine running. The flow is fine if the engine runs well. The only reason these things have fuel pressure gauges is that it was the cheapest thing to measure back in the day to give you an indication of a pump failure or a leak. Of course, the usual caveat applies: whenever you get an erroneous indication from a cockpit gauge, the first thing to do check the accuracy of the gauge. Skip

Yesterday, I emailed Surefly about the discrepancy between the fuse location depicted in the engine installation manual and the description in the airframe installation manual and I got this reply back this morning: Skip,Thank you. We are aware of the possibility of confusion there and we are going to change that diagram soon.BillSureFly Electronic IgnitionTechnical Support817-373-5161www.surefly.aero

Overhaul has a specific meaning (see below). If it was overhauled, the logbook entry should so state. The reference to the overhaul manual is just a reference to the approved data used to inspect, repair and reassemble the engine. It’s a repair, not an overhaul. Wonder why the pistons were replaced? 43.2 Records of overhaul and rebuilding. (a) No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being overhauled unless— (1) Using methods, techniques, and practices acceptable to the Administrator, it has been disassembled, cleaned, inspected, repaired as necessary, and reassembled; and (2) It has been tested in accordance with approved standards and technical data, or in accordance with current standards and technical data acceptable to the Administrator, which have been developed and documented by the holder of the type certificate, supplemental type certificate, or a material, part, process, or appliance approval under part 21 of this chapter. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-11_CHG-1.pdf Skip

I noticed that, too. I think the idea was probably to cushion the descent with the hydraulics during normal extension, but have it free fall faster to ensure it engages the down locks when you release the pressure. I always liked the Arrow III with the longer wing best. The T-tail screwed up the IV — no one I know could ever get a smooth liftoff with that one. Biggest gripe with the Cherokees was that stupid hydraulic seat adjustment. Hit it my mistake and the seat goes to the floor and it’s almost impossible to raise it again while seated.

Nice. A couple of nitpicks: Standard practice is to put the circuit protection close to the power source so the fuse should really be at the battery end of the wire to protect the wire from a short circuit. This is confusing because the Engine installation instructions have drawings that look like the picture. But the Airframe installation instruction is clear. 2.7. Power Wire Routing: a) Route the power wire from the power source to the SIM following the shortest course. b) Locate the 10A fuse (or other appropriate 10A circuit protection device) as close to the power source as possible. c) Secure the wire along its entire route, protect from chafing and provide strain relief across areas of movement. Guidance for wire routing, chafe protection and strain relief can be found in FAA Advisory Circular 43.13-1b Chapter 11-137 & 11-138 d) Strip both ends of the power wire and crimp appropriately sized ring terminals onto each end. Do not use solder terminals. e) Connect the ring terminals per the circuit diagram in section 2.6. P-lead shields should ideally be grounded at one end only as a shield should never be able to conduct current. Mooney typically grounds them at the ignition switch (but this may vary by model, so check). However, if there is no radio interference, it should be fine even if grounded at both ends. Skip

The thing that seems to kill Lycomings is corrosion — rust — of the lifters and camshaft and, to a lesser extent, nitrided cylinders. What keeps them going is frequent flights and oil changes and living in a low humidity part of the country. Oil analysis is good. Camguard may be helpful. Borescoping cylinders is easy. There’s no non-invasive way to check the cam. If it were mine, I’d change the oil every 25 hours or at least a couple of times a year and get oil analysis and just enjoy it until something shows up, Skip

You don’t need a modern highly automated airplane to screw up given bogus instrument indications if you don’t know how to deal with the failures. A plain vanilla 727 will do, https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR7513.pdf Skip

The emergency gear extension system was just a pressure release that let the gear free fall into the down locks. Vle was less than Vne, but only about 10 knots lower than cruise speed. Skip

Good design practice would dictate that a backup system should not share critical components with the system it is backing up. Mooney violates this in that the mechanical system is identical for the electric and emergency extension means. So, the failure modes protected against are electrical only. Cessna singles have a similar issue in that the normal and emergency systems both require hydraulic fluid so a leak will make neither available. I always marveled at the utility and simplicity of the Piper Cherokees. For the gear, there are no up-locks — hydraulic pressure holds the gear up. Pretty much any failure results in the gear extending. There are a lot of other things about the Cherokee design that are well thought out. If they were just faster... Skip

I don’t know how strong the tail tie down is. But it is probably designed for a mostly vertical load (it’s a tie down) whereas wenching would be a mostly horizontal load. My mechanic likes to put about 120 lbs of shot bags on the horizontal stabilizer when jacking since Mooney has a service instruction admonishing not to jack by anchoring the tail tie down. Skip

Not in this case. These are special Mooney parts that are threaded on the front trim shaft screw (beneath the trim wheel) and act as trim stops. The stepped nuts have a machined step that forms the stop instead of the nut jamming at the end of travel. Skip

Perhaps I confused some with my questions. I am not particularly interested in trying to rejuvenate a malfunctioning transducer. But, I believe some MSers with fully functioning transducers have taken some trouble to tweak the K-factor to improve the accuracy of the fuel burn recorded by the totalizer compared to the actual fuel used from the tanks. I'm interested in collecting data on what K-factor they ended up with. Thanks, Skip P.S. Hoppes is recommended by both Lycoming and Precision Airmotive (Tempest) for cleaning brass fuel injector nozzles. It's a good solvent. Don't drink it.

I know several of you have tweaked K-factors to get more accurate fuel flow readings from the Floscan 201B transducer. I'm curious about the results. What make/model instrument are you using with the 201B? What model Mooney? What K-factor was marked on the 201B? What K-factor did you end up with to get the most accurate fuel burn? Skip

If the pressure is high enough to overpower the float needle valve, it will raise the float level and flood the engine. I had this happen in a Beaver seaplane when the fuel pump failed and I had to use the manual wobble pump. I got a bit too enthusiastic pumping (I was over a rocky coastline in Alaska at 500' with no safe place to set down) and caused the engine to stop. It started again when I stopped pumping and the fuel level went back down to the operating range. Output pressure varies with flow for lever type fuel pumps but it should stay within reasonable bounds. The fuel pressure is not what's important -- it's the fuel flow that counts. If the engine runs properly at full power, the pump is putting out enough flow to run the engine and low pressure indication might not caused by the pump. Here's a good description of the operation of these pumps:

In that case, I would try running the electric trim to the stops and see if that trips the switch. You will need to reproduce the problem before you can troubleshoot it to isolate the cause. You might also consider paying for a bit of troubleshooting teleconsulting with @Bob Weber. Skip

The original design had jam nuts for the trim stops that can -er, jam -- if you run the trim hard to the stops. Some have reported that the electric trim servo can have enough torque to jam the system such that manual operation of the trim wheel to break the jam is difficult or impossible. The "stepped" nuts stop against the step rather than by jamming the threads.

Ever notice how your iPad starts to act weird if you don't power it down once in a while? In my experience, a lot of software doesn't like to run continuously due to memory leaks and other issues. Even Boeing can't get it right. FAA Issues Order For Boeing To Fix Computer Issue Within 15 Days FlightGlobal (3/19) reports that the FAA “has issued an airworthiness directive to address a computer issue that could lead to incorrect flight data being displayed in Boeing 787 cockpits,” which applies to 787-8s, 787-9s and 787-10s. The “order responds to a report that the 787’s ‘common core system’ can experience data monitoring problems after the system has been continuously powered for 51 days.” Data “monitoring problems can cause issues with the 787’s ‘common data network,’ which handles all the flight-critical data, including airspeed, altitude, attitude and engine operation, says the FAA’s order.” Consequences “can include display in the cockpit of ‘misleading’ attitude, altitude, airspeed and engine operation data, says the FAA, or the aircraft could lose stall and overspeed warnings.” The order “requires airlines, within 15 days of 20 March, to complete actions detailed in a February service bulletin issued by Boeing to address the issue.”

Thanks for finding an official reference.

You can easily raise the nose wheel of a Skyhawk by pushing down on the tail (be careful, you have to do it at a tailcone bulkhead — C-172s have developed stabilizer spar cracks from repeatedly manhandling the stabilizer to maneuver the plane on the ground). Not so with the Mooney - there is a lot more weight on the nose wheel. Skip

Yes, the switch is also a breaker. I assume you have a King autopilot in which case the manual electric trim is part of the autopilot system. There are no limit switches as the trim servo has a friction clutch that slips when the trim reaches the stop. The problem could be something with the servo, or the switch getting weak, or the autopilot. My KAP 150 autopilot had an intermittent problem that would trip the trim switch/breaker. If you frequently run the trim to the stops, you might want to make sure you the stepped stop nuts to prevent trim jamming. It’s also a good idea to periodically manually run the trim wheel from stop to stop to check the trim system for friction. Skip

If you go for a ferry permit, I would keep it really simple: you want to go from point a to point b with an inop tach. With the FAA, you don't want to volunteer too much information. In my experience, you definitely do not want to make up procedures using unapproved equipment. Think what you are asking if you do this: You are asking someone from the FAA to approve something that they probably don't have the knowledge or authority to authorize. That's a recipe for not getting approval. The O-360 is approved for continuous operation at 2700 rpm. If the governor is working you can just fly with the prop control all the way in. It's not a big deal and shouldn't be an issue with the FSDO if you keep it simple.

Interesting thoughts on landings which is always a fun topic. I don't think Mooneys are any more difficult to land than other single engine airplanes and the OP stated that he got pretty good at it in about 20 landings. That was likely because he was already good at landing airplanes. The original question was about the nose wheel coming down a bit hard after the mains have touched down. This is a commonly noticed characteristic of Mooneys and is due to the position of the mains relative to the CG (the effect is more pronounced with forward CG) and amplified by the stiff nose wheel suspension system. Airplanes can be safely landed at a wide range of speeds as Ross @Shadrach noted. The important criteria for a successful landing are proper attitude (nose high so that the mains touch first), minimum sink rate, aligned with the runway centerline, and no side drift. This is true for any tricycle gear airplane: Mooney or 737. The current Private Pilot ACS states the requirement for acceptable landings (meaning you pass your practical test) as: "Touch down at a proper pitch attitude, within 400 feet beyond or on the specified point, with no side drift, and with the airplane’s longitudinal axis aligned with and over the runway center/landing path." So what about full stall landings? These came about with conventional gear light airplanes since the gear geometry was such that a full stall landing resulted in a 3- point touchdown -- the hallmark of a good aviator at the time. When larger, heavier airliners like the DC-3 came into being, wheel landings were typically preferred. Wheel landings are performed at speeds well above stall giving greater control throughout the landing maneuver. Even in smaller airplanes, wheel landings were preferred if there were gusty winds or crosswinds. So, why were we all taught to do full stall landings in tricycle gear airplanes? I can't speak for other instructors, but I always taught them in Cessnas and Pipers because I wanted the student to learn to fully control the airplane all the way through flare and touchdown, and flying all the way to a stall is the only way I could really know that they had learned to do that. Besides, they're fun. But, they aren't necessary to make a good landing. In Stick and Rudder, Wolfgang Langewiesche went so far at to call 3-point (full stall in the taildraggers he was addressing) landings unsafe: "It is essentially an unsafe and unbeautiful maneuver, for it requires that the ship be flown near the stall or actually into a stall, that is, that the pilot throw the airplane deliberately out of control -- and near the ground at that." Now, I would not call full stall landings unbeautiful (especially in a taildragger) but they certainly can be unsafe in strong and gusty crosswinds. Once we get past flying trainers and move into higher performance airplanes, full stall landings become less useful. Higher performance airplanes have higher wing loading, perhaps laminar flow airfoils, maybe multiple engines. The higher wing loading and advanced airfoils tend to have a sharper stall break with maybe less aerodynamic warning. With multi-engined airplanes you don't want to be in the air below Vmca. The full stall landing puts us in a precarious position of momentarily being at the mercy of a gust, the extra time in the air floating in ground effect waiting for the final loss of lift burns up runway and lengthens the landing, and as noted, the higher the nose wheel the more carefully it has to be lowered. Now, sometimes, on a calm day, I still do full stall landings in my M20J. It's a skill maintenance thing. I like to maintain the capability to fly confidently over the largest envelope that the airplane is capable of safely operating. But, in the normal course of flying I cross the threshold at 65 KIAS with a little power, fly down close to the runway, smoothly pitch up to a nose high attitude while simultaneously reducing the power to idle and let the plane settle onto the mains. Sometimes I might hear the stall horn; sometimes not. But, that's not how I judge the quality of the landing. Skip

Things that help: Be on speed, in trim. Flare just enough so that the nose wheel is clear but don't try to land in a nose high, full stall. (Actually, this is the best way to land any high performance airplane. Ever see a 737 do a full stall landing?). Some people roll in nose up trim during the flare, but I don't like this as it makes a go around difficult. Power causes a pitch up and flying out of ground effect causes a pitch up, and if you also have the trim nose up, you have a handful. Skip

Float carburetors are relatively insensitive to fuel pressure so long there is enough flow to run the engine at the power set. The float bowl acts as a head-type pressure regulator to set the pressure at the inlet side of the main jet -- the pressure on the other side being equal to the venturi pressure -- by controlling the fuel level (head) in the float bowl. Since the float bowl is vented to atmospheric pressure, the fuel pressure across the float needle valve drops from whatever the pump puts out to atmospheric. As long as there is enough flow, it really doesn't matter what this pressure drop is, so the indication of a failing fuel pump is generally not enough fuel flow rather than reduced pressure. When the pressure is low but you have fuel flow, the first (and most dangerous) possibility is a fuel leak between the pump and the carburetor. Whenever there is a questionable gauge reading, the first thing to try (after ruling out leaks) is to T in a calibrated gauge to eliminate instrumentation. With any electric transducer, wiring and grounding are also likely culprits. Skip Edit: I don't think this was as clear as it might be, so let me see if I can summarize the main points: 1. All fuel metering systems (float carbs, pressure carbs, fuel injection) incorporate some sort of pressure regulation so that fluctuations in fuel pressure are isolated from the metering system. In a float carb, pressure is regulated by maintaining a constant fuel level in the float bowl. This means that fluctuating pressure (within reason) should not greatly affect fuel flow. 2. The fuel pump puts out flow against the restriction of the float needle valve and the pressure in that line is related to the flow rate. Generally, higher flows mean less restriction and lower pressure. 3. There must be pressure in line if fuel is flowing. A low pressure reading is most likely a measurement problem or a leak. 4. The only time I had a fuel pump fail, both flow and pressure dropped to zero. Skip