PT20J

Perhaps the limiting case is not a static load issue. Hard to tell without having access to the structures analysis from Mooney and Rocket. Skip

Redistribution of weight might affect load on individual members. FSDO approving engineering of STC might have approved a lower factor of safety.

Well, the increased weight goes in the cabin and the load must be carried by the wing which is attached to the fuselage in the vicinity of the tube in question. Since we seem to have some amateur engineers here, perhaps you could calculate the limit load on this tube as a function of gross weight for us and settle the matter. If you are not capable of performing that calculation, perhaps it might be best to trust that the Mooney engineers did it correctly. Skip

Flying it until it needs something expensive and then unloading it isn’t necessarily a bad idea. I did that with my first airplane. I paid $40K for a 1978 J with 750 hrs on it in 1986. I did some minor avionics upgrades and replaced the interior. In 1993 at 1500 hrs the cam was starting to go. It needed an engine, paint and some more serious avionics upgrades. Rather than put another $40-50K in it, I sold it to All American for $45K (yes, Ken Shoupe knew the engine condition). I just wanted to do other things with the money. But, I had planned it that way which is different than being forced to sell because of an expensive maintenance bill. I used to have a spreadsheet I found somewhere that showed how to fully account for the long term cost of home ownership. If you filled in all the numbers honestly, you’d convince yourself to just rent. Skip

Well according to the IPC snippet that @Oldguy posted it was .035 for 2740 lb gross and increased to .049 for 2900 lb gross. Skip

It might be helpful if you posted or linked to the RAM info you are referring to. I don’t see any reference to running deeply LOP with fine wires. The measured BSFC improvement was with a turbocharged engine at climb power at 100F ROP. RAM’s recommendations for LOP are very conservative - they only promise to honor a warranty if there is FAA-approved written documentation approving LOP operation for your airplane. They don’t recommend peak or LOP operation at all for twin Cessnas. Skip

I think WT refers to wall thickness. Thicker wall tube used for higher gross weight.

Yep, the autopilot failure in the sim was much more realistic — and difficult to detect and recover from — than the standard unusual attitude recovery maneuvers.

Thanks for the update. Many threads leave out the conclusion which remains forever a mystery.

Peter Morton headed the team at Boeing that designed the 75/76 flight decks. He once told me that the biggest problem in early service was that everything was so automated (in order to eliminate the FE) that there was little to do in cruise and the pilots would get into discussions about what they had learned in ground school and try stuff. “Let’s what happens when we flip this switch...” I think the 727 was Hoot Gibson’s favorite, too. Skip

I recently bought a laminated one from Sporty’s. It comes rolled up in a tube and it’s more durable, not too stiff to unroll flat, and you can write on it with a dry erase pen if you want.

I recently did an IPC in a AATD. We did have to fly a circle to land approach in the airplane only because the AATD wasn’t approved for that maneuver, but everything else was done in the AATD. Skip

I’m not arguing with you. I just answered your “what would you do question” based on my understanding of what FARs 91.215 and 91.225 require. I see no reason to violate the rules just to reduce frequency congestion, but that’s just me.

I have some experience with this having worked on the first generation of PCATDs. I spent a lot of time with the FAA discussing certification in the early 1990s. Back then, the FAA had three major concerns: 1. They didn't have any data to prove that anything less than a full motion simulator was effective for transferring skills from the device to the airplane. 2. They were concerned about the fidelity of the simulators. Early designs had poor flight dynamics modelling and the computers were too slow to have acceptable frame rates. 3. They believed strongly that real knobs and switches were necessary. Any mention of a mouse sent them running for the hills. The first issue was pretty much put to bed when the FAA funded a study (I can't recall - I think it was University of North Dakota but it might have been Embry-Riddle) that showed positive transfer of skills from a simple simulator to the airplane. The second issue has been solved by software and hardware advances So, the last major hurdle is the user interface. Computer touch screens have improved and more and more airplane systems are using touch screens. Perhaps at some point it will all come together. Thirty years ago, the FAA was very skeptical. Today, there are a lot of believers in low cost simulators within the FAA. My prediction is that some day you will be able to get a relatively inexpensive device that you can use at home and log -- unless the AATD and BATD manufacturers successfully lobby against it to protect their market. (If you think that can't happen, read up on how Intuit has successfully lobbied to keep the IRS from working on an online tax filing system that would obviate the need for TurboTax). Skip

That does not meet the definition of an emergency and if you declared you would most likely get a call from the FSDO to explain it. The proper thing to do would be to contact ATC before penetrating the Mode-C veil and inform them of the situation. They're not likely to care and you would be legal flying beneath the Class B unless they told you to stay clear. Skip

I spent my working career in tech. There are open systems and closed systems. For example: PCs are open, Mac is closed. Android is open, iPhone is closed, Aspen is open, Garmin is (mostly) closed. A closed system gives the company complete control over the technology and pricing. An open system forces the company to innovate and add value because it cannot build technical or legal barriers to competition. I’ve built both. Open systems are more challenging to design because you have to work with everything. Closed systems are good for stockholders; open systems are good for consumers. Do you think Garmin would be introducing new products as often if there were not competition from open system companies? Why would they? Look how long they rode the GNS because there wasn’t real competition. I would expect a few hiccups with something as complicated at the Aspen PFD. It looks deceptively simple to a pilot operating the user interface. But take a look at the installation manual and see all the configurations necessary to make it work with all the current and legacy equipment it works with. And think of the test matrix necessary every time something changes. Then remember the fundamental rule of engineering that there is no such thing as a single change. As someone who has built a lot of complicated stuff, I’m amazed by what Aspen has accomplished. By the way, I just got a service bulletin from Garmin for my brand new GTX 345 for new software to prevent it from failing to display some ADS-B traffic. So everyone has issues. My considered advice is to go Garmin if you are extremely risk adverse. If you want maximum flexibility now and in the unknowable future, go with open system providers. Skip

Agree. This is great: Tax dollars fund NAVSTAR for the military. Then civilians start using it. Then they turn off SA and WAAS gets developed. Then the FAA builds RNAV approaches using it and bases Next Gen ATC system on it and saves a lot of money decommissioning old navaids. But... The military still owns the GPS system and can bugger it up whenever they want. Think it’s just a navigation issue? Read the link I posted in the GPS outages thread where there was at least one documented loss of control when the interference screwed with the GPS-aided AHRS in a business jet and shut down the yaw damper. Skip

I think you are correct. The LOA will specify. I found this summary of a very confusing subject. https://www.ast-simulators.com.au/resources/simulator-levels-explained To add to the confusion, in FAA parlance, a Flight Simulator has to be very high fidelity, with a visual system and 3 axis motion base. Think airline training or FlightSafety. But, Microsoft for many years has made a software product called Flight Simulator which name the original author, Bruce Artwick, trademarked. This is why no competing products are called flight simulators. I would be interested in what others find the most useful hardware/software setups for practicing at home. Skip

To log the time for currency requires a Advanced Aviation Training Device (AATD) that is FAA approved. A Letter of Authorization (LOA) will stipulate the approved uses and limitations. https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs800/afs810/media/FAA_Approved_Airplane_ATDs.pdf Bottom line is that you won’t find an affordable personal device for logging time. Your best bet is to find a flight school with an approved AATD to use. As noted, under the latest rules an instructor is no longer required for logging any currency time in an AATD since this is not considered training. If you just want to maintain proficiency, there are lots of relatively inexpensive flight controls that when coupled with a PC running MS Flight Simulator or X-plane can provide useful practice. An intriguing idea is to couple this with PilotEdge https://www.pilotedge.net I’ve heard favorable reviews of PilotEdge but have never tried it and would be interested in the experiences of any MSers that have used it. Skip

During a tour of NORCAL TRACON a few years ago I asked what they do about inadvertent incursions of the class B - someone squawking 1200 that they're not talking to cutting a corner for instance. The manager said that if it doesn't cause a conflict they don't care and they are busy and don't need any extra paperwork...BUT there is a quality control group off somewhere that has a video feed and watches over the controllers and if they notice it, TRACON gets a call and they have to follow up.

Now you got me curious. Where does the ff sensor go on a 231? I assumed it had a fuel return line And if not, how does it account for the return fuel?

In my professional life, I have worked for seven tech companies, some large, some small, some public, some privately held. The only statement about morality I ever heard was a CEO saying, "We have a moral obligation to maximize the shareholder's return on investment." Employees know when the company is cutting corners; it's not a secret internally and the priorities are communicated from the top down.

It depends. An ideal engine would fire the spark plugs at top dead center (TDC) and the mixture would ignite all at once and expand and push the piston down. But in a real engine the mixture takes time to burn. The flame fronts begin at the spark plugs and progress to meet in the middle. During this time the piston is moving -- first up toward TDC and then down again. This means that the size of the combustion chamber is shrinking and then expanding while the mixture is burning. Together these effects result in the combustion chamber pressure rising to a peak and then dropping off. It's the overall average pressure (engineers call it brake mean effective pressure, BMEP) that does the work of pushing the piston, not just the peak pressure. But where in the cycle the peak is located and the height of the peak have a lot to do with efficiency and engine stresses. There is an optimum point for the peak which is generally somewhere in the vicinity of 15 degrees after TDC where the engine generates the most torque and this will be the most efficient place to operate (maximum torque for a given amount of fuel). Generally higher peaks transfer more heat to the cylinder heads. Also, if the peak is too high and especially when combined with high CHTs, the anti-knock value of the gasoline will be exceeded and detonation may occur. Since magento timing is fixed and propeller efficiency considerations limit our range of rpm, our primary means of affecting peak pressure is the mixture control. Leaner mixtures burn slower and move the peak later in the cycle. This has the effect of lowering the peak and making the engine more efficient. It also reduces power output because the BMEP is reduced. At low power settings (let's say 65% and below) the heat load on the engine is less and you can run the mixture wherever you want. At full power, full rich is required. In between, your best proxy to determine that your peak pressure is not too high is CHT. High CHT weakens the metal in the cylinder heads, stresses the valves and decreases their life and also (and more importantly) reduces the detonation margin. So what about 50 ROP? Well, on the good side, when you want more power, it provides a compromise between best power and best economy (usually peak or leaner) mixtures. On the bad side it is the mixture that produces the highest peak pressure and the highest CHT. Is this really bad? Well, it depends on the power demanded from the engine. At 65%, no problem. At higher powers, it's OK if the CHTs stay in check (Lycoming's long-standing recommendation has been 435 for high performance cruise and 400 for economy cruise. I'd go with 400F max). If the CHTs get too high, you have to reduce power or adjust the mixture richer or leaner. High CHT and high power is what you really want to avoid. Remember, back when all the engine and airplane operator manuals were written we didn't have such good instrumentation and gas was cheap. Simple rules were created to make engine operation simple and safe for us amateur pilots (The professionals had gads of engine instruments and a flight engineer to keep things in check). Now we have better instrumentation, gas and engines are expensive and we know more. This has opened up a whole range of possibilities. The best advice from those that have a lot of experience is to understand what happens when you move the red knob and then make up your own simple rules based on what you want to accomplish. Mike Busch for instance clearly states that he is more interested in longevity than speed and he runs his engines at 65% or less and LOP. His engines typically make it well past TBO. Others have discovered that they can cruise at 80%+ power when well LOP and still have cool CHTs. Hope this helps. Skip

Here's an interesting article, especially the part about the effect on the jet's autopilot. Seems like more and more avionics includes GPS-aided AHRS -- kind of makes one wonder... https://www.ctsys.com/blog/entry/how-interference-testing-affect-gps-navigation.html Skip

This is the Mooney factory mounting for the Floscan (now owned by JPI) transducer on the IO-360. The bracket mounts to a couple of studs on the top of the sump non the left side of the engine. ing In this scheme, the transducer is actually mounted upside down. The reason its supposed to be mounted with the wires up is that there is a little vent on the top that way to vent any vapor that may get into it. I talked to a tech rep at JPI and he said it's not all that important. I was trying to improve the accuracy of my system and I went to some trouble to mount it in the same position but right side up (had to make a new bracket with some standoffs) and it made absolutely no difference. Skip