A64Pilot

“Blind rivets” are any rivet that is set by pulling on a stem and that covers everything from cheap dept store “pop” rivets to Cherry Max rivets. So you just can’t make blanket statements about them as a group. However Cherry Max rivets are a structural rivet and can replace an aluminum solid in any application that the drawing doesn’t specify a particular rivet. ( that I’m aware of anyway) Understand the drawing always takes precedence, if the drawing specifies something then that’s what you must use unless you get DER approval or similar. On edit, now that I think about it that’s not always true either I’ve deviated from drawings several times like installing nut plates where the drawing called for PK screws for example and if I had riveted on inspection covers I’d likely install nut plates and put them back on with screws too. A Cherry Max rivet has a steel stem that when the rivet is pulled breaks off of course but there is also a steel collar that locks the stem in place, so the rivet has a steel “core” that makes it stronger than an aluminum solid, both in shear and tension although a rivet should never be put in a tension load. However they are heavier and in my opinion uglier, a lot more expensive, often require special pullers to install, and are a PIA to drill out to remove. That steel locking ring must be removed, then you can punch out the steel stem, then you can drill the rivet. I grind the ring out of a button head one, but a countersunk one you can’t and it’s very difficult to drill out steel surrounded by aluminum without buggering up the hole, then it’s oversize rivet time. In other words in my opinion a Cherry Max rivet is never used if a solid can be driven without excessive work to do so.

Ref shooting rivets with paint on them, by all means do so. I’ve had troublesome rivets on a fleet that I used to manage that replacing the Cherry Max rivets was a temp fix, but if we drilled them out cleaned out the hole with Trichloroethane (strong degreaser, I’m sure bad for the ozone layer) and dipped the rivets in Epoxy primer and shot them wet it was a permeant fix. Pretty sure oil or hydraulic fluid was getting into the rivets and that was allowing them to work, the primer sealed the rivet we think. The other side of the vertical fin that was shot with solids wasn’t a problem. Ref can a blind rivet replace a solid, yes a Cherry Max can replace an aluminum solid, but many special rivets like Monel I don’t think so, but a Cherry Max is a real PIA to remove so my advice is don’t use them unless there is no other way.

Republic built a turboprop that the prop was supersonic, it was nicknamed the “Thunderscreech” do to its horrible sound level. Scroll down to the section entitled noise, because if I told you, most wouldn’t believe me. https://en.wikipedia.org/wiki/Republic_XF-84H_Thunderscreech

The warp speed calculator also corrected for temp and maybe DA, I know temp changes Mach quite a bit but don’t know about DA. Seems like it would because the speed of sound in water is quite fast, I assume due to density? Speed of sound is variable and the warp speed calculator took that into account. Anyway I think from memory our little airplane had a 108” prop and we turned it at 2200 RPM, that gave it a Mach number of about .9 and made it the loudest airplane we manufactured, for whatever reason Ag planes are exempt from noise regulations, but that airplane is also the only Ag plane that’s also Certified in the normal category, and it’s restricted to 2000 RPM then, but we increased the allowable torque limit so that the HP remained the same at 750 SHP. Of course the Ag drivers aren’t stupid and understand that the higher torque is the gearbox limit and the gearbox doesn’t care about RPM, so they turn both the higher RPM AND the higher torque and get 825 SHP out of the 750 SHP certified engine

Mine too, but if it gets hot it stops working

Oh, and never turn off your anti smash and crash lights, except maybe if your in IMC, they are your last defense against accidentally leaving your master on.

The way the wing tips are you may be right, but my 81 J still has the factory wing tip strobes, no tail strobe was installed. I think as bad as this sounds but as far as lights are concerned that basically as long as there is an attempt, no one cares, no one as in FAA. On my C-140 I put Whelen wing tip strobes on years ago as I didn’t have to pay for them, but kept the silly winking light that had replaced the original Grimes rotating beacon years ago, I figured more lights couldn’t hurt and if I removed the winky light then I’d have a hole to patch and paint. It’s tough I think to find a place to put one light that will give all around coverage for instance, yet before strobes that’s all there was.

I think the new AD the pilot can accomplish assuming of course they do their own oil change, if they have someone else do it, then there shouldn’t be any additional charge, because any licensed mechanic should be inspecting the filter anyway, and saying you complied with the AD is just another line in the oil change entry. However I wouldn’t be surprised if some do add some additional charge, it’s getting tough to make a living, just like where we eat Breakfast every Sun morning the coffee costs $2.50 now as they try to sneak in charges to stay afloat. If in fact and I think it is, but if an Automobile dealer gets $100 an hour more labor than an Aviation shop, no wonder why there is a shortage of good aircraft mechanics. Anyway just an opinion, but if you fall into the possible for the 2017 AD and are worried I’d do the AD. But as the 2024 AD does not require disassembly and should provide the same level of safety with just filter inspections it does make one wonder if the tear down is required. I couldn’t post last night, kept getting this message, was I the only one?

Now that you say it that’s what I remember, but didn’t until you posted and jogged my memory

Me, I’d comply with the 2024 AD, which I’m already complying with if I understand it, and I’d hope everyone else is too, and Ignore the 2017 until or unless it rears it’s ugly head. I don’t think it’s going to amount to much because if it was, especially since it’s been ongoing for what 7 years and pretty much none of us have heard about it the likelihood of a rash of failures is pretty remote (in my opinion). This AD sounds to me like a CYA for I guess the FAA, or maybe Lycoming, who knows which, perhaps both? Truth is we are all just finding steel in the filter away from something much more expensive than this, and the gear worry me. We have ALL heard of cam / lifter failures, how many have heard of these bushings failing? Does insurance cover a gear up if the actuator quits? I don’t honestly know but I think maybe they don’t cover material failure or it would cover a bad cam too? So as I see it we are all flirting with disaster as it is, you either deal with it whatever way you can, or you sell. Not trying to be nasty, but Certified aviation has always been like this and no aircraft make that I know of is Immune. At least we don’t have a wing spar AD etc, but as the fleet continues to age we are likely to see more AD’s. The C-210 I had a wing spar AD to deal with and honestly I suspect failing it would condemn the airframe as I don’t know what it would cost to fix it as opposed to the value of the aircraft, no idea. But small end rod bushings ought to not be all that hard or expensive honestly, not compared to what it could be.

I’m failing to understand the Angst here? I agree I wouldn’t want a defective part in my engine, but If I understand it and I’m not saying that I’m an expert because full disclose I’m going off only what I read here, but this AD isn’t requiring anything to be done that shouldn’t already be done anyway? IE inspecting the oil filter and suction screen? It doesn’t even require it to be done by a licensed mechanic. Heck it even tells you where to go because before this AD if I found bearing material I would immediately suspect the worst and remove the engine and split the case, it could be a large money saver. How much less intrusive would you like it to be and how? Ref the I don’t know if the new ones are any better or not, again I can’t be 100% certain, but using a tool to determine if the bearing has enough interference fit screams to me that either the rod bore is oversized or the bushing undersized and not a materials defect issue. Now this thing could grow arms and legs like the crank AD did, but as it began in 2007 seemingly I think it’s unlikely to do so.

The R-1340 RPM red line is 2250, usual cruise 2000. I’m pretty sure the T-6 airshow planes are turning faster than 2250 just for the noise. How much I’m not sure but the old Thrushes ran the same motor and prop and while they were loud, they weren’t that loud.

One thing that kills the aerobatic engines is the prop is a big gyroscope, and doing all that flipping around etc is hell on the crankshaft, the lighter the prop of course the less effect so the wooden MT’s are I think very popular, and an aerobatic prop does just the opposite pitch wise from oil pressure loss, they increase pitch where out props go flat, reason is imagine running wide open at High RPM, lose oil pressure for a sec and the prop go flat, RPM would get excessive, but if it increases pitch then it loads and slows engine and it’s safer. Turbine props do the same, they got to feather at loss of oil pressure. In this video a Reno air racer loses oil pressure, prop goes flat, explodes, engine RPM goes to god know where and engine rapidly disassembles itself, listen to the audio, engine sounds like an air ratchet.

I don’t think Mooney’s props are anywhere near supersonic, because of ground clearance they are short to start with and do any of our motors turn more than 2700? What is close to supersonic is the 1340’s on like a T-6 due to length and a C-185 on floats with a “Borer” as in long prop that is turning 2850 RPM Warp drive propellors used to have an excellent tip speed calculator online, but I’m having trouble finding it, maybe someone with better search skills can?

If it’s an Overhaul and not an exchange I think your smart for doing it before you see metal in the oil, If done near TBO my experience is overhauls are far less expensive because nearly all the expensive bits are serviceable. Once one starts making metal it’s probably more cost effective to pony up the big bucks for either a zero time or factory exchange, I’ve seen field overhauls end up costing more by the time a new crank etc are purchased. I know 470’s, 520 and 550’s are essentially the same motors but I’ve always had better luck with 520’s than most 550 owners I know,,but most of my experience is with them in Cessna’s which run them hard. (300 HP)

Turbine conversions make more sense for larger aircraft. If your really serious contact Bill Hatfield at www.turbineconversions.com I’ve done quite a lot if work with Bill, he STC’d a 10,500 lb tailwheel for me and developed the cowling a military aircraft we built called the Archangel. Bill is surely very old now but he has a very good relationship with the feds and gets things done, sort of an Ag specialists but he also put a -21 Pratt in 206’s primarily as jump planes https://turbineconversions.com/conversions/turbine-206-cessna/

The ones I have experience with did, on UH-1’s, they were on the top of the engine cowling and you could hear them when you turned the battery on, wearing a helmet. But they were probably larger maybe than one put on small airplanes?

Ref cleaning switches, by all means do so as a temp measure, but be aware it’s almost always a temporary fix as most switches have some kind of plating on them and most of the time they get intermittent when this plating wears off and cleaning won’t of course replace the plating. Switches that trigger a relay so that they are only carrying a tiny amount of power last a very long time as opposed to those that carry significant amount of current due to arcing of the contacts. Then all contact cleaners are not created equal, I’ve had the best luck with Deoxit, it’s not cheap but compared to the price of these switches it’s just pennie’s. Ref are there any other approved switches? Download and read this AC ref parts substitution for antique aircraft, ALL Mooney’s are antique aircraft and this AC covers every Mooney ever made, in particular electrical parts are about the easiest to substitute, many if not nearly all are Standard Parts. So look up Standard parts, I think if you could find a switch that would work and carry the amperage then yes it’s approved. I would quote this AC in the logbook entry though. This AC has been out since 09, so 15 years? Not likely to change and surely every FAA inspector is aware of it. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_23-27.pdf On edit, I use contact cleaner as a troubleshooting measure, if the problem goes away when I clean a switch, then it’s likely that’s the problem so I try to find a switch.

I had to go pick up someone in the C-210 years ago, pulled it out and the front tire was low so I had someone fill it up and cranked up and left after he did, when I landed the nose went down so far I was sure the nose gear had collapsed, but it was just a flat tire. I taxied off the runway, filled it up and it held air? It continued to hold air too, I figure the valve stem must have gotten cocked to the side after being filled the first time, and the person who filled it being in a hurry didn’t reinstall the valve cap. Just a guess but nothing else made sense. If you look at an aircraft valve cap, first it’s metal, but if you look inside of it you will see an O-ring, this O-ring would most probably have kept me from landing with a flat. Nitrogen in tires is silly, maybe some justification in Oleo struts, but tires it’s just a profit for someone selling you something you have no need of.

“Leaning it out” may burn carbon and fuel residue off of plugs making it so they will fire more easily, oil and or gas will allow a path to ground for the spark energy is why a “fouled” plug will not fire reliably, that and of course the compression in the cylinder also inhibits the spark, why sometimes a plug will seem to operate normally until it’s installed in the cylinder. Decent video, Auto based and of course they are trying to sell plugs and at what Auto plugs cost, why not toss them? Fuel fouling is one reason why a flooded engine is tough to start too. Anyone who used to race two strokes is very familiar with plug fouling. Trail riding I would sometimes have to stop, pull the plug soak it in gas and just burn it to get it so it would fire reliably, this didn’t always work but often did. A plug at higher power is a sort of glow plug in that it’s the hot spot in the cylinder, it’s that way to keep clean, obviously it’s a fine line getting it hot enough to stay clean, yet not so hot that it becomes a point of ignition prior to the spark

Issue with Fl is many that move down from up North that can afford it want to live on the coast in big cities, and the money there is in bizjets, not little old antique airplanes, from my limited observation more and more the little airplanes aren’t even wanted as I think they take up the space that the big money airplanes want. Fl population is expanding and assets of all types are limited. So it pretty much means that if you want a roof, especially if you want walls for your little antique, that means going inland, and if your willing to do that I’d recommend you looking into a fly in community, airpark whatever you call it. It’s not as expensive as you may think, I always thought it was out of my price range until I looked into it, and if you enjoy flying it’s a complete game changer, so much more convenient that you will fly much more often, but if you have to live near the beach, especially if you want to live in a big city and have your airplane nearby, it’s going to be tough to have a single engine piston, there I guess the idea of I’ll scrap the airplane every x number of years and buy another comes from, there just isn’t many other options. I’ve even seen PC-12’s, King Air’s etc tied down permanently or at least during “Season”. Season meaning snow bird season, not Hurricane season. It’s sad to see almost every year a Hurricane chew up airplanes tied down on the coast. I’ve heard several times, “Oh well that’s what insurance is for” As a general statement Fl is growing too fast and beginning to outstrip its infrastructure, if you buy in Fl be darn sure you check out the flood potential for wherever you buy, subdivisions that didn’t used to flood now flood easily as developments are being built so fast they overwhelm the drainage system, and the truth is if you build in a swamp don’t be surprised if you flood, but that’s becoming common and I don’t believe the people moving in know that flooding is a concern because that’s new to them.

The purpose of a turbo is to increase charge density of course, but you also increase charge density by cooling, so the effect of an inter cooler is very similar to an increase in boost, except of course there is a point of diminishing returns by just increasing boost, because compression adds heat and you get to a point that your adding so much heat that even with higher pressure you lose density. So long story short, an inter cooler will increase performance under most conditions, especially steady state like aircraft fly but remember it takes fuel to make HP, so if everything else is the same, fuel burn will increase with the HP. TANSTAAFL We can draw similarities with Autos, but Auto’s we run lots of boost to significantly increase HP, and an auto turbo can increase efficiency by utilizing otherwise waste heat. But aircraft we aren’t so much running high boost as we are maintaining HP as air density decreases and as we aren’t really running much boost there isn’t enough efficiency increase to overcome the decrease in efficiency from lower compression ratio. Compared to an auto at 10 PSI or more boost 40” MP is not much. My motorhome Diesel regularly runs 30 or more PSI and that’s what pushing 100” MP for example?

The redline on most aircraft engines usually isn’t an engine redline, but a prop redline, and even then it’s almost never a structural limit, it’s usually a noise limit. Usually, I’m sure there are exceptions, there always are. Now it IS a limit and therefore we have to obey it of course. Very often the Redline is a way for the engine manufacturer to limit the engine HP, for example the 235 IO-540 redline is 2400 because that’s 235 HP while the lower compression carbureted O-540 is I think 2600 because that’s where 235 HP occurs. Then in most cases it’s a continuous limit too, whereas in say automobile engines for example it’s rarely a continuous limit. The IO-520 in the C-210 I had was allowed to turn 2850 and make 300 HP, for 5 min, it was an exception to the rule, continuous limit was 2700. I’m pretty sure it couldn’t be Certified that way now because it was noisy at 2850. I’m also pretty sure the 5 min limit was due to heat build up, not a structural engine limit. Increase HP and of course you do that by increasing heat, if you exceed the cooling systems capacity then of course you can’t do that for long. But anyway we shouldn’t think of our aircraft engines redline in the same we we do our cars or motorcycles, those are usually actual engine structural and or heat limits and you can’t hold redline for long before something bad happens, where the average airplane can hold redline continuously.

It does, but if one owns their own hangar and has room for two, a simple airplane really isn’t that expensive to own. I don’t remember what I paid for my 140 20 years or so ago, I think about 12K or about the same as an average used car back then, but it has cost nearly nothing to maintain as it’s just a simple carbureted lawnmower engine that’s as easy as it gets to work on, runs on car gas etc. I should overhaul the cylinders as I have high oil temp that’s from blow by I’m pretty sure, but it’s been that way for all of those 20 years, I’ll get around to it eventually It’s not a traveling machine, but for those that have those big expensive fast Mooney’s you’re missing out on some really good local fly ins to grass strips etc. or just flying around one late Summer afternoon with the window open and your arm on the window sill. It’s the complete opposite to those that want fancy glass to entertain themselves with, it’s simple stick and rudder flying, great for spins etc. From what I have heard my 140 is worth now it’s pretty much doubled in value meaning that I won’t really make money if I sold it but that I would have owned and enjoyed it for the last 20 years essentially for free, plus it’s not in danger of being legislated into non existence as it burns car gas and believe it or not but every part is readily available, even large airframe parts inexpensively, no little $3,0000 springs. There is a lot to be said for having a simple inexpensive airplane. As I continue to grow older one day of course I’ll sell the Mooney, but I plan on keeping the 140 until I can’t get in and out of it

Ref poor torque for a Wankel. Mazda fixed that on the four rotor motor in the 787 by having variable length intake tubes. In fact it ended up having about the flattest torque curve of any race motor. https://www.roadandtrack.com/car-culture/a36062874/mazda-787b-r26-variable-length-intake/