A64Pilot

It’s difficult to near impossible to get an O-470 LOP, some have said if they run short of WOT that the partially closed throttle plate causes enough turbulence to atomize the fuel enough to do so, and some have said if you run some carb heat that helps too, that they can barely get LOP. I’ve never tried myself. But you can pretty easily operate one just rich of peak without any tricks Sometimes we just never know, my guess is it was likely pre-ignition and of course many argue that pre-ignition is always the precursor to detonation, but does it matter who’s on first? From an owners perspective you still end up with a big bill, so does it matter who shot John? What matters of course is how to prevent it in the future, there are many ways to get into detonation, it can be as easy as forgetting to go rich before going full throttle to climb etc.

The max CHT’s are just that, Max. The engine manufacturer has to demonstrate that the engine won’t destroy itself at those numbers, not that it won’t suffer from significantly increased wear / stress etc. Lycoming in several places has printed for max longevity to run 400F or LOWER CHT. and I think the max on Lycoming is 500 F, so they want you running at least 100F cooler than Max for long life. Remember Cyl temp is an indicator of stress the engine is under it’s not just cyl head temp, it’s other components as well and of course hot heads is one of those things that significantly reduces detonation margin, unless you find yourself in a box canyon or something and have to climb at Vx or similar to clear terrain there is no need to operate at high cyl head temps. Get into the habit of cruise climbing, that is at much higher speeds than Vy and you can keep cyl head temp in the middle of the green most days. The generally accepted percent power where you can’t hurt a Continental with mixture is 65%, Lycoming it seems has a greater margin of 75%. 65% and 75% does not mean that if you operate higher than those numbers LOP that you will detonate, those numbers just mean if you operate below them and make a mistake and allow the engine to enrichen that your mistake shouldn’t be a costly one.

If your ROP and descend yes you are getting leaner the more you descend. However if I’m over 75% power in a descent of 500 FPM or higher my J model will exceed VNE, so it’s unlikely to say the least that many descend at over 75% power I would think, plus obviously the higher airspeed results in much cooler cyl head temps than climbing, so it’s very unlikely your going to get into detonation in a descent However most climb at the highest power available, that’s the difference

The helicopter cylinder and piston, they tried to polish out the damage then wisely gave up. He wasn’t attempting LOP ops, I doubt any helicopter guy would attempt that. He thought his fuel burn was excessive so they leaned the fuel servo out based on an internet expert. Luckily when it started making noise at a hover they started looking, they thought collapsed lifter, I thought maybe stuck valve, but it was detonation, of I guess you would call it “light” detonation.

I think there is more mis-fueling possibly than we realize and or fuel contamination Apparently as the new fuel trucks require DEF, it seems people are putting DEF into the Prist tanks. https://www.ainonline.com/aviation-news/business-aviation/2019-05-27/def-contamination-downs-two-citations I remember taxiing an R-1340 Thrush over to the Albany Ga FBO telling the kid to top it off and as we are standing right in front of the big ole 9 cyl Radial he says these things take Jet, right? At least he asked, I never thought I’d have to specify. My private airplanes, I’m the only one that is allowed to refuel them. Not saying that’s what happened there, who knows, maybe an intake leak, pre-ignition point whether carbon or piece of metal, maybe a damaged plug? I assume it was not running car gas?

I don’t disagree, if your let’s call it truly LOP you can’t detonate. The issue as I see it is you have to maintain a pretty narrow EGT range, once you get say -50 or so LOP power falls off of a cliff, it’s safe just slow. Then there are engines that will run LOP but just barely, my newly overhauled with new Millenium cylinders IO-540-W1A5D with Gami injectors and new fine wires wouldn’t run any deeper than -10 or maybe -20 LOP before it got rough, so it’s margin was even smaller. It didn’t take a whole lot to put it into a mixture where detonation is possible. That’s why I preach to run at a power setting that no matter what you can’t get into detonation. Maybe it’s just me, but I occasionally make mistakes, be flying for awhile and realize the boost pump is on, I’ve even found myself trimming out in cruise to discover the flaps were in takeoff position. As I said all it could take is a slight climb without re-leaning to put yourself into a mixture that you could detonate, and I know if I fly long enough that’s one of those mistakes I’ll eventually make and I’m past the point of gaining experience, I’m at the point where every year in truth I’m not as good as I was the year before, for over 30 years I flew professionally, nearly every day I had Wx. Now I’m doing good to fly twice a week, but I’m determined to fly at least every week.

Lift table would probably be out of my price range, but I’m hoping to find a good wheeled cart to put things on as they are removed. Every now and again people age out or die and there is a hangar sale. I want some jacks, I made some out of pipe stands but they need work To add to the wish list, a Big as in 48” or so floor fan, mine came from home depot, and just the opposite, some form of heat. I have two of the kerosene heaters that look like a jet engine and sound like a blast furnace. a little one and a big one, Leave quite a bit to be desired but the bigger one puts out a huge amount of heat and will heat the whole hangar. I run Jet-A in the thing, seems to stink less. I’ve been told ULSD burns clean too, but am hesitant to try because the old Diesel didn’t and would ruin one. I only use it a few times a year as the real cold days in Fl you can count on your fingers. I define cold as below freezing, I know others think that’s warm.

In my opinion the only issue with a (D) magneto is it’s becoming more and more difficult / expensive to have one overhauled and seemingly few of the younger generation of Mag specialists are taking them on, every year it seems the number of shops decreases. That’s why I’m rooting for an electronic replacement, not because I think there is anything wrong with a (D) mag just it seems to be headed to the orphanage. I just hope what happened to ADSB will happen to them, that is they will become less expensive, but maybe not. Another opinion of mine is slippage marks are fine, but I think during oil changes develop the habit of grabbing it and trying pretty hard to make it turn, it shouldn’t of course.

I don’t know who else but I do. I keep thinking I need to try the bungee trick, but keep forgetting. I think it would work better than the chair. I’ve got one of those Da** mechanics stools on wheels that slides out from under you if you just lean in the thing. I need to throw it away, an overturned bucket would be better than that thing.

You changed what I said tremendously adding what you think. The gist of what I said was that it’s possible to hurt the engine if your attention is somewhere else at high power and the mixture drift towards rich, like say be overwhelmed getting IFR reroutes and be assigned a higher altitude How many have harmed their engines from detonation, I’d say hundreds, maybe more in the last year, my Brother detonated the IO-520 to death in the C-210, and my neighbor detonated a cylinder not to death but enough to have to replace it on his new Helicopter IO-540. That’s two that I’m personally close two. In fact that’s the only piston engine damage that were family or close friends. However if my Brother had been lower power it wouldn’t have happened, but he was trying to keep up with me in a 1,000 HP crop duster. The helicopter, well they can’t really fly at low power The gist of what I said is that you can’t hurt one by running any mixture below 75% power in a Lycoming, so why take the risk of attempting LOP above that? Why even try to cruise above that? For those that money isn’t an object sure cruise high power and replace the engine as necessary, but if money is no object, why try for high power LOP? When in fact if your LOP it’s not likely you can actually get high power, for high power you want 100 ROP. Ref why cruise at lower power, see attached, you do so for greatly increased engine life, ANY engine if run very hard doesn’t last nearly as long as one that isn’t. For maximum service life, maintain the following recommended limits for continuous cruise operation: Engine power setting – 65% of rated or less. Cylinder head temperatures – 400˚ F. or below. Oil temperature – 165˚ F. – 220˚ F. From here and other places, this is just the first Google hit on https://www.lycoming.com/content/leaning-lycoming-engines#:~:text=For maximum service life%2C maintain,Oil temperature – 165˚ F. The reason I post these things is for those that are new enough etc to be asking questions on a forum. I try to give them info that they won’t hurt their engines, then later if they decided they want to go further they can. My Brother didn’t know what he was doing, the helicopter guy was following some internet experts advice, cost my Brother a new engine, the helicopter guy just a cylinder, he got lucky. Both had engine monitors, both first sense of trouble was an unusual noise, My Brother thought the gear were “thumping” the helicopter guy heard a rattle, thought he had a collapsed lifter, replaced that etc before finally borescoping it and finding damage

CHT closely follows power output, a reason CHT drops as you go LOP is due to the power drop. Depending on how you label high power, high power isn’t possible LOP or of course we could takeoff and climb LOP. Be foolish to do so but full throttle LOP is possible, significant drop in power and there is risk, but you can do it. Don’t, because you could get yourself in trouble trying, best BSFC is just a bit LOP, roughly -20F, which isn’t much, enrichen just a tad and then your running full throttle at peak, which I think most agree could get you into detonation, and that could be a $50,000 oops and or a forced landing. Personally the biggest reason for me to run LOP is efficiency, and you get even more efficient by slowing down. I cruise LOP almost always, usually at 8 GPH, yes that’s quite a bit off of full throttle, but I burn even less fuel than a Piper Cub or my C-140 as a function of fuel mileage, and it’s not just a little bit, it’s a whole lot less. It’s surprising when you run the numbers. At 6 GPH I’m 50% faster than a Cub in a four place airplane burning about .5 GPH more, but that’s slow even for me. I don’t have an analyzer in this aircraft, I have before but the way I fly I don’t need one, it’s s misconception that you have to have one to run LOP, you don’t, just be sure to stay below a power setting where you could cause damage, which is something that I think you should do anyway. Stay South of 10 GPH, for me well South and yiu can do anything you want to with the red knob and not hurt the engine. I’ve become risk adverse in my Retirement, the cost benefit analysis of high power LOP just isn’t there for me.

LOP power calculations are pretty easy, because power is purely a function of fuel if your LOP knowing an engines efficiency to calculate the power produced you just multiply fuel burn by let’s just call it the efficiency number, for our angle valve 360’s I believe that number is 15, so 9.4 GPH x 15 = 141 HP which is less than 75% so you were safe. As 75% power is 150 HP it stands to reason if your LOP any fuel burn up to 10 GPH is safe, above can be but you can make a mistake and cause damage, below 10 GPH and at least in theory you can’t. Still always watch CHT, open the cowl flaps if needed. That number isn’t hard set in stone as of course higher RPM has greater frictional losses and there is only one LOP setting that achieves the greatest BSFC etc, but if I’m correct and our number is 15 it’s close enough, you can get deep into the weeds for sake of argument, but your splitting hairs LOP power is a function of fuel flow because if your LOP that by definition means there is excess air available for combustion so fuel flow is the limiting factor. Oh and I may be misremembering the number as I cruise well below that as I’m seeking efficiency and willing to sacrifice some speed for it, so I’m. ever near the limits. It’s really tough to make a case for anything but LOP cruise assuming you’re cruising at low power anyway. Only time ROP is really called for is down low where high power is possible or if your in a hurry and time is more important than efficiency, or maybe at very high altitude where LOP just can’t make enough power, you have to go to best power to get up there. At least in a NA engine people want to argue that you can go just as fast LOP as you can ROP but it’s not true, highest power is only at one mixture and that’s best power mixture, any mixture other than it is less power.

I don’t really have an exact definition of red box or red fin or whatever, but I know detonation is not primarily a function of mixture, it’s more predicated on possible ignition sources like too hot a heat range plugs or carbon or maybe an exposed tang of a helicoil etc (yes I know these are pre-ignition but as the result is essentially the same does it matter)? In the cockpit you can’t tell the difference. But also MP and just plain on how hot is the combustion chamber (cyl head temps) So in other words it’s sort of like the fire triangle, you have to have all three for a fire. To get into detonation and engine damage you pretty much have to have all three. A mixture that can support detonation, an ignition source and a high enough power setting to enable it, although power setting and heat are very closely related. Heat in itself can be considered an ignition source, pure detonation doesn’t require a hot “thing” but heat alone is enough, think Diesel engine where heat from compression along with very low octane fuel is enough. So often detonation is caused by requiring high power to climb over those mountains or whatever that results in high cyl head temps that are aggravated by slow climb airspeeds like Vy for example and the coffin nail could be the pilot who doesn’t want to spend the couple of GPH that actually may be so rich that it slightly decreases power and has nothing but negative results, except that it keeps cyl head temps down. Lower RPM increases the likelyhood of detonation, remember how the 70’s cars would ping on a hill but if you pushed the pedal down causing a downshift the pinging would stop? If and this is an arguable point, but IF you keep cyl head temps below 400F on a Lycoming IO-360 it’s not likely you can get into detonation period, not in a normal world climbing to a cruise altitude or at a cruise altitude. However the extra 2 GPH or so that pretty much guarantees you can’t get into detonation if you run that mixture for 10 min and fuel cost $5 a gl then it cost you $6. $6 per trip is a cup of fancy coffee, pretty cheap insurance, I say 10 min because I don’t care how high or how long your climbing, after the first 10 min of climbing your power is down so much that it’s likely you can’t get detonation from mixture anyway Plus the lower cyl head temp you get is less stress on the engine and less stress will result in longer at least cyl life, and most of the time people measure engine health by cyl health. I’ve almost never seen rod clearance measured when cylinders are removed to see how much bearing wear there is. This is of course assuming no one mis fueled you with Jet or your not trying to run car gas or something

Sometimes, but not always. What your saying of course is “you get what you pay for” which is not always the case, more and more things are sold that are grossly overpriced including services and as always a lot of add ons are sold, that very often drive the price up with very little value. This is true with pretty much everything so in order to protect yourself you need to have more than a basic knowledge of the product or service you’re purchasing. I know quite a bit about somethings and insurance is not one of those things, so I basically have to rely on what seems logical, but I do know enough to understand that’s a poor knowledge base. In short I’m the furthest thing from a subject matter expert when it comes to insurance, in fact I’ve pretty much avoided insurance as a rule. However I know of several instances where the ambulance chaser refused what seemed to be a guaranteed win based solely on the the person at fault either had no insurance or very low limits. I believe in lawyer speak they were “judgement proof”. I think their first step is to ensure that payment of a large judgement is viable, if it’s not they don’t pursue the case, because of course it’s a business and they exist to make money, not to help people or ensure justice is done etc. So it seems logical if during discovery they discover you have a very large insurance policy they would sue as opposed to almost none and your assets would be difficult to get, it would seem that maybe the best way to protect yourself is to do whatever you can to protect assets and that a large insurance policy could possibly increase the likelihood of you being sued and possibly you lose your assets as well as the policy amount. Maybe we are better off with just the legally required min insurance? This from a Retired perspective as I think my Mil Retirement, disability and Social Security are difficult to get which just leaves primarily Retirement savings to protect as I think the house is also safe, Mooney and other vehicles aren’t I don’t think enough to get them excited

From what I’m understanding of your question your last sentence is key. No as long as your operating within OEM specs you shouldn’t be hurting anything. I have zero turbo experience but it’s my limited understanding that it would be very difficult to be at a harmful mixture setting detonation wise that wont have you exceeding TIT, perhaps turbo operators will chime in. It’s my limited understanding that TIT is your limiting number mixture wise. But again surely those with turbo experience will chime in.

Maybe this has been brought up already, but I recently just bought a 2 Mil umbrella policy, which excludes aviation and personal watercraft and maybe something else. The umbrella policy isn’t egregiously expensive, but the required auto policy minimums aren’t cheap. But it has me concerned ref Dewey Cheatem and Howe injury attorneys. Did I just make myself a big target since in discovery they can find out that I have a 2 Mil umbrella policy? So to make this about aviation, let’s assume due to age or whatever that I have very low insurance limits, and I’ve done whatever I can to protect assets, put them in an irrevocable trust or whatever. In other words I’m not an easy target, isn’t it logical that I’m less of a target than if I had a big insurance policy? Then to further the discussion, since my policy is enough to whet the ambulance chasers desire, is it more or less likely that they will get a judgement in excess of my policy limits? In other words is does big insurance policies protect you or possibly just the opposite? Of course I know what the insurance companies say, they sold me a 2 mil umbrella policy, but am I actually more exposed now?

An issue using CHT as a means of determining detonation is that there is a not insignificant lag between what could be going on in the combustion chamber and the time required to heat the mass of the head until it registers as too hot. Excessive combustion temps and or detonation damage is cumulative, you can get into “light detonation” several times with no apparent issue then one day a hole appears in your piston dome. It’s pretty much like all redlines on an engine, you can exceed most redlines by a significant amount with no apparent damage, but often damage is accumulating, you think you didn’t hurt anything but you might have. You see it often in turbines, people over temp them on takeoffs and since nothing happened they think it’s not harmful, but the compressor turbine is stretching and cracks are beginning unknown to the operator, then one day it lets go, and often when it breaks they aren’t exceeding the redline. Follow what @PT20J is saying and you and your engine will have a long and happy experience, just because you can do something if your really paying attention doesn’t mean that you should or there is much advantage in doing so, accept .1 or .2 GPH higher fuel burn or 1 or 2 kts cruise for the additional safety it provides, your engine will thank you.

It’s actually who made it, it’s the most common tailwheel out there. Scott years ago sold it to Alaska Bushwheels, so now the parts you buy etc are for an AK Bushwheels 3200, parts are identical, but I think they paint theirs gold. Trivia but Maule invented the steerable tailwheel, before his they didn’t steer. BAS I think makes handles that go into the tail boom for ground handling, Maule has a bar that attaches to the spring so you can pull it around and someone else makes one with two little wheels you put the tailwheel tire onto. https://basinc-aeromod.com/tail_pull_handles.php Bigger heavier aircraft like a Steerman, T6 and crop dusters are towed by a big V shaped probably 15 ft long tow bar that attaches to the mains. But 99% of us do what Hank said, I had the Maule tow bar but rarely used it just did as Hank said, if your having trouble with the 170 your doing it wrong. My Maule with an IO-540 was much heavier than a 170. To push forward you push the door post and pull on the strut if needed to keep it straight. I push the rudder on my 140 as I can steer a little that way. Ideally you push a tailwheel backward though. I have more conventional gear time than a nose dragger, I prefer them myself, anybody can land a nose dragger

However over and over it’s always been the aircraft that fly the most that seem to break the least, seems they just like to fly? Military we didn’t do Annuals, we did phases, on the AH-64 they were every 250 hours regardless of calendar time, on average I’d say an aircraft went through a phase every 24 months. As I said everything was on computer and therefore it was easy to build stats if you wanted, one of those was the most trouble free hours were the last 50 before phase and the worst were the first 50 out of phase. Now it’s likely but unproven that may have been because the most often an aircraft flew was just before phase as phases were scheduled and you needed to burn the time off to make the schedule, and it had sat often for a month during phase of course not flying. But maybe it was because a whole lot of stuff had been taken apart and it took awhile to work the bugs out, plus of course often parts were robbed from the phase bird to keep the rest of the fleet flying, furthering the amount of disassembly that was done. So yes there were things broken in phase but actual “maintenance induced failures were very rare” I have never had one in a GA airplane, sure I’ve had the occasional leak or something like right now I’m changing the motor mounts on my C-140 and noticed the alternator that I installed last year had a slight oil leak on its gasket, was that maintenance induced? Or just one of those things that happens every so often? I have no idea. I used to tell people if you came into the hangar at night when no one was there that if you listened carefully you could hear them breaking. Joking of course but I swear the more they flew the more reliable they were and the very early Apaches were terrible, we would crank five and cross our fingers that four would make the mission. 90% of the time they broke before they broke ground, if they flew away it was very uncommon for one to break in flight.

Now I’m not beating on you if moving the selector during before or after runup gives you comfort then by all means go ahead. I’ll tell you what I used to tell my Commanders that going through a full pre-flight and run-up every day at the crack of dawn trying to ensure readiness is as logical as turning on a light every hour to ensure the thing didn’t burn out while it was turned off. Of course we check free and clear of all flight controls, but most don’t include flaps and maybe that is where the operate the fuel selector comes from. ‘On the 210, there was no looseness or anything else that gave warning the lever was going to fall off, just one day it did. Arguably if the screw was checked frequently for tightness that would have prevented my failure, so maybe we should be putting a screwdriver on it every run-up or pre flight? You can’t reduce risks to zero and there is some point to where it becomes silly, or we would be depanneling the aircraft on every pre flight checking every flight control. Heck it seems it’s mags that almost fall off that cause 1000 times more forced landings than fuel selectors, yet I’ve rarely if ever heard of anyone that checks them for condition and security, especially the dual mag as we only have one.

I’m an A&P/IA and don’t think it’s a big deal largely because mechanical things that break do so with little warning meaning just because it worked on run up doesn’t mean the next time it will. We used to do “Stand to” in the Army where we would go out first thing in the morning and run everything up, creating a whole lot of unnecessary work for me, because lots of especially electronics would fail when first powered up. We tracked everything by computer even back then, there was no decrease in failure rates after a couple of days of Stand to so it didn’t decrease failure rates. Over the years it became obvious that usually instructors who always had zero mechanical training would come up with what they thought were good ideas and incorporate them into training. Latest thing that annoys me is the puppy mill flight schools in Fl are apparently teaching teardrop traffic pattern entries. Had one of them do a 180 on downwind the other day executing his “teardrop”. When did teardrop traffic pattern entries come into existence? What happened to mid field downwind? But back to the tank selector if it makes you feel good do it, however as someone who’s disassembled a few I can’t imagine the failure mode where the selector could click into the next position and not still flow fuel, and wonder are you really performing an “MOC” maintenance operational check on a fuel valve by requiring less than full fuel flow through it? I don’t know about you, but on run up my fuel flow isn’t close to the 19 GPH I burn on takeoff. So did you induce a partial failure by mucking with the thing on run-up and you going to find that out on takeoff? My only issue I’ve ever had with one was I had the handle come off on me I think in the C-210, it didn’t but it could have come off in off or partially to selected tank, luckily it came off after the tank was selected. Now I don’t muck with the thing until I’m in cruise, select fullest tank at the beginning of let down if tanks are way out of balance. The whole tank selector thing has me a little baffled to be honest, why do we even have the things? Did it come from the Military where you could be shot in one tank and wanted to keep all of the fuel running out of that tank? The Thrush crop duster has been built since 1965, it has no fuel selector, just on and off and that’s worked well for 60 years?

Do an experiment, take your filter out and run it up on clean pavement, note your MP, then install the filter, repeat run-up. The difference in MP as long as your filter is clean is difficult to determine it’s so slight, so how can a K&N or any other filter add any significant MP if no filter at all doesn’t? Older J models had ram air, which of course both bypassed the filter and was in fact ram air, the performance difference was so slight Mooney discontinued the ram air, and Mooney wasn’t the type of company to decrease performance which of course is cruise speed. So how can just a filter make a significant difference if no filter plus ram air wasn’t worth it?

A handheld works and I think if you just want to listen that a scanner is probably cheaper. I’ve thought they same thing, just haven’t really researched it yet.

Buy some office chairs, the kind with wheels from Goodwill.

I haven’t seen a bad filter, I’m not a fan of K&N as others have posted when you take one out of your car for cleaning you notice dirt on the clean side of the filter in the air box, and you don’t with an OEM paper one, but does that mean it’s bad in an airplane? I don’t know. My belief is if you don’t see prop erosion your in a pretty clean environment. Every airplane that has carburetor heat that I’ve seen bypasses the filter when the heat is on and of course if you have ram air and use it, your bypassing the filter too. I think people like me that fly off of grass strips probably need a filter more than most, I don’t go full throttle until I pass through 20 kts, yet I’m getting significant prop erosion from the Fl sand, so I know I’m getting sand in my air filter, I’m using the brackett because that’s what’s there and have no plans on changing. I don’t see dust on the clean side. People that do oil analysis will get a better idea from silicone readings, if you do and silicone is high I’d first look for leaks and if you can’t find any sure pop for a paper filter, it’s likely there is a reason why just about every auto and truck farm tractor etc made comes with one. I’ve wondered how can they work when wet? I’ve assumed without looking it’s not paper but some fiber or something?