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Lukasz

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Everything posted by Lukasz

  1. I'm always greatly impressed by photos showing a warbird in formation with a modern jetfighter. It's the best tribute to the power of old birds, even if the jet is cheating a bit with the flaps Last year a friend of mine photographed a Hurricane flying in pair with Tornado - it was impressive, even though the Hurry was at full power and Tornado almost in landing configuration
  2. I'm glad to hear that Have fun!
  3. I've just performed an experiment I've invited my younger brother to take controls of three X-Plane helicopters. As he hadn't had ANY previous flying simulator experience (short of Star Wars X-Wing games), I told him which stick does what and instructed to use small moves. That's all. He pulled on the collective and got into the air. The nose was going around, so he pushed left pedal. All the time he was really sweating, doing hard work on the cyclic At first it was a rollercoaster ride, a crazy and barely controlled aerobatic display, a real fight to keep the blue side up, but after few minutes he got used to it, more or less stabilized the bird and even managed to land on a nearest runway - without breaking anything, although the exact touch down point was somewhat random. He used proper nose-up dynamic braking technique though, and that was something I didn't tell him about! The Force must be strong in this one After the rides, I've asked him about the experience. To my surprise, he enjoyed the most DF 206, even though it was the first helo on the line and theoretically at that point he had the least amount of experience in flying helos in general. He said, it was easy and smooth, as soon as he got used to the controls - more to their coupling, than lag. He found BK117s flight stabilisation to be too twitchy. He said: "it's hard to control the thing, because when I see an instability and want to correct for it, the flight computer does the same thing and the net result is that we both overcontrol the aircraft, making it to move more than desired". My bro liked the quick control response, but missed the "inertia" feel of the Jet Ranger. Also he made a note of "small moves" requirement - which was totally opposite to his X-Wing technique. He said, that he "used to make a big move and watched what happens, and then to correct the attitude with another big move". Here, he quickly found, that such approach won't work and adjusted for making of small moves, as well as making them before the aircraft did any substantial attitude change. Honestly, I was surprised, that he didn't crash, managed to fly all the birds from their cockpits after like 30 seconds of instruction and landed 3 times, more or less where I told him to land (and after each landing nothing was broken). And he actually enjoyed the ride!
  4. http://www.youtube.com/watch?v=SaD1AkfTwFQ Contrary to a popular belief, this is a very easy to fly helicopter - hovering included. The only thing you have to do, is to take advantage of its characteristics, rather than trying to fight it. 0. Set up the training flight over the "zebra" on a runway end. This and the runway itself, will provide excellent visual cues, that will substantially increase your spatial orientation and make all drifts/attitude changes more visible. 1. Take note of the relative position of the end of the runway, with regards to GPS antenna and red placard between windshields. Your goal in hovering is to maintain this relative position as smoothly and as precisely as possible. 2. Smoothly add the right amount of left antitorque pedal, while increasing collective before liftoff. Center the cyclic. 3. Immediately after liftoff, apply a bit of left bank with a smooth, small cyclic move. This is to counter lateral drift to the right, created by tail rotor thrust. Hold this left bank (about 2-3 degrees) during hovering. Hold pitch attitude by visual cues. 4. Use small and smooth but very frequent moves on the cyclic, to hold the bird in a constant attitude. Immediately counter any drifts and changes in pitch/bank with small moves. 5. Try to undercontrol, rather than to overcontrol. The inertia of the aircraft really wants it to hold it in one place, all you have to do is to eliminate/counter any small instabilities that will show up. But if you overcontrol and push the bird in any direction hard, then you'll have to fight the inertia to stop the aircraft again. 6. Try to be quick on the stick, but to maneuver the bird slowly. It gives you the time required to perform all the stabilising moves on the cyclic, as well as coordinate collective with antitorque. Also, you won't overstress the bird that way (it IS possible). 7. The rather big aft cyclic movements during lowering down, were to counter nose-down tendency during descend, when I've increased vertical speed. That's an example, how you have to adjust the rate and amount of controls input, to the rate and amount of instability encountered. 8. Always anticipate, what the bird can do next and react in advance, but with a smaller controls input than it would appear to be required. Have your eyes outside of the cockpit, concentrate on faraway characteristic terrain features. Observe the surroundings and gauges either with the corner of an eye, or with a quick glance from time to time. You're in control and you decide, when and where to move the bird - not the other way. Command the aircraft, do not follow it. It will take A LOT of hours to learn it, but once you'll get it - it will stay forever with you and the satisfaction from the achievement will be great! Also, purchase a set of rudder/antitorque pedals. While it is possible to fly helicopters with a twist-stick alone (in fact that's how I've learned to hover), it will be MUCH harder without separate pedals. Saitek's are reasonably cheap, accurate and durable. I use them and can recommend, just set the centering spring to minimum force. In addition to the video description, here are my two posts on the topic, hidden somewhere here: Small moves on the stick - do not overcontrol and anticipate what the bird can do next and react before it does it - stay one step before the helo and don't allow it to dictate what you should do. Famous translational lift "dip" for example. When slowing down to a hover, have an eye on airspeed indicator and when you see that the critical speed approaches, shift your attention to VSI. Smoothly add the right amount of collective at the first sign of VSI drop. At the same time, when you pull the collective, add some antitorque pedal and you'll maintain full control throughout this critical phase of flight. Also experiment with the gross weight, for your training sessions. Some prefer it to be light, others like it heavy. The biggest trouble with setting a helicopter on oilrig is that you have to look close to the bird, to keep an eye on all these funny metal pipes and parts, that are waiting to entangle with rotors on a slightes loss of concentration by pilot, while it would be best to look far away during hovering and nailing that pad with peripheral vision and quick looks only. Also close and relatively high walls and towers surrounding pads on an oilrig tend to mislead with regards to judging helicopter's attitude and movement relative to the pad. In order to overcome that, try setting up in such a way, where you have only sea directly in front of you, with the oilrig itself left on one side of a helo. Just pay attention to where the tailrotor goes Wink Or try practising landing on land based helipads first, trying to put a bird right in the middle runway "numbers" will be also OK. After you're capable of landing on the numbers, try to squeeze with both skids into a "belly" of "6" on a RWY06 and after mastering that, move onto oilrig itself. The goal is to get used to tight landing spaces and helicopter's movement*, so you'll have on your head only managing the visual distractions provided by oilrig's shape. Also try not to hover over the pad for the extended periods of time, try landing straight from the flight, with continuous slowing down the airspeed, so you can hit hover and the pad at the same time. * for example: you're hovering and suddenly ground in front of you moves downward rapidly. Why? Does the helicopter climb rapidly or the tail went down and the bird starts to quickly accelerate backwards? Or: helo is drifting sideways. How much input does it take to arrest the movement: twice as much, exactly the same or half of what seems to be right? Have a look at my other videos on Youtube (I've finally managed to resolve uploading issues), as all of them are dedicated to Bell 206 so far. No sound nor music (except for the first one) so play your favourite tune and enjoy Most of them were recorded "live" during Alaska Challenge 2011 event and I could post a day-by-day diary, if you're interested. 1400nm in Bell 206 over 8 days, with real alaskan weather The engine management tutorials will be resumed, when I have more (much more, actually) time to write
  5. There is a small, but substantial difference between default Bell 206 and DreamFoil's 206. I strongly recommend trying the second one, as it's both easier and "more realistic" in flight. While I really enjoy BK117, I still prefer DF's 206 over any other helo, freeware or payware. I'm going to post a short hovering tutorial in "I'm new to X-Plane!" section. Edit: link to tutorial http://forums.x-pilot.com/index.php?topic=1950.0
  6. http://www.youtube.com/watch?v=jEA2y3AlUGk Talk about stability
  7. And I can see even from here, that flight attendants are wearing British Airways uniforms I don't have the courage to fly over this scenery in person, because I'm afraid to be stucked to this single island forever and not wanting to fly anywhere else
  8. My first payware aircraft ever and one of the favourite planes. I've considered it to be perfect, and it was, but now you've made it even better. Thanks
  9. I would add orange-black tiger stripes to crew's helmets The rest is perfect!
  10. http://www.xpgoodway.com/modules.php?name=FAQ&myfaq=yes&id_cat=10&categories=#40 GoodWay Flight Planner FAQ (Frequently Asked Questions) · What are the differences between the freeware version and the shareware version? Well, the Shareware version includes all the utilities of the Freeware version and in addition: * The ability to print maps, flight plans and airport plans * The ability to export maps and airport plans in JPG format * The ability to export the flight plan in TXT format that can be read and displayed by X-Plane * The ability to export a special format of the flight plan that will be interpreted and loaded into X-Plane FMC * The ability to create your own aircraft hangar * The ability to have GoodWay display the ENV files available on your hard drive * The ability to display the actual flight path over the programmed flight plan * The ability to download and install the ENV files of the GLOS program * The ability to automatically update the software * The ability to download the real weather Metar file * The ability to set all X-Plane parameters and then place you at the commands of your aircraft ready for takeoff Please note that these options are NOT available in the freeware version In other words, you can't export a flight plan, into X-Plane, from a freeware version of Goodway. I have purchased full version and it's as easy as clicking one button [export to fms] and then copying this newly created file file to appropriate X-Plane subfolder. I highly recommend paying for this very useful resource, for it's additional capabilities and for supporting people doing really good job. Goodway is more than worthy investment.
  11. Old school CRM.
  12. Exercises like that, are far from being pointless. By doing them, you gain a lot of movement coordination and spatial orientation, that will improve your flying in general and might get you out of trouble one day - rotorcraft or not. Just because a typical helipad is twice as large as a helicopter, it doesn't mean, that we should land whenever the bird wants Also, this level of precision, as shown on your screenhot, is mandatory for awarding Hovercontrol Certified Pilot badge, which is not easy. Well done! One note though. BK117, in all its greatness, is a poor trainer, as flight stabilisation system does part of the job for you, thus preventing you from learning and honing that part. Bell 206, or even MD500, would be a better choice. Training with them will be harder at first, but the time invested will pay off more, at a later point.
  13. Welcome to the flock
  14. "Patient more, you should be."
  15. Where did you land today? ;D
  16. Sure that both of them exploded as hell It was an automatic CCRP release, from straight level flight between 2000-3000ft, if I remember correctly. The target was stationary and it was a training flight. During A-10 combat missions, at first I was deactivating area defenses with IR Mavericks at standoff ranges and then I was dropping HD (high drag=parachute retarded) bombs from low altitude-high speed flight or casette bombs with CCIP from a dive, depending on a target and threat level. Lots of flares were used during those attacks, just in case. Most often I was limited by the flares first, ordnance second and fuel third. As for the F-16, similar tactics worked, with an addition of high altutide Paveway precise CCRP bombing and medium altitude CCRP releases of series of casette bombs, on convoys moving along the road (BAI or interdiction flights). Sometimes, I was just dropping ordinary Mk.48s throught overcast, out of 25000-30000ft on larger targets, like factories or ports (similar stunts were performed in Iraq, so that's not that insane, as it would look like at first). I've almost never used dive-toss method, as it was too ineffective and too dangerous for my liking. There were also other stunts performed, as it was a truly multirole aircraft Now I don't have the time to regularly fly more than two sims (X-Plane or Condor), but I really miss that times. Sentry 1, Cougar 5 checking in. Cougar 5, be advised, boogies at bullseye...
  17. Old Flaming Cliffs. My current computer won't run DCS A-10 on a satisfactory level, as it barely runs Ka-50. Why don't you post a complete review, Simon? You've got obvious talent for writing Yeah, screens and videos are pretty, but my biggest concerns regarding Ka-50 were cheating AI (shooting manpads at me through trees, having eyes all around head, popping up out of nowhere, etc.) and a notorious mission structure "player vs. the rest of the world, with insane time limit included". Not to mention, that the missions most often started with engines already running - so where's the point of actually modelling and learning the whole startup? For me, the absolute benchmarks in modern military flight sims were Jane's Longbow 2 and Falcon 4.0 (SuperPak 3&4, then Allied Force). They weren't perfect and had their own quirks, but the overall experience was just unforgettable. So, is the newest DCS an experience on its own, or rather just another place to blow things up?
  18. Thanks! However there is much more to that plane, than just the repaint The peak in the background is Mt.Everest...
  19. http://www.fly-sea.com/challenger/ "This event will bring you to some of the most interesting places in Alaska. Event consists of 4 stages or 20 legs. Start line is opened on 19.03.2011 and will remain opened till 23.03.2011 for all those who wish to join us at later stage. As all Challenger events, it will last slightly more than a week, till 27.03.2011. Once crews reach the Kodiak, we will announce the bonus leg. Awards will be presented in accordance with our standard rules and practices." "Common rules apply for all Challenger events First, there is a "gentlemen agreement" that: * you will NOT use GPS and other RNAV equipment, but only conventional radio navigation or visual flying * both IFR and VFR is approved * crash detection is ON * all flight are flown online (VATSIM/IVAO) * you will limit use of autopilot to cruise flight * in case of crash or incident - you will call Challenger maintenance team (thickbox in PIREP form) which will fix your airplane, usually within the same day, so you can proceed with the event after the repair (you will be notified when airplane is ready)." Sounds like my kind of flying Since lately I've been flying around Alaska anyway, I've decided to join the event, before I'll leave that area. Here is a complete track layout as seen in Goodway: In order to be able to fly all the segments, I had to divide them differently from the "stages" concept mentioned on the event website, because of real life time constraints: Day 1 - 19.III - PAKT-PAPG - 135nm - 1:21(100KTAS) - 0:54(150KTAS) Day 2 - 20.III - PAPG-PAOH - 143nm - 1:26(100KTAS) - 0:58(150KTAS) Day 3 - 21.III - PAOH-PAGY - 130nm - 1:18(100KTAS) - 0:52(150KTAS) Day 4 - 22.III - PAGY-PACY - 224nm - 2:14(100KTAS) - 1:29(150KTAS) Day 5 - 23.III - PACY-PAVD - 138nm - 1:23(100KTAS) - 0:55(150KTAS) Day 6 - 24.III - PAVD-PASX - 160nm - 1:36(100KTAS) - 1:03(150KTAS) Day 7 - 25.III - PASX-PAIL - 155nm - 1:33(100KTAS) - 1:02(150KTAS) Day 8 - 26.III - PAIL-PADQ - 226nm - 2:16(100KTAS) - 1:30(150KTAS) Day 9 - 27.III - extra time for unexpected delays and for the last secret segment As you can see, it's doable time-wise (add some time for preflight preparations and touch'n'goes at airfields between the first and the last ones on each day). Navigation also shouldn't be too hard, as there are plenty of NDBs along the route, as well as shoreline landmarks. The whole route is pretty well documented on the website (charts etc.), there is also skyvector.com with its real life sectional VFR charts (+current weather information - a VERY important item in Alaskan flying!). I plan to do my flying as written above, on VATSIM between 2000Z-2300Z, reg as always SP-KTL and I think I'll take Bell 206. Too much fixed wings lately See you in the airspace, let's show the world how X-Plane pilots fly 8)
  20. Lukasz

    Mountain flying

    http://www.youtube.com/watch?v=A3WKlXVs-dc&feature=channel_video_title It's a recording from a "live" flight I did some time ago, but for some reason Youtube refused to upload it at the time. I was pulling my hair off and using every available codec, so that's why it does look so bad. Source material got lost during cleaning of my hard drive (I really needed that 2GB+ of storage space back then), so that's all I have. Enjoy
  21. That is exactly why it is a perfect trainer Small moves on the stick - do not overcontrol and anticipate what the bird can do next and react before it does it - stay one step before the helo and don't allow it to dictate what you should do. Famous translational lift "dip" for example. When slowing down to a hover, have an eye on airspeed indicator and when you see that the critical speed approaches, shift your attention to VSI. Smoothly add the right amount of collective at the first sign of VSI drop. At the same time, when you pull the collective, add some antitorque pedal and you'll maintain full control throughout this critical phase of flight. Also experiment with the gross weight, for your training sessions. Some prefer it to be light, others like it heavy.
  22. Musica! When I was looking through a dictionary in search for an appropriate title for this part of engine guide, I've found "instrumentation" and a description attached to it was the following: "the act of arranging a piece of music for an orchestra and assigning parts to the different musical instruments". For some of us the sound of aircraft engine is a very pleasant music, but the definition above sounds like too much, right? Well, not really. However, when we translate it into something like this : "the act of measuring a performance of an engine and assigning indications to the different panel instruments", it starts to make sense. When I add, that the gauges are not completely separated from each other and their indications are interconnected and must be examined together with the others, then comparing a pilot to a conductor, having an eye on an orchestra of engine monitoring instruments, is completely justified. "Hey, you there, on the trumpet! Your manifold pressure is a bit too high!" Between Mt. Cylinder and Exhaust Peak Before we move onto instruments themselves, we need to take a look at score first. Here is a chart extracted from a Power Point presentations I've found on the Internet http://www.eaa42.org/misc/gregs_show.ppt Various sources credit it to Advanced Pilot's Seminars, GAMI and William "Bill" Compton. The chart shows, what happens inside an engine when a pilot pulls mixture lever towards lean position (read the chart from left to right). At first all parameters rise, next they peak - although at different points - and after that, they all fall. Some of them are directly reflected on respective gauges and the others are not, therefore it is double important to memorize this chart, in order to have a complete picture of engine's operation during a flight. EGT means Exhaust Gas Temperature and is a direct indication of mixture's "quality". For an engine to run, we need a specific fuel to air ratio and EGT peaks when this ratio is perfect - fuel and air are mixed in just the right proportions (from a chemical point of view). EGT peak is the reference point, that differs so called rich-of-peak (ROP) and lean-of-peak (LOP) engine operation. CHT means Cylinder Head Temperature and is a direct indication of how hard the engine is being pushed by the pilot. Have a look at the next curve, labelled ICP (Internal Cylinder Pressure). Both the CHT and ICP have the same shape - the more pressure (=stress inside of the engine), the more heat. CHT usually peaks around 50OF ROP. HP means horsepower and shows how much useful work the engine is doing at the moment. The more power, the more thrust (minus losses due to propeller's (in)efficiency), which means more aircraft performance. Higher speed, better climb, shorter take off distance, more payload on board. Power usually peaks around 80OF ROP. Let's stop for a moment here. How is that, the perfect fuel to air ratio (EGT peak) doesn't result in best power generated? Do you remember, when I've written, that fuel and air doesn't mix uniformly? There are always mixture pockets of various fuel-to-air ratios inside the cylinders. Some parts of the whole mixture have perfect ratio, some are too lean and others too rich. The pockets with perfect ratio burn happily at the highest (peak) temperature, which is shown by the gauge. However, the pockets with richer or leaner ratios, burn less efficiently or don't burn at all and leave cylinders as hot air and fuel molecules, without generating as much power, as the perfectly burned pockets did. In order to compensate for that, you have to supply the engine with a little bit of extra fuel, to give that air molecules more chances to "meet" with fuel and burn, generating additional power in the process. But adding more fuel to the mix, makes the mixture more rich and moves it out of the "perfect" spot on the EGT scale. That's why the maximum power is achieved rich of peak and with lower EGTs, instead of on the EGT peak itself. OK, but why doesn't max power match max pressures (=max CHT) inside the cylinders? Do you remember, when I've written previously, that the mixture doesn't "explode all at once", but it takes it's time (miliseconds, but still...) to "light up" and create any useful pressure on the piston? Imagine it, as a wall of flame expanding from a spark plug and moving towards piston, cylinder's walls and head. In fact, it is called a flame front and one interesting thing about it, is that a pilot has some influence over its speed. By making the mixture richer, you can slow it down and leaner mixture will speed it up (to a point). Remember, that the engine is a precisely timed machine. Ignition must take place in just the right moment of crankshaft rotation, so that the peak pressure takes place when the engine is "prepared" to take it. By making the mixture leaner, you also make the mixture to burn faster and light up completely, before the engine had a chance to rotate far enough behind TDC, to make a good use of the pressure increase. At this point, it isn't prepared yet to take the pressure, the pressure rises rapidly, but the piston doesn't "go down" as fast as it could, if it was at the right position. So, the hot gases want to expand, but the slow moving piston holds them in place. The pressure rises even more and that is the reason behind ICP/CHT peak at the leaner mixture, than max power mixture. Obviously, when you lean the mixture even farther, the power drops, the amount of burned fuel decreases and so the pressure also starts to drop. This sounds tricky and pretty useless in an "easy guide", but in fact it's VERY important. Understanding of these concepts is critical to avoiding serious damage to the engine. At least in real life, since most of simulators don't model at all, any of these details. However clever plugins could change that Have you ever wondered, why An-2 plugin fails the engine, when you overheat or overboost it? Right By the way, that's more or less me, trying to write this guide, regardless of "external distractions" http://www.youtube.com/watch?v=Zq8k8Rsd9oY The last curve on the chart, marked 1/BSFC represents engine fuel efficiency. BSFC stands for Brake Specific Fuel Consumption and the curve normally has U shape, the lowest point on it being the lowest consumption of fuel unit per unit of generated power during a specific amount of time. For example 0.5lb of fuel used per every 1hp generated during an hour of engine's operation. Thus an imaginary 180hp engine of such BSFC, would use 90lb (14.9gal) of fuel for every hour at full power. On this chart, the BSFC curve was flipped upside-down, to rather indicate engine efficiency, which is the highest at the point, where BSFC is the lowest. Take note, how the efficiency changes, with mixture setting and power being generated. Engine overboozed Your grandmothers may have told you hair raising tales of aircraft engines being completely destroyed in seconds, or even violently exploding, at the most unsuitable moment, like a dramatic climbout to jump over that mountain or trees, popping out of the fog ahead. I don't know about you, but I couldn't sleep afterwards, haunted by visions of bent crankshafts, burned valves, exploded cylinders or pistons completely thrown out of the engines. And while in my grandmother's stories, the usual culprit for that was some kind of gremlins, the effects were true. Such damage is possible and did happen in real life, due to deficiences in engine operation, maintenance or design (seldom occurence, but it can happen). Even using a wrong type of fuel will ruin your day (there is even a separate failure in X-Plane for simulating that). Avgas is avgas, right? Wrong! Piston engines, while being built basically for containing high pressure, high temperature, almost-explosive burning of fuel, do have their design limits, like any other devices or machinery out there. It will break, if you manage to heat it up too much or if you allow too high pressures inside the cylinders. Let's leave design and maintenance matters aside, as they are not much relevant to flight simulators and concentrate on deficiencies in operation, which can destroy an engine in two ways: by detonation and preignition. Remember, that both of them can develop separately or at the same time and one can act as a trigger, starting the development of the other. Regardless of its name, detonation is the more gentle of the two, if anyone can call as such an engine damaging process. It's because it starts at low level, then moves to medium and only then turns into heavy detonation, which actually can do devastating damage. Worth noting is that, while light and medium stages don't violently damage the engine, they can easily and quickly become the heavy case and that's why it's best to avoid detonation at all, regardless of its severity. For the detonation to develop, an engine must be operated at high power and lean mixture. Such conditions lead to increase of CHT and ICP and all four of them make a favorable environment for the detonation to start. High power means high peak pressure. Lean mixture means faster flame front and even more peak pressure. This combination of faster, more violent combustion and increased pressure, increases CHT. As the engine gets hotter, it promotes even faster mixture burning (=faster flame front) which increases peak pressure even further, with every next cycle. As you can see, it takes some time for this condition to develop, but it's self propelling snowball mechanism, which will do something bad, sooner or later. How soon? It depends on how fast everything rises up and in what condition is your engine, but don't expect more than few minutes. Maybe five, maybe one. The point is, you can't increase CHT forever. Aluminium, as every metal or alloy, has it's temperature limits, above which it looses its strength and becomes weak and plastic. Think of cold plasticine here, which is hard and stiff when you get it out of the box, but becomes easily mouldable after it was heated by the hands. Now take the increased pressure into the equation and you end up with a "plastic" engine, that has to fight more than usual stress, trying to explode it from the inside. That doesn't look any good and one can only imagine, why this condition was named "detonation". What is worth noting, is that turbo- and supercharged engines are more prone to detonation, because turbos mean more pressure inside cylinders - even when the engine is being operated correctly. NA engines are relatively detonation-free, but that doesn't mean, that you can relax and push the engine to the max. Turbo or not - it CAN happen to everyone. Also running constant RPM propeller down to low RPM, while setting the engine up for high power, "moves" peak pressure closer to the TDC - exactly, as the lean mixture does. What to do then, to avoid detonation? Do the opposite to the things, that cause it When at high power, like during take off and climb (or go around!) set full mixture (although be sensitive about high elevation airfields here...) and max RPM, in order to have the flame front nice and slow and the peak pressure in the right moment during crankshaft rotation. Have an eye on CHT and do not allow it to move too high. Also pay attention to such situation, when CHT still "in the green" but moving up fast, which is an indication of "CHT runaway" and a clear sign of something very very bad going on inside the engine. Do the same, if your engine starts showing signs of detonation: add fuel to the mixture, increase prop RPM, change to a lower power setting, cool the engine by opening cowl flaps or increasing airspeed (decrease climb vertical speed-increase IAS or even slightly dive for a moment). Preignition, while may sound more politely, than "detonation", in fact is a real killer. It won't take the time to develop - as soon as the conditions are right, the engine will explode. There are seconds here, instead of minutes. Sometimes even less than seconds. Conditions for the preignition to develop are the same, as in a detonation case: higher than usual temperature and higher than usual pressure. Preignition often is a product of detonation, but it can develop on its own, as well. What happens during preignition event, is that the mixture ignites before the spark plug fires. In other words, you've just made a diesel engine out of your powerplant, where fuel-air mixture ignites by itself, without any spark, because it is compressed and heated enough by the engine alone Now picture that: normally, the spark fires, slow flame front takes the time to light up the mixture and by the time it is starting to exercise pressure on the piston, it is past TDC and on it's way down, ready to take the pressure and make something actually useful out of it, apart from smell and noise. During preignition however, the mixture ignites out of the increased levels of heat and pressure (and does it very violently, forget about nice 'n' slow flame front!) before the piston had a chance to move into it's usual position. It may be at TDC or even before top dead center, when the mixture ignites (or rather explodes). Piston is being brutally hammered by the pressure and the result is either bent/broken crankshaft or exploded cylinder. Or both - remember, this is a heavy piece of metal, being plastic out of the excessive heat, rotating wildly at high speed. If you've ever worked with wood, then you know that you have to hammer the nails with just the right amount of speed, force and at the right angle (i.e. directly from above). If you do that, the nail will nicely go into the woodwork you're trying to assemble. But if you miss the "required parameters", the nail will bend, jump out or go in at angle, usually damaging the wood. Not good! So please think of the nails and wood (as well as of cold and warm plasticine), every time when abusing the engine These two might know something about that already "I wonder, what does this button do?" Now once we have all the theory covered, we can move onto more practical side of engine management. There is a number of various, often exotic gauges on the panel and while it might look, as if they're put there for the cockpit to be more "professional" and busy place, all of them actually have their purpose. Remember, gauges do cost in real life and they also add to aircraft's empty weight, so they better show anything useful, if they're going to be added to the panel! Some of the info will overlap with what was already written, but I've decided to write it here again, so you don't have to jump up and down, between chart description and gauges here. EGT - Exhaust Gas Temperature Mixture quality. An EGT peak means the best proportion between fuel and air, while peak EGT minus about 75OF to 100OF ROP means best power (for a given throttle/RPM combination). Stay more than 250-270OF ROP and you should be safe from detonation. Or even better, take you plane to sea level, set max power and max mixture and note the EGT. That's your full power indication and do not go above it, while leaning to compensate for altitude effects, when at full power. Below 65% of power, you can set EGT (and thus mixture lever) wherever you like, as the power is too small to do any damage to the engine. Do not go "over the peak", unless your plane is LOP capable, more on which later. Some gauges have an asterisk mark on them, that's the maximum allowable exhaust temperature, so stay below it. Also EGT is the only gauge, that clearly shows which engine has failed, on multiengine piston planes. Don't try to judge by MP or RPM - instead have a look on EGT, because where is no fire, there is no EGT FF - Fuel Flow Indirect power and range indicator. Ah, have you ever wondered, how to set some specific power %, without need for memorizing vast power charts from POH? In reality, it's more than easy. Since you will climb at full power anyway, we have that one down. Descends are flown at reduced power, so that's also off the table. What's left, is cruise. Pick up one or two best RPM settings (2300 should be good all around default) for a cruise (for a given plane) and look into the POH for FF at that power setting for a given altitude. FFs published in POHs are usually "leaned for best power". All you need to do, is to take this plane to this altitude and set this cruise power - roughly set FF with throttle, RPM with propeller and EGT with mixture. Fine tune the indications to be perfect and note FF and EGT. Now's the best part As long as you maintain these parameters, the engine will produce almost exactly the same amount of power, regardless of altitude (+/- 3-5hp)! I've tested this in X-Plane and it works, for NA and turbo engines alike It also works for fixed pitch propellers, although at low altitudes the power will be lower, because of lower RPM (C172 showed 10hp difference). So, after this one single test flight, you'll have your 65%, for example. After you set EGT and RPM, the FF gauge basically turns into a power gauge. Over specific FF = over 65%, under this FF = under 65%, thus safe for mixture experiments. If you don't have such detailed POH, then use X-Plane's data stripes and experiment with values. Life is good With FF and IAS you can also calculate range that can be covered on the fuel aboard. Take fuel amount and divide it by FF - that's how long you can fly. Multiply that by TAS and you'll have your range For example FF is 10gph, fuel tank's indication after the climb is 300lb, alt is 15000 and KIAS is 120. 10gph is 60,2lb/h. 120KIAS is 156KTAS. 300/60,2 is 4,98 h of flight. So 4,98h at 156 knots gives us 776,8nm, without reserves and 659,8nm with 45 minutes reserve (how I've calculated that, is for you to determine You should have enough insight by now. I've assumed reserve FF and alt to be the same as cruise). By the way, ALWAYS fly with 45-60 minutes reserve, especially with real weather and double especially on Vatsim or similar network! MP or MAP - Manifold Pressure Indirect power and cylinder pressure indicator. This gauge alone won't tell you anything, short of indicating whether or not you're overboosting supercharged engine. But high MP with normal EGT will indicate normal high power, with high EGT will indicate unsafe condition, but with high EGT and low FF will indicate cruise in LOP. Too high MP with too low prop RPM is also unsafe. Too low MP may indicate high altitude, above critical altitude, turbine failure or gauge failure. So always combine MP indication with other gauges, as it will give you the picture you're looking for - that's why a complete understanding of engine operation is so important and also so satisfying for everyday flying You have to create an "engine picture" in your head, for the duration of the entire flight, instead of just "keeping the needles in green". Also take a note, that MP shows "air component" and FF shows "fuel component" of the fuel-air mixture, while EGT shows how well these two work together. Nice, eh? RPM - Revolutions Per Minute Indirect power and cylinder pressure indicator (for a constant speed prop). On an engine with a direct connection between the engine and propeller, it shows the common speed of both. For an engine with a reduction gearbox between it and its propeller, this gauge may show one or the other. By the way remember, that if a gearbox is installed, then it's always making the prop to turn slower, than the engine, because engines like to run fast (because ignition timing is tuned for the max stress = full power and speed) and propellers like to run slow (because of propeller's tips going supersonic when at high RPM, which is bad). The more RPM the more power, and vice versa. The more difference between high MP and low RPM, the more pressure increase inside the cylinders. You may have heard the term "oversquare", which is a common description of this difference between these two values. An engine running at 25"MP and at 2500RPM is running "square", as well as is an egine running at 30"MP and 3000RPM. Just divide RPM by 100 and that will be MP (in inches of mercury), that is required to run square. Any combination, that have "more" MP over RPM is "oversquare" and anything with less MP, than RPM is undersquare. So 30"MP @ 2500RPM would be oversquare, and 25"MP @ 3000RPM would be undersquare. How much oversquare is permitted? Always consult POH (youl'll hear that more than once yet). However as a rule of thumb to be used in a simulator, you can assume an oversquare of 4-5" to be safe for NA GA engines and of 8-9" for TC GA engines. For example, C172 at takeoff may be running 30"MP @ 2500RPM, which is 5" oversquare. Safe, provided that mixture lever is fully "in". As usual, old & powerfull radials and "hot water twelves" might have different limits and they are very fussy about maintaining correct parameters - because of power. The more powerfull the engine, the more careful you need to be, while operating it. Why? Because high power means high stresses, but the engineering and the metallurgy behind those beasts are exactly the same, as in your low powered "ornithopter" (where in addition to engine at full power, pilot has to flap both arms and ears, for a takeoff to be successful ). So, such engines, with lots of power, are operating closer to "the edge" and the allowed operator's error margin is smaller. I'm hijacking my own post AGAIN Back to gauges! CHT - Cylinder Head Temperature Engine happiness indicator Yes, that's exactly what this gauge is indicating. As long as you maintain proper engine temperature, it will be happy and it will continue to work as designed. Cool it too much or make it too hot and it may thank you for cooperation and quit - sometimes quite literally! While it's true, that too hot engine becomes plastic and can't stand stresses inside the cylinders, the same stands true for an engine that is too cold. Cold engine is very stiff and it is generally known, that stiff bodies don't take stresses well and break easily. Glass, for example. That's why wings are elastic (to a point, of course) and why you have to heat up the engine before takeoff - it has to be somehow plastic, but not too much, so it can take the stresses that come with full power operation. There is a catch, however Manufacturers often "cheat" and move the upper redline too high, so that the pilot could push the engine further and have "more powerfull" plane. Remember, that in real life planes must sell and higher performance planes sell better? Right. Regardless of engine type and power, you should maintain CHT between 200 and 400OF (roughly 100-200OC, easy to remember), with cruise temperature somewhere between. Even if the green zone on the gauge tell otherwise. Will engine fail immediately, if you move outside of this range? It depends, on how far and how fast you'll move. Small excursions may only shorten the TBO, while bigger ones (like 100OF, especially on the "hot side") may break the engine inflight (or during next takeoff... you'll never know, as this damage is cumulative). By the way, do you now understand, why during the WW2 ground crews were putting so much effort, between every flight, into the maintenance of these engines? Do you believe, that in a heat of a dogfight, ALL the limits were faithfully respected? There is yet another catch You can exceed engine limits, even badly, but it will be cool, well inside the limits. How is that possible? Cold air. Very cold air, in fact, like during winter. Just don't push the engine too much on the cold days and you'll be fine What about high altitudes? It's also cold up there! Yes, but the air is also much more thin, thus precluding from using full power anyway. Either the engine will starve without the air or the drag on the fuselage and the propeller will be so much reduced, that the power required for a flight will be also smaller. How to maintain CHT within the parameters? You have to maintain equilibrium between heating from the inside and cooling form the outside. When one side prevails, decrease it or increase the other. At first try cowl or radiator flaps, if you have them. The next step is to increase/decrease airspeed, in order to do the same to the cooling airflow running around the engine itself or external cooler, found on most warbirds. The slower the flow, the less cooling effect. For long climbs at high gross, try to use step climb technique - if you could couple it with the reduction in plane's weight, due to fuel burn, it would be even better and pro (remember about that aerodynamic efficiency stuff, with regards to weight and altitude?) In the end, you could also reduce power, but that should be considered as a last resort move, because less power means less performance - which is bad for a situation requiring it, as in climb. But as a rule, always climb at full power. If you can't - decrease VS in order to increase IAS an cooling airflow. Also try not to load the aircraft up to gross weight on hot, sunny days or at high elevation airports. The supercharged engine might have the power required to overcome the effects of hot (=thinner) air, but also you have to think about the performance of propellers, wings and control surfaces. P & T - oil pressure and temperature Secondary engine happiness indicators. Peas and teas (I must be half-engine, because a good tea really makes me happy ) They need to be looked upon together. Both high - engine is working too hard (and may be very unhappy about that soon...), high P and low T - oil too cold and too dense (not good, increased engine wear, do not push the engine), low P and high T - oil level too low (an oil leak! a serious emergency! yikes!), one high or low and the other normal - monitor carefully, as it may develop into something nasty, also it may indicate a faulty gauge. Oil is mainly used for lubricating the moving parts inside the engine, for changing prop pitch and for lubricating turbine bearings. You need the sufficient pressure so it can be injected into all the small places, to lubricate metal there and prevent it from touching while moving at some crazy RPM. You need the right temperature, so it is fluid enough, not too much and not too little - the same as you want the engine to be a little plastic, but not too much. Oil temperature rises, when there is metal to metal contact already (too little oil to lubricate every part) or when the airflow around the oil cooler is too small (too low airspeed or the engine is working too hard and heats the oil too much, so the oil cooler is overwhelmed and throws the towel). Cold oil is more dense, hence the increase in pressure. This is normal for engine start and both of them should "normalize" after the engine and oil are heated up to their working temperatures. Do not exceed 900-1000RPM until that happens! You risk damaging or shortening life of a "dry" and cold engine. Abnormal oil pressure may also indicate other mechanical failure, like low pressure - oil pump failure. TIT - Turbine Inlet Temperature Mixture quality. Found on turbine-equipped engines, same rules as for EGT apply. Well, maybe with some small twists, to make our life even better and more interesting There is always upper limit for TIT, for turbonormalized engines it is usually in the lower 1300s and for the "truly supercharged" the common limit is set at 1650OF; the POH will have the right values. Try not to exceed these values, really. Turbine works in even hotter environment than egine's parts and also it spins MUCH faster. So the design limits are even tighter here. Even few seconds in "the danger zone" above the redline and that's it. Remember that rule, because turboprops are even more sensitive to rough handling. But what else would you expect from an engine basically build around a turbocharger? If your engine has a turbo, then TIT gauge "replaces" EGT gauge in funcionality and you should always lean mixture with the help of TIT indications. EGT may still be installed, but only as a secondary and backup instrument. Take a note of a slight difference in indications between the two. That's it, as far as gauges go. Some engines on some planes may use other gauges, but you won't see them on "normal" modern GA planes. Also, these exotic gauges are usually self-explanatory. Rich is not always good So far we've deliberately stayed on the "rich" side of EGT peak, because that's how most of the engines are operated. That doesn't mean however, that lean of peak or LOP engine operation isn't possible. It is, and also it's a better way to use the piston engines. Engine is more fuel efficient, because there is no excessive unburned fuel, leaving the exhaust pipes - only excessive air, which is for free. There is no risk of fouling the sparkplugs with the deposits of rich mixture burning. The engine runs cooler, for the same power setting. The concept isn't new, as Lindbergh used LOP principles to stretch the maximum range of his plane, during his famous flight over the Atlantic Ocean and later he has passed his knowledge to the crews of US bombers, taking their part in WW2. Old piston powered airliners, from a more elegent era also utilised LOP, for increased range and minimized fuel burn. With the beginning of a jet era, the concept was forgotten, only to be "reinvented" recently, with the help from modern engine instrumentation and design details. Why not to use it then, if it's that good? It's because most of the modern engines can't handle LOP well. They start to run roughly and quit, when you lean the mixture too much. All of it is caused by the fact, that each cylinder is receiving a little different fuel-air mixture. Some are lean, some are rich and the others may be somewhere in between or even farther in either way. When you pull that mixture lever, some cylinders "move" behing the peak and run at various levels of lean of peak, while the others are still on the rich side, some more rich and some less rich. Again have a look at the power chart: While the power curve on the rich side is more or less on the same level, on the lean side it drops more visibly. Which means, that you can get away with some minor differences in mixture ratio between cylinders on the rich side and still have nicely running engine, while at the same time it is a no-go on the lean side, as even small differences in mixture will produce big differences in power output between cylinders. The uneven power distribution between cylinders means, that some want to turn the crankshaft faster and harder, while the others are more laid back. And since all of them are on the same crankshaft, this causes uneven stress distribution, as well as over- and underrevving of the cylinders, with regards of the speeds commanded by their respective mixture settings. That is the real cause behing engine rough running when too lean. It's like having two different personalities under one roof, one waking up and going to sleep early, and the other partying until daylight and sleeping till midday. There will be roughness between them, for sure! So in order to be able to run the engine on the lean side of EGT peak, mixture ratio must be equalized between the cylinders, so that all of them "peak" at the same moment and develop the same amount of power - or at least to make the differences of such small magnitude, that they won't cause engine roughness, as was demonstrated on the rich side. It's relatively easy on the fuel injected engines. All you need to do, is to measure the exact amount of air, that the each cylinder is receiving and then to produce custom fuel injectors, that will supply right amount of fuel, so that every cylinder is running on the same fuel to air ratio. Unfortunately, carbureted engines usually have so bad fuel/air distribution between cylinders, that nothing can be done. They're "stucked" on the rich side. By the way, radial engines are in general more "willing" to run LOP, because of their geometry. All pipes, that supply fuel and air to the cylinders, have identical lengths and shapes, which allows for very similar fuel to air ratios between cylinders. Another thing is that you need all the cylinders either on rich or on the lean side. You can't operate the engine "halfway". It's always either rich or lean. But how do we know, what are the cylinders doing, with one EGT gauge? That's why anyone wanting to use LOP absolutely have to install a kind of all-cylinder engine monitoring system. It can be either modern multichannel engine monitoring gauge or a built-in element of an engine page in a glass cockpit installation. It's fine, as long as it can provide at least separate EGT and CHT readings for every cylinder. Six cylinders - six "stripes", but usually these systems have a lot of other useful functions and with that in mind, they are also recommended for engines that can't run LOP. Why? Imagine that you have four cylinder engine, with cylinders #1 and #2 being the hottest ones. CHT probe was installed on #1, but it's #2 that has experienced CHT runaway... Now #2 is going haywire, but you still see perfect readout for #1 and you think, that the rest of the three cylinders are performing in a similar way. First sign of trouble you'll ever receive, is well beyond last point, at which any corrective action was possible. Obiously, this is no good! It doesn't really matter for simulators, but if you want to faithfully replicate proper engine operation techniques, then use LOP only on fuel-injected engines, with appropriate monitoring installation. Either stick to planes, that are equipped as such or try Lean Assist addon found in the x-plane.org download manager. It's free and fun to use and it opens new possibilities for flight planning One thing to remember, though. When running LOP, you have less power available, in general. You can make up for it to some degree, by running approximately 3" higher MP. Fuel flow and fuel economy will be from the lean side, but this additional MP raises pressures inside the cylinders a bit, which allows for an increase in power output. Flying in such manner, allows for about 20% increase in fuel efficiency, at the cost of about 5% decrease in performance. A fair trade, if you ask me Again, have a look at the Power Point presentation mentioned at the beginning of this post. That's all for today Now, repeat after me: piston engines are fun, piston engines are fun
  23. I see. Thanks for straightening it up, so we all can learn
  24. Thanks for the comments As for the turbos, power recovery "device-turbine" probably got lost in the translation, as not every source I've read so far, was originally in English Also sometimes I think of two names for something, at the same time, and just type in the wrong one. Although I try to check what I've written before posting, some "typos" somehow manage to slip into the text. For the "super-turbo" distinction, even engine manufacturers do confuse things, "creating" TSIO type engines. From what I know, it should be either T (turbocharged) or S (supercharged) Injected horizontally Opposed engine. So either TIO or SIO. Some sources I've found, made the same mistake and I've mentioned such designation for the record. But it should be like the undelined designations in the guide: either turbocharger or supercharger. By the way "TSIO" engines are of the turbocharged type, nothing "super" about them, only a stream of hot exhaust gas
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