Military climbing procedure
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Seeing as Frederf was not arguing for a climb at Vy… just explaining the maths behind the MIL climb profile.
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Don’t worry, Blu3 I don’t believe anyone’s arguing here, his info was super useful. I think it’s spelled “math” brother
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Just like I (and the rest of the English speaking world) spell standardisation without a “z”.
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Thanks for all the replies and help.
I’m currently thinking about a way how the climb profile can actually be calculated from the FM.dat file given thrust, drag, weight and drag factor. I want to be able to read an FM file and calculate fuel usage, playtime, maximum MIL ceiling, maximum sustained G in MIL and so on to allow for a better planning so that when you know your weight and drag factor, you know how much fuel it will take to complete the flight and see what your joker, bingo and power margin you do have. Which is cool for planning and useful when you create your own TE.
And of course, I want to learn C++ 'cause not being able to code a decent program sucks in times of the internet of things and industry 4.0 or whatever you name it. Yes, there are a couple of nicer languages, but C++ is cross-platform and Qt is important for me for a couple of reasons so I’m going the hard way.
But, after some weeks of pain and fail, there is finally something that works to some degree::woohoo:
Which is pretty cool since I have no experience in no programming language except machine PLC’s or Visual Basic. Currently, I only have the F-16C blk52, but it is an array I can fill with any FM.dat file (at least I hope so, F-16’s should work). So, some time I might be able to chose any F-16 variant and calculate how much fuel you use, what power margin one has available and so on. Even the playtime on a waypoint and waypoint actions like refuel or CAP could maybe be added which would be cool. I’ve been thinking about a save and open option, providing templates and so on…
But since I’m an absolute beginner, I might take years to complete it :rofl:
I’m not holding back the source code- if anyone tells me about that license stuff with using Qt Creator community edition and wants to see the source code, I’m zipping it up, compiling it and there you go.
I just want to be able to make subsequent releases on my own since this is my personal training project. I don’t think it is ready to be released to the public although the basic things work. I’m still learning a lot, but sometimes the whole thing chances a lot, some new classes appear, old ones disappear- you know what I mean if you remember your first steps in programming
Well, lot of things are cool, not all of the cool things are useful. The speed converter Mach-TAS-EAS-CAS-EAS-TAS-Mach which is already in the code would be cool and useful once integrated in the UI.
Learned a lot of physics on the way. Like what is a compressibility error or the difference between TAS, EAS, and CAS.
But that climb thing is giving me a serious headache… For the fuel usage, it does not matter this much. I don’t even calculate descends, no turns, nothing, just plain level flight and the climbs. But originally, I wanted to calculate the profile out of the dat file since it differs depending on weight, drag factor and of course the airplane and engine used to fly it.
Now, I am thinking about making some file in which the table for the “real life climb” is stored. But hey, someone must have calculated it and some jetplane engineer said “if you do is that way, it will be the best way to do it- write it in that manual” and he said that based on math and numbers. My personal guess is that it is simplified by only using the drag factor for easier use + a few % for fuel effectiveness (climb is not so steep- total flight profile is more fuel efficient).
Basically, I now have calculated the best climb rate, but not the most fuel efficient one.Maybe I’ll just create a table for each variant, display that in the UI and calculate all climbs based on that…
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Hi Tobias,
I’d recommend looking into Python / QT which is much more friendly to the beginning programmer than C++… yet I see you’ve some results to show already, good work!
I think the QT licensing is rather lenient when not making money off of the resulting product, but I’d have to check that in detail. QT has been around for ages alongside GTK in the Unix / Linux world, so I’d be quite confused to find out their licensing sucked.
All the best, Uwe
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errrr not 100% sure but ain’t WDP doing this already?
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……
But don’t tell anybody, thats classified…
Gr Falcas
Don’t worry it will be a secret between me and you… I’ll take it to my grave…
:lol: -
Don’t worry it will be a secret between me and you… I’ll take it to my grave…
:lol:So will do everybody here
…
I’d recommend looking into Python / QT which is much more friendly to the beginning programmer than C++… yet I see you’ve some results to show already, good work!
…Thank you very much! I already noticed the C++ is rather hard for a beginner. About 15-20 years ago, I tried to learn C (was about 15 years old or so) but I gave up back then. C++/Qt is used in our machine controls too (cross-platform Linux and Windows), so I decided to go for this option.
A couple of months later, I remember my trouble with C back then and all the advices about Java and Python- and decided to go for one of these next… I think I should have chosen the other way 'round.
However, making strict use of the C++ OOP features finally provides a good way to solve all those things that really limit C in the more modern environment nowadays. Like having a decent UI which is rarely ever seen in pure C applications. I heard that it is pretty easy to provide an UI with Python, but well- decisions are made, the path is set and there we go.
Since I “grew up” with machine controls and coding PLC’s which is pretty much like assembler basically, the whole OOP thing is rather new to me. But I think that good programming is always a way of thinking, not a way of the language you are using. After all, I must say that knowing how to create and keep an OOP structure without getting lost in the code you wrote 2 months ago is actually harder than learning the language itself. But developing some sort of clean code structure and following the OOP approach also holds the biggest potential and saves work afterwards.
Still, I’m pretty sure that if I look into that code two years later I will facepalm myselfYep, WDP has the RL climb profiles for each F-16 block (depending on engine) from there RL manuals.
But don’t tell anybody, thats classified@TobiasA, Keep on going and enjoy coding.
Gr Falcas
Thank you very much! I am using WDP which is an outstanding program. My thought was that it was possible to calculate that best climb profile out of the FM.dat file, knowing that WDP uses the RL manual table made me think different about that approach.
The difficult thing is that the Vy climb is a real profile with various mach numbers and altitude figures you need to follow and the RL table is way easier- hold CAS until Mach matches, then hold Mach.
I think I will include those RL tables for all the F-16 variants in a special file. So, whenever I have a table, the table is used and if not, I assume a Vy climb.
Still, the calculation might come in handy if there is no table provided (thinking about non-viper airframes).My co-worker told me that if you use Qt for an open-source application and do not change the libraries you could even release it as beerware or so. Well, I could just provide the source code for it as a zip file and there we go.
Thank you all for your kind help!
Regards, Tobias
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Instead of maximizing excess thrust for each chunk of altitude, maximize climb rates (ft/min). If you look for best excess thrust, like you did, you’ll get slow, steep climbs that make it to the required altitude using the least amount of fuel, but like Frederf said, it’ll end up costing more fuel by the time you get to the target because of the increased cruise length. If you try to maximize your climb rate and therefore minimize time spent at each altitude, then the answers that pop out are shallower, faster climbs that are a lot closer to the IRL falcon climb schedule. Now, idk if this is the absolute minimum or not, but it certainly results in less fuel being burned by the time you reach the target area (climb and cruise combined).
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I did a test to 25,000 with wing bags and AA Load out back int he 4.32 days. Afterburner takeoff to 25,000 vs MP Takeoff to 25,000 both climbing at 350 Knots. I think I set weather to standard atmosphere as well. The total leg length was 100 NM from TO to testing waypoint at 25,000… Difference was a couple hundred pounds or less. If it’s not going to be a long flight at cruise… AB works just as well as a cruise climb. AB burns more in climb but gets you up to cruise faster so you take advantage of lower power setting at cruise longer. Rough numbers but not the knockout punch I expected. Honestly I just use WDP as it’s based on the real thing anyway.
However, TobiasA I enjoy programming in C# and any excuse to write some code is enjoyable!
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Nobody flies long enough distance/time in BMS to need cruise settings is part of the issue here.
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Nobody flies long enough distance/time in BMS to need cruise settings is part of the issue here.
Can you explain why it wouldn’t be prudent to operate at the most efficient speed and fuel burn vs Mil power for the duration of flight, specifically depending on drag factor and load out? How are cruise power settings exactly not needed, regardless of distance or time?
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Can you explain why it wouldn’t be prudent to operate at the most efficient speed and fuel burn vs Mil power for the duration of flight, specifically depending on drag factor and load out? How are cruise power settings exactly not needed, regardless of distance or time?
Someone I once regarded as a close friend advised me once, that cruise speeds even when most efficient, were not always the most prudent speeds to fly at, in the interests of controllability and reaction to detected threats in close quarters. At the time, I made the counter argument (and still happen to cleave to it) that those speeds were still most applicable for certain phases of flight in certain operational cases - to and from an area for instance, or max endurance whilst on CAP in another instance.
More recently though, its apparent to me that few people fly prototypically, and few people fly missions of long enough range or duration for those power settings to make a big difference to their planned operation. Most folks express surprise at the idea of a total mission radius in excess of 250 miles, while prototypically, anything less is considered a short range mission. As I said above: most folks just dont fly far enough for it to matter to them. Once you start to fly a little more realistically, as some wings do, these things suddenly start to matter a whole lot more.
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It is not very easy to stay in front of a monitor flying a mission longer than 300 Nm. It can be done but the eyes will start to suffer as well as we are not getting money, so it is a big investment of time.
But I will follow you discussion because it is becoming very interesting this subject.
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I have to agree that for the most part flying efficiently as far as a cruise climb won’t net you much in BMS due to the short flights we have, other than an attaboy for having the most fuel remaining when you return. The trick is to fly efficiently while flying in formation with your lead pilot. Nothing worse than getting to the FLOT and your wingman has 1500 - 2000 lbs less than you. Not so hard to keep the gas in fingertip but when you are maneuvering tactically and trying to stay in position proper technique will net you lots of fuel savings and keep you out of the Afterburner! This is where I focus my fuel savings techniques!
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@bill_3810:
The trick is to fly efficiently while flying in formation with your lead pilot. Nothing worse than getting to the FLOT and your wingman has 1500 - 2000 lbs less than you.
Its worth noting that as much onus there lies on the lead as on the wingie.
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It is not very easy to stay in front of a monitor flying a mission longer than 300 Nm. It can be done but the eyes will start to suffer as well as we are not getting money, so it is a big investment of time.
But I will follow you discussion because it is becoming very interesting this subject.
I hear yeah… When I had my full cockpit and was single, I would love flying 3 hour plus missions in the Balkans… Now being married with kids, I have to stick to short missions in Korea that are not too much longer than one hour.
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@bill_3810:
I have to agree that for the most part flying efficiently as far as a cruise climb won’t net you much in BMS due to the short flights we have, other than an attaboy for having the most fuel remaining when you return. The trick is to fly efficiently while flying in formation with your lead pilot. Nothing worse than getting to the FLOT and your wingman has 1500 - 2000 lbs less than you. Not so hard to keep the gas in fingertip but when you are maneuvering tactically and trying to stay in position proper technique will net you lots of fuel savings and keep you out of the Afterburner! This is where I focus my fuel savings techniques!
That’s just simply not true. Let’s just go with a 200 mile flight (home plate to target) I guarantee you can save approximately 1000 lbs or more by using the correct climb schedule, cruise speed and power settings until fence in, and decent profiles on RTB which means more time over the target and more fuel to react to changing situations. It doesn’t matter if it’s 50 miles or 800 miles every flight should be at the most efficient possible and it’s incredibly easy to do. It takes about 15 mins to plan the performance of the airplane tops.
Look up the F-16 supplement and flight manuals on Google, break into the book, study the tables and calculate the applicable numbers. You should calculate all takeoff performance, time to climb, speed and fuel burn, optimum and mil cruise, penetration or max range descent and landing performance for every flight. BMS is within 1% of the real world numbers IMHO, it is one of the best flight and engine models ever simulated, Falcon nails it.