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#4
01-03-2011, 01:49 AM
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Figured i'd pop in since i see frequent threads about navigation lately.
In short, i learned to really navigate by flying small civilian aircrat and some WWII warbirds in FSX on a friend's PC. In a bit more detail, the repeater/gyroscopic compass in most allied birds combines the function of a compass (the single needle) with the function of an "i want to fly there"/desired heading indicator (the dual needles), Let's say you are flying on a DF server where there are no pre-set waypoints. You just need to look at your ingame map and the briefing to estimate a bearing from your spawning base to your targets. So, a P38 or P47 taking off from SE England and attacking V1 sites on the French coast would probably need to fly a SSE heading to target and a NNW heading back to base. Let's say that you estimate this to be about 120 degrees magnetic, rotate the dual needle until it points to 120, take off and turn until the single needle (your actual heading) is between the dual ones (your desired heading). The nifty thing about it all? You don't need to manually calculate the reciprocal heading back to base. Just turn until the single needle (your actual heading) is again aligned with the dual needles (your desired heading), but this time with their "arrowheads" pointing opposite each other. Voila, you are now flying a heading of 300 magnetic back to home base, which is the reciprocal of the one you flew to target (120+180=300) and you didn't even need to do any math. Pretty useful when dodging flak and 109s, right?  As for the ADFs now, here comes the trademark friggin' wall of text  First of all, there's lot's that could be said that others have said better. If anyone's having trouble with it, i suggest checking out this link: http://www.navfltsm.addr.com/ Yes, it's based on the microsoft FS series of sims. Yes, it also has some good information that we might need  You don't need to bother with the sections about the VORs, since these are post-WWII directional beacons. These not only tell you where the beacon is in relation to your aircraft, but on which magnetic radial you are flying as well, while the older NDBs (non directional beacons) that we have in IL2 4.10 only point straight to the beacon. This happens because NDBs only broadcast a single signal, while VORs broadcast a second pulse that can be used to judge the radial, one magnetic degree at a time. By all means read through the relevant sections if you are interested in how modern aircraft navigate, but for the purposes of IL2 4.10 all you need to look up are the sections dealing with the NDBs. A simple way to put it would be to say that VORs are a more refined and accurate combination of an NDB/ADF (NDB is the beacon, ADF is the gauge in your cockpit that points to it) and the directional beacon that we have on the allied carriers in Il2 4.10 (the YE thingy). Anyway, the fundamentals to remember about NDB/ADF navigation are as follows: 1) NDB (non directional beacon) is the transmitter, ADF (automatic direction finder) is the gauge in your cockpit that points to it. 2) The ADF gives you the selected beacon's bearing in relation to your aircraft. ADF doesn't provide a specific course, only a bearing. However, you can still fly specific radials with an NDB, the only drawback is that you need to overfly the beacon first while a modern VOR would supply your instruments with the precise radial you are flying in relation to it right off the bat. It makes perfect sense, if i overfly a beacon on a heading of 120 and the ADF needle is pointing to 120 before i pass the beacon and to 300 after i pass it, it's obvious that i am flying on the 120/300 radial of the beacon. This is the third fundamental point here and the trick behind accurate NDB/ADF navigation that will help you find your targets or your base in bad weather: 3) When flying directly to/from ANY beacon, radials and bearings coincide when flying TO the beacon, or are the reciprocal of each other when flying away FROM the beacon. To avoid confusion with reciprocals, make a good habit of thinking about radials as straight lines on the map that originate from the beacon and spread out in both directions. For example, a heading of 090 magnetic is just a due east heading, but when flying directly to or from a beacon on such a heading i like to say that i'm on the beacon's 270/90 radial. In this manner, one can fly semi-blind even in WWII era scenarios and find targets if the distances involved are not too great (within the beacon's signal reception range that is). For example, a cross channel ground attack mission with a couple of beacons placed on the coast of England and France for each team could be flown just this way: 1) Work out the target's bearing from the beacon, NOT from your spawning location. Let's just assume this is 150 degrees. 2) Tune the beacon and fly directly from your home base to it, no need for math, just follow the needle and apply some heading correction in case of wind drift. 3) When the ADF indicator reverses, that's your cue that you have overflown the beacon. When this happens (or when you get the erratic needle movement/flying through the lack of reception cone directly overhead it), you turn to fly the heading that corresponds to the target's bearing from the beacon, which in our case is 150 magnetic. 4) Try to fly so that your compass stays at 150 magnetic and your ADF indicator points along the 150/330 line (since you're flying away from the beacon, the ADF needle's "head" will show 330 which is the bearing to the beacon and the "tail" will show 150). 5) If the ADF needle starts veering off to the side you are getting off course, so turn to intercept it. For small corrections a heading change of 15 degrees is fine, with some experience you can use 30 degrees and for aggressively intercepting a course as much as 45 or 60 degrees of heading change can be used. Fly this way for half a minute or so (depending on your airspeed and possible wind drift, the needed heading change and time that you fly it to intercept a course will vary), then turn back to your original heading of 150 and check for alignment to confirm you are flying the chosen radial (compass at 150 magnetic and ADF on the 150/330 line), correcting again as necessary. With a bit of practice and experience you'll be able to keep course just fine, even turning slightly into the wind to incorporate course correction for wind drift. This is essentially the difference between homing on a landmark (simply pointing the nose towards it) and tracking towards it (flying a precise course) and there's a very good visual explanation of the difference between them at that link near the start of my post. 6) As long as you do all this hard to describe but relatively easy to do stuff, you will be flying more or less aligned with the 150/330 radial of the beacon, which is the course that will take you straight to the target. Flying only by compass or ADF you can only fly headings, but flying both of the instruments at the same time in the manner described here, you can actually fly specific courses as long as the beacon's range permits. 7) After attacking the target reverse the process. Fly directly from target to beacon by ADF, then as you overfly the beacon fly the specific radial that will get you back to home base in the same manner. Of course, various factors could complicate things. Your mission profile might take you outside the beacon's reception range, you might drift off course because of a dogfight, etc, but by combining visual navigation with ADF navigation you will be able to cope just fine. For example, let's say i drift away from the target area due to a dogfight and to top it off, the target was already out of the beacon reception range. Apparently, my entire carefully constructed plan has gone down the tubes since i need to be flying directly to/from the beacon to be able to fly a course and not just headings, which i can't receive. Or has it? The solution would be to combine visual navigation (check the map against the ground below) with the repeater compass and the ADF. Instead of having to blindly estimate a heading to fly all the way back to base, i would just need to estimate an approximate heading to take me back to the target area. From that point on, i could once again fly the reverse of my ingress route by using the desired heading indicator on my repeater compass until i picked up a signal from the beacon, then fly directly to it by ADF and finally back to base as i overfly the beacon by the course keeping method we already outlined. I hope i'm making sense here, but the truth is that no matter how simple it is once you do it, it always looks more difficult in text and better if i bust out the crayons and do a poor picture in MSpaint. Just try that link (http://www.navfltsm.addr.com/) as it provides more in-depth explanations and visual aids. I don't have 4.10 installed yet (i'm in the middle of an XP to win7 64 migration) but i'm confident i could find any decent sized target flying this way even in poor weather and low cloud cover, as long as it's not a total overcast from 200ft AGL and upwards. I wish i had time to build a few sample missions but i'm totally useless wit the FMB I think that as time goes by and more mission builders grasp the basics of radio navigation, we'll be seeing some very creative use of beacons in online missions. A final word on the whole deal...don't fret about extreme precision. Modern aircraft are equipped with systems and readouts that combine VOR, NDB, GPS, inertial navigation computers, DME readouts (distance measuring equipment, it tells you how far away the tuned VOR beacon is) and their instruments are still calibrated in scales that allow straying as much as 1-2 miles off course, even in today's ultra-precise and strictly regulated instrument flying airspace. During one of my visits to my FSX flying friend and using an excellent 3rd party add-on (the Boeing Stratocruiser by A2A, an early 50s airliner) i have flown all the way from my hometown airport in northern Greece to Gatwick, by ADF navigation alone. It's very much possible to do, just not as precise as modern instruments. In IL2 4.10 you only have NDBs and an ADF during wartime, so cut yourself some slack and enjoy learning how to do it. As long as your radio nav places you within visual identification distance of your chosen waypoints, you are doing just fine
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#5
01-03-2011, 02:58 AM
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Well I have just copied and pasted that info into a text file and will give it a good read later, so thanks Blackdog Kt, but first - I am going to have to do something with my BBC and Honolulu WAV files....GlenMiller coming through my cockpit radio in unmolested VHF Digital sound quality is too much for me to bear at the mo'........
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#6
01-03-2011, 09:49 AM
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Quote:
It also occurs to me that if two or more bombers were aiming for a target in range of two beacons then you can plot the bearings from both beacons to the IP point for the bomb run. The lead bomber tunes to one beacon and flies using it as you have described but the second bomber tunes to the second beacon, follows the lead bomber and when his RDF shows the predefined bearing has been reached you know you are at the IP even if it is obscured by cloud and you can turn on to the targets bearing and drop to the bombadiers position.
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#7
01-03-2011, 01:53 PM
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Quote:
See, it's simple once people start thinking about is as simple lines drawn on the map In fact, tuning two beacons at the same time and plotting their bearing intersection on the map can give you your exact position.
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