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#1
09-25-2013, 03:01 PM
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Quote:
Thank you for to share that tool with us.  But if you are a FMB user, surely you will need to considere the wind speed and its direction also (well... it's if you are including any wind in your designed missions). In such case, the E-6B would be almost a 'must have': with that tool you will can calculate a lot of things relative to the flight. In this link you will find general information about the E-6B: http://en.wikipedia.org/wiki/E6B Following this link you can download de user manual of the E6-B in .pdf format: E6-B Instructions And in this link you'll have a realistic on-line simulation of the E6-B (it's a bit tricky to use: with left click and dragging you can move the disks; and with right click you can zoom it in and out): http://www.pilotinside.com/images/tools/e6b/e6b.htm#top Give it a try, and let me know if you find it useful. Have fun! 
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#2
09-25-2013, 05:23 PM
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I use Pilotwizz app on my Iphone
Last edited by KG26_Alpha; 09-25-2013 at 05:30 PM.
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#3
09-25-2013, 05:59 PM
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 That app has many of the features of an E6-B... and surelly with it you can compute faster than me. However to recreate the enviroment of the '40s, for me my E6-B, a printed map, a pair of pencils, my plotter, and a song of Glenn Miller or the Andrews Sisters, are essential. LOL The main difference between the app and the E6-B is you can use your iPhone inflight, wihile I must pause the game for to make my calculations, because I need my two hands to handle the E6-B. Please, when you can, have a look at the links I've posted before.
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#4
09-25-2013, 06:13 PM
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Im very familiar with the Wizz Wheel E6B
I just find it so obsolete (slow) for IL2 1946, with "Pilotwizz" I can use it on the fly very quickly  Also The test maps from earlier in this thread >>> http://forum.1cpublishing.eu/showthread.php?t=40740 I used are showing @ -5' temp at @ 4000m This still calculates from the tables as I have been using for years. 270kph ias 330kph tas 4000m alt OAT -5'C So somethings making them drop long if all the calculations are correct...........What inputs are the AI using for their bombing routines, as they don't seem to have a problem ? . Last edited by KG26_Alpha; 09-25-2013 at 07:19 PM.
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#5
09-26-2013, 09:03 PM
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After reading your last post, I've conducted a test for each of both maps mentioned in that treath: Crimea and Moscow1 (winter). I've done them with a B-25J because this aircraft is equipped with all the relevant guages for these tests: OAT, IAS/TAS, and Altimeter. The payload were 2 x 1000 lbs bombs, being the targets: - Crimea: a ring target placed in the air base of Simferopol (altitude = 800 ft =243 m ASL). Moscow: the same type of target at the same altitude ASL, placed in the air base near to Vyazma. The following data were obtained from the gauges readings (none was calculated, except the speeds in km/h): CRIMEA: - Wind speed = 0 - OAT at GL: 25 ºC - Altitude during final approach to target: 13050 ft = 3970 m - OAT at level bombing: 0ºC (should be -1 ºC) - IAS = 160 mph = 258 km/h - TAS = 200 mph = 323 km/h MOSCOW WINTER: - Wind speed = 0 - OAT at GL: -17 ºC - Altitude during final approach to target: 13615 ft = 4150 m - OAT at level bombing: -40ºC (should be -44 ºC) - IAS = 160 mph = 258 km/h - TAS = 186 mph = 300 km/h Comparing this readings with the IAS/TAS charts, the data of the Crimea map are quite similar to them. The reason: the OAT at that altitude presents an irrelevant difference (-1 ºC). But the outcomes obtained in the Moscow Winter map are too different when they are compared with the charts, due to the OAT differences as at GL as well as at flight altitude, like it is expected IRL. I've engaged the Autopilot to have complete freedom for to read the gauges inflight, and because I was interested to see how the AI did do it. May be an average AI bombardier is a bit idiot...the point is that it missed its targets in both maps, with the bombs falling too short and too far.  Anyway, I think the AI uses the gauges readings as inputs for the bombsite. I have screenshots of the gauges in both missions. Tomorrow I'll try to upload them, and also I shall perform several flights in both maps to find out what data are the best to adjust the bombsite. We will see the results... I hope.
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#6
09-30-2013, 08:00 PM
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Well... Finally I could perform a new test today to record an 8 minutes' .ntrk file: the last week end I should fix some issues with my hardware.
I've flown a bomb raid with a B-25 in the winter map of Moscow, and I can confirm all what I've said before: 1) The inputs for the bombsight must be the 'true altitude = indicated altitude - target altitude' (as ever), and the TAS corrected by OAT. 2) The OAT is indicated by the 'Free Air Temp' guages, or (if the plane has not such gauge) it must be calculated according to the Atmosphere International Standard (AIS) regarding of the altitude and the GL temperature. 3) The IAS/TAS charts and tables made and used before the release of the patch 4.11, are useless now. You can see it in the attached .zip file. Note that the speed used to set the bombsight is in knots, because yet was not fixed and old issue of the B-25: the TAS in the IAS/TAS gauge is indicated in mph, but the TAS must be converted into knots before it could be used as the speed input for its bombsight. The values used in that test were: Indicated ALT = 13150 ft Target ALT = 800 ft True ALT = 12350 ft OAT = -40 ºC IAS = 190 mph TAS = 220 mph = 190 KTS Payload: 2 x 1000 lbs bombs The red values were used as inputs for the bombsight. The bombs were released in automatic mode. The target was missed by very few yards, as we can expect: IRL it was practically impossible to perform precision strikes with high level bombing using the '40s optical devices, and a direct impact on an intended target was a matter of good luck. For pin point strikes, it's better to use dive bombers. For medium or heavy bombers it is better to use the carpet bombing tactics. For me, this test (together with others which I've done) is conclusive. Perhaps now we could talk about the other factors: wind speed, wind direction and how they affect the Ground Speed in navigation and level bombing.
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#7
10-01-2013, 07:48 PM
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Please repeat the test using a Russian Bombsite.
Bomb ground strike position relative to the bombsite aiming angle is the point to note also, testing shows this is wrong/different OAT air density or something is having an effect ? If so new bombsite calculation tables are needed for v4.11 > I have been a bit too busy to test again with new data this week but this is from a guide pre v4.11, hopefully the same theory applies to current game versions and the problem is else where.  Equations of motion v = velocity, u = initial velocity, a = acceleration, s = distance, t = time. s = ut + ½at2 v = u = s/t (unaccelerated) Fig 1.2. The aircraft is heading from right to left at speed, v, when it releases a bomb at A. Initially the bomb continues to move with the aircraft, but starts to drop as gravity accelerates it downwards. The bomb follows a parabolic path, represented by the blue line. AB is the height, h, of the aircraft and BC is the forward throw, R, of the bomb. If the bomb takes time, t, to reach the ground, g is the acceleration due to gravity and we ignore air resistance for the moment, then the equations of motion give us the following: AB = h = ½gt² -- eq 1 BC = R = vt -- eq 2 We know the height, h, speed, v, and g is a constant 9.81 m/s², so we can find t from eq 1 and substitute for t in eq 2 to find the forward throw, R: R = v 2h/g) -- eq 3 The angle between the horizontal – the dotted line in fig – and the point of impact at C is, of course, the angle, a, from fig 1.1 above. This is what we want to know when we come to aim the bomb and is the same angle as ACB in fig 2. As we now know 2 sides of the triangle, AB and BC, we can find the angle: Tan ACB = AB/BC = h/[v 2h/g)] -- eq 4 DIVE-BOMBING In the previous example we used the height to find the time the bomb is in the air (equation 1) and then used equation 2 to find the forward throw of the bomb. From these two pieces of information we could deduce the angle corresponding to the amount the bomb drops from the horizontal. We can do exactly the same when the bomb is released from a dive at an angle, degrees. The situation is slightly more complex, however, because the bomb now has an initial downwards velocity (v.sin ) and the horizontal velocity (v.cos ) is not quite the same as the airspeed. The equations for AB and BC now become: AB = h = vt.sin + ½gt² -- eq 5 BC = R = vt.cos -- eq Equation 5 results in a quadratic equation, which can be solved to find t. Equation 6 can then give the forward throw, R, which allows us to find AB/BC and then the sight angle. This would be quite tedious to solve for each combination of dive angle, airspeed and release height, but it is not too difficult to produce a spreadsheet, which will do the sums for us once we enter the desired parameters. The dive angle, , is found by noting height, h, and range, D, to the point on the ground under the cross hairs at the moment of bomb release. Tan = h/D -- eq 7 Air resistance. We have not yet considered the effect of air resistance on the falling bomb. Once the bomb leaves the aircraft it will start to slow down. However, so long as the bomb does not produce any lift (either up or down), the drag will only act back along the bomb’s direction of travel. The bomb will slow down and take longer to reach the end point, C in the above fig, but it will follow the same path and still reach that point. . Last edited by KG26_Alpha; 10-01-2013 at 09:10 PM.
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