%BFL calculation in CCIP
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What is the formula to calculate %BFL in CCIP DB for any target, given it’s coordinates and altitude?
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What is the formula to calculate %BFL in CCIP DB for any target, given it’s coordinates and altitude?
You need more information than the target position and altitude.
I dont know the formula - but its a ballistic solution, so you will need to know the release altitude and range from target, release airspeed, and dive angle at a minimum. I think for BMS, free fall bombs all share the same ballistic profile? IRL it of course depends on the bomb, as to how it falls - so that is another variable.
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You need more information than the target position and altitude.
I dont know the formula - but its a ballistic solution, so you will need to know the release altitude and range from target, release airspeed, and dive angle at a minimum. I think for BMS, free fall bombs all share the same ballistic profile? IRL it of course depends on the bomb, as to how it falls - so that is another variable.
The data you mention is known as well as the calculations of all parameters concerning CCIP….but…%BFL.
Reference:
1. Realism patch 5 manual DB mission planning p.94.
2. WDP HADB tab by Falcas.
3. Kotar Range Ops by RD.So…let me rephrase: given all the ballistic data as per the above reference what is the formula to calculate %BFL as RD wrote in the Kotar range ops, events data, p.5?
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If you knew the AOD and the IPP as well as the airplane position at initial track you could figure it out. The AOP to target angle plus the IPP is the total FPM-to-pipper PBIL length. The angular fraction of AOP-to-target and AOP-to-IPP is %BFL.
Page 5’s table doesn’t have enough info on it’s own but here’s an attempt for the 30 DB entry:
1. Base height 8,000’, on pull there is some altitude lost which is a value you’d need to get from another source. Let’s say 500’ so tracking begins 7,500’.
2. Tracking range to AOP is dive angle and height. 1/tan(30°) x height is 12,990’.
3. We don’t have AOD so here’s a guess: initial tracking range to target is base distance minus a canted turn radius. AOD is tracking range to AOP minus tracking range to target. 12990-10410 = 2,580’. Sounds about right.
4. If AOP is 30° below horizon then target is 35.8° below horizon.
5. Normally we’d use the release solution pipper angle (fixed sight) but the pipper is not fixed in CCIP so we’d have to know what the calculated pipper angle is at initial tracking (if it’s even on the HUD). There’s absolutely no way for me to calculate that with any accuracy so I’m going to use 15° as a placeholder.
6. Lastly we take the AOP-to-target arc (5.8°) and divide by PBIL arc (15°) to get 38.7%.In a proper calculation you’d use massively more accurate numbers in steps 1, 3, and 5. You want the best possible AOD and position at initial track to calculate the target depression angle. When using a fixed pipper the total length is the pipper setting minus AOA. When using a calculated pipper the total length is whatever the ballistic solution is under the initial track conditions or clamped to HUD bottom if it’s too large.
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Thanks Frederf !
Tried playing with your suggestions…sadly…yet…the numbers don’t add up to a consistent way of an accurate calculation of %BFL.
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Just curious:
Can you explain what %Bfl is and why you need it?
Thx
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Just curious:
Can you explain what %Bfl is and why you need it?
Thx
BFL a.k.a Bomb Fall Line in CCIP A-G mode. It’s the vertical line in the HUD connecting the flight path marker and CCIP pipper. The percentage of the BFL may used as a simple visual cue for the correct dive angle and to meet the other dive bomb run parameters.
