investigating 2.9.12.5336 FA-18C AGM-84D Harpoon BOL - wrong bearing

BJ55 · February 1

Harpoons are flying the wrong bearing, tested with HSI in both true and magnetic heading.

Attached mission and tracks.

Edited February 1 by BJ55

Lord Vader · February 3

Like the manual states in the excerpt you posted above, the BRG sets the direction of the missile "relative to ownship", not the missile's own heading. I replayed your track and using your own settings, the missiles are deployed correctly in those bearings. What am I missing?

BJ55 · February 3

3 hours ago, Lord Vader said:

the BRG sets the direction of the missile "relative to ownship", not the missile's own heading

With no HPTP It's intended as "relative to launch position" (BOL: Bearing Only Launch) , so it's the missile own heading once fired.

In the case above the missile goes BRG169 mag - (HSI175 true - HSI168 mag) = BRG162 mag.

For some reason the code is subtracting mag. dec. from mag. heading.

Edited February 3 by BJ55

BJ55 · Saturday at 09:17 AM

Any news on this bug?

BIGNEWY · Monday at 07:32 AM

Hi,

we've tried to reproduce the mentioned issue and aside a few minor deviations of 1 or 2 degrees we cannot see a big discrepancy. If you have newer tracks that demonstrate a considerable deviation that could render the weapon unusable, please do post them and we'll take a look.

thank you

BJ55 · 2025-07-30T05:48:42Z

Use a map with a big magvar, launch from distance (>40nm) and observe the difference from commanded magnetic bearing and missile flight path magnetic bearing, the difference is explained in my previous comment, this leads to the target being outside of missile radar search cone.