Fire control TODO list

[colingeniet]

For the AJS mostly.

Weapon panel:

• 3D model
• Weapon selector knob.
  Implementing it requires to have the ground crew weapon panel in one form or another.
  My current plan is to make the ground crew weapon panel as a canvas dialog, and have the loadout dialog do the ground crew settings automatically. This way, one can either
  • Use custom loadouts (with Equipment - Fuel and Payload), and take care of ground crew settings manually.
  • Or use preset loadouts (with AJS-37 - Fuel/Loadout), and never care about the ground crew panel.
• Distance selector
  • Firing interval for bombs
  • Target wingspan for A/A
• SERIE/IMPULS switch. Should affect
  • Rb 04, Rb 15
  • ARAK long range aiming mode.
  • training bombs
• MÅLVAL switch (Rb 04 and Rb 15 search mode). Won't be implemented in the foreseeable future.

Weapon behaviour:

• In general, many weapons can be fired without being in mode ANF.
  The mode selector has more to do with the SI/CI presentation.
  For several weapons, ANF mode enables more advanced aiming features.
  I detail which modes should be allowed for each weapon below, from what I found in the different parts of the SFI. When I say 'any mode', it of course excludes FK and BER.
  edit: I am starting to think that these restriction stated throughout the manual only have to do with aiming displays, and not actually inhibiting the fire controls. Trying to summarize what I found: (references are in SFI part 3 chap 7 unless stated otherwise)

  • Generalities (sec 1.1.1): "firing is also possible in modes NAV,SPA,LANDNING, with some restrictions"
  • Rb 04 (sec 2.4.3): explicitly says NAV,ANF,SPA,LANDNING (but in anything but ANF, no aiming information is displayed)
  • AKAN/ARAK (sec 3): talks about aiming in mode ANF, then aiming in mode NAV. That's it.
  • bombs (sec 4): same as AKAN/ARAK, with more submodes
  • Rb 05: explicitly says "firing is also possible with with mode selector in any position". There is no aiming display
  • Rb 75: Talks about ANF and NAV. SFI part 2 states that seeker no longer works in mode LANDNING
  • Rb 15 and m/90: Can be fired in modes NAV,ANF,SPA. For Rb 15, the behaviour of the missile is different in modes NAV/SPA (personal thought: if any weapon is going to be locked when in the wrong mode, it is these: they are the ones involving the Viggen computer the most, by far).
  • A/A modes: (chap 8 sec 6.4) works in any mode

  To summarize:

  • AKAN,ARAK,bombs,Rb75: NAV or ANF.
    • Is SPA missing because it is actually not available, or because of lazy copying from AJ manual?
    • This is for aiming modes. Can they be fired without aiming mode? Bombs: surely not, because CCRP. Others: SFI part 1 shows a computer controlled relay which can inhibit everything. So I want to say no (it might have been different on AJ).
  • A/A modes: anything
  • Rb 04 and Rb 05: anything (Rb 04 aiming only in ANF)
  • Rb 15 and m/90: NAV,ANF,SPA (need to check details of aiming mode)

• Rb 04

  • Release envelop (commended altitude, altitude warning, ...) 240 ±190m
  • ~1sec firing delay.

• Rb 15

  • All the waypoint navigation
  • Firing in mode NAV, SPA. In that case, it just follows a straight trajectory (pretty much the current behaviour).
  • Release envelop (commended altitude, altitude warning, ...) 50­-2000m
  • No mention of firing delay. I should probably delete it.

• Rb 05.

  • Battery dies 40s after unsafing the trigger. Unsafing and re-safing makes the missile unusable. (Do I want to be an ***hole by implementing this?)
  • Disable proximity fuse if not fired in A/A mode (weapon selector knob).

• Rb 75.

  • Locking on targets through EP 13 (controlled with radar stick). Very hard, I have no idea how to deal with this.
  • ~1sec firing delay.

• AKAN/ARAK

  • ARAK always fire all rockets.

• m/71

  • Firing interval selector

• m/90

  • Waypoint target
  • Release envelop computation (going to be hard).

• IR missiles

  • Check details about the quick select button. Apparently it is the same as autothrottle disengage (when gear is up), and also cycles through IR missiles. (SFI part 2) (that was a misinterpretation)
  • ~1sec firing delay.
  • Seeker can only be uncaged after unsafing. SFI part 1 seemed to imply that, but SFI part 2 says differently. I don't see a reason for it to be impossible, so I'll thrust part 2.
  • I see no reason to not allow firing them without lock, but the seeker should probably remain still (so lock-on after launch as in missile.nas won't do). Realistically it will never find a target, so it might be fine to just not let it lock on anything.
  • Seeker should be cooled. Not sure about the condition to activate cooling. Cooler fluid is in the pylon, not the missile (if I thrust wikipedia, this is same as USN, whereas USAF has cooler in the missile). Presumably this means longer cooling duration, thus it could be permanently cooled (as long as aircraft is on).

Then, there is everything related to displays. Which is going to be fun.

As for the JA:

• Missile firing delay? ~1sec for everything seems reasonable.
• I don't think there is any such thing as a master arm switch. The knob we're using certainly isn't that (it's for training modes).
  Can we just remove it? That would make weapon selection more awkward, requiring to rely a lot more on the TI (early JA variants don't have this issue since they have a dedicated weapon selection panel).
  Fixed in hud-rework, with new aiming mode, and some changes to the controls.

More cool things from JA37D manual:

• The button under the trigger safety releases the rb74 seeker. Probably keybinding shift-U. Physically unusable while trigger is safe.
• The altitude reference button (shift-R) toggles between boresight and radar control for the rb74 seeker (also toggles rb99 mode, but I have no idea what that is).
• The TI menus for seeker control, and the 'auto-uncage' mode are likely not a thing.
• What about uncaging without a lock? The fact that the uncage button is below the safety makes me think this is not intended use, thus the seeker search pattern probably doesn't exist.
• IIUC the trigger must be held before firing a missile.
• IIUC IR seekers are cooled as soon as the missile get the 'preparation signal' (whatever that means). Also cooling TI button doesn't exist AFAIK. I assume that like the AJS cooling fluid is in the pylon, thus cooling duration may be more than 1 hour, and cooling may be enabled all the time.
• Should it be possible to fire missiles without lock? No source, but I would think yes for IR ones (which would then be just wasted? cf question for AJS), and no for radar ones.