I was thinking, when Learning to Fly is duped, the max wanted level is set to zero just as normal, but it continues like that even after the mission is over. I noticed that during Air Raid CJ is immune to most types of damage (like explosions, falling from buildings, being run over by a tram, and also someone told me that he is also bulletproof), so I was wondering, is there a way to dupe Air Raid and keep those immunities. So far I tried duping it and fail it or dupe it and pass it but he loses those immunities? Also, I wonder why he is able to keep the minigun ammo but not the immunities?

Learning to Fly keeps the 0 wanted level because of this part of the script

:DESERT5_954 {2040390} 0A0E: disable_text_with_style 1 {2040394} 03BA: clear_cars_from_cube_cornerA 44@ 45@ 0.0 cornerB 46@ 47@ 50.0 {2040418} 08F8: display_stat_update_box 0 {2040422} 07A8: enable_area69_sam 0 {2040426} 096A: enable_flying_helis 0 {2040430} 050F: get_max_wanted_level_to 239@ {2040435} 01F0: set_max_wanted_level_to 0 [...]

get_max_wanted_level_to puts the value of maximum wanted level in the global variable 239@. 239@ therefore has the value 6. Then, set_max_wanted_level_to sets the maximum to 0.

However, since it's duped, this is run twice. On the second time, get_max_wanted_level_to puts the value 0 on 239@.

Later, this is how the game recovers the value when the mission ends

{2070031} 01F0: set_max_wanted_level_to 239@

So the maximum wanted level is 0 after the mission is finished.

In Air Raid, this is how CJ is set to take no damage

{1861306} 02AB: set_actor $PLAYER_ACTOR immunities BP 1 FP 1 EP 1 CP 1 MP 1

This is run on mission pass

{1873485} 02AB: set_actor $PLAYER_ACTOR immunities BP 0 FP 0 EP 0 CP 0 MP 0

And this is run on mission fail

{1873757} 02AB: set_actor $PLAYER_ACTOR immunities BP 0 FP 0 EP 0 CP 0 MP 0

However, this does not mean it's not possible. If during Air Raid you start a mission that doesn't crash the game, you'd probably be able to keep the immunities, as long as it's not cleared by other factors (In GTA 3 you can get immunity easily, but it's cleared when you start a mission. Same in TBOGT)

edit:

As for the minigun, I'm not entirely sure how the opcodes work. 04F4 puts CJ in turret mode and 0465 removes CJ from turret mode. I assume the game only keeps track of the minigun ammo from the second instance and fails to remove the first because it's no longer tracking it. Then again I'm not sure why the jetpack causes it to fail to remove the ammo as well. Someone with better knowledge of these opcodes can answer

Cool, thanks for your answer! Just one more thing, if someone does find a mission that cancels Air Raid without crashing the game and manages to keep the immunities, do you know if those would remaing after saving and then loading the game?

I also don't know that, but I just tried in GTA 3 and after saving (without reloading) the immunity was removed. Would need to be tested once it is found in SA but I don't have much faith in it working.

Saving immunities for player can't work because player is deliberately made full immune during save routine and therefore he always loses them on regaining control.

Besides, all immunities for player are removed during mission cleanup, after cutscenes and with 01B4 opcode with parameter 1.

01B4 - Sets whether player control is enabled.

So after each call you lose immunity. They give you back control.

It also means that we need a different method of becoming invincible than one where control is taken away from you, anyways, are there even any?