This method has a very high risk if used in a full game speedrun.

I'd suggest this parts setup:

• Onboard Self-Defense Jammer

• Next Gen High-Pressure Components Lv. 1

• Variable Cycle Engine Lv. 1

• Queen’s Custom

• High-Power Enhanced Shells Lv. 1

• High-Output Laser Generator Lv. 1

• Laser Beam Expander Lv. 1

• Light Condenser Correction Device Lv. 1

Restarting from checkpoint 19-1 once you reach it is absolutely crucial for this method because you need all of your flares, a lot of ammo and all of your health.

Once you load in, go full throttle and directly behind the Arsenal Bird then take out both of its Main Propellers immediately. Stay behind it at all times and be close to it.

Note that the Laser cannon is undamageable until the mission is updated.

You can take out a Pulse Laser if you still have time before the mission update, this will lessen the pressure when targeting the Laser cannon later. (DON'T destroy both of them yet as this will make you lose time due to reaction dialogue.)

Now to the most dangerous part of the method.

Once you notice that the mission is about to be updated invert your plane then go under the Arsenal Bird and get closer to the Laser cannon (Not too close though) and be careful of crashing into the Arsenal Bird. The timing of the flare usage is absolutely crucial in this section. As you don't want to use your flares too early or flare on missiles that aren't "dangerous" (such as lone normal (Not AAMs from the Arsenal Bird) missiles when you're low on damage or is still undamaged). Keep in mind you can take up to 3 normal missiles (if you are less than 15% damaged. Higher than 15% you can take up to 2 missiles) before everything becomes dangerous. (Missiles are basically one-shot at this point).

It's up to you to determine what missiles aren't dangerous (such as lone (one missile) missiles from UAVs as you don't want to flare them because they won't kill you or do high damage like AAMs).

Once the mission is updated, spam your machine gun and PLSL at the Laser cannon (DON'T forget to flare as needed and don't crash). Once it's destroyed, go full throttle and break off of the Arsenal Bird. If done successfully, the shield will get activated twice and it will stay up after the 2nd activation until it's completely gone. It should start "disappearing" at approximately 16:45;000 on the timer (This can still happen earlier or get delayed a little. It all seems to depend on dialogue progression.)

Additional Notes:

1. Flares will only effect the missiles that are beeping and are flashing on the HUD rapidly.
2. This method should always be successful (Unless you get shut down obviously). The stuff that rely on RNG are the missiles that are fired at you and the dialogue progression.
3. Once the shield is gone, destroy the Pulse Laser/s while Avril is still talking to avoid time loss due to reaction dialogue.
4. The Laser cannon has to be destroyed before the 1st shield activation. The skip will still partially work if done during the 2nd activation but this will obviously lose you time.

Good luck! I'm hoping this helps. Tell me if I missed anything.