to me this looks like misunderstanding on how the game works....
WHEN a mission spawns opposition that will chase you, unless they get killed, what you experience is for the most part how things will work....
First part, there is a difference between by beating the interdiction attempt or submitting/failing....
Beating, you successfully evade the interdiction, the NPC is still after you and since you are still mostly going in a stright line towards your destionation, bad guy pops up behind you and interdicts again, and again, and again... and when they do, they pull you to them! so you loose distance to your target....
Failing/submitting, now tye come after you muich faster, as their FSD is cooled down as fast as yours... so you enter Super cruise, and they can enter shortly after, and once again, you are most likely just flying in a straight line towards your target, and getting pulled back to the NPC again...
Now, WHEN the games spawns these NPCs. it will tell you, you will get a mission update stating this fact, and how many there will be.. Killing them yourself in a Type 9, is quite a tall order, so that is usually not an option. But who said you had to kill them! one way to kill them, is to survive long enough for Authorities to arrive, now boosting in straight line away is bad, since the authotrity ships arrive where entered the instance, so if you have boosted away 10km that means any auythority ships arriving have to chase your 10+km to even begin to take care of that NPC. So better distracting NPC while you wait and evade. add a SLF hangar, and hire a pilot, and launch it and it will attack the NPC, and soon will the NPC target your SLF instead of you, and this will make the wait for authority easier... NPC will still rtandomly target you, so evade and whatever you do, do not shoot yourself at NPC...
Once Authorioty has arrived, usualluy 2-3 ships, they focus target the NPC and stick around until NPC is dead, and since your SLF hit it, you should get the mission bonus and the bounty the NPC had.
Now the above can still be quite tricky, and you could very well die before authority arrives... so the best course of action is to avoid even getting interdicted. and this means new Supercruise flying skills. DO NOT FLY IN A STRAIGHT LINE TOWARDS THE TARGET when a mission NPC is announced!
Becasuse the NPC will spawn near the start, ie, BEHIND YOU. so all the NPC need todo, is to masterfully fly around the star, which they can fail, and then line behind you and start to chain interdict you... so what you want todo, is to fly of in something like a 90 degree of course and fly in a giant loop towards the target, idealy you should arrive at your target from the opposite side, from if you had flown directly towards the target...
What this accomplishes, is that for the NPC to get behind you, they have to fly further away, and then turn around, but since you are going in big arc, they have to chase the location where they can interdict you from... and with some practice, you will arrive safely near the station and they will only jump in on you when you are near the station and now they will turn and run.
To make this easier, ALWAYS target the NPC chasing you, look at your radar. if they are behind you, they are in a position where they might be able to interdict you. also pay attention to their direction (their hologram), as that shows their relative heading towards you, and they will always have the same direction on their hologram when they can interdict you, so if you see them lining up behind you, make turn. and if get caught in a bad spot, jump to another system for another go...you will most of the time, get some time to start the arc flying path, before the NPC arrives in the system again.
Now the flying in an arc thing does not cost you that much extra time, especially if you take into consideration any time that would be lost if you got interdicted...
Sidenote about supercruise, pay attention to your speed, as flying close to starts, planets etc slows you down... so when flying away from the star, pick a heading that do not have planets in the path...that will build up your speed and thus distance faster...
Also NPC AI are a bit stupid, they will gladly crash into whatever planet/star that is beetween you and them. so an
expert (elite) move, is to actually on purpose, place a planet between you and the NPC...and they will most of the time, crash into the planet, and be gone for quite some time... before they can chase you again! this one takes quite alot of practice pull off... but it is very fun when it happens... I rarely can do these on purpose, but I can see when it happens!
Another thing to pay attention to is the level of the mission, the higher the level, like Dangerous, Deadly, Elite, they will most likely spawn those Anacondas, that will eat your Type 9 for breakfast in seconds...and the best defence aganst this is to newer get interdicted from them!!!
A few nots on outfitting....you are not here to fight, you are here to survive.. avoiding interdictions is the best defence, but when things go bad, more hitpoints is always better to have...
- Skip the bi-weave shields, you need as much shields as possible, so install A-rated shield. even better would be a prismatic shield, but that is a 4-5 week long wait to get that one, but well worth it.
- Use military grade composite hull.
- SLF if you are going with this option, place it in the size 6 slot, as that will give you two fighters, so once the first get destroyed, you can launch the 2nd one directly, and hopefully that one lasts until the 1st fighter have been rebuilt. If you only have a size 5 SLF, you must wait for the rebuild process to complete befgore you can launch it again. meaning, more time for NPC to shoot at you...
*Put 4 A-rated shield boosters.
Normally when using a trade build, you have the shield in the size 5 slot, but if you have problem surviving, then pick a bigger slot, so the size 6, or 7 and lastly the size 8..
Another strategy could be, once mission NPC's spawn, make the deliver the best you can and then change your build, but the biggest shield in, add the SLF and then bait the NPC's to be killed by the authority ships, and then once all mission targets have been destroyed, swap back to the cargo optimised build and complete the mission as normal.
I have on purpose avoided mention anything about engineering, as it is not needed, but anything that can improve your defence, is beneficial in these situations. Even Grade 1, Grade 2 etc of these are worth it! and these are cheap compared to the Grade 5! So for survivability, these are recommendations to do. There are ofcourse other sutff like the FSD,that always is good things to upgrade...
- Heavy Duty Hull
- Reinforced Shields
- Heavy Duty on Shields boosters (this will cause a power problem! and require Overcharged Powerplant!)