I’ve concluded with experimentation that if you use the autopilot in the F18, you can’t trim it out for landing. It doesn’t seem to fully disengage and can do weird stuff. But when flown without autopilot, behaves very normally for landing.
You can use autothrottle though.
Ive learned to never turn it on. Also NO assist options that affect aircraft performance should be on. It will interfere with its built in FBW assists. If you do that, she flies rather level on her own. Auto pilot went haywire too many times for me too.
Which FA-18E. Contact the creator if you think there is something wrong.
Quick and simple:
-You need to read up on the 18E more. There is no autopilot like an airliner. It’s different.
-Fpah, Alt, heading, heading select and coupled heading only, and you must select the waypoint for it to navigate to.
-Auto throttle does not change the speed and you can’t set a speed with a dial, it can only hold it at the current speed. Manually adjust speed, then engage to set.
-As soon as the gear lock down, it goes into landing mode ( AoA mode ) for carrier landings, to ensure the arrestor hook snags a cable) and this is where you use trim to align the nose to match the "E bracket) Once this is done, the flight computer will hold AoA as long as your gentle on the stick. Speed affects this, so be close to landing speed.
Other than landing/take off, there is no trim-do not touch it. (it has auto trim ) Turn the ap button to off for landing, it fights against the AoA mode.
If you’re refering to the stock 18e, it has a couple issues ( reported zen desk ) see here FA18E
As a side bar-you don’t have to land at the AoA for surface landings. You can ignore the W/E and put it down gentle as a feather on the mains. But it can tip of the mains if your not careful and/or there is a crosswind. Best to slam it down a little, to get weight on the gear and hit the brakes.
Stock. And that link was to a different complaint. I’m familiar with how the autopilot works. I have key maps for the auto throttle. I’m very familiar with the autopilot and how it works. it isn’t hard to understand. I’m used to using altitude hold in the DCS Charlie version. There is still a massive glitch in it. I’m leaving it alone until and if they fix it. But it clearly is causing glitches that have nothing to do with proper Autopilot usage.
Right now it’s pretty much “an insult to F18s”. According to my best friend who actually flies these monsters. So unfortunately I’m not touching it either while it’s that terrible. Can’t believe the link with Top Gun and then spit out stuff like this. As you can tell I’m quite passionate about top gun and fighter jets in general 
sorry about that
Perhaps you can ask your friend how we disable all autopilot functions using the displays?
Can’t seem to figure out how other than using a keyboard command to ‘disable autopilot’.
- Cheers