The API for AircraftRealism has changed to work with the new Factorio 2.0. Mainly, AircraftRealism no longer modifies the plane, you only tell it the grounded/airborne plane prototypes. You have the flexibility to change all the prototype values yourself.

Shadows are done differently now that should (hopefully) be easier for you. You create the sprites, and pass an array of sprite names to the API.

The current AircraftRealism 2.0.0 release is incomplete, I will add back the rest of the features (runway, collisions) in a newer version
Let me know if you need any help.

https://github.com/jaihysc/Factorio-AircraftRealism/blob/2.0.0/Docs/AddingNewPlanes.md

Excellent, and thanks for the heads up!

Heya, I gave it an honest attempt but trying to update for 2.0 has my head spinning, the documentation is plenty good for those who know a thing or two about factorio modding but its been two years and my head was spinning trying to figure out what to do, i check other mods to see how they did it, and while I could sort of see how it was done, I couldn't find any patterns that stood out to me. If your willing to still help im all ears! but until then the mod is firmly stuck as it is.

Hi yes I can help with that. Here are your mod's file updated to 2.0

info.json, change minimum AircraftRealism version and factorio_version

{
    "name": "AC-Aircraft",
    "version": "1.2.3",
    "title": "AC Aircraft - PBY",
    "author": "AngryCeltic/Turretproblems",
    "dependencies": ["base >= 1.1.0", "AircraftRealism >= 2.0.0"],
    "description": "Adds the PBY5 Catalina, a very famous aircraft to Factorio. This particular version has been made to more closely match the style of the game.",
    "factorio_version": "2.0"
}

recipe.lua, expensive mode is gone, an icon is required

data:extend({
  {
    type = "recipe",
    name = "PBY5",
    enabled = false,
    energy_required = 5,
    ingredients =
    {
      {type = "item", name = "engine-unit",     amount = 28},
      {type = "item", name = "iron-plate",      amount = 10},
      {type = "item", name = "iron-gear-wheel", amount = 40},
    },
    results = {{type = "item", name = "PBY5", amount = 1}},
    icon = "__AC-Aircraft__/graphics/PBY5_icon.png"
  },
})

technology.lua, no space allowed in name property

data:extend({
  {
    type = "technology",
    name = "EarlySeaplanes",
    icon_size = 128, icon_mipmaps = 4,
    icon = "__AC-Aircraft__/graphics/PBY5_icon.png",
    effects =
    {
      { type = "unlock-recipe", recipe = "PBY5" },
    },
    prerequisites = {"automobilism"},
    unit =
    {
      count = 250,
      ingredients =
      {
        {"automation-science-pack", 1},
        {"logistic-science-pack", 1},
      },
      time = 30
    },
    order = "e-c-c"
  },
})

entity.lua, modify collision_mask, add energy source
You can play around with the collision masks and make it burn fuel

    -- item = true, meltable = true, object = true, player = true, is_object = true, is_lower_object = true
    collision_mask = { layers = {object = true}},
    energy_source = {type = "void"},

Now to make it fly

-- data.updates.lua
local api = require("__AircraftRealism__.api")

local flyingPlane = table.deepcopy(data.raw.car["PBY5"])
flyingPlane.name = "PBY5-flying"
flyingPlane.collision_mask = { layers = {} }
-- Remove the shadow layer
flyingPlane.animation = { layers = {flyingPlane.animation.layers[1], flyingPlane.animation.layers[2]}}
data:extend{flyingPlane}

-- Create the shadows
spriteNames = {}
for i=0,63 do
    local fileIdx = math.floor(i / 8) + 1
    local yOffset = i % 8
    spriteNames[i + 1] = "PBY5-shadow-" .. tostring(i)
    local sprite = {
        type = "sprite",
        name = "PBY5-shadow-" .. tostring(i),
        filename = "__AC-Aircraft__/graphics/PBY5-shadow-" .. tostring(fileIdx) .. ".png",

        width = 1024,
        height = 1024,
        x = 0,
        y = yOffset * 1024,

        shift = util.by_pixel(20, -10/3),
        scale = 0.75
    }
    data:extend{sprite}
end

api.register_plane({
    grounded_name = "PBY5",
    airborne_name = "PBY5-flying",
    transition_speed_setting = "aircraft-transition-speed-PBY5",
    shadow_sprite = spriteNames,
    shadow_end_speed = 50 / 216 -- Animation ends 50 km/h after takeoff
})

settings.lua

data:extend({
    {
        type = "double-setting",
        name = "aircraft-transition-speed-PBY5",
        setting_type = "runtime-global",
        minimum_value = 10,
        default_value = 139,
    },
})

I don't get messages for Factorio, so if you have any more questions you can message me on Discord (same name haih_ys) and I'll reply to you faster