Plane how to make it follow mouse whenever left mouse button is pressed?

So I'm making a plane script that replaces the character on spawn but I want the part to follow wherever I click/click and hold like in most plane games but mine it bugs out and sets the velocity very high and the rotation very awkwardly

The issue is on line 49 and line 50 I included the whole script just incase something else somewhere else ended up being the cause

--Plane Creator--

local Workspace = game:GetService("Workspace")
local Lighting = game:GetService("Lighting")
local StarterGui = game:GetService("StarterGui")
local StarterPack = game:GetService("StarterPack")
local player = game.Players.LocalPlayer
local mouse = player:GetMouse()

print(player.Name)

local speed = 0
local Engine = false
local c = Instance.new("Model", workspace)
local a = Instance.new("Part", c)
local b = game.Workspace.Camera
local f = Instance.new("NumberValue", c)
local d = Instance.new("BodyVelocity", a)
local e = Instance.new("NumberValue", c)
a.Size = Vector3.new(2, 2, 4)
a.Position = Vector3.new(0, 2.5, 0)
a.Name = "Engine"
b.CameraSubject = a
b.CameraType = "Attach"
c.Name = player.Name .. "'s Plane"
d.Name = "Velocity"
d.Velocity = Vector3.new(0, 0, 0)
e.Name = "Speed"
e.Value = 15
speed = e.Value
f.Name = "Health"
f.Value = 100
-- inputs

function onKeyPress(inputObject, gameProcessedEvent)
	-- variables
local input = game:GetService("UserInputService")
local W = inputObject.KeyCode == Enum.KeyCode.W
local A = inputObject.KeyCode == Enum.KeyCode.A
local D = inputObject.KeyCode == Enum.KeyCode.D
local F = inputObject.KeyCode == Enum.KeyCode.F
local E = inputObject.KeyCode == Enum.KeyCode.E
local x1 = d.Velocity.x
local y1 = d.Velocity.y
local z1 = d.Velocity.z

	--d.Velocity = d.Velocity + mouse.hit.p
mouse.Button1Down:connect(function(down)
	a.Rotation = mouse.hit.p -- ISSUE HERE
	d.Velocity = mouse.hit.p -- ISSUE HERE
end)
if A then
	a.Rotation = a.Rotation + Vector3.new(0,0 ,-15)
	--d.Velocity = Vector3.new(-speed, y1, z1)
elseif D then
	a.Rotation = a.Rotation + Vector3.new(0,0 ,15)	
	--d.Velocity = Vector3.new(speed, y1, z1)
elseif F then
	local ray = Ray.new(a.CFrame.p, (mouse.Hit.p - a.CFrame.p).unit * 300)
	local part, position = workspace:FindPartOnRay(ray, player.Character, false, true)
		local beam = Instance.new("Part", workspace)
		beam.BrickColor = BrickColor.new("Bright red")
		beam.FormFactor = "Custom"
		beam.Material = "Neon"
		beam.Transparency = 0
		beam.Anchored = true
		beam.Locked = true
		beam.CanCollide = false
 
		local distance = (a.CFrame.p - position).magnitude		
		
		beam.Size = Vector3.new(0.3, 0.3, distance)
		beam.CFrame = CFrame.new(a.CFrame.p, position) * CFrame.new(0, 0, -distance / 2)
 
		game:GetService("Debris"):AddItem(beam, 0.1)
elseif E then
	if Engine == false then
	Engine = true
	print("Engine on")
	local i = 1
	while i < 10 do
		i = i + 1
		speed = speed + 2
		end
	else
		Engine = false
		print("Engine off")
		end
	end
end
game:GetService("UserInputService").InputBegan:connect(onKeyPress)

Right now I have the script in the StarterPlayerScripts inside the StarterPlayer

You should be using BodyGyro, which kind of forces its target to face toward a certain Vector3, instead of setting the plane's rotation.

If you want your plane to fly to the mouse's position on click until the player clicks on something else, you should try using BodyPosition, and set the position to the player's mouse hit point.