How to fixed model shaking [AI] finding humanoid?

the model shakes when there is two or more target its confused on where to go i think, how do i fixed it.

local plane = script.Parent.Parent
local eng = script.Parent.Engine
local trail = script.Parent.Fire
local gun = script.Parent.Gun
local target = ""
local backup = plane:Clone()
local parts = {gun, eng, trail}
local c = plane.BodyKit:GetChildren()
for i = 1, #c do
    table.insert(parts, c[i])
end


function onDie()
    if connection ~= nil then
        connection:disconnect()
    end
    local c = game.Workspace:GetChildren()
    local ore = {}
    for i = 1, #c do
        if c[i]:FindFirstChild("Htitanium") ~= nil and c[i] ~= target and c[i].Htitanium.Health > 0 and plane.Immune:FindFirstChild(c[i].Name) == nil then
            table.insert(ore, c[i])
        end
    end
    if #ore == 0 then

        return
    end
    local a = 500
    for i = 1, #ore do
        local mag = (ore[i].Ore.Position - eng.Position).magnitude
        if mag < a then
            a = mag
        end
    end
    for i = 1, #ore do
        if (ore[i].Ore.Position - eng.Position).magnitude == a then
            target = ore[i]
        end
    end
    connection = target.Htitanium.Died:connect(onDie)
end



function clean()
    wait(0.5)
    script.Parent = workspace
    plane:Remove()
    local c = backup:Clone()
    wait(2.5)
    c.Parent = workspace
    c:MakeJoints()
    script:Remove()
end



while true do
    if (eng.Position - gun.Position).magnitude >= 10 then
        eng.BodyPosition.maxForce = Vector3.new(0,0,0)
        plane:BreakJoints()
        for i = 1, #parts do
            parts[i].RotVelocity = Vector3.new(math.random(-25,25),math.random(-25,25),math.random(-25,25))
            parts[i].CFrame = eng.CFrame + Vector3.new(math.random(-2,2),math.random(-2,2),math.random(-2,2))
            local bv = Instance.new("BodyVelocity")
            bv.Parent = parts[i]
            bv.velocity = parts[i].Position - eng.Position
        end
        clean()
        break
    end
    eng.BodyPosition.position = eng.Position + eng.CFrame.lookVector
    onDie()
    if target ~= "" then
        eng.BodyGyro.cframe = CFrame.new(eng.Position, target.Ore.Position)
        local a = math.random(0,10)

    end

    wait(0.1)
end