Problem when retrieving data from a table

I created the branch model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Sucursal extends Model
{
    protected $table = "sucursal";
    public $primaryKey = 'ID_SUC';
    public $timestamps = false;
}

I created the controller (I want to show the branch table data in index):

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Sucursal;

class SucursalController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $flights = App\Sucursal::all();
       return view('sucursal', compact('flights')); 
    }

    /**
     * Show the form for creating a new resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        return view('sucursal/create');
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)
    {
        //
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show($id)
    {
        //
    }

    /**
     * Show the form for editing the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function edit($id)
    {
        //
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        //
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        //
    }
}

When trying to save I get the following error

What is failing? I do not understand, I'm not importing the model in the controller when writing: use App\Sucursal ?