Airplane

public class AirplaneMover : MonoBehaviour
{
    [SerializeField] private float _speed;

    private Transform _transform;

    private void Awake()
    {
        _transform = transform;
    }
    void Update()
    {
        _transform.position += Vector3.forward * _speed * Time.deltaTime;
    }
}


//-------------------------------------------------------------------------------------------------------
public class Dropper : MonoBehaviour
{
    [SerializeField] private GameObject _droppedObject;
    [SerializeField] private Transform _dropPoint;

    [Range(50, 500)]
    [SerializeField] private float _dropPower = 400;

    [Range(.2f, 20)]
    [SerializeField] private float _dropDelay = 1f;

    private float _time;


    private void Start()
    {
        _time = 0;
    }

    private void Update()
    {
        _time += Time.deltaTime;

        if (_time >= _dropDelay)
        {
            Drop();
            _time = 0;
        }
    }

    private void Drop()
    {
        Vector3 force = new Vector3(Random.Range(-0.25f, 0.25f), 0, 1f) * _dropPower;

        GameObject droppedItem = Instantiate(_droppedObject, _dropPoint.position, Quaternion.identity);
        droppedItem.GetComponent<Rigidbody>().AddForce(force);
    }
}