Movement When Character is in air.

So i'm not the best at implementing new code so I've ran into an issue. I've got a basic character controller that works great other then the fact that i cant control movement of the character while in the air. This is my current code that i'm working with and i just cant find a way to allow the movement in air. Any input is most appreciated.

 public class PlayerMovement : MonoBehaviour
 {
     public PlayerStates playerStates;

     [Header("Inputs")]
     public string HorizontalInput = "Horizontal";
     public string VerticalInput = "Vertical";
     public string RunInput = "Run";
     public string JumpInput = "Jump";

     [Header("Player Motor")]
     [Range(1f,15f)]
     public float walkSpeed;
     [Range(1f,15f)]
     public float runSpeed;
     [Range(1f,15f)]
     public float JumpForce;
     public Transform FootLocation;

     [Header("Animator and Parameters")]
     public Animator CharacterAnimator;
     public float HorzAnimation;
     public float VertAnimation;
     public bool JumpAnimation;
     public bool LandAnimation;

     [Header("Sounds")]
     public List<AudioClip> FootstepSounds;
     public List<AudioClip> JumpSounds;
     public List<AudioClip> LandSounds;

     CharacterController characterController;

     float _footstepDelay;
     AudioSource _audioSource;
     float footstep_et = 0;

     // Use this for initialization
     void Start()
     {
         characterController = GetComponent<CharacterController>();
         _audioSource = gameObject.AddComponent<AudioSource>();
     }

     // Update is called once per frame
     void Update()
     {
         //handle controller
         HandlePlayerControls();

         //sync animations with controller
         SetCharacterAnimations();

         //sync footsteps with controller
         PlayFootstepSounds();
     }

     void HandlePlayerControls()
     {
         float hInput = Input.GetAxisRaw(HorizontalInput);
         float vInput = Input.GetAxisRaw(VerticalInput);

         Vector3 fwdMovement = characterController.isGrounded == true ? transform.forward * vInput : Vector3.zero;
         Vector3 rightMovement = characterController.isGrounded == true ? transform.right * hInput : Vector3.zero;

         float _speed = Input.GetButton(RunInput) ? runSpeed : walkSpeed;
         characterController.SimpleMove(Vector3.ClampMagnitude(fwdMovement + rightMovement, 1f) * _speed);

         if (characterController.isGrounded)
             Jump();

         //Managing Player States
         if (characterController.isGrounded)
         {
             if (hInput == 0 && vInput == 0)
                 playerStates = PlayerStates.Idle;
             else
             {
                 if (_speed == walkSpeed)
                     playerStates = PlayerStates.Walking;
                 else
                     playerStates = PlayerStates.Running;

                 _footstepDelay = (2/_speed);
             }
         }
         else
             playerStates = PlayerStates.Jumping;
     }

     void Jump()
     {
         if (Input.GetButtonDown(JumpInput))
         {
             StartCoroutine(PerformJumpRoutine());
             JumpAnimation = true;
         }
     }

     IEnumerator PerformJumpRoutine()
     {
         //play jump sound
         if (_audioSource)
             _audioSource.PlayOneShot(JumpSounds[Random.Range(0, JumpSounds.Count)]);

         float _jump = JumpForce;

         do
         {
             characterController.Move(Vector3.up * _jump * Time.deltaTime);
             _jump -= Time.deltaTime;
             yield return null;
         }
         while (!characterController.isGrounded);

         //play land sound
         if (_audioSource)
             _audioSource.PlayOneShot(LandSounds[Random.Range(0, LandSounds.Count)]);

     }

     void SetCharacterAnimations()
     {
         if (!CharacterAnimator)
             return;

         switch (playerStates)
         {
             case PlayerStates.Idle:
                 HorzAnimation = Mathf.Lerp(HorzAnimation, 0, 5 * Time.deltaTime);
                 VertAnimation = Mathf.Lerp(VertAnimation, 0, 5 * Time.deltaTime);
                 break;

             case PlayerStates.Walking:
                 HorzAnimation = Mathf.Lerp(HorzAnimation, 1 * Input.GetAxis("Horizontal"), 5 * Time.deltaTime);
                 VertAnimation = Mathf.Lerp(VertAnimation, 1 * Input.GetAxis("Vertical"), 5 * Time.deltaTime);
                 break;

             case PlayerStates.Running:
                 HorzAnimation = Mathf.Lerp(HorzAnimation, 2 * Input.GetAxis("Horizontal"), 5 * Time.deltaTime);
                 VertAnimation = Mathf.Lerp(VertAnimation, 2 * Input.GetAxis("Vertical"), 5 * Time.deltaTime);
                 break;

             case PlayerStates.Jumping:
                 if (JumpAnimation)
                 {
                     CharacterAnimator.SetTrigger("Jump");
                     JumpAnimation = false;
                 }
                 break;
         }

         LandAnimation = characterController.isGrounded;
         CharacterAnimator.SetFloat("Horizontal", HorzAnimation);
         CharacterAnimator.SetFloat("Vertical", VertAnimation);
         CharacterAnimator.SetBool("isGrounded", LandAnimation);
     }

     bool onGround()
     {
         bool retVal = false;

         if (Physics.Raycast(FootLocation.position, Vector3.down, 0.1f))
             retVal = true;
         else
             retVal = false;

         return retVal;
     }

     void PlayFootstepSounds()
     {
         if (playerStates == PlayerStates.Idle || playerStates == PlayerStates.Jumping)
             return;

         if (footstep_et < _footstepDelay)
             footstep_et += Time.deltaTime;
         else
         {
             footstep_et = 0;
             _audioSource.PlayOneShot(FootstepSounds[Random.Range(0, FootstepSounds.Count)]);
         }
     }

 }

}