Maintenance Status for Aircraft (#1311)

* Update AircraftStatus.php

* EN

* DE

* ES

* IT

* PT-BR

app/Models/Enums/AircraftStatus.php

@@ -7,6 +7,7 @@ use App\Contracts\Enum;
 class AircraftStatus extends Enum
 {
     public const ACTIVE = 'A';
+    public const MAINTENANCE = 'M';
     public const STORED = 'S';
     public const RETIRED = 'R';
     public const SCRAPPED = 'C';
@@ -14,6 +15,7 @@ class AircraftStatus extends Enum
 
     public static $labels = [
         self::ACTIVE      => 'aircraft.status.active',
+        self::MAINTENANCE => 'aircraft.status.maintenance',
         self::STORED      => 'aircraft.status.stored',
         self::RETIRED     => 'aircraft.status.retired',
         self::SCRAPPED    => 'aircraft.status.scrapped',