public string CreateNewElem([FromBody] AircraftsDTO element)
 {
     if (!ModelState.IsValid)
     {
         return("Not valid data");
     }
     try
     {
         crewService.Create(element);
         return("Created the new element");
     }
     catch (Exception e)
     {
         return(e.Message);
     }
 }
 public string UpdateElem(int id, [FromBody] AircraftsDTO element)
 {
     if (!ModelState.IsValid)
     {
         return("Not valid data");
     }
     try
     {
         crewService.Update(id, element);
         return("Updated new elemnt");
     }
     catch (Exception e)
     {
         return(e.Message);
     }
 }