function WrightAI::GetBestRouteEngine(tile_1, tile_2) {
    local engine_list = AIEngineList(AIVehicle.VT_AIR);
	engine_list.Valuate(AIEngine.CanRefitCargo, this.cargoId);
	engine_list.KeepValue(1);
	
	local small_aircraft = AIAirport.GetAirportType(tile_1) == AIAirport.AT_SMALL || AIAirport.GetAirportType(tile_2) == AIAirport.AT_SMALL ||
						   AIAirport.GetAirportType(tile_1) == AIAirport.AT_COMMUTER || AIAirport.GetAirportType(tile_2) == AIAirport.AT_COMMUTER;
	if (small_aircraft) {
	    engine_list.Valuate(AIEngine.GetPlaneType);
	    engine_list.RemoveValue(AIAirport.PT_BIG_PLANE);
	}
	
	local helicopter = AIAirport.GetAirportType(tile_1) == AIAirport.AT_HELIPORT || AIAirport.GetAirportType(tile_2) == AIAirport.AT_HELIPORT ||
	                   AIAirport.GetAirportType(tile_1) == AIAirport.AT_HELIDEPOT || AIAirport.GetAirportType(tile_2) == AIAirport.AT_HELIDEPOT ||
					   AIAirport.GetAirportType(tile_1) == AIAirport.AT_HELISTATION || AIAirport.GetAirportType(tile_2) == AIAirport.AT_HELISTATION;
	if (helicopter) {
	    engine_list.Valuate(AIEngine.GetPlaneType);
		engine_list.KeepValue(AIAirport.PT_HELICOPTER);
	}

	engine_list.Valuate(AIEngine.GetMaxSpeed);
    engine_list.Sort(AIList.SORT_BY_VALUE, AIList.SORT_DESCENDING);
	
	local dist = AIMap.DistanceSquare(tile_1, tile_2);
	engine_list.Valuate(WrightAI.GetMaximumOrderDistance);
	engine_list.KeepAboveValue(dist - 1);
	engine_list.Sort(AIList.SORT_BY_VALUE, AIList.SORT_DESCENDING);
	AILog.Warning(AIEngine.GetName(engine_list.Begin()) + " maximum distance is " + engine_list.GetValue(engine_list.Begin())); 

	if (engine_list.Count() == 0) {
	    return null;
	} else {
	    return engine_list.Begin();
	}
}

function::WrightAI::GetMaximumOrderDistance(engine) {
    local dist = AIEngine.GetMaximumOrderDistance(engine);
	return dist == 0 ? 0xFFFFFFFF : dist;
}