--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/aircraft_cmd.c	Tue Jan 02 19:19:48 2007 +0000
@@ -0,0 +1,2120 @@
+/* $Id$ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "aircraft.h"
+#include "debug.h"
+#include "functions.h"
+#include "station_map.h"
+#include "table/strings.h"
+#include "map.h"
+#include "tile.h"
+#include "vehicle.h"
+#include "depot.h"
+#include "engine.h"
+#include "command.h"
+#include "station.h"
+#include "news.h"
+#include "sound.h"
+#include "player.h"
+#include "airport.h"
+#include "vehicle_gui.h"
+#include "table/sprites.h"
+#include "newgrf_engine.h"
+#include "newgrf_callbacks.h"
+#include "newgrf_text.h"
+#include "newgrf_sound.h"
+#include "date.h"
+
+static bool AirportMove(Vehicle *v, const AirportFTAClass *apc);
+static bool AirportSetBlocks(Vehicle *v, AirportFTA *current_pos, const AirportFTAClass *apc);
+static bool AirportHasBlock(Vehicle *v, const AirportFTA *current_pos, const AirportFTAClass *apc);
+static bool AirportFindFreeTerminal(Vehicle *v, const AirportFTAClass *apc);
+static bool AirportFindFreeHelipad(Vehicle *v, const AirportFTAClass *apc);
+static void AirportGoToNextPosition(Vehicle *v, const AirportFTAClass *apc);
+static void CrashAirplane(Vehicle *v);
+
+static void AircraftNextAirportPos_and_Order(Vehicle *v);
+static byte GetAircraftFlyingAltitude(const Vehicle *v);
+
+static const SpriteID _aircraft_sprite[] = {
+	0x0EB5, 0x0EBD, 0x0EC5, 0x0ECD,
+	0x0ED5, 0x0EDD, 0x0E9D, 0x0EA5,
+	0x0EAD, 0x0EE5, 0x0F05, 0x0F0D,
+	0x0F15, 0x0F1D, 0x0F25, 0x0F2D,
+	0x0EED, 0x0EF5, 0x0EFD, 0x0F35,
+	0x0E9D, 0x0EA5, 0x0EAD, 0x0EB5,
+	0x0EBD, 0x0EC5
+};
+
+/* Helicopter rotor animation states */
+enum HelicopterRotorStates {
+	HRS_ROTOR_STOPPED,
+	HRS_ROTOR_MOVING_1,
+	HRS_ROTOR_MOVING_2,
+	HRS_ROTOR_MOVING_3,
+};
+
+/* Find the nearest hangar to v
+ * INVALID_STATION is returned, if the player does not have any suitable
+ * airports (like helipads only)
+ */
+static StationID FindNearestHangar(const Vehicle *v)
+{
+	const Station *st;
+	uint best = 0;
+	StationID index = INVALID_STATION;
+	TileIndex vtile = TileVirtXY(v->x_pos, v->y_pos);
+
+	FOR_ALL_STATIONS(st) {
+		if (st->owner == v->owner && st->facilities & FACIL_AIRPORT &&
+				GetAirport(st->airport_type)->nof_depots > 0) {
+			uint distance;
+
+			// don't crash the plane if we know it can't land at the airport
+			if ((AircraftVehInfo(v->engine_type)->subtype & AIR_FAST) &&
+					(st->airport_type == AT_SMALL || st->airport_type == AT_COMMUTER) &&
+					!_cheats.no_jetcrash.value)
+				continue;
+
+			// v->tile can't be used here, when aircraft is flying v->tile is set to 0
+			distance = DistanceSquare(vtile, st->airport_tile);
+			if (distance < best || index == INVALID_STATION) {
+				best = distance;
+				index = st->index;
+			}
+		}
+	}
+	return index;
+}
+
+#if 0
+// returns true if vehicle v have an airport in the schedule, that has a hangar
+static bool HaveHangarInOrderList(Vehicle *v)
+{
+	const Order *order;
+
+	FOR_VEHICLE_ORDERS(v, order) {
+		const Station *st = GetStation(order->station);
+		if (st->owner == v->owner && st->facilities & FACIL_AIRPORT) {
+			// If an airport doesn't have a hangar, skip it
+			if (GetAirport(st->airport_type)->nof_depots != 0)
+				return true;
+		}
+	}
+
+	return false;
+}
+#endif
+
+int GetAircraftImage(const Vehicle* v, Direction direction)
+{
+	int spritenum = v->spritenum;
+
+	if (is_custom_sprite(spritenum)) {
+		int sprite = GetCustomVehicleSprite(v, direction);
+
+		if (sprite != 0) return sprite;
+		spritenum = orig_aircraft_vehicle_info[v->engine_type - AIRCRAFT_ENGINES_INDEX].image_index;
+	}
+	return direction + _aircraft_sprite[spritenum];
+}
+
+SpriteID GetRotorImage(const Vehicle *v)
+{
+	const Vehicle *w;
+
+	assert((v->subtype & 1) == 0);
+
+	w = v->next->next;
+	if (is_custom_sprite(v->spritenum)) {
+		SpriteID spritenum = GetCustomRotorSprite(v, false);
+		if (spritenum != 0) return spritenum;
+	}
+
+	/* Return standard rotor sprites if there are no custom sprites for this helicopter */
+	return SPR_ROTOR_STOPPED + w->u.air.state;
+}
+
+void DrawAircraftEngine(int x, int y, EngineID engine, uint32 image_ormod)
+{
+	const AircraftVehicleInfo* avi = AircraftVehInfo(engine);
+	int spritenum = avi->image_index;
+	int sprite = (6 + _aircraft_sprite[spritenum]);
+
+	if (is_custom_sprite(spritenum)) {
+		sprite = GetCustomVehicleIcon(engine, DIR_W);
+		if (sprite == 0) {
+			spritenum = orig_aircraft_vehicle_info[engine - AIRCRAFT_ENGINES_INDEX].image_index;
+			sprite = (6 + _aircraft_sprite[spritenum]);
+		}
+	}
+
+	DrawSprite(sprite | image_ormod, x, y);
+
+	if (!(avi->subtype & AIR_CTOL)) {
+		SpriteID rotor_sprite = GetCustomRotorIcon(engine);
+		if (rotor_sprite == 0) rotor_sprite = SPR_ROTOR_STOPPED;
+		DrawSprite(rotor_sprite, x, y - 5);
+	}
+}
+
+static int32 EstimateAircraftCost(EngineID engine_type)
+{
+	return AircraftVehInfo(engine_type)->base_cost * (_price.aircraft_base>>3)>>5;
+}
+
+
+/**
+ * Calculates cargo capacity based on an aircraft's passenger
+ * and mail capacities.
+ * @param cid Which cargo type to calculate a capacity for.
+ * @param engine Which engine to find a cargo capacity for.
+ * @return New cargo capacity value.
+ */
+uint16 AircraftDefaultCargoCapacity(CargoID cid, EngineID engine_type)
+{
+	const AircraftVehicleInfo *avi = AircraftVehInfo(engine_type);
+
+	assert(cid != CT_INVALID);
+
+	/* An aircraft can carry twice as much goods as normal cargo,
+	 * and four times as many passengers. */
+	switch (cid) {
+		case CT_PASSENGERS:
+			return avi->passenger_capacity;
+		case CT_MAIL:
+			return avi->passenger_capacity + avi->mail_capacity;
+		case CT_GOODS:
+			return (avi->passenger_capacity + avi->mail_capacity) / 2;
+		default:
+			return (avi->passenger_capacity + avi->mail_capacity) / 4;
+	}
+}
+
+
+/** Build an aircraft.
+ * @param tile tile of depot where aircraft is built
+ * @param p1 aircraft type being built (engine)
+ * @param p2 bit 0 when set, the unitnumber will be 0, otherwise it will be a free number
+ */
+int32 CmdBuildAircraft(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	int32 value;
+	Vehicle *vl[3], *v, *u, *w;
+	UnitID unit_num;
+	const AircraftVehicleInfo *avi;
+	const AirportFTAClass* ap;
+	Engine *e;
+
+	if (!IsEngineBuildable(p1, VEH_Aircraft, _current_player)) return_cmd_error(STR_ENGINE_NOT_BUILDABLE);
+
+	value = EstimateAircraftCost(p1);
+
+	// to just query the cost, it is not neccessary to have a valid tile (automation/AI)
+	if (flags & DC_QUERY_COST) return value;
+
+	if (!IsHangarTile(tile) || !IsTileOwner(tile, _current_player)) return CMD_ERROR;
+
+	SET_EXPENSES_TYPE(EXPENSES_NEW_VEHICLES);
+
+	avi = AircraftVehInfo(p1);
+
+	// Prevent building aircraft types at places which can't handle them
+	ap = GetAirport(GetStationByTile(tile)->airport_type);
+	if ((avi->subtype & AIR_CTOL ? HELICOPTERS_ONLY : AIRCRAFT_ONLY) == ap->acc_planes) {
+		return CMD_ERROR;
+	}
+
+	// allocate 2 or 3 vehicle structs, depending on type
+	if (!AllocateVehicles(vl, avi->subtype & AIR_CTOL ? 2 : 3) ||
+			IsOrderPoolFull()) {
+		return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
+	}
+
+	unit_num = HASBIT(p2, 0) ? 0 : GetFreeUnitNumber(VEH_Aircraft);
+	if (unit_num > _patches.max_aircraft)
+		return_cmd_error(STR_00E1_TOO_MANY_VEHICLES_IN_GAME);
+
+	if (flags & DC_EXEC) {
+		CargoID cargo;
+		uint x;
+		uint y;
+
+		v = vl[0];
+		u = vl[1];
+
+		v->unitnumber = unit_num;
+		v->type = u->type = VEH_Aircraft;
+		v->direction = 3;
+
+		v->owner = u->owner = _current_player;
+
+		v->tile = tile;
+//		u->tile = 0;
+
+		x = TileX(tile) * TILE_SIZE + 5;
+		y = TileY(tile) * TILE_SIZE + 3;
+
+		v->x_pos = u->x_pos = x;
+		v->y_pos = u->y_pos = y;
+
+		u->z_pos = GetSlopeZ(x, y);
+		v->z_pos = u->z_pos + 1;
+
+		v->x_offs = v->y_offs = -1;
+//		u->delta_x = u->delta_y = 0;
+
+		v->sprite_width = v->sprite_height = 2;
+		v->z_height = 5;
+
+		u->sprite_width = u->sprite_height = 2;
+		u->z_height = 1;
+
+		v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
+		u->vehstatus = VS_HIDDEN | VS_UNCLICKABLE | VS_SHADOW;
+
+		v->spritenum = avi->image_index;
+//		v->cargo_count = u->number_of_pieces = 0;
+
+		v->cargo_cap = avi->passenger_capacity;
+		u->cargo_cap = avi->mail_capacity;
+
+		v->cargo_type = CT_PASSENGERS;
+		u->cargo_type = CT_MAIL;
+
+		v->cargo_subtype = 0;
+
+		v->string_id = STR_SV_AIRCRAFT_NAME;
+//		v->next_order_param = v->next_order = 0;
+
+//		v->load_unload_time_rem = 0;
+//		v->progress = 0;
+		v->last_station_visited = INVALID_STATION;
+//		v->destination_coords = 0;
+
+		v->max_speed = avi->max_speed;
+		v->acceleration = avi->acceleration;
+		v->engine_type = p1;
+
+		v->subtype = (avi->subtype & AIR_CTOL ? 2 : 0);
+		v->value = value;
+
+		u->subtype = 4;
+
+		/* Danger, Will Robinson!
+		 * If the aircraft is refittable, but cannot be refitted to
+		 * passengers, we select the cargo type from the refit mask.
+		 * This is a fairly nasty hack to get around the fact that TTD
+		 * has no default cargo type specifier for planes... */
+		cargo = FindFirstRefittableCargo(p1);
+		if (cargo != CT_INVALID && cargo != CT_PASSENGERS) {
+			uint16 callback = CALLBACK_FAILED;
+
+			v->cargo_type = cargo;
+
+			if (HASBIT(EngInfo(p1)->callbackmask, CBM_REFIT_CAPACITY)) {
+				callback = GetVehicleCallback(CBID_VEHICLE_REFIT_CAPACITY, 0, 0, v->engine_type, v);
+			}
+
+			if (callback == CALLBACK_FAILED) {
+				/* Callback failed, or not executed; use the default cargo capacity */
+				v->cargo_cap = AircraftDefaultCargoCapacity(v->cargo_type, v->engine_type);
+			} else {
+				v->cargo_cap = callback;
+			}
+
+			/* Set the 'second compartent' capacity to none */
+			u->cargo_cap = 0;
+		}
+
+		e = GetEngine(p1);
+		v->reliability = e->reliability;
+		v->reliability_spd_dec = e->reliability_spd_dec;
+		v->max_age = e->lifelength * 366;
+
+		_new_vehicle_id = v->index;
+
+		v->u.air.pos = MAX_ELEMENTS;
+
+		/* When we click on hangar we know the tile it is on. By that we know
+		 * its position in the array of depots the airport has.....we can search
+		 * layout for #th position of depot. Since layout must start with a listing
+		 * of all depots, it is simple */
+		{
+			const Station* st = GetStationByTile(tile);
+			const AirportFTAClass* apc = GetAirport(st->airport_type);
+			uint i;
+
+			for (i = 0; i < apc->nof_depots; i++) {
+				if (st->airport_tile + ToTileIndexDiff(apc->airport_depots[i]) == tile) {
+					assert(apc->layout[i].heading == HANGAR);
+					v->u.air.pos = apc->layout[i].position;
+					break;
+				}
+			}
+			// to ensure v->u.air.pos has been given a value
+			assert(v->u.air.pos != MAX_ELEMENTS);
+		}
+
+		v->u.air.state = HANGAR;
+		v->u.air.previous_pos = v->u.air.pos;
+		v->u.air.targetairport = GetStationIndex(tile);
+		v->next = u;
+
+		v->service_interval = _patches.servint_aircraft;
+
+		v->date_of_last_service = _date;
+		v->build_year = u->build_year = _cur_year;
+
+		v->cur_image = u->cur_image = 0xEA0;
+
+		v->random_bits = VehicleRandomBits();
+		u->random_bits = VehicleRandomBits();
+
+		VehiclePositionChanged(v);
+		VehiclePositionChanged(u);
+
+		// Aircraft with 3 vehicles (chopper)?
+		if (v->subtype == 0) {
+			w = vl[2];
+
+			u->next = w;
+
+			w->type = VEH_Aircraft;
+			w->direction = 0;
+			w->owner = _current_player;
+			w->x_pos = v->x_pos;
+			w->y_pos = v->y_pos;
+			w->z_pos = v->z_pos + 5;
+			w->x_offs = w->y_offs = -1;
+			w->sprite_width = w->sprite_height = 2;
+			w->z_height = 1;
+			w->vehstatus = VS_HIDDEN | VS_UNCLICKABLE;
+			w->spritenum = 0xFF;
+			w->subtype = 6;
+			w->cur_image = SPR_ROTOR_STOPPED;
+			w->random_bits = VehicleRandomBits();
+			/* Use rotor's air.state to store the rotor animation frame */
+			w->u.air.state = HRS_ROTOR_STOPPED;
+			VehiclePositionChanged(w);
+		}
+		GetPlayer(_current_player)->num_engines[p1]++;
+
+		InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
+		RebuildVehicleLists();
+		InvalidateWindow(WC_COMPANY, v->owner);
+		if (IsLocalPlayer())
+			InvalidateWindow(WC_REPLACE_VEHICLE, VEH_Aircraft); //updates the replace Aircraft window
+	}
+
+	return value;
+}
+
+
+static void DoDeleteAircraft(Vehicle *v)
+{
+	DeleteWindowById(WC_VEHICLE_VIEW, v->index);
+	RebuildVehicleLists();
+	InvalidateWindow(WC_COMPANY, v->owner);
+	DeleteDepotHighlightOfVehicle(v);
+	DeleteVehicleChain(v);
+	InvalidateWindowClasses(WC_AIRCRAFT_LIST);
+}
+
+/** Sell an aircraft.
+ * @param tile unused
+ * @param p1 vehicle ID to be sold
+ * @param p2 unused
+ */
+int32 CmdSellAircraft(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	Vehicle *v;
+
+	if (!IsValidVehicleID(p1)) return CMD_ERROR;
+
+	v = GetVehicle(p1);
+
+	if (v->type != VEH_Aircraft || !CheckOwnership(v->owner)) return CMD_ERROR;
+	if (!IsAircraftInHangarStopped(v)) return_cmd_error(STR_A01B_AIRCRAFT_MUST_BE_STOPPED);
+
+	SET_EXPENSES_TYPE(EXPENSES_NEW_VEHICLES);
+
+	if (flags & DC_EXEC) {
+		// Invalidate depot
+		InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
+		DoDeleteAircraft(v);
+		if (IsLocalPlayer())
+			InvalidateWindow(WC_REPLACE_VEHICLE, VEH_Aircraft); // updates the replace Aircraft window
+	}
+
+	return -(int32)v->value;
+}
+
+/** Start/Stop an aircraft.
+ * @param tile unused
+ * @param p1 aircraft ID to start/stop
+ * @param p2 unused
+ */
+int32 CmdStartStopAircraft(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	Vehicle *v;
+	uint16 callback;
+
+	if (!IsValidVehicleID(p1)) return CMD_ERROR;
+
+	v = GetVehicle(p1);
+
+	if (v->type != VEH_Aircraft || !CheckOwnership(v->owner)) return CMD_ERROR;
+
+	// cannot stop airplane when in flight, or when taking off / landing
+	if (v->u.air.state >= STARTTAKEOFF && v->u.air.state < TERM7)
+		return_cmd_error(STR_A017_AIRCRAFT_IS_IN_FLIGHT);
+
+	/* Check if this aircraft can be started/stopped. The callback will fail or
+	 * return 0xFF if it can. */
+	callback = GetVehicleCallback(CBID_VEHICLE_START_STOP_CHECK, 0, 0, v->engine_type, v);
+	if (callback != CALLBACK_FAILED && callback != 0xFF) {
+		StringID error = GetGRFStringID(GetEngineGRFID(v->engine_type), 0xD000 + callback);
+		return_cmd_error(error);
+	}
+
+	if (flags & DC_EXEC) {
+		if (IsAircraftInHangarStopped(v)) {
+			DeleteVehicleNews(p1, STR_A014_AIRCRAFT_IS_WAITING_IN);
+		}
+
+		v->vehstatus ^= VS_STOPPED;
+		InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+		InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
+		InvalidateWindowClasses(WC_AIRCRAFT_LIST);
+	}
+
+	return 0;
+}
+
+/** Send an aircraft to the hangar.
+ * @param tile unused
+ * @param p1 vehicle ID to send to the hangar
+ * @param p2 various bitmasked elements
+ * - p2 bit 0-3 - DEPOT_ flags (see vehicle.h)
+ * - p2 bit 8-10 - VLW flag (for mass goto depot)
+ */
+int32 CmdSendAircraftToHangar(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	Vehicle *v;
+
+	if (p2 & DEPOT_MASS_SEND) {
+		/* Mass goto depot requested */
+		if (!ValidVLWFlags(p2 & VLW_MASK)) return CMD_ERROR;
+		return SendAllVehiclesToDepot(VEH_Aircraft, flags, p2 & DEPOT_SERVICE, _current_player, (p2 & VLW_MASK), p1);
+	}
+
+	if (!IsValidVehicleID(p1)) return CMD_ERROR;
+
+	v = GetVehicle(p1);
+
+	if (v->type != VEH_Aircraft || !CheckOwnership(v->owner) || IsAircraftInHangar(v)) return CMD_ERROR;
+
+	if (v->current_order.type == OT_GOTO_DEPOT && !(p2 & DEPOT_LOCATE_HANGAR)) {
+		if (!!(p2 & DEPOT_SERVICE) == HASBIT(v->current_order.flags, OFB_HALT_IN_DEPOT)) {
+			/* We called with a different DEPOT_SERVICE setting.
+			 * Now we change the setting to apply the new one and let the vehicle head for the same hangar.
+			 * Note: the if is (true for requesting service == true for ordered to stop in hangar) */
+			if (flags & DC_EXEC) {
+				TOGGLEBIT(v->current_order.flags, OFB_HALT_IN_DEPOT);
+				InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+			}
+			return 0;
+		}
+
+		if (p2 & DEPOT_DONT_CANCEL) return CMD_ERROR; // Requested no cancelation of hangar orders
+		if (flags & DC_EXEC) {
+			if (v->current_order.flags & OF_UNLOAD) v->cur_order_index++;
+			v->current_order.type = OT_DUMMY;
+			v->current_order.flags = 0;
+			InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+		}
+	} else {
+		bool next_airport_has_hangar = true;
+		StationID next_airport_index = v->u.air.targetairport;
+		const Station *st = GetStation(next_airport_index);
+		/* If the station is not a valid airport or if it has no hangars */
+		if (!IsValidStation(st) || st->airport_tile == 0 || GetAirport(st->airport_type)->nof_depots == 0) {
+			StationID station;
+
+			// the aircraft has to search for a hangar on its own
+			station = FindNearestHangar(v);
+
+			next_airport_has_hangar = false;
+			if (station == INVALID_STATION) return CMD_ERROR;
+			st = GetStation(station);
+			next_airport_index = station;
+
+		}
+
+		if (flags & DC_EXEC) {
+			v->current_order.type = OT_GOTO_DEPOT;
+			v->current_order.flags = OF_NON_STOP;
+			if (!(p2 & DEPOT_SERVICE)) SETBIT(v->current_order.flags, OFB_HALT_IN_DEPOT);
+			v->current_order.refit_cargo = CT_INVALID;
+			v->current_order.dest = next_airport_index;
+			InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+			if (v->u.air.state == FLYING && !next_airport_has_hangar) {
+				/* The aircraft is now heading for a different hangar than the next in the orders */
+				AircraftNextAirportPos_and_Order(v);
+				v->u.air.targetairport = next_airport_index;
+			}
+		}
+	}
+
+	return 0;
+}
+
+
+/** Refits an aircraft to the specified cargo type.
+ * @param tile unused
+ * @param p1 vehicle ID of the aircraft to refit
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0-7) - the new cargo type to refit to
+ * - p2 = (bit 8-15) - the new cargo subtype to refit to
+ */
+int32 CmdRefitAircraft(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
+{
+	Vehicle *v;
+	int pass, mail;
+	int32 cost;
+	CargoID new_cid = GB(p2, 0, 8);
+	byte new_subtype = GB(p2, 8, 8);
+	const AircraftVehicleInfo *avi;
+	uint16 callback = CALLBACK_FAILED;
+
+	if (!IsValidVehicleID(p1)) return CMD_ERROR;
+
+	v = GetVehicle(p1);
+
+	if (v->type != VEH_Aircraft || !CheckOwnership(v->owner)) return CMD_ERROR;
+	if (!IsAircraftInHangarStopped(v)) return_cmd_error(STR_A01B_AIRCRAFT_MUST_BE_STOPPED);
+
+	avi = AircraftVehInfo(v->engine_type);
+
+	/* Check cargo */
+	if (new_cid > NUM_CARGO || !CanRefitTo(v->engine_type, new_cid)) return CMD_ERROR;
+
+	SET_EXPENSES_TYPE(EXPENSES_AIRCRAFT_RUN);
+
+	/* Check the refit capacity callback */
+	if (HASBIT(EngInfo(v->engine_type)->callbackmask, CBM_REFIT_CAPACITY)) {
+		/* Back up the existing cargo type */
+		CargoID temp_cid = v->cargo_type;
+		byte temp_subtype = v->cargo_subtype;
+		v->cargo_type = new_cid;
+		v->cargo_subtype = new_subtype;
+
+		callback = GetVehicleCallback(CBID_VEHICLE_REFIT_CAPACITY, 0, 0, v->engine_type, v);
+
+		/* Restore the cargo type */
+		v->cargo_type = temp_cid;
+		v->cargo_subtype = temp_subtype;
+	}
+
+	if (callback == CALLBACK_FAILED) {
+		/* If the callback failed, or wasn't executed, use the aircraft's
+		 * default cargo capacity */
+		pass = AircraftDefaultCargoCapacity(new_cid, v->engine_type);
+	} else {
+		pass = callback;
+	}
+	_returned_refit_capacity = pass;
+
+	cost = 0;
+	if (IsHumanPlayer(v->owner) && new_cid != v->cargo_type) {
+		cost = GetRefitCost(v->engine_type);
+	}
+
+	if (flags & DC_EXEC) {
+		Vehicle *u;
+		v->cargo_cap = pass;
+
+		u = v->next;
+		mail = (new_cid != CT_PASSENGERS) ? 0 : avi->mail_capacity;
+		u->cargo_cap = mail;
+		if (v->cargo_type == new_cid) {
+			v->cargo_count = min(pass, v->cargo_count);
+			u->cargo_count = min(mail, u->cargo_count);
+		} else {
+			v->cargo_count = 0;
+			u->cargo_count = 0;
+		}
+		v->cargo_type = new_cid;
+		v->cargo_subtype = new_subtype;
+		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+		InvalidateWindow(WC_VEHICLE_DEPOT, v->tile);
+		RebuildVehicleLists();
+	}
+
+	return cost;
+}
+
+
+static void CheckIfAircraftNeedsService(Vehicle *v)
+{
+	const Station* st;
+
+	if (_patches.servint_aircraft == 0) return;
+	if (!VehicleNeedsService(v)) return;
+	if (v->vehstatus & VS_STOPPED) return;
+
+	if (v->current_order.type == OT_GOTO_DEPOT &&
+			v->current_order.flags & OF_HALT_IN_DEPOT)
+		return;
+
+	if (_patches.gotodepot && VehicleHasDepotOrders(v)) return;
+
+	if (IsAircraftInHangar(v)) {
+		VehicleServiceInDepot(v);
+		return;
+	}
+
+	st = GetStation(v->current_order.dest);
+	// only goto depot if the target airport has terminals (eg. it is airport)
+	if (IsValidStation(st) && st->airport_tile != 0 && GetAirport(st->airport_type)->terminals != NULL) {
+//		printf("targetairport = %d, st->index = %d\n", v->u.air.targetairport, st->index);
+//		v->u.air.targetairport = st->index;
+		v->current_order.type = OT_GOTO_DEPOT;
+		v->current_order.flags = OF_NON_STOP;
+		InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+	} else if (v->current_order.type == OT_GOTO_DEPOT) {
+		v->current_order.type = OT_DUMMY;
+		v->current_order.flags = 0;
+		InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+	}
+}
+
+void OnNewDay_Aircraft(Vehicle *v)
+{
+	int32 cost;
+
+	if (v->subtype > 2) return;
+
+	if ((++v->day_counter & 7) == 0) DecreaseVehicleValue(v);
+
+	CheckOrders(v);
+
+	CheckVehicleBreakdown(v);
+	AgeVehicle(v);
+	CheckIfAircraftNeedsService(v);
+
+	if (v->vehstatus & VS_STOPPED) return;
+
+	cost = AircraftVehInfo(v->engine_type)->running_cost * _price.aircraft_running / 364;
+
+	v->profit_this_year -= cost >> 8;
+
+	SET_EXPENSES_TYPE(EXPENSES_AIRCRAFT_RUN);
+	SubtractMoneyFromPlayerFract(v->owner, cost);
+
+	InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+	InvalidateWindowClasses(WC_AIRCRAFT_LIST);
+}
+
+void AircraftYearlyLoop(void)
+{
+	Vehicle *v;
+
+	FOR_ALL_VEHICLES(v) {
+		if (v->type == VEH_Aircraft && v->subtype <= 2) {
+			v->profit_last_year = v->profit_this_year;
+			v->profit_this_year = 0;
+			InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+		}
+	}
+}
+
+static void AgeAircraftCargo(Vehicle *v)
+{
+	if (_age_cargo_skip_counter != 0) return;
+
+	do {
+		if (v->cargo_days != 0xFF) v->cargo_days++;
+		v = v->next;
+	} while (v != NULL);
+}
+
+static void HelicopterTickHandler(Vehicle *v)
+{
+	Vehicle *u;
+	int tick,spd;
+	SpriteID img;
+
+	u = v->next->next;
+
+	if (u->vehstatus & VS_HIDDEN) return;
+
+	// if true, helicopter rotors do not rotate. This should only be the case if a helicopter is
+	// loading/unloading at a terminal or stopped
+	if (v->current_order.type == OT_LOADING || (v->vehstatus & VS_STOPPED)) {
+		if (u->cur_speed != 0) {
+			u->cur_speed++;
+			if (u->cur_speed >= 0x80 && u->u.air.state == HRS_ROTOR_MOVING_3) {
+				u->cur_speed = 0;
+			}
+		}
+	} else {
+		if (u->cur_speed == 0)
+			u->cur_speed = 0x70;
+
+		if (u->cur_speed >= 0x50)
+			u->cur_speed--;
+	}
+
+	tick = ++u->tick_counter;
+	spd = u->cur_speed >> 4;
+
+	if (spd == 0) {
+		u->u.air.state = HRS_ROTOR_STOPPED;
+		img = GetRotorImage(v);
+		if (u->cur_image == img) return;
+	} else if (tick >= spd) {
+		u->tick_counter = 0;
+		u->u.air.state++;
+		if (u->u.air.state > HRS_ROTOR_MOVING_3) u->u.air.state = HRS_ROTOR_MOVING_1;
+		img = GetRotorImage(v);
+	} else {
+		return;
+	}
+
+	u->cur_image = img;
+
+	BeginVehicleMove(u);
+	VehiclePositionChanged(u);
+	EndVehicleMove(u);
+}
+
+static void SetAircraftPosition(Vehicle *v, int x, int y, int z)
+{
+	Vehicle *u;
+	int safe_x;
+	int safe_y;
+
+	v->x_pos = x;
+	v->y_pos = y;
+	v->z_pos = z;
+
+	v->cur_image = GetAircraftImage(v, v->direction);
+	if (v->subtype == 0) v->next->next->cur_image = GetRotorImage(v);
+
+	BeginVehicleMove(v);
+	VehiclePositionChanged(v);
+	EndVehicleMove(v);
+
+	u = v->next;
+
+	safe_x = clamp(x, 0, MapMaxX() * TILE_SIZE);
+	safe_y = clamp(y - 1, 0, MapMaxY() * TILE_SIZE);
+	u->x_pos = x;
+	u->y_pos = y - ((v->z_pos-GetSlopeZ(safe_x, safe_y)) >> 3);;
+
+	safe_y = clamp(u->y_pos, 0, MapMaxY() * TILE_SIZE);
+	u->z_pos = GetSlopeZ(safe_x, safe_y);
+	u->cur_image = v->cur_image;
+
+	BeginVehicleMove(u);
+	VehiclePositionChanged(u);
+	EndVehicleMove(u);
+
+	u = u->next;
+	if (u != NULL) {
+		u->x_pos = x;
+		u->y_pos = y;
+		u->z_pos = z + 5;
+
+		BeginVehicleMove(u);
+		VehiclePositionChanged(u);
+		EndVehicleMove(u);
+	}
+}
+
+/** Handle Aircraft specific tasks when a an Aircraft enters a hangar
+ * @param *v Vehicle that enters the hangar
+ */
+void HandleAircraftEnterHangar(Vehicle *v)
+{
+	Vehicle *u;
+
+	v->subspeed = 0;
+	v->progress = 0;
+
+	u = v->next;
+	u->vehstatus |= VS_HIDDEN;
+	u = u->next;
+	if (u != NULL) {
+		u->vehstatus |= VS_HIDDEN;
+		u->cur_speed = 0;
+	}
+
+	SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos);
+}
+
+static void PlayAircraftSound(const Vehicle* v)
+{
+	if (!PlayVehicleSound(v, VSE_START)) {
+		SndPlayVehicleFx(AircraftVehInfo(v->engine_type)->sfx, v);
+	}
+}
+
+static bool UpdateAircraftSpeed(Vehicle *v)
+{
+	uint spd = v->acceleration * 2;
+	byte t;
+
+	v->subspeed = (t=v->subspeed) + (byte)spd;
+	spd = min(v->cur_speed + (spd >> 8) + (v->subspeed < t), v->max_speed);
+
+	// adjust speed for broken vehicles
+	if (v->vehstatus & VS_AIRCRAFT_BROKEN) spd = min(spd, 27);
+
+	//updates statusbar only if speed have changed to save CPU time
+	if (spd != v->cur_speed) {
+		v->cur_speed = spd;
+		if (_patches.vehicle_speed)
+			InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+	}
+
+	if (!(v->direction & 1)) spd = spd * 3 / 4;
+
+	if (spd == 0) return false;
+
+	if ((byte)++spd == 0) return true;
+
+	v->progress = (t = v->progress) - (byte)spd;
+
+	return t < v->progress;
+}
+
+// get Aircraft running altitude
+static byte GetAircraftFlyingAltitude(const Vehicle *v)
+{
+	switch (v->max_speed) {
+		case 37: return 162;
+		case 74: return 171;
+		default: return 180;
+	}
+}
+
+static bool AircraftController(Vehicle *v)
+{
+	Station *st;
+	const AirportMovingData *amd;
+	Vehicle *u;
+	byte z,newdir,maxz,curz;
+	GetNewVehiclePosResult gp;
+	uint dist;
+	int x,y;
+
+	st = GetStation(v->u.air.targetairport);
+
+	// prevent going to 0,0 if airport is deleted.
+	{
+		TileIndex tile = st->airport_tile;
+
+		if (tile == 0) tile = st->xy;
+		// xy of destination
+		x = TileX(tile) * TILE_SIZE;
+		y = TileY(tile) * TILE_SIZE;
+	}
+
+	// get airport moving data
+	amd = GetAirportMovingData(st->airport_type, v->u.air.pos);
+
+	// Helicopter raise
+	if (amd->flag & AMED_HELI_RAISE) {
+		u = v->next->next;
+
+		// Make sure the rotors don't rotate too fast
+		if (u->cur_speed > 32) {
+			v->cur_speed = 0;
+			if (--u->cur_speed == 32) SndPlayVehicleFx(SND_18_HELICOPTER, v);
+		} else {
+			u->cur_speed = 32;
+			if (UpdateAircraftSpeed(v)) {
+				v->tile = 0;
+
+				// Reached altitude?
+				if (v->z_pos >= 184) {
+					v->cur_speed = 0;
+					return true;
+				}
+				SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos+1);
+			}
+		}
+		return false;
+	}
+
+	// Helicopter landing.
+	if (amd->flag & AMED_HELI_LOWER) {
+		if (UpdateAircraftSpeed(v)) {
+			if (st->airport_tile == 0) {
+				// FIXME - AircraftController -> if station no longer exists, do not land
+				// helicopter will circle until sign disappears, then go to next order
+				// * what to do when it is the only order left, right now it just stays in 1 place
+				v->u.air.state = FLYING;
+				AircraftNextAirportPos_and_Order(v);
+				return false;
+			}
+
+			// Vehicle is now at the airport.
+			v->tile = st->airport_tile;
+
+			// Find altitude of landing position.
+			z = GetSlopeZ(x, y) + 1;
+			if (st->airport_type == AT_OILRIG) z += 54;
+			if (st->airport_type == AT_HELIPORT) z += 60;
+
+			if (z == v->z_pos) {
+				u = v->next->next;
+
+				// Increase speed of rotors. When speed is 80, we've landed.
+				if (u->cur_speed >= 80) return true;
+				u->cur_speed += 4;
+			} else if (v->z_pos > z) {
+				SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos-1);
+			} else {
+				SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos+1);
+			}
+		}
+		return false;
+	}
+
+	// Get distance from destination pos to current pos.
+	dist = myabs(x + amd->x - v->x_pos) +  myabs(y + amd->y - v->y_pos);
+
+	// Need exact position?
+	if (!(amd->flag & AMED_EXACTPOS) && dist <= (amd->flag & AMED_SLOWTURN ? 8U : 4U))
+		return true;
+
+	// At final pos?
+	if (dist == 0) {
+		DirDiff dirdiff;
+
+		if (v->cur_speed > 12) v->cur_speed = 12;
+
+		// Change direction smoothly to final direction.
+		dirdiff = DirDifference(amd->direction, v->direction);
+		// if distance is 0, and plane points in right direction, no point in calling
+		// UpdateAircraftSpeed(). So do it only afterwards
+		if (dirdiff == DIRDIFF_SAME) {
+			v->cur_speed = 0;
+			return true;
+		}
+
+		if (!UpdateAircraftSpeed(v)) return false;
+
+		v->direction = ChangeDir(v->direction, dirdiff > DIRDIFF_REVERSE ? DIRDIFF_45LEFT : DIRDIFF_45RIGHT);
+		v->cur_speed >>= 1;
+
+		SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos);
+		return false;
+	}
+
+	if (!(amd->flag & AMED_NOSPDCLAMP) && v->cur_speed > 12) v->cur_speed = 12;
+
+	if (!UpdateAircraftSpeed(v)) return false;
+
+	if (v->load_unload_time_rem != 0) v->load_unload_time_rem--;
+
+	// Turn. Do it slowly if in the air.
+	newdir = GetDirectionTowards(v, x + amd->x, y + amd->y);
+	if (newdir != v->direction) {
+		if (amd->flag & AMED_SLOWTURN) {
+			if (v->load_unload_time_rem == 0) v->load_unload_time_rem = 8;
+			v->direction = newdir;
+		} else {
+			v->cur_speed >>= 1;
+			v->direction = newdir;
+		}
+	}
+
+	// Move vehicle.
+	GetNewVehiclePos(v, &gp);
+	v->tile = gp.new_tile;
+
+	// If vehicle is in the air, use tile coordinate 0.
+	if (amd->flag & (AMED_TAKEOFF | AMED_SLOWTURN | AMED_LAND)) v->tile = 0;
+
+	// Adjust Z for land or takeoff?
+	z = v->z_pos;
+
+	if (amd->flag & AMED_TAKEOFF) {
+		z += 2;
+		maxz = GetAircraftFlyingAltitude(v);
+		if (z > maxz) z = maxz;
+	}
+
+	if (amd->flag & AMED_LAND) {
+		if (st->airport_tile == 0) {
+			v->u.air.state = FLYING;
+			AircraftNextAirportPos_and_Order(v);
+			// get aircraft back on running altitude
+			SetAircraftPosition(v, gp.x, gp.y, GetAircraftFlyingAltitude(v));
+			return false;
+		}
+
+		curz = GetSlopeZ(x, y) + 1;
+
+		if (curz > z) {
+			z++;
+		} else {
+			int t = max(1, dist - 4);
+
+			z -= ((z - curz) + t - 1) / t;
+			if (z < curz) z = curz;
+		}
+	}
+
+	// We've landed. Decrase speed when we're reaching end of runway.
+	if (amd->flag & AMED_BRAKE) {
+		curz = GetSlopeZ(x, y) + 1;
+
+		if (z > curz) {
+			z--;
+		} else if (z < curz) {
+			z++;
+		}
+
+		if (dist < 64 && v->cur_speed > 12) v->cur_speed -= 4;
+	}
+
+	SetAircraftPosition(v, gp.x, gp.y, z);
+	return false;
+}
+
+
+static void HandleCrashedAircraft(Vehicle *v)
+{
+	uint32 r;
+	Station *st;
+	int z;
+
+	v->u.air.crashed_counter++;
+
+	st = GetStation(v->u.air.targetairport);
+
+	// make aircraft crash down to the ground
+	if (v->u.air.crashed_counter < 500 && st->airport_tile==0 && ((v->u.air.crashed_counter % 3) == 0) ) {
+		z = GetSlopeZ(v->x_pos, v->y_pos);
+		v->z_pos -= 1;
+		if (v->z_pos == z) {
+			v->u.air.crashed_counter = 500;
+			v->z_pos++;
+		}
+	}
+
+	if (v->u.air.crashed_counter < 650) {
+		if (CHANCE16R(1,32,r)) {
+			static const DirDiff delta[] = {
+				DIRDIFF_45LEFT, DIRDIFF_SAME, DIRDIFF_SAME, DIRDIFF_45RIGHT
+			};
+
+			v->direction = ChangeDir(v->direction, delta[GB(r, 16, 2)]);
+			SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos);
+			r = Random();
+			CreateEffectVehicleRel(v,
+				GB(r, 0, 4) + 4,
+				GB(r, 4, 4) + 4,
+				GB(r, 8, 4),
+				EV_EXPLOSION_SMALL);
+		}
+	} else if (v->u.air.crashed_counter >= 10000) {
+		// remove rubble of crashed airplane
+
+		// clear runway-in on all airports, set by crashing plane
+		// small airports use AIRPORT_BUSY, city airports use RUNWAY_IN_OUT_block, etc.
+		// but they all share the same number
+		CLRBITS(st->airport_flags, RUNWAY_IN_block);
+		CLRBITS(st->airport_flags, RUNWAY_IN_OUT_block); // commuter airport
+		CLRBITS(st->airport_flags, RUNWAY_IN2_block); // intercontinental
+
+		BeginVehicleMove(v);
+		EndVehicleMove(v);
+
+		DoDeleteAircraft(v);
+	}
+}
+
+static void HandleBrokenAircraft(Vehicle *v)
+{
+	if (v->breakdown_ctr != 1) {
+		v->breakdown_ctr = 1;
+		v->vehstatus |= VS_AIRCRAFT_BROKEN;
+
+		if (v->breakdowns_since_last_service != 255)
+			v->breakdowns_since_last_service++;
+		InvalidateWindow(WC_VEHICLE_VIEW, v->index);
+		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+	}
+}
+
+
+static void HandleAircraftSmoke(Vehicle *v)
+{
+	static const struct {
+		int8 x;
+		int8 y;
+	} smoke_pos[] = {
+		{  5,  5 },
+		{  6,  0 },
+		{  5, -5 },
+		{  0, -6 },
+		{ -5, -5 },
+		{ -6,  0 },
+		{ -5,  5 },
+		{  0,  6 }
+	};
+
+	if (!(v->vehstatus & VS_AIRCRAFT_BROKEN)) return;
+
+	if (v->cur_speed < 10) {
+		v->vehstatus &= ~VS_AIRCRAFT_BROKEN;
+		v->breakdown_ctr = 0;
+		return;
+	}
+
+	if ((v->tick_counter & 0x1F) == 0) {
+		CreateEffectVehicleRel(v,
+			smoke_pos[v->direction].x,
+			smoke_pos[v->direction].y,
+			2,
+			EV_SMOKE
+		);
+	}
+}
+
+static void ProcessAircraftOrder(Vehicle *v)
+{
+	const Order *order;
+
+	switch (v->current_order.type) {
+		case OT_GOTO_DEPOT:
+			if (!(v->current_order.flags & OF_PART_OF_ORDERS)) return;
+			if (v->current_order.flags & OF_SERVICE_IF_NEEDED &&
+					!VehicleNeedsService(v)) {
+				v->cur_order_index++;
+			}
+			break;
+
+		case OT_LOADING: return;
+
+		default: break;
+	}
+
+	if (v->cur_order_index >= v->num_orders) v->cur_order_index = 0;
+
+	order = GetVehicleOrder(v, v->cur_order_index);
+
+	if (order == NULL) {
+		v->current_order.type = OT_NOTHING;
+		v->current_order.flags = 0;
+		return;
+	}
+
+	if (order->type == OT_DUMMY && !CheckForValidOrders(v)) CrashAirplane(v);
+
+	if (order->type  == v->current_order.type  &&
+			order->flags == v->current_order.flags &&
+			order->dest  == v->current_order.dest)
+		return;
+
+	v->current_order = *order;
+
+	// orders are changed in flight, ensure going to the right station
+	if (order->type == OT_GOTO_STATION && v->u.air.state == FLYING) {
+		AircraftNextAirportPos_and_Order(v);
+		v->u.air.targetairport = order->dest;
+	}
+
+	InvalidateVehicleOrder(v);
+
+	InvalidateWindowClasses(WC_AIRCRAFT_LIST);
+}
+
+/** Mark all views dirty for an aircraft.
+ * @param v vehicle to be redrawn.
+ */
+static void MarkAircraftDirty(Vehicle *v)
+{
+		v->cur_image = GetAircraftImage(v, v->direction);
+		if (v->subtype == 0) {
+			v->next->next->cur_image = GetRotorImage(v);
+		}
+		MarkAllViewportsDirty(v->left_coord, v->top_coord, v->right_coord + 1, v->bottom_coord + 1);
+}
+
+static void HandleAircraftLoading(Vehicle *v, int mode)
+{
+	if (v->current_order.type == OT_NOTHING) return;
+
+	if (v->current_order.type != OT_DUMMY) {
+		if (v->current_order.type != OT_LOADING) return;
+		if (mode != 0) return;
+		if (--v->load_unload_time_rem != 0) return;
+
+		if (CanFillVehicle(v) && (v->current_order.flags & OF_FULL_LOAD ||
+				(_patches.gradual_loading && !HASBIT(v->load_status, LS_LOADING_FINISHED)))) {
+			SET_EXPENSES_TYPE(EXPENSES_AIRCRAFT_INC);
+			if (LoadUnloadVehicle(v, false)) {
+				InvalidateWindow(WC_AIRCRAFT_LIST, v->owner);
+				MarkAircraftDirty(v);
+			}
+			return;
+		}
+
+		{
+			Order b = v->current_order;
+			v->current_order.type = OT_NOTHING;
+			v->current_order.flags = 0;
+			MarkAircraftDirty(v);
+			if (!(b.flags & OF_NON_STOP)) return;
+		}
+	}
+	v->cur_order_index++;
+	InvalidateVehicleOrder(v);
+}
+
+static void CrashAirplane(Vehicle *v)
+{
+	uint16 amt;
+	Station *st;
+	StringID newsitem;
+
+	v->vehstatus |= VS_CRASHED;
+	v->u.air.crashed_counter = 0;
+
+	CreateEffectVehicleRel(v, 4, 4, 8, EV_EXPLOSION_LARGE);
+
+	InvalidateWindow(WC_VEHICLE_VIEW, v->index);
+
+	amt = 2;
+	if (v->cargo_type == CT_PASSENGERS) amt += v->cargo_count;
+	SetDParam(0, amt);
+
+	v->cargo_count = 0;
+	v->next->cargo_count = 0,
+	st = GetStation(v->u.air.targetairport);
+	if (st->airport_tile == 0) {
+		newsitem = STR_PLANE_CRASH_OUT_OF_FUEL;
+	} else {
+		SetDParam(1, st->index);
+		newsitem = STR_A034_PLANE_CRASH_DIE_IN_FIREBALL;
+	}
+
+	SetDParam(1, st->index);
+	AddNewsItem(newsitem,
+		NEWS_FLAGS(NM_THIN, NF_VIEWPORT|NF_VEHICLE, NT_ACCIDENT, 0),
+		v->index,
+		0);
+
+	SndPlayVehicleFx(SND_12_EXPLOSION, v);
+}
+
+static void MaybeCrashAirplane(Vehicle *v)
+{
+	Station *st;
+	uint16 prob;
+	uint i;
+
+	st = GetStation(v->u.air.targetairport);
+
+	//FIXME -- MaybeCrashAirplane -> increase crashing chances of very modern airplanes on smaller than AT_METROPOLITAN airports
+	prob = 0x10000 / 1500;
+	if (((st->airport_type == AT_SMALL) || (st->airport_type == AT_COMMUTER)) && (AircraftVehInfo(v->engine_type)->subtype & AIR_FAST) && !_cheats.no_jetcrash.value) {
+		prob = 0x10000 / 20;
+	}
+
+	if (GB(Random(), 0, 16) > prob) return;
+
+	// Crash the airplane. Remove all goods stored at the station.
+	for (i = 0; i != NUM_CARGO; i++) {
+		st->goods[i].rating = 1;
+		SB(st->goods[i].waiting_acceptance, 0, 12, 0);
+	}
+
+	CrashAirplane(v);
+}
+
+// we've landed and just arrived at a terminal
+static void AircraftEntersTerminal(Vehicle *v)
+{
+	Station *st;
+	Order old_order;
+
+	if (v->current_order.type == OT_GOTO_DEPOT) return;
+
+	st = GetStation(v->u.air.targetairport);
+	v->last_station_visited = v->u.air.targetairport;
+
+	/* Check if station was ever visited before */
+	if (!(st->had_vehicle_of_type & HVOT_AIRCRAFT)) {
+		uint32 flags;
+
+		st->had_vehicle_of_type |= HVOT_AIRCRAFT;
+		SetDParam(0, st->index);
+		// show newsitem of celebrating citizens
+		flags = (v->owner == _local_player) ? NEWS_FLAGS(NM_THIN, NF_VIEWPORT|NF_VEHICLE, NT_ARRIVAL_PLAYER, 0) : NEWS_FLAGS(NM_THIN, NF_VIEWPORT|NF_VEHICLE, NT_ARRIVAL_OTHER, 0);
+		AddNewsItem(
+			STR_A033_CITIZENS_CELEBRATE_FIRST,
+			flags,
+			v->index,
+			0);
+	}
+
+	old_order = v->current_order;
+	v->current_order.type = OT_LOADING;
+	v->current_order.flags = 0;
+
+	if (old_order.type == OT_GOTO_STATION &&
+			v->current_order.dest == v->last_station_visited) {
+		v->current_order.flags =
+			(old_order.flags & (OF_FULL_LOAD | OF_UNLOAD | OF_TRANSFER)) | OF_NON_STOP;
+	}
+
+	SET_EXPENSES_TYPE(EXPENSES_AIRCRAFT_INC);
+	LoadUnloadVehicle(v, true);
+	MarkAircraftDirty(v);
+	InvalidateWindowWidget(WC_VEHICLE_VIEW, v->index, STATUS_BAR);
+	InvalidateWindowClasses(WC_AIRCRAFT_LIST);
+}
+
+static void AircraftLand(Vehicle *v)
+{
+	v->sprite_width = v->sprite_height = 2;
+}
+
+static void AircraftLandAirplane(Vehicle *v)
+{
+	AircraftLand(v);
+	if (!PlayVehicleSound(v, VSE_TOUCHDOWN)) {
+		SndPlayVehicleFx(SND_17_SKID_PLANE, v);
+	}
+	MaybeCrashAirplane(v);
+}
+
+// set the right pos when heading to other airports after takeoff
+static void AircraftNextAirportPos_and_Order(Vehicle *v)
+{
+	const Station* st;
+	const AirportFTAClass *apc;
+
+	if (v->current_order.type == OT_GOTO_STATION ||
+			v->current_order.type == OT_GOTO_DEPOT)
+		v->u.air.targetairport = v->current_order.dest;
+
+	st = GetStation(v->u.air.targetairport);
+	apc = GetAirport(st->airport_type);
+	v->u.air.pos = v->u.air.previous_pos = apc->entry_point;
+}
+
+static void AircraftLeaveHangar(Vehicle *v)
+{
+	v->cur_speed = 0;
+	v->subspeed = 0;
+	v->progress = 0;
+	v->direction = 3;
+	v->vehstatus &= ~VS_HIDDEN;
+	{
+		Vehicle *u = v->next;
+		u->vehstatus &= ~VS_HIDDEN;
+
+		// Rotor blades
+		u = u->next;
+		if (u != NULL) {
+			u->vehstatus &= ~VS_HIDDEN;
+			u->cur_speed = 80;
+		}
+	}
+
+	VehicleServiceInDepot(v);
+	SetAircraftPosition(v, v->x_pos, v->y_pos, v->z_pos);
+	InvalidateWindowData(WC_VEHICLE_DEPOT, v->tile);
+	InvalidateWindowClasses(WC_AIRCRAFT_LIST);
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+///////////////////   AIRCRAFT MOVEMENT SCHEME  ////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+static void AircraftEventHandler_EnterTerminal(Vehicle *v, const AirportFTAClass *apc)
+{
+	AircraftEntersTerminal(v);
+	v->u.air.state = apc->layout[v->u.air.pos].heading;
+}
+
+static void AircraftEventHandler_EnterHangar(Vehicle *v, const AirportFTAClass *apc)
+{
+	VehicleEnterDepot(v);
+	v->u.air.state = apc->layout[v->u.air.pos].heading;
+}
+
+// In an Airport Hangar
+static void AircraftEventHandler_InHangar(Vehicle *v, const AirportFTAClass *apc)
+{
+	// if we just arrived, execute EnterHangar first
+	if (v->u.air.previous_pos != v->u.air.pos) {
+		AircraftEventHandler_EnterHangar(v, apc);
+		return;
+	}
+
+	// if we were sent to the depot, stay there
+	if (v->current_order.type == OT_GOTO_DEPOT && (v->vehstatus & VS_STOPPED)) {
+		v->current_order.type = OT_NOTHING;
+		v->current_order.flags = 0;
+		return;
+	}
+
+	if (v->current_order.type != OT_GOTO_STATION &&
+			v->current_order.type != OT_GOTO_DEPOT)
+		return;
+
+	// if the block of the next position is busy, stay put
+	if (AirportHasBlock(v, &apc->layout[v->u.air.pos], apc)) return;
+
+	// We are already at the target airport, we need to find a terminal
+	if (v->current_order.dest == v->u.air.targetairport) {
+		// FindFreeTerminal:
+		// 1. Find a free terminal, 2. Occupy it, 3. Set the vehicle's state to that terminal
+		if (v->subtype != 0) {
+			if (!AirportFindFreeTerminal(v, apc)) return; // airplane
+		} else {
+			if (!AirportFindFreeHelipad(v, apc)) return; // helicopter
+		}
+	} else { // Else prepare for launch.
+		// airplane goto state takeoff, helicopter to helitakeoff
+		v->u.air.state = (v->subtype != 0) ? TAKEOFF : HELITAKEOFF;
+	}
+	AircraftLeaveHangar(v);
+	AirportMove(v, apc);
+}
+
+// At one of the Airport's Terminals
+static void AircraftEventHandler_AtTerminal(Vehicle *v, const AirportFTAClass *apc)
+{
+	// if we just arrived, execute EnterTerminal first
+	if (v->u.air.previous_pos != v->u.air.pos) {
+		AircraftEventHandler_EnterTerminal(v, apc);
+		// on an airport with helipads, a helicopter will always land there
+		// and get serviced at the same time - patch setting
+		if (_patches.serviceathelipad) {
+			if (v->subtype == 0 && apc->helipads != NULL) {
+				// an exerpt of ServiceAircraft, without the invisibility stuff
+				v->date_of_last_service = _date;
+				v->breakdowns_since_last_service = 0;
+				v->reliability = GetEngine(v->engine_type)->reliability;
+				InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
+			}
+		}
+		return;
+	}
+
+	if (v->current_order.type == OT_NOTHING) return;
+
+	// if the block of the next position is busy, stay put
+	if (AirportHasBlock(v, &apc->layout[v->u.air.pos], apc)) return;
+
+	// airport-road is free. We either have to go to another airport, or to the hangar
+	// ---> start moving
+
+	switch (v->current_order.type) {
+		case OT_GOTO_STATION: // ready to fly to another airport
+			// airplane goto state takeoff, helicopter to helitakeoff
+			v->u.air.state = (v->subtype != 0) ? TAKEOFF : HELITAKEOFF;
+			break;
+		case OT_GOTO_DEPOT:   // visit hangar for serivicing, sale, etc.
+			if (v->current_order.dest == v->u.air.targetairport) {
+				v->u.air.state = HANGAR;
+			} else {
+				v->u.air.state = (v->subtype != 0) ? TAKEOFF : HELITAKEOFF;
+			}
+			break;
+		default:  // orders have been deleted (no orders), goto depot and don't bother us
+			v->current_order.type = OT_NOTHING;
+			v->current_order.flags = 0;
+			v->u.air.state = HANGAR;
+	}
+	AirportMove(v, apc);
+}
+
+static void AircraftEventHandler_General(Vehicle *v, const AirportFTAClass *apc)
+{
+	assert("OK, you shouldn't be here, check your Airport Scheme!" && 0);
+}
+
+static void AircraftEventHandler_TakeOff(Vehicle *v, const AirportFTAClass *apc) {
+	PlayAircraftSound(v); // play takeoffsound for airplanes
+	v->u.air.state = STARTTAKEOFF;
+}
+
+static void AircraftEventHandler_StartTakeOff(Vehicle *v, const AirportFTAClass *apc)
+{
+	v->sprite_width = v->sprite_height = 24; // ??? no idea what this is
+	v->u.air.state = ENDTAKEOFF;
+}
+
+static void AircraftEventHandler_EndTakeOff(Vehicle *v, const AirportFTAClass *apc)
+{
+	v->u.air.state = FLYING;
+	// get the next position to go to, differs per airport
+	AircraftNextAirportPos_and_Order(v);
+}
+
+static void AircraftEventHandler_HeliTakeOff(Vehicle *v, const AirportFTAClass *apc)
+{
+	const Player* p = GetPlayer(v->owner);
+	v->sprite_width = v->sprite_height = 24; // ??? no idea what this is
+	v->u.air.state = FLYING;
+	// get the next position to go to, differs per airport
+	AircraftNextAirportPos_and_Order(v);
+
+	// check if the aircraft needs to be replaced or renewed and send it to a hangar if needed
+	// unless it is due for renewal but the engine is no longer available
+	if (v->owner == _local_player && (
+				EngineHasReplacementForPlayer(p, v->engine_type) ||
+				((p->engine_renew && v->age - v->max_age > p->engine_renew_months * 30) &&
+				HASBIT(GetEngine(v->engine_type)->player_avail, _local_player))
+			)) {
+		_current_player = _local_player;
+		DoCommandP(v->tile, v->index, DEPOT_SERVICE | DEPOT_LOCATE_HANGAR, NULL, CMD_SEND_AIRCRAFT_TO_HANGAR | CMD_SHOW_NO_ERROR);
+		_current_player = OWNER_NONE;
+	}
+}
+
+static void AircraftEventHandler_Flying(Vehicle *v, const AirportFTAClass *apc)
+{
+	Station *st;
+	byte landingtype;
+	AirportFTA *current;
+	uint16 tcur_speed, tsubspeed;
+
+	st = GetStation(v->u.air.targetairport);
+	// flying device is accepted at this station
+	// small airport --> no helicopters (AIRCRAFT_ONLY)
+	// all other airports --> all types of flying devices (ALL)
+	// heliport/oilrig, etc --> no airplanes (HELICOPTERS_ONLY)
+	// runway busy or not allowed to use this airstation, circle
+	if (v->subtype != apc->acc_planes &&
+			st->airport_tile != 0 &&
+			(st->owner == OWNER_NONE || st->owner == v->owner)) {
+		// {32,FLYING,NOTHING_block,37}, {32,LANDING,N,33}, {32,HELILANDING,N,41},
+		// if it is an airplane, look for LANDING, for helicopter HELILANDING
+		// it is possible to choose from multiple landing runways, so loop until a free one is found
+		landingtype = (v->subtype != 0) ? LANDING : HELILANDING;
+		current = apc->layout[v->u.air.pos].next;
+		while (current != NULL) {
+			if (current->heading == landingtype) {
+				// save speed before, since if AirportHasBlock is false, it resets them to 0
+				// we don't want that for plane in air
+				// hack for speed thingie
+				tcur_speed = v->cur_speed;
+				tsubspeed = v->subspeed;
+				if (!AirportHasBlock(v, current, apc)) {
+					v->u.air.state = landingtype; // LANDING / HELILANDING
+					// it's a bit dirty, but I need to set position to next position, otherwise
+					// if there are multiple runways, plane won't know which one it took (because
+					// they all have heading LANDING). And also occupy that block!
+					v->u.air.pos = current->next_position;
+					SETBITS(st->airport_flags, apc->layout[v->u.air.pos].block);
+					return;
+				}
+				v->cur_speed = tcur_speed;
+				v->subspeed = tsubspeed;
+			}
+			current = current->next;
+		}
+	}
+	v->u.air.state = FLYING;
+	v->u.air.pos = apc->layout[v->u.air.pos].next_position;
+}
+
+static void AircraftEventHandler_Landing(Vehicle *v, const AirportFTAClass *apc)
+{
+	const Player* p = GetPlayer(v->owner);
+	AircraftLandAirplane(v);  // maybe crash airplane
+	v->u.air.state = ENDLANDING;
+	// check if the aircraft needs to be replaced or renewed and send it to a hangar if needed
+	if (v->current_order.type != OT_GOTO_DEPOT && v->owner == _local_player) {
+		// only the vehicle owner needs to calculate the rest (locally)
+		if (EngineHasReplacementForPlayer(p, v->engine_type) ||
+			(p->engine_renew && v->age - v->max_age > (p->engine_renew_months * 30))) {
+			// send the aircraft to the hangar at next airport
+			_current_player = _local_player;
+			DoCommandP(v->tile, v->index, DEPOT_SERVICE, NULL, CMD_SEND_AIRCRAFT_TO_HANGAR | CMD_SHOW_NO_ERROR);
+			_current_player = OWNER_NONE;
+		}
+	}
+}
+
+static void AircraftEventHandler_HeliLanding(Vehicle *v, const AirportFTAClass *apc)
+{
+	AircraftLand(v); // helicopters don't crash
+	v->u.air.state = HELIENDLANDING;
+}
+
+static void AircraftEventHandler_EndLanding(Vehicle *v, const AirportFTAClass *apc)
+{
+	// next block busy, don't do a thing, just wait
+	if (AirportHasBlock(v, &apc->layout[v->u.air.pos], apc)) return;
+
+	// if going to terminal (OT_GOTO_STATION) choose one
+	// 1. in case all terminals are busy AirportFindFreeTerminal() returns false or
+	// 2. not going for terminal (but depot, no order),
+	// --> get out of the way to the hangar.
+	if (v->current_order.type == OT_GOTO_STATION) {
+		if (AirportFindFreeTerminal(v, apc)) return;
+	}
+	v->u.air.state = HANGAR;
+
+}
+
+static void AircraftEventHandler_HeliEndLanding(Vehicle *v, const AirportFTAClass *apc)
+{
+	// next block busy, don't do a thing, just wait
+	if (AirportHasBlock(v, &apc->layout[v->u.air.pos], apc)) return;
+
+	// if going to helipad (OT_GOTO_STATION) choose one. If airport doesn't have helipads, choose terminal
+	// 1. in case all terminals/helipads are busy (AirportFindFreeHelipad() returns false) or
+	// 2. not going for terminal (but depot, no order),
+	// --> get out of the way to the hangar IF there are terminals on the airport.
+	// --> else TAKEOFF
+	// the reason behind this is that if an airport has a terminal, it also has a hangar. Airplanes
+	// must go to a hangar.
+	if (v->current_order.type == OT_GOTO_STATION) {
+		if (AirportFindFreeHelipad(v, apc)) return;
+	}
+	v->u.air.state = (apc->nof_depots != 0) ? HANGAR : HELITAKEOFF;
+}
+
+typedef void AircraftStateHandler(Vehicle *v, const AirportFTAClass *apc);
+static AircraftStateHandler * const _aircraft_state_handlers[] = {
+	AircraftEventHandler_General,        // TO_ALL         =  0
+	AircraftEventHandler_InHangar,       // HANGAR         =  1
+	AircraftEventHandler_AtTerminal,     // TERM1          =  2
+	AircraftEventHandler_AtTerminal,     // TERM2          =  3
+	AircraftEventHandler_AtTerminal,     // TERM3          =  4
+	AircraftEventHandler_AtTerminal,     // TERM4          =  5
+	AircraftEventHandler_AtTerminal,     // TERM5          =  6
+	AircraftEventHandler_AtTerminal,     // TERM6          =  7
+	AircraftEventHandler_AtTerminal,     // HELIPAD1       =  8
+	AircraftEventHandler_AtTerminal,     // HELIPAD2       =  9
+	AircraftEventHandler_TakeOff,        // TAKEOFF        = 10
+	AircraftEventHandler_StartTakeOff,   // STARTTAKEOFF   = 11
+	AircraftEventHandler_EndTakeOff,     // ENDTAKEOFF     = 12
+	AircraftEventHandler_HeliTakeOff,    // HELITAKEOFF    = 13
+	AircraftEventHandler_Flying,         // FLYING         = 14
+	AircraftEventHandler_Landing,        // LANDING        = 15
+	AircraftEventHandler_EndLanding,     // ENDLANDING     = 16
+	AircraftEventHandler_HeliLanding,    // HELILANDING    = 17
+	AircraftEventHandler_HeliEndLanding, // HELIENDLANDING = 18
+	AircraftEventHandler_AtTerminal,     // TERM7          = 19
+	AircraftEventHandler_AtTerminal,     // TERM8          = 20
+	AircraftEventHandler_AtTerminal,     // HELIPAD3       = 21
+	AircraftEventHandler_AtTerminal,     // HELIPAD4       = 22
+};
+
+static void AirportClearBlock(const Vehicle *v, const AirportFTAClass *apc)
+{
+	// we have left the previous block, and entered the new one. Free the previous block
+	if (apc->layout[v->u.air.previous_pos].block != apc->layout[v->u.air.pos].block) {
+		Station *st = GetStation(v->u.air.targetairport);
+
+		CLRBITS(st->airport_flags, apc->layout[v->u.air.previous_pos].block);
+	}
+}
+
+static void AirportGoToNextPosition(Vehicle *v, const AirportFTAClass *apc)
+{
+	// if aircraft is not in position, wait until it is
+	if (!AircraftController(v)) return;
+
+	AirportClearBlock(v, apc);
+	AirportMove(v, apc); // move aircraft to next position
+}
+
+// gets pos from vehicle and next orders
+static bool AirportMove(Vehicle *v, const AirportFTAClass *apc)
+{
+	AirportFTA *current;
+	byte prev_pos;
+
+	// error handling
+	if (v->u.air.pos >= apc->nofelements) {
+		DEBUG(misc, 0, "[Ap] position %d is not valid for current airport. Max position is %d", v->u.air.pos, apc->nofelements-1);
+		assert(v->u.air.pos < apc->nofelements);
+	}
+
+	current = &apc->layout[v->u.air.pos];
+	// we have arrived in an important state (eg terminal, hangar, etc.)
+	if (current->heading == v->u.air.state) {
+		prev_pos = v->u.air.pos; // location could be changed in state, so save it before-hand
+		_aircraft_state_handlers[v->u.air.state](v, apc);
+		if (v->u.air.state != FLYING) v->u.air.previous_pos = prev_pos;
+		return true;
+	}
+
+	v->u.air.previous_pos = v->u.air.pos; // save previous location
+
+	// there is only one choice to move to
+	if (current->next == NULL) {
+		if (AirportSetBlocks(v, current, apc)) {
+			v->u.air.pos = current->next_position;
+		} // move to next position
+		return false;
+	}
+
+	// there are more choices to choose from, choose the one that
+	// matches our heading
+	do {
+		if (v->u.air.state == current->heading || current->heading == TO_ALL) {
+			if (AirportSetBlocks(v, current, apc)) {
+				v->u.air.pos = current->next_position;
+			} // move to next position
+			return false;
+		}
+		current = current->next;
+	} while (current != NULL);
+
+	DEBUG(misc, 0, "[Ap] cannot move further on Airport! (pos %d state %d)", v->u.air.pos, v->u.air.state);
+	DEBUG(misc, 0, "[Ap] airport entry point: %d, Vehicle: %d", apc->entry_point, v->index);
+	assert(0);
+	return false;
+}
+
+// returns true if the road ahead is busy, eg. you must wait before proceeding
+static bool AirportHasBlock(Vehicle *v, const AirportFTA *current_pos, const AirportFTAClass *apc)
+{
+	const AirportFTA *reference = &apc->layout[v->u.air.pos];
+	const AirportFTA *next = &apc->layout[current_pos->next_position];
+
+	// same block, then of course we can move
+	if (apc->layout[current_pos->position].block != next->block) {
+		const Station *st = GetStation(v->u.air.targetairport);
+		uint32 airport_flags = next->block;
+
+		// check additional possible extra blocks
+		if (current_pos != reference && current_pos->block != NOTHING_block) {
+			airport_flags |= current_pos->block;
+		}
+
+		if (HASBITS(st->airport_flags, airport_flags)) {
+			v->cur_speed = 0;
+			v->subspeed = 0;
+			return true;
+		}
+	}
+	return false;
+}
+
+// returns true on success. Eg, next block was free and we have occupied it
+static bool AirportSetBlocks(Vehicle *v, AirportFTA *current_pos, const AirportFTAClass *apc)
+{
+	AirportFTA *next = &apc->layout[current_pos->next_position];
+	AirportFTA *reference = &apc->layout[v->u.air.pos];
+
+	// if the next position is in another block, check it and wait until it is free
+	if ((apc->layout[current_pos->position].block & next->block) != next->block) {
+		uint32 airport_flags = next->block;
+		Station* st = GetStation(v->u.air.targetairport);
+		//search for all all elements in the list with the same state, and blocks != N
+		// this means more blocks should be checked/set
+			AirportFTA *current = current_pos;
+		if (current == reference) current = current->next;
+		while (current != NULL) {
+			if (current->heading == current_pos->heading && current->block != 0) {
+				airport_flags |= current->block;
+				break;
+			}
+			current = current->next;
+		};
+
+		// if the block to be checked is in the next position, then exclude that from
+		// checking, because it has been set by the airplane before
+		if (current_pos->block == next->block) airport_flags ^= next->block;
+
+		if (HASBITS(st->airport_flags, airport_flags)) {
+			v->cur_speed = 0;
+			v->subspeed = 0;
+			return false;
+		}
+
+		if (next->block != NOTHING_block) {
+			SETBITS(st->airport_flags, airport_flags); // occupy next block
+		}
+	}
+	return true;
+}
+
+static bool FreeTerminal(Vehicle *v, byte i, byte last_terminal)
+{
+	Station *st = GetStation(v->u.air.targetairport);
+	for (; i < last_terminal; i++) {
+		if (!HASBIT(st->airport_flags, _airport_terminal_flag[i])) {
+			// TERMINAL# HELIPAD#
+			v->u.air.state = _airport_terminal_state[i]; // start moving to that terminal/helipad
+			SETBIT(st->airport_flags, _airport_terminal_flag[i]); // occupy terminal/helipad
+			return true;
+		}
+	}
+	return false;
+}
+
+static uint GetNumTerminals(const AirportFTAClass *apc)
+{
+	uint num = 0;
+	uint i;
+
+	for (i = apc->terminals[0]; i > 0; i--) num += apc->terminals[i];
+
+	return num;
+}
+
+static bool AirportFindFreeTerminal(Vehicle *v, const AirportFTAClass *apc)
+{
+	/* example of more terminalgroups
+	 * {0,HANGAR,NOTHING_block,1}, {0,255,TERM_GROUP1_block,0}, {0,255,TERM_GROUP2_ENTER_block,1}, {0,0,N,1},
+	 * Heading 255 denotes a group. We see 2 groups here:
+	 * 1. group 0 -- TERM_GROUP1_block (check block)
+	 * 2. group 1 -- TERM_GROUP2_ENTER_block (check block)
+	 * First in line is checked first, group 0. If the block (TERM_GROUP1_block) is free, it
+	 * looks at the corresponding terminals of that group. If no free ones are found, other
+	 * possible groups are checked (in this case group 1, since that is after group 0). If that
+	 * fails, then attempt fails and plane waits
+	 */
+	if (apc->terminals[0] > 1) {
+		Station *st = GetStation(v->u.air.targetairport);
+		AirportFTA *temp = apc->layout[v->u.air.pos].next;
+
+		while (temp != NULL) {
+			if (temp->heading == 255) {
+				if (!HASBITS(st->airport_flags, temp->block)) {
+					int target_group;
+					int i;
+					int group_start = 0;
+					int group_end;
+
+					//read which group do we want to go to?
+					//(the first free group)
+					target_group = temp->next_position + 1;
+
+					//at what terminal does the group start?
+					//that means, sum up all terminals of
+					//groups with lower number
+					for (i = 1; i < target_group; i++)
+						group_start += apc->terminals[i];
+
+					group_end = group_start + apc->terminals[target_group];
+					if (FreeTerminal(v, group_start, group_end)) return true;
+				}
+			} else {
+				/* once the heading isn't 255, we've exhausted the possible blocks.
+				 * So we cannot move */
+				return false;
+			}
+			temp = temp->next;
+		}
+	}
+
+	// if there is only 1 terminalgroup, all terminals are checked (starting from 0 to max)
+	return FreeTerminal(v, 0, GetNumTerminals(apc));
+}
+
+static uint GetNumHelipads(const AirportFTAClass *apc)
+{
+	uint num = 0;
+	uint i;
+
+	for (i = apc->helipads[0]; i > 0; i--) num += apc->helipads[i];
+
+	return num;
+}
+
+
+static bool AirportFindFreeHelipad(Vehicle *v, const AirportFTAClass *apc)
+{
+	// if an airport doesn't have helipads, use terminals
+	if (apc->helipads == NULL) return AirportFindFreeTerminal(v, apc);
+
+	// if there are more helicoptergroups, pick one, just as in AirportFindFreeTerminal()
+	if (apc->helipads[0] > 1) {
+		const Station* st = GetStation(v->u.air.targetairport);
+		const AirportFTA* temp = apc->layout[v->u.air.pos].next;
+
+		while (temp != NULL) {
+			if (temp->heading == 255) {
+				if (!HASBITS(st->airport_flags, temp->block)) {
+					int target_group;
+					int i;
+					int group_start = 0;
+					int group_end;
+
+					//read which group do we want to go to?
+					//(the first free group)
+					target_group = temp->next_position + 1;
+
+					//at what terminal does the group start?
+					//that means, sum up all terminals of
+					//groups with lower number
+					for (i = 1; i < target_group; i++)
+						group_start += apc->helipads[i];
+
+					group_end = group_start + apc->helipads[target_group];
+					if (FreeTerminal(v, group_start, group_end)) return true;
+				}
+			} else {
+				/* once the heading isn't 255, we've exhausted the possible blocks.
+				 * So we cannot move */
+				return false;
+			}
+			temp = temp->next;
+		}
+	} else {
+		// only 1 helicoptergroup, check all helipads
+		// The blocks for helipads start after the last terminal (MAX_TERMINALS)
+		return FreeTerminal(v, MAX_TERMINALS, GetNumHelipads(apc) + MAX_TERMINALS);
+	}
+	return false; // it shouldn't get here anytime, but just to be sure
+}
+
+static void AircraftEventHandler(Vehicle *v, int loop)
+{
+	v->tick_counter++;
+
+	if (v->vehstatus & VS_CRASHED) {
+		HandleCrashedAircraft(v);
+		return;
+	}
+
+	if (v->vehstatus & VS_STOPPED) return;
+
+	/* aircraft is broken down? */
+	if (v->breakdown_ctr != 0) {
+		if (v->breakdown_ctr <= 2) {
+			HandleBrokenAircraft(v);
+		} else {
+			v->breakdown_ctr--;
+		}
+	}
+
+	HandleAircraftSmoke(v);
+	ProcessAircraftOrder(v);
+	HandleAircraftLoading(v, loop);
+
+	if (v->current_order.type >= OT_LOADING) return;
+
+	// pass the right airport structure to the functions
+	// DEREF_STATION gets target airport (Station *st), its type is passed to GetAirport
+	// that returns the correct layout depending on type
+	AirportGoToNextPosition(v, GetAirport(GetStation(v->u.air.targetairport)->airport_type));
+}
+
+void Aircraft_Tick(Vehicle *v)
+{
+	int i;
+
+	if (v->subtype > 2) return;
+
+	if (v->subtype == 0) HelicopterTickHandler(v);
+
+	AgeAircraftCargo(v);
+
+	for (i = 0; i != 6; i++) {
+		AircraftEventHandler(v, i);
+		if (v->type != VEH_Aircraft) // In case it was deleted
+			break;
+	}
+}
+
+void UpdateOilRig(void)
+{
+	Station* st;
+
+	FOR_ALL_STATIONS(st) {
+		if (st->airport_type == 5) st->airport_type = AT_OILRIG;
+	}
+}
+
+// need to be called to load aircraft from old version
+void UpdateOldAircraft(void)
+{
+	Station *st;
+	Vehicle *v_oldstyle;
+	GetNewVehiclePosResult gp;
+
+	// set airport_flags to 0 for all airports just to be sure
+	FOR_ALL_STATIONS(st) {
+		st->airport_flags = 0; // reset airport
+		// type of oilrig has been moved, update it (3-5)
+		if (st->airport_type == 3) st->airport_type = AT_OILRIG;
+	}
+
+	FOR_ALL_VEHICLES(v_oldstyle) {
+	// airplane has another vehicle with subtype 4 (shadow), helicopter also has 3 (rotor)
+	// skip those
+		if (v_oldstyle->type == VEH_Aircraft && v_oldstyle->subtype <= 2) {
+			// airplane in terminal stopped doesn't hurt anyone, so goto next
+			if (v_oldstyle->vehstatus & VS_STOPPED && v_oldstyle->u.air.state == 0) {
+				v_oldstyle->u.air.state = HANGAR;
+				continue;
+			}
+
+			AircraftLeaveHangar(v_oldstyle); // make airplane visible if it was in a depot for example
+			v_oldstyle->vehstatus &= ~VS_STOPPED; // make airplane moving
+			v_oldstyle->u.air.state = FLYING;
+			AircraftNextAirportPos_and_Order(v_oldstyle); // move it to the entry point of the airport
+			GetNewVehiclePos(v_oldstyle, &gp); // get the position of the plane (to be used for setting)
+			v_oldstyle->tile = 0; // aircraft in air is tile=0
+
+			// correct speed of helicopter-rotors
+			if (v_oldstyle->subtype == 0) v_oldstyle->next->next->cur_speed = 32;
+
+			// set new position x,y,z
+			SetAircraftPosition(v_oldstyle, gp.x, gp.y, GetAircraftFlyingAltitude(v_oldstyle));
+		}
+	}
+}
+
+void UpdateAirplanesOnNewStation(Station *st)
+{
+	GetNewVehiclePosResult gp;
+	Vehicle *v;
+	byte takeofftype;
+	uint16 cnt;
+	// only 1 station is updated per function call, so it is enough to get entry_point once
+	const AirportFTAClass *ap = GetAirport(st->airport_type);
+	FOR_ALL_VEHICLES(v) {
+		if (v->type == VEH_Aircraft && v->subtype <= 2) {
+			if (v->u.air.targetairport == st->index) { // if heading to this airport
+				/* update position of airplane. If plane is not flying, landing, or taking off
+				 *you cannot delete airport, so it doesn't matter
+				 */
+				if (v->u.air.state >= FLYING) { // circle around
+					v->u.air.pos = v->u.air.previous_pos = ap->entry_point;
+					v->u.air.state = FLYING;
+					// landing plane needs to be reset to flying height (only if in pause mode upgrade,
+					// in normal mode, plane is reset in AircraftController. It doesn't hurt for FLYING
+					GetNewVehiclePos(v, &gp);
+					// set new position x,y,z
+					SetAircraftPosition(v, gp.x, gp.y, GetAircraftFlyingAltitude(v));
+				} else {
+					assert(v->u.air.state == ENDTAKEOFF || v->u.air.state == HELITAKEOFF);
+					takeofftype = (v->subtype == 0) ? HELITAKEOFF : ENDTAKEOFF;
+					// search in airportdata for that heading
+					// easiest to do, since this doesn't happen a lot
+					for (cnt = 0; cnt < ap->nofelements; cnt++) {
+						if (ap->layout[cnt].heading == takeofftype) {
+							v->u.air.pos = ap->layout[cnt].position;
+							break;
+						}
+					}
+				}
+			}
+		}
+	}
+}