--- a/aircraft_cmd.c	Sun Jan 30 18:40:52 2005 +0000
+++ b/aircraft_cmd.c	Sun Jan 30 18:51:08 2005 +0000
@@ -364,7 +364,7 @@
 
 	v = GetVehicle(p1);
 
-	if (!CheckOwnership(v->owner) || !CheckStoppedInHangar(v))
+	if (v->type != VEH_Aircraft || !CheckOwnership(v->owner) || !CheckStoppedInHangar(v))
 		return CMD_ERROR;
 
 	if (flags & DC_EXEC) {

--- a/ship_cmd.c	Sun Jan 30 18:40:52 2005 +0000
+++ b/ship_cmd.c	Sun Jan 30 18:51:08 2005 +0000
@@ -919,7 +919,7 @@
 
 	v = GetVehicle(p1);
 
-	if (!CheckOwnership(v->owner))
+	if (v->type != VEH_Ship || !CheckOwnership(v->owner))
 		return CMD_ERROR;
 
 	if (!IsShipDepotTile(v->tile) || v->u.road.state != 0x80 || !(v->vehstatus&VS_STOPPED))

--- a/train_cmd.c	Sun Jan 30 18:40:52 2005 +0000
+++ b/train_cmd.c	Sun Jan 30 18:51:08 2005 +0000
@@ -873,7 +873,7 @@
 
 	v = GetVehicle(p1);
 
-	if (v->type == 0 || !CheckOwnership(v->owner))
+	if (v->type != VEH_Train || !CheckOwnership(v->owner))
 		return CMD_ERROR;
 
 	// get first vehicle in chain