diff --git a/ogn/collect/logbook.py b/ogn/collect/logbook.py
index 84a8759..7ae6e0b 100644
--- a/ogn/collect/logbook.py
+++ b/ogn/collect/logbook.py
@@ -107,23 +107,24 @@ def compute_logbook_entries(session=None):
     upd = update(Logbook) \
         .where(and_(Logbook.device_id == complete_flights.c.device_id,
                     or_(and_(Logbook.takeoff_airport_id == complete_flights.c.takeoff_airport_id,
-                             Logbook.takeoff_timestamp == complete_flights.c.takeoff_timestamp),
-                        Logbook.takeoff_airport_id == null()),
-                    or_(and_(Logbook.landing_airport_id == complete_flights.c.landing_airport_id,
-                             Logbook.landing_timestamp == complete_flights.c.landing_timestamp),
-                        Logbook.landing_airport_id == null()))) \
+                             Logbook.takeoff_timestamp == complete_flights.c.takeoff_timestamp,
+                             Logbook.landing_airport_id == null()),
+                        and_(Logbook.takeoff_airport_id == null(),
+                             Logbook.landing_airport_id == complete_flights.c.landing_airport_id,
+                             Logbook.landing_timestamp == complete_flights.c.landing_timestamp)))) \
         .values({"takeoff_timestamp": complete_flights.c.takeoff_timestamp,
                  "takeoff_track": complete_flights.c.takeoff_track,
                  "takeoff_airport_id": complete_flights.c.takeoff_airport_id,
                  "landing_timestamp": complete_flights.c.landing_timestamp,
                  "landing_track": complete_flights.c.landing_track,
                  "landing_airport_id": complete_flights.c.landing_airport_id,
-                 "duration": complete_flights.c.duration})
+                 "duration": complete_flights.c.duration,
+                 "max_altitude": 1})
 
     result = session.execute(upd)
-    counter = result.rowcount
+    update_counter = result.rowcount
     session.commit()
-    logger.debug("Updated logbook entries: {}".format(counter))
+    logger.debug("Updated logbook entries: {}".format(update_counter))
 
     # unite all computated flights ('incomplete' and 'complete')
     union_query = complete_flight_query.union(
@@ -136,12 +137,13 @@ def compute_logbook_entries(session=None):
     # consider only if not already stored
     new_logbook_entries = session.query(union_query) \
         .filter(~exists().where(
-            and_(Logbook.reftime == union_query.c.reftime,
-                 Logbook.device_id == union_query.c.device_id,
-                 or_(Logbook.takeoff_airport_id == union_query.c.takeoff_airport_id,
+            and_(Logbook.device_id == union_query.c.device_id,
+                 or_(and_(Logbook.takeoff_airport_id == union_query.c.takeoff_airport_id,
+                          Logbook.takeoff_timestamp == union_query.c.takeoff_timestamp),
                      and_(Logbook.takeoff_airport_id == null(),
                           union_query.c.takeoff_airport_id == null())),
-                 or_(Logbook.landing_airport_id == union_query.c.landing_airport_id,
+                 or_(and_(Logbook.landing_airport_id == union_query.c.landing_airport_id,
+                          Logbook.landing_timestamp == union_query.c.landing_timestamp),
                      and_(Logbook.landing_airport_id == null(),
                           union_query.c.landing_airport_id == null())))))
 
@@ -158,8 +160,8 @@ def compute_logbook_entries(session=None):
                                       new_logbook_entries)
 
     result = session.execute(ins)
-    counter = result.rowcount
+    insert_counter = result.rowcount
     session.commit()
-    logger.debug("New logbook entries: {}".format(counter))
+    logger.debug("New logbook entries: {}".format(insert_counter))
 
-    return counter
+    return "{}/{}".format(update_counter, insert_counter)
diff --git a/tests/collect/test_logbook.py b/tests/collect/test_logbook.py
index 2b93a61..0795ce5 100644
--- a/tests/collect/test_logbook.py
+++ b/tests/collect/test_logbook.py
@@ -11,6 +11,11 @@ class TestDB(unittest.TestCase):
     engine = None
     app = None
 
+    TAKEOFF_KOENIGSDF_DD0815       = "INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'"
+    LANDING_KOENIGSDF_DD0815       = "INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:05:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'"
+    LANDING_KOENIGSDF_DD0815_LATER = "INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-02 10:05:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'"
+    TAKEOFF_OHLSTADT_DD4711        = "INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Ohlstadt' and d.address = 'DD4711'"
+
     def setUp(self):
         os.environ['OGN_CONFIG_MODULE'] = 'config.test'
         from ogn.commands.dbutils import engine, session
@@ -32,88 +37,89 @@ class TestDB(unittest.TestCase):
         session.commit()
         pass
 
-    def count_logbook_entries(self):
-        session = self.session
-        logbook_query = session.query(Logbook)
-        i = 0
-        for logbook in logbook_query.all():
-            i = i + 1
-            print("{} {} {} {} {} {}".format(logbook.id, logbook.device_id, logbook.takeoff_airport_id, logbook.takeoff_timestamp, logbook.landing_airport_id, logbook.landing_timestamp))
-
-        return i
-
     def test_single_takeoff(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+        session.execute(self.TAKEOFF_KOENIGSDF_DD0815)
         session.commit()
 
-        compute_logbook_entries(session)
-        self.assertEqual(self.count_logbook_entries(), 1)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/1')
 
     def test_single_landing(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+        session.execute(self.LANDING_KOENIGSDF_DD0815)
         session.commit()
 
-        compute_logbook_entries(session)
-        self.assertEqual(self.count_logbook_entries(), 1)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/1')
 
     def test_different_takeoffs(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Ohlstadt' and d.address = 'DD4711'")
+        session.execute(self.TAKEOFF_KOENIGSDF_DD0815)
+        session.execute(self.TAKEOFF_OHLSTADT_DD4711)
         session.commit()
 
-        compute_logbook_entries(session)
-        self.assertEqual(self.count_logbook_entries(), 2)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/2')
 
     def test_takeoff_and_landing(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:05:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+        session.execute(self.TAKEOFF_KOENIGSDF_DD0815)
+        session.execute(self.LANDING_KOENIGSDF_DD0815)
         session.commit()
 
-        compute_logbook_entries(session)
-        self.assertEqual(self.count_logbook_entries(), 1)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/1')
 
     def test_takeoff_and_landing_on_different_days(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-02 10:05:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+        session.execute(self.TAKEOFF_KOENIGSDF_DD0815)
+        session.execute(self.LANDING_KOENIGSDF_DD0815_LATER)
         session.commit()
 
-        compute_logbook_entries(session)
-        self.assertEqual(self.count_logbook_entries(), 2)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/2')
 
     def test_update(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+        session.execute(self.TAKEOFF_KOENIGSDF_DD0815)
         session.commit()
-        compute_logbook_entries(session)
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:05:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/1')
+
+        session.execute(self.LANDING_KOENIGSDF_DD0815)
         session.commit()
-        compute_logbook_entries(session)
 
-        self.assertEqual(self.count_logbook_entries(), 1)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '1/0')
+
+        session.execute(self.TAKEOFF_OHLSTADT_DD4711)
+        session.commit()
+
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/1')
 
-    @unittest.skip("Doesnt work... dont know why. Fix it!")
     def test_update_wrong_order(self):
         session = self.session
 
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:05:00', FALSE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
+        session.execute(self.LANDING_KOENIGSDF_DD0815)
         session.commit()
-        compute_logbook_entries(session)
-        session.execute("INSERT INTO takeoff_landing(device_id, airport_id, timestamp, is_takeoff) SELECT d.id, a.id, '2016-06-01 10:00:00', TRUE FROM airport a, device d WHERE a.name='Koenigsdorf' and d.address = 'DD0815'")
-        session.commit()
-        compute_logbook_entries(session)
 
-        self.assertEqual(self.count_logbook_entries(), 1)
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '0/1')
+
+        session.execute(self.TAKEOFF_KOENIGSDF_DD0815)
+        session.commit()
+
+        entries_changed = compute_logbook_entries(session)
+        self.assertEqual(entries_changed, '1/0')
 
 if __name__ == '__main__':
     unittest.main()