diff --git a/modules/aeolus/datasource.py b/modules/aeolus/datasource.py
index 4f51c2d4182a4b784273d54012fdfccc7a4358db..74c72b7faa53081da49cb6368db52af33d1e3586 100644
--- a/modules/aeolus/datasource.py
+++ b/modules/aeolus/datasource.py
@@ -77,8 +77,8 @@ class CLAVRx(Files):
 
 
 class RAOBfiles(Files):
-    def __init__(self, files_path):
-        super().__init__(files_path, 10, 'raob_soundings*.cdf')
+    def __init__(self, files_path, file_time_span=10):
+        super().__init__(files_path, file_time_span, 'raob_soundings*.cdf')
 
     def get_datetime(self, pathname):
         filename = os.path.split(pathname)[1]
@@ -371,6 +371,6 @@ def get_datasource(files_path, source, file_time_span=10, band='14'):
     elif source == 'GFS':
         return GFSfiles(files_path)
     elif source == 'RAOB':
-        return RAOBfiles(files_path)
+        return RAOBfiles(files_path, file_time_span)
     else:
         raise GenericException('Unknown data source type')
\ No newline at end of file