diff --git a/aviary/variable_info/variable_meta_data.py b/aviary/variable_info/variable_meta_data.py
index 24b47761c..bbc6a88b4 100644
--- a/aviary/variable_info/variable_meta_data.py
+++ b/aviary/variable_info/variable_meta_data.py
@@ -3097,6 +3097,7 @@
     },
     units='unitless',
     desc='fuselage diameter to wing span ratio',
+    default_value=0.0,  # added
 )
 
 add_meta_data(
@@ -3194,6 +3195,7 @@
     },
     units='unitless',
     desc='fuselage length to diameter ratio',
+    default_value=0.0,  # added
 )
 
 add_meta_data(