diff --git a/src/MNH/aircraft_balloon_evol.f90 b/src/MNH/aircraft_balloon_evol.f90
index df46755874821a8398828a587259a1f068512053..18a996be054912a357ede5fd2950a837d3b810d0 100644
--- a/src/MNH/aircraft_balloon_evol.f90
+++ b/src/MNH/aircraft_balloon_evol.f90
@@ -1,4 +1,4 @@
-!MNH_LIC Copyright 1994-2018 CNRS, Meteo-France and Universite Paul Sabatier
+!MNH_LIC Copyright 2000-2020 CNRS, Meteo-France and Universite Paul Sabatier
 !MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
 !MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt  
 !MNH_LIC for details. version 1.
@@ -128,7 +128,8 @@ END MODULE MODI_AIRCRAFT_BALLOON_EVOL
 !!      October, 2016 (G.DELAUTIER) LIMA
 !!     March,28, 2018 (P. Wautelet) replace TEMPORAL_DIST by DATETIME_DISTANCE
 !!  Philippe Wautelet: 05/2016-04/2018: new data structures and calls for I/O
-!!
+!  P. Wautelet 01/10/2020: bugfix: initialize GSTORE
+!
 !! --------------------------------------------------------------------------
 !       
 !*      0. DECLARATIONS
@@ -346,6 +347,7 @@ ALLOCATE(XSVW_FLUX(SIZE(PSV,1),SIZE(PSV,2),SIZE(PSV,3),SIZE(PSV,4)))
 ILUOUT = TLUOUT%NLU
 !
 ZR = 0.
+GSTORE = .FALSE.
 !
 !*      1.0  initialization of processor test
 !            --------------------------------
diff --git a/src/MNH/ini_aircraft_balloon.f90 b/src/MNH/ini_aircraft_balloon.f90
index 28c4089c937c4c79aef7ea02cc65e7fa21cc6012..4377a1add07d4fffb84fd15bc0a80459a68fd201 100644
--- a/src/MNH/ini_aircraft_balloon.f90
+++ b/src/MNH/ini_aircraft_balloon.f90
@@ -3,6 +3,10 @@
 !MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt  
 !MNH_LIC for details. version 1.
 !-----------------------------------------------------------------
+! Modifications:
+!  P. Wautelet 01/10/2020: bugfix: DEFAULT_FLYER: add missing default values
+!-----------------------------------------------------------------
+
 !      #########################
 MODULE MODI_INI_AIRCRAFT_BALLOON
 !      #########################
@@ -319,15 +323,24 @@ TPFLYER%STEP   = 60.     ! s
 !
 TPFLYER%LAT     = XUNDEF
 TPFLYER%LON     = XUNDEF
+TPFLYER%XLAUNCH = XUNDEF! X coordinate of launch
+TPFLYER%YLAUNCH = XUNDEF! Y coordinate of launch
 TPFLYER%ALT     = XUNDEF
 TPFLYER%WASCENT = 5.     ! m/s
 TPFLYER%RHO     = XUNDEF
 TPFLYER%PRES    = XUNDEF
+TPFLYER%DIAMETER= XUNDEF
+TPFLYER%AERODRAG= XUNDEF
+TPFLYER%INDDRAG = XUNDEF
+TPFLYER%VOLUME  = XUNDEF
+TPFLYER%MASS    = XUNDEF
 !
 TPFLYER%SEG     = 0
 TPFLYER%SEGCURN = 1
 TPFLYER%SEGCURT = 0.
 !
+TPFLYER%ALTDEF   = .FALSE.
+!
 TPFLYER%X_CUR   = XUNDEF
 TPFLYER%Y_CUR   = XUNDEF
 TPFLYER%Z_CUR   = XUNDEF