diff --git a/engine/src/components/afterburner.cpp b/engine/src/components/afterburner.cpp
index 57aefb77c..160afd4b7 100644
--- a/engine/src/components/afterburner.cpp
+++ b/engine/src/components/afterburner.cpp
@@ -48,6 +48,7 @@ void Afterburner::Load(std::string upgrade_key,
     double consumption = UnitCSVFactory::GetVariable(unit_key, "Afterburner_Usage_Cost", 1.0);
     SetConsumption(consumption);
 
+    // We calculate percent operational as a simple average
     operational = (thrust.Percent() + speed.Percent()) / 2 * 100;
 }      
 
@@ -81,6 +82,7 @@ void Afterburner::Damage() {
     thrust.RandomDamage();
     speed.RandomDamage();
 
+    // We calculate percent operational as a simple average
     operational = (thrust.Percent() + speed.Percent()) / 2 * 100;
 }
 
diff --git a/engine/src/components/drive.cpp b/engine/src/components/drive.cpp
index 64c72cb14..0c3a1aa20 100644
--- a/engine/src/components/drive.cpp
+++ b/engine/src/components/drive.cpp
@@ -97,6 +97,7 @@ void Drive::Load(std::string upgrade_key,
     speed = Resource<double>(UnitCSVFactory::GetVariable(unit_key, "Default_Speed_Governor", std::string("0.0")), 
                                                          game_speed, minimal_drive_functionality);
 
+    // We calculate percent operational as a simple average
     operational = (yaw.Percent() + pitch.Percent() + roll.Percent() +
                   lateral.Percent() + vertical.Percent() + forward.Percent() + 
                   retro.Percent() + speed.Percent() +
@@ -170,6 +171,7 @@ void Drive::Damage() {
     max_roll_left.RandomDamage();
     max_roll_right.RandomDamage();
 
+    // We calculate percent operational as a simple average
     operational = (yaw.Percent() + pitch.Percent() + roll.Percent() +
                   lateral.Percent() + vertical.Percent() + forward.Percent() + 
                   retro.Percent() + speed.Percent() +