diff --git a/src/flightlog_fields_presenter.js b/src/flightlog_fields_presenter.js
index f387fcc3..fd21c49d 100644
--- a/src/flightlog_fields_presenter.js
+++ b/src/flightlog_fields_presenter.js
@@ -1337,15 +1337,19 @@ FlightLogFieldPresenter.presentFlags = function (flags, flagNames) {
 FlightLogFieldPresenter.presentChangeEvent = function presentChangeEvent(
   flags,
   lastFlags,
-  flagNames
-) {
+  flagNames)
+{
   let eventState = "";
   let found = false;
-
-  for (let i = 0; i < flagNames.length; i++) {
+  const maxModeNumber = 32;   // int has 32 bit only! We have not to roll bit shift 1<<i for i values grate then 31 !!!
+  let modesCount = flagNames.length;
+  if (modesCount > maxModeNumber) {
+    modesCount = maxModeNumber;
+  }
+  for (let i = 0; i < modesCount; i++) {
     if ((1 << i) & (flags ^ lastFlags)) {
       // State Changed
-      eventState += `|${flagNames[i]} ${(1 << i) & flags ? "ON" : "OFF"}`;
+      eventState += `${found ? "|" : ""}${flagNames[i]} ${(1 << i) & flags ? "ON" : "OFF"}`;
       found = true;
     }
   }
diff --git a/src/grapher.js b/src/grapher.js
index 8b87641d..ca177a0b 100644
--- a/src/grapher.js
+++ b/src/grapher.js
@@ -629,11 +629,11 @@ export function FlightLogGrapher(
         drawEventLine(
           x,
           labelY,
-          `Flight Mode Change${FlightLogFieldPresenter.presentChangeEvent(
+          FlightLogFieldPresenter.presentChangeEvent(
             event.data.newFlags,
             event.data.lastFlags,
             FLIGHT_LOG_FLIGHT_MODE_NAME
-          )}`,
+          ),
           "rgba(0,0,255,0.75)",
           3
         );