diff --git a/dump1090.c b/dump1090.c
index c5826c0..67db2da 100644
--- a/dump1090.c
+++ b/dump1090.c
@@ -2768,64 +2768,71 @@ void interactiveShowData(void) {
           || (((flags & (MODEAC_MSG_MODES_HIT | MODEAC_MSG_MODEC_OLD )) == 0                    ) && (msgs > 127) ) 
            ) {
             int altitude = a->altitude, speed = a->speed;
-            char squawk[5] = "    ";
+            char strSquawk[5] = " ";
+            char strFl[6]     = " ";
+            char strTt[5]     = " ";
+            char strGs[5]     = " ";
 
             // Convert units to metric if --metric was specified
             if (Modes.metric) {
                 altitude = (int) (altitude / 3.2828);
-                speed    = (int) (speed * 1.852);
+                speed    = (int) (speed    * 1.852);
             }
         
-            if (altitude > 99999) {
-                altitude = 99999;
-            } else if (altitude == -999900) {
-                altitude = 0;
-            } else if (altitude  < -9999) {
-                altitude = -9999;
-            }
-        
-            if (a->modeA) {
-                sprintf(squawk, "%04x", a->modeA);
-            }
+            if (a->bFlags & MODES_ACFLAGS_SQUAWK_VALID) {
+                snprintf(strSquawk,5,"%04x", a->modeA);}
+
+            if (a->bFlags & MODES_ACFLAGS_SPEED_VALID) {
+                snprintf (strGs, 5,"%3d", speed);}
+
+            if (a->bFlags & MODES_ACFLAGS_HEADING_VALID) {
+                snprintf (strTt, 5,"%03d", a->track);}
         
             if (msgs > 99999) {
-                msgs = 99999;
-            }
+                msgs = 99999;}
         
-            if (Modes.interactive_rtl1090 != 0) {
-                char fl[5] = "    ";
-                char tt[5] = "   ";
-                char gs[5] = "   ";
+            if (Modes.interactive_rtl1090) { // RTL1090 display mode
 
-                if (altitude > 0) {
-                    sprintf(fl,"F%03d",(altitude/100));
-                }
-                if (speed > 0) {
-                    sprintf (gs,"%3d",speed);
-                }
-                if (a->track > 0) {
-                    sprintf (tt,"%03d",a->track);
+                if (a->bFlags & MODES_ACFLAGS_ALTITUDE_VALID) {
+                    snprintf(strFl,6,"F%03d",(altitude/100));
                 }
                 printf("%06x %-8s %-4s         %-3s %-3s %4s        %-6d  %-2d\n", 
-                a->addr, a->flight, fl, gs, tt, squawk, msgs, (int)(now - a->seen));
+                a->addr, a->flight, strFl, strGs, strTt, strSquawk, msgs, (int)(now - a->seen));
 
-            } else {
-                char mode[5]               = "    \0";
+            } else {                         // Dump1090 display mode
+                char strMode[5]               = "    ";
+                char strLat[8]                = " ";
+                char strLon[9]                = " ";
                 unsigned char * pSig       = a->signalLevel;
                 unsigned int signalAverage = (pSig[0] + pSig[1] + pSig[2] + pSig[3] + 
                                               pSig[4] + pSig[5] + pSig[6] + pSig[7] + 3) >> 3; 
 
                 if ((flags & MODEAC_MSG_FLAG) == 0) {
-                    mode[0] = 'S';
+                    strMode[0] = 'S';
                 } else if (flags & MODEAC_MSG_MODEA_ONLY) {
-                    mode[0] = 'A';
+                    strMode[0] = 'A';
                 }
-                if (flags & MODEAC_MSG_MODEA_HIT) {mode[2] = 'a';}
-                if (flags & MODEAC_MSG_MODEC_HIT) {mode[3] = 'c';}
+                if (flags & MODEAC_MSG_MODEA_HIT) {strMode[2] = 'a';}
+                if (flags & MODEAC_MSG_MODEC_HIT) {strMode[3] = 'c';}
 
-                printf("%06x  %-4s  %-4s  %-8s %5d  %3d  %3d  %7.03f %8.03f  %3d %5d   %2d\n",
-                a->addr, mode, squawk, a->flight, altitude, speed, a->track,
-                a->lat, a->lon, signalAverage, msgs, (int)(now - a->seen));
+                if (a->bFlags & MODES_ACFLAGS_LATLON_VALID) {
+                    snprintf(strLat, 8,"%7.03f", a->lat);
+                    snprintf(strLon, 9,"%8.03f", a->lon);
+                }
+
+                if (a->bFlags & MODES_ACFLAGS_AOG) {
+                    snprintf(strFl, 6," grnd");
+                } else if (a->bFlags & MODES_ACFLAGS_ALTITUDE_VALID) {
+                    snprintf(strFl, 6, "%5d", altitude);
+                }
+
+//              printf("%06x  %-4s  %-4s  %-8s %5d  %3d  %3d  %7.03f %8.03f  %3d %5d   %2d\n",
+//              a->addr, strMode, strSquawk, a->flight, altitude, speed, a->track,
+//              a->lat, a->lon, signalAverage, msgs, (int)(now - a->seen));
+
+                printf("%06x  %-4s  %-4s  %-8s %5s  %3s  %3s  %7s %8s  %3d %5d   %2d\n",
+                a->addr, strMode, strSquawk, a->flight, strFl, strGs, strTt,
+                strLat, strLon, signalAverage, msgs, (int)(now - a->seen));
             }
             count++;
         }