diff --git a/htdocs/lib/MapMarkers.js b/htdocs/lib/MapMarkers.js
index 62a4e60d..828753db 100644
--- a/htdocs/lib/MapMarkers.js
+++ b/htdocs/lib/MapMarkers.js
@@ -109,7 +109,10 @@ MarkerManager.prototype.ageAll = function() {
     var now = new Date().getTime();
     var data = this.markers;
     $.each(data, function(id, x) {
-        if (!x.age(now - x.lastseen)) delete data[id];
+        if (x.ttl && now >= x.ttl)
+            delete data[id];
+        else if (x.lastseen && !x.age(now - x.lastseen))
+            delete data[id];
     });
 };
 
@@ -651,6 +654,7 @@ AircraftMarker.prototype = new Marker();
 
 AircraftMarker.prototype.update = function(update) {
     this.lastseen = update.lastseen;
+    this.ttl      = update.ttl;
     this.mode     = update.mode;
     this.comment  = update.location.comment;
     // HFDL, ACARS, VDL2, ADSB
diff --git a/htdocs/lib/MessagePanel.js b/htdocs/lib/MessagePanel.js
index 5b961f8f..4b8e4999 100644
--- a/htdocs/lib/MessagePanel.js
+++ b/htdocs/lib/MessagePanel.js
@@ -523,10 +523,10 @@ AdsbMessagePanel.prototype.render = function() {
                 '<th class="flight">Flight</th>' +
                 '<th class="aircraft">Aircraft</th>' +
                 '<th class="squawk">Squawk</th>' +
-                '<th class="distance">Dist&nbsp;(km)</th>' +
+                '<th class="distance">Dist</th>' +
                 '<th class="altitude">Alt&nbsp;(ft)</th>' +
                 '<th class="speed">Speed&nbsp;(kt)</th>' +
-                '<th class="rssi">Sig&nbsp;(dB)</th>' +
+                '<th class="rssi">Signal</th>' +
             '</tr></thead>' +
             '<tbody></tbody>' +
         '</table>'
@@ -542,7 +542,7 @@ AdsbMessagePanel.prototype.pushMessage = function(msg) {
     var odd = false;
     msg.aircraft.forEach(entry => {
         // Signal strength
-        var rssi = entry.rssi? entry.rssi : '';
+        var rssi = entry.rssi? entry.rssi + '&nbsp;dB' : '';
 
         // Flight identificators
         var flight =
@@ -583,7 +583,7 @@ AdsbMessagePanel.prototype.pushMessage = function(msg) {
                    : entry.flight?   entry.flight
                    : null;
 
-            distance = this.distanceKm(entry, this.receiver_pos);
+            distance = this.distanceKm(entry, this.receiver_pos) + '&nbsp;km';
             if (id) distance = this.linkToMap(id, distance);
         }
 
diff --git a/owrx/aircraft.py b/owrx/aircraft.py
index 4d291941..b36f93c1 100644
--- a/owrx/aircraft.py
+++ b/owrx/aircraft.py
@@ -34,9 +34,9 @@ MODE_S_FORMATS = [
 ADSB_CATEGORIES = {
   "A0": (0, 0),  # No ADS-B emitter category information
   "A1": (3, 0),  # Light (< 15500 lbs)
-  "A2": (5, 0),  # Small (15500 to 75000 lbs)
-  "A3": (4, 0),  # Large (75000 to 300000 lbs)
-  "A4": (0, 0),  # High vortex large (aircraft such as B-757)
+  "A2": (4, 1),  # Small (15500 to 75000 lbs)
+  "A3": (5, 0),  # Large (75000 to 300000 lbs)
+  "A4": (4, 0),  # High vortex large (aircraft such as B-757)
   "A5": (1, 7),  # Heavy (> 300000 lbs)
   "A6": (7, 0),  # High performance (> 5g acceleration and 400 kts)
   "A7": (6, 5),  # Rotorcraft, regardless of weight
@@ -81,7 +81,7 @@ class AircraftLocation(LatLngLocation):
             # Add APRS-like aircraft symbol (red or blue, depending on mode)
             res["symbol"] = { "x": 0, "y": 0 }
         # Convert aircraft-specific data into APRS-like data
-        for x in ["icao", "aircraft", "flight", "speed", "altitude", "course", "destination", "origin", "vspeed", "squawk", "rssi", "msglog"]:
+        for x in ["ttl", "icao", "aircraft", "flight", "speed", "altitude", "course", "destination", "origin", "vspeed", "squawk", "rssi", "msglog"]:
             if x in self.data:
                 res[x] = self.data[x]
         # Return APRS-like dictionary object