diff --git a/OTX_ETX/bw128x64/SRC/yaapu7.lua b/OTX_ETX/bw128x64/SRC/yaapu7.lua
index 61ea6cc6..8b338cbe 100644
--- a/OTX_ETX/bw128x64/SRC/yaapu7.lua
+++ b/OTX_ETX/bw128x64/SRC/yaapu7.lua
@@ -221,6 +221,9 @@ status.showMinMaxValues = false
 status.terrainLastData = getTime()
 status.terrainEnabled = 0
 status.airspeedEnabled = 0
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 
 -- 00 05 10 15 20 25 30 40 50 60 70 80 90
 -- MIN MAX
@@ -563,6 +566,11 @@ local function reset()
   noTelemetryData = 1
   hideNoTelemetry = false
   ---------------
+  -- READY TO ARM (RDY sensor)
+  ---------------
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
+  ---------------
   -- FLIGHT TIME
   ---------------
   lastTimerStart = 0
@@ -655,7 +663,20 @@ local function resetHash()
   hashByteIndex = 0
 end
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if string.find(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif string.find(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId, value, now)
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  status.lastPassthroughTime = now
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     telemetry.roll = (math.min(bit32.extract(value,0,11),1800) - 900) * 0.2
@@ -740,6 +761,7 @@ local function processTelemetry(appId, value, now)
       if msgEnd then
         -- push and display message
         local severity = (bit32.extract(value,7,1) * 1) + (bit32.extract(value,15,1) * 2) + (bit32.extract(value,23,1) * 4)
+        checkReadyToArmMessage(msgBuffer)
         pushMessage( severity, msgBuffer)
         playHash()
         resetHash()
@@ -813,6 +835,7 @@ local function crossfirePop()
           -- hash support
           updateHash(data[i])
         end
+        checkReadyToArmMessage(msgBuffer)
         pushMessage(severity, msgBuffer)
         -- hash audio support
         playHash()
@@ -1117,7 +1140,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not telemetryEnabled() then
     return
   end
@@ -1416,6 +1458,14 @@ local function background()
   end
   -- SLOW: this runs at 4Hz (every 250ms)
   if (bgclock % 4 == 0) then
+    -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+    if status.lastPassthroughTime ~= 0 then
+      local elapsed = now - status.lastPassthroughTime
+      if elapsed > 800 or elapsed < 0 then
+        status.readyToArm = false
+        status.lastPassthroughTime = 0
+      end
+    end
     setSensorValues()
     updateTotalDist(now)
   end
diff --git a/OTX_ETX/bw212x64_f2/SRC/yaapu9.lua b/OTX_ETX/bw212x64_f2/SRC/yaapu9.lua
index 5521a8e4..69580410 100644
--- a/OTX_ETX/bw212x64_f2/SRC/yaapu9.lua
+++ b/OTX_ETX/bw212x64_f2/SRC/yaapu9.lua
@@ -211,6 +211,9 @@ status.flightTime = 0    -- updated from model timer 3
 status.timerRunning = 0  -- triggered by landcomplete from AP
 status.showMinMaxValues = false
 status.airspeedEnabled = 0
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 
 -- 00 05 10 15 20 25 30 40 50 60 70 80 90
 -- MIN MAX
@@ -551,6 +554,11 @@ local function reset()
   noTelemetryData = 1
   hideNoTelemetry = false
   ---------------
+  -- READY TO ARM (RDY sensor)
+  ---------------
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
+  ---------------
   -- FLIGHT TIME
   ---------------
   lastTimerStart = 0
@@ -643,7 +651,20 @@ local function resetHash()
   hashByteIndex = 0
 end
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if string.find(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif string.find(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId, value, now)
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  status.lastPassthroughTime = now
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     telemetry.roll = (math.min(bit32.extract(value,0,11),1800) - 900) * 0.2
@@ -726,6 +747,7 @@ local function processTelemetry(appId, value, now)
       if msgEnd then
         -- push and display message
         local severity = (bit32.extract(value,7,1) * 1) + (bit32.extract(value,15,1) * 2) + (bit32.extract(value,23,1) * 4)
+        checkReadyToArmMessage(msgBuffer)
         pushMessage( severity, msgBuffer)
         playHash()
         resetHash()
@@ -788,6 +810,7 @@ local function crossfirePop()
           -- hash support
           updateHash(data[i])
         end
+        checkReadyToArmMessage(msgBuffer)
         pushMessage(severity, msgBuffer)
         -- hash audio support
         playHash()
@@ -1086,7 +1109,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not telemetryEnabled() then
     return
   end
@@ -1380,6 +1422,14 @@ local function background()
   end
   -- SLOW: this runs at 4Hz (every 250ms)
   if (bgclock % 4 == 0) then
+    -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+    if status.lastPassthroughTime ~= 0 then
+      local elapsed = now - status.lastPassthroughTime
+      if elapsed > 800 or elapsed < 0 then
+        status.readyToArm = false
+        status.lastPassthroughTime = 0
+      end
+    end
     setSensorValues()
     updateTotalDist(now)
   end
diff --git a/OTX_ETX/bw212x64_f4/SRC/yaapu9.lua b/OTX_ETX/bw212x64_f4/SRC/yaapu9.lua
index 45481a1d..29648a41 100644
--- a/OTX_ETX/bw212x64_f4/SRC/yaapu9.lua
+++ b/OTX_ETX/bw212x64_f4/SRC/yaapu9.lua
@@ -221,6 +221,9 @@ status.showMinMaxValues = false
 status.terrainLastData = getTime()
 status.terrainEnabled = 0
 status.airspeedEnabled = 0
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 
 -- 00 05 10 15 20 25 30 40 50 60 70 80 90
 -- MIN MAX
@@ -563,6 +566,11 @@ local function reset()
   noTelemetryData = 1
   hideNoTelemetry = false
   ---------------
+  -- READY TO ARM (RDY sensor)
+  ---------------
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
+  ---------------
   -- FLIGHT TIME
   ---------------
   lastTimerStart = 0
@@ -655,7 +663,20 @@ local function resetHash()
   hashByteIndex = 0
 end
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if string.find(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif string.find(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId, value, now)
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  status.lastPassthroughTime = now
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     telemetry.roll = (math.min(bit32.extract(value,0,11),1800) - 900) * 0.2
@@ -740,6 +761,7 @@ local function processTelemetry(appId, value, now)
       if msgEnd then
         -- push and display message
         local severity = (bit32.extract(value,7,1) * 1) + (bit32.extract(value,15,1) * 2) + (bit32.extract(value,23,1) * 4)
+        checkReadyToArmMessage(msgBuffer)
         pushMessage( severity, msgBuffer)
         playHash()
         resetHash()
@@ -813,6 +835,7 @@ local function crossfirePop()
           -- hash support
           updateHash(data[i])
         end
+        checkReadyToArmMessage(msgBuffer)
         pushMessage(severity, msgBuffer)
         -- hash audio support
         playHash()
@@ -1117,7 +1140,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not telemetryEnabled() then
     return
   end
@@ -1416,6 +1458,14 @@ local function background()
   end
   -- SLOW: this runs at 4Hz (every 250ms)
   if (bgclock % 4 == 0) then
+    -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+    if status.lastPassthroughTime ~= 0 then
+      local elapsed = now - status.lastPassthroughTime
+      if elapsed > 800 or elapsed < 0 then
+        status.readyToArm = false
+        status.lastPassthroughTime = 0
+      end
+    end
     setSensorValues()
     updateTotalDist(now)
   end
diff --git a/OTX_ETX/c320x240/SD/WIDGETS/yaapu/main.lua b/OTX_ETX/c320x240/SD/WIDGETS/yaapu/main.lua
index 46c61d81..1f2dd9c1 100644
--- a/OTX_ETX/c320x240/SD/WIDGETS/yaapu/main.lua
+++ b/OTX_ETX/c320x240/SD/WIDGETS/yaapu/main.lua
@@ -321,6 +321,9 @@ status.noTelemetryData = 1
 status.hideNoTelemetry = false
 status.showDualBattery = false
 status.showMinMaxValues = false
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 -- MAP
 status.screenTogglePage = 1
 status.mapZoomLevel = 1
@@ -1270,12 +1273,26 @@ end
 -- Lookup table for 10^x
 local POW10 = {[0]=1, [1]=10, [2]=100, [3]=1000}
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if sFind(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif sFind(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId,value,now)
   -- local global tables cache
   local t = telemetry
   local s = status
   local c = conf
 
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  s.lastPassthroughTime = now
+
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     t.roll = (m_min(b_extract(value,0,11),1800) - 900) * 0.2
@@ -1360,6 +1377,7 @@ local function processTelemetry(appId,value,now)
       s.msgBuffer = (s.msgBuffer or "")..t_concat(chunk)
       if msgEnd then
         local severity = (b_extract(value,7,1) * 1) + (b_extract(value,15,1) * 2) + (b_extract(value,23,1) * 4)
+        checkReadyToArmMessage(s.msgBuffer)
         utils.pushMessage( severity, s.msgBuffer)
         playHash()
         resetHash()
@@ -1800,6 +1818,9 @@ local function resetTelemetry()
   -- RSSI
   telemetry.rssi = 0
   telemetry.rssiCRSF = 0
+  -- READY TO ARM (RDY sensor)
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
 end
 
 local function resetStatus()
@@ -1959,7 +1980,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not utils.telemetryEnabled() then
     return
   end
@@ -2351,6 +2391,7 @@ local function crossfirePop()
           updateHash(data[i])
         end
         status.msgBuffer = table.concat(msg)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage(severity, status.msgBuffer)
         -- hash audio support
         playHash()
@@ -2491,6 +2532,14 @@ local function task2HzB(widget, now)
       updateCog = 1
     end
   end
+  -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+  if status.lastPassthroughTime ~= 0 then
+    local elapsed = now - status.lastPassthroughTime
+    if elapsed > 800 or elapsed < 0 then
+      status.readyToArm = false
+      status.lastPassthroughTime = 0
+    end
+  end
   setSensorValues()
   calcFlightTime()
   -- update gps telemetry data
diff --git a/OTX_ETX/c320x480/SD/WIDGETS/yaapu/main.lua b/OTX_ETX/c320x480/SD/WIDGETS/yaapu/main.lua
index ee0b355b..b2535f93 100644
--- a/OTX_ETX/c320x480/SD/WIDGETS/yaapu/main.lua
+++ b/OTX_ETX/c320x480/SD/WIDGETS/yaapu/main.lua
@@ -321,6 +321,9 @@ status.noTelemetryData = 1
 status.hideNoTelemetry = false
 status.showDualBattery = false
 status.showMinMaxValues = false
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 -- MAP
 status.screenTogglePage = 1
 status.mapZoomLevel = 1
@@ -1091,7 +1094,20 @@ local function wrap360(angle)
     return res
 end
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if string.find(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif string.find(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId,value,now)
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  status.lastPassthroughTime = now
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     telemetry.roll = (math.min(bit32.extract(value,0,11),1800) - 900) * 0.2
@@ -1176,6 +1192,7 @@ local function processTelemetry(appId,value,now)
       status.msgBuffer = status.msgBuffer..table.concat(chunk)
       if msgEnd then
         local severity = (bit32.extract(value,7,1) * 1) + (bit32.extract(value,15,1) * 2) + (bit32.extract(value,23,1) * 4)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage( severity, status.msgBuffer)
         playHash()
         resetHash()
@@ -1625,6 +1642,9 @@ local function resetTelemetry()
   -- RSSI
   telemetry.rssi = 0
   telemetry.rssiCRSF = 0
+  -- READY TO ARM (RDY sensor)
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
 end
 
 local function resetStatus()
@@ -1784,7 +1804,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not utils.telemetryEnabled() then
     return
   end
@@ -2170,6 +2209,7 @@ local function crossfirePop()
           updateHash(data[i])
         end
         status.msgBuffer = table.concat(msg)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage(severity, status.msgBuffer)
         -- hash audio support
         playHash()
@@ -2310,6 +2350,14 @@ local function task2HzB(widget, now)
       updateCog = 1
     end
   end
+  -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+  if status.lastPassthroughTime ~= 0 then
+    local elapsed = now - status.lastPassthroughTime
+    if elapsed > 800 or elapsed < 0 then
+      status.readyToArm = false
+      status.lastPassthroughTime = 0
+    end
+  end
   setSensorValues()
   calcFlightTime()
   -- update gps telemetry data
diff --git a/OTX_ETX/c480x272/SD/WIDGETS/yaapu/main.lua b/OTX_ETX/c480x272/SD/WIDGETS/yaapu/main.lua
index 9383e35e..b68eb53a 100644
--- a/OTX_ETX/c480x272/SD/WIDGETS/yaapu/main.lua
+++ b/OTX_ETX/c480x272/SD/WIDGETS/yaapu/main.lua
@@ -321,6 +321,9 @@ status.noTelemetryData = 1
 status.hideNoTelemetry = false
 status.showDualBattery = false
 status.showMinMaxValues = false
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 -- MAP
 status.screenTogglePage = 1
 status.mapZoomLevel = 1
@@ -1091,7 +1094,20 @@ local function wrap360(angle)
     return res
 end
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if string.find(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif string.find(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId,value,now)
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  status.lastPassthroughTime = now
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     telemetry.roll = (math.min(bit32.extract(value,0,11),1800) - 900) * 0.2
@@ -1176,6 +1192,7 @@ local function processTelemetry(appId,value,now)
       status.msgBuffer = status.msgBuffer..table.concat(chunk)
       if msgEnd then
         local severity = (bit32.extract(value,7,1) * 1) + (bit32.extract(value,15,1) * 2) + (bit32.extract(value,23,1) * 4)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage( severity, status.msgBuffer)
         playHash()
         resetHash()
@@ -1625,6 +1642,9 @@ local function resetTelemetry()
   -- RSSI
   telemetry.rssi = 0
   telemetry.rssiCRSF = 0
+  -- READY TO ARM (RDY sensor)
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
 end
 
 local function resetStatus()
@@ -1784,7 +1804,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not utils.telemetryEnabled() then
     return
   end
@@ -2177,6 +2216,7 @@ local function crossfirePop()
           updateHash(data[i])
         end
         status.msgBuffer = table.concat(msg)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage(severity, status.msgBuffer)
         -- hash audio support
         playHash()
@@ -2317,6 +2357,14 @@ local function task2HzB(widget, now)
       updateCog = 1
     end
   end
+  -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+  if status.lastPassthroughTime ~= 0 then
+    local elapsed = now - status.lastPassthroughTime
+    if elapsed > 800 or elapsed < 0 then
+      status.readyToArm = false
+      status.lastPassthroughTime = 0
+    end
+  end
   setSensorValues()
   calcFlightTime()
   -- update gps telemetry data
diff --git a/OTX_ETX/c480x320/SD/WIDGETS/yaapu/main.lua b/OTX_ETX/c480x320/SD/WIDGETS/yaapu/main.lua
index 9383e35e..b68eb53a 100644
--- a/OTX_ETX/c480x320/SD/WIDGETS/yaapu/main.lua
+++ b/OTX_ETX/c480x320/SD/WIDGETS/yaapu/main.lua
@@ -321,6 +321,9 @@ status.noTelemetryData = 1
 status.hideNoTelemetry = false
 status.showDualBattery = false
 status.showMinMaxValues = false
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 -- MAP
 status.screenTogglePage = 1
 status.mapZoomLevel = 1
@@ -1091,7 +1094,20 @@ local function wrap360(angle)
     return res
 end
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if string.find(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif string.find(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId,value,now)
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  status.lastPassthroughTime = now
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     telemetry.roll = (math.min(bit32.extract(value,0,11),1800) - 900) * 0.2
@@ -1176,6 +1192,7 @@ local function processTelemetry(appId,value,now)
       status.msgBuffer = status.msgBuffer..table.concat(chunk)
       if msgEnd then
         local severity = (bit32.extract(value,7,1) * 1) + (bit32.extract(value,15,1) * 2) + (bit32.extract(value,23,1) * 4)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage( severity, status.msgBuffer)
         playHash()
         resetHash()
@@ -1625,6 +1642,9 @@ local function resetTelemetry()
   -- RSSI
   telemetry.rssi = 0
   telemetry.rssiCRSF = 0
+  -- READY TO ARM (RDY sensor)
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
 end
 
 local function resetStatus()
@@ -1784,7 +1804,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not utils.telemetryEnabled() then
     return
   end
@@ -2177,6 +2216,7 @@ local function crossfirePop()
           updateHash(data[i])
         end
         status.msgBuffer = table.concat(msg)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage(severity, status.msgBuffer)
         -- hash audio support
         playHash()
@@ -2317,6 +2357,14 @@ local function task2HzB(widget, now)
       updateCog = 1
     end
   end
+  -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+  if status.lastPassthroughTime ~= 0 then
+    local elapsed = now - status.lastPassthroughTime
+    if elapsed > 800 or elapsed < 0 then
+      status.readyToArm = false
+      status.lastPassthroughTime = 0
+    end
+  end
   setSensorValues()
   calcFlightTime()
   -- update gps telemetry data
diff --git a/OTX_ETX/c800x480/SD/WIDGETS/yaapu/main.lua b/OTX_ETX/c800x480/SD/WIDGETS/yaapu/main.lua
index fe11a6c4..fc788c76 100644
--- a/OTX_ETX/c800x480/SD/WIDGETS/yaapu/main.lua
+++ b/OTX_ETX/c800x480/SD/WIDGETS/yaapu/main.lua
@@ -321,6 +321,9 @@ status.noTelemetryData = 1
 status.hideNoTelemetry = false
 status.showDualBattery = false
 status.showMinMaxValues = false
+-- READY TO ARM (RDY sensor)
+status.readyToArm = false
+status.lastPassthroughTime = 0
 -- MAP
 status.screenTogglePage = 1
 status.mapZoomLevel = 1
@@ -1270,12 +1273,26 @@ end
 -- Lookup table for 10^x
 local POW10 = {[0]=1, [1]=10, [2]=100, [3]=1000}
 
+-- RDY sensor: the ready to arm evidence is scoped to the current FC power cycle
+local function checkReadyToArmMessage(msg)
+  if sFind(msg, "ArduCopter V", 1, true) ~= nil then
+    -- FC boot banner, a new power cycle invalidates any previous evidence
+    status.readyToArm = false
+  elseif sFind(msg, "using GPS", 1, true) ~= nil then
+    -- "EKF3 IMUx is using GPS", the FC has a GPS aided EKF solution
+    status.readyToArm = true
+  end
+end
+
 local function processTelemetry(appId,value,now)
   -- local global tables cache
   local t = telemetry
   local s = status
   local c = conf
 
+  -- RDY sensor: track link freshness, a passthrough frame was just decoded
+  s.lastPassthroughTime = now
+
   if appId == 0x5006 then -- ROLLPITCH
     -- roll [0,1800] ==> [-180,180]
     t.roll = (m_min(b_extract(value,0,11),1800) - 900) * 0.2
@@ -1360,6 +1377,7 @@ local function processTelemetry(appId,value,now)
       s.msgBuffer = (s.msgBuffer or "")..t_concat(chunk)
       if msgEnd then
         local severity = (b_extract(value,7,1) * 1) + (b_extract(value,15,1) * 2) + (b_extract(value,23,1) * 4)
+        checkReadyToArmMessage(s.msgBuffer)
         utils.pushMessage( severity, s.msgBuffer)
         playHash()
         resetHash()
@@ -1800,6 +1818,9 @@ local function resetTelemetry()
   -- RSSI
   telemetry.rssi = 0
   telemetry.rssiCRSF = 0
+  -- READY TO ARM (RDY sensor)
+  status.readyToArm = false
+  status.lastPassthroughTime = 0
 end
 
 local function resetStatus()
@@ -1959,7 +1980,26 @@ local function calcFlightTime()
   status.flightTime = model.getTimer(2).value
 end
 
+-- RDY sensor: 100 when the FC is effectively ready to arm, 0 otherwise
+local function getReadyToArmValue()
+  -- no recent passthrough frame, the FC is powered down or the link is gone
+  if status.lastPassthroughTime == 0 then
+    return 0
+  end
+  -- authoritative, the FC announced a GPS aided EKF solution this power cycle
+  if status.readyToArm == true then
+    return 100
+  end
+  -- fallback composite from the repeating 0x5002 GPS STATUS frame
+  if (telemetry.gpsStatus or 0) >= 3 and (telemetry.gpsHdopC or 100) <= 14 and (telemetry.numSats or 0) >= 10 then
+    return 100
+  end
+  return 0
+end
+
 local function setSensorValues()
+  -- RDY is published even without a live link so it can always fall back to 0
+  setTelemetryValue(0x060F, 0, 2, getReadyToArmValue(), 0 , 0 , "RDY")
   if not utils.telemetryEnabled() then
     return
   end
@@ -2355,6 +2395,7 @@ local function crossfirePop()
           updateHash(data[i])
         end
         status.msgBuffer = table.concat(msg)
+        checkReadyToArmMessage(status.msgBuffer)
         utils.pushMessage(severity, status.msgBuffer)
         -- hash audio support
         playHash()
@@ -2495,6 +2536,14 @@ local function task2HzB(widget, now)
       updateCog = 1
     end
   end
+  -- RDY sensor: expire the ready to arm state 8s after the last passthrough frame
+  if status.lastPassthroughTime ~= 0 then
+    local elapsed = now - status.lastPassthroughTime
+    if elapsed > 800 or elapsed < 0 then
+      status.readyToArm = false
+      status.lastPassthroughTime = 0
+    end
+  end
   setSensorValues()
   calcFlightTime()
   -- update gps telemetry data