diff --git a/Models/Instruments/PFD/PFD.nas b/Models/Instruments/PFD/PFD.nas
index 423689fc..46f6af22 100644
--- a/Models/Instruments/PFD/PFD.nas
+++ b/Models/Instruments/PFD/PFD.nas
@@ -396,7 +396,7 @@ var canvas_PFD_base = {
 		
 		me["AI_agl"].setText(sprintf("%s", math.round(math.clamp(gear_agl_cur, 0, 2500))));
 		
-		if (gear_agl_cur < 400 and pts.Velocities.groundspeed.getValue() > 50 and pts.Controls.Engines.Engine.throttlePos[0].getValue() < 0.78 and pts.Controls.Engines.Engine.throttlePos[1].getValue() < 0.78) {
+		if (gear_agl_cur < 400 and pts.Velocities.groundspeedKt.getValue() > 50 and pts.Controls.Engines.Engine.throttlePos[0].getValue() < 0.78 and pts.Controls.Engines.Engine.throttlePos[1].getValue() < 0.78) {
 			me["tailstrikeInd"].show();
 		} else {
 			me["tailstrikeInd"].hide();