diff --git a/Nasal/globals.nas b/Nasal/globals.nas
index 1413a8e23..d7bba2886 100644
--- a/Nasal/globals.nas
+++ b/Nasal/globals.nas
@@ -14,6 +14,9 @@ var M2NM = 1 / NM2M;
 var KT2MPS = 0.5144444444;             # knots to m/s
 var MPS2KT = 1 / KT2MPS;
 
+var FPS2KT = 0.5924838012958964;        # fps to knots
+var KT2FPS = 1 / FPS2KT;
+
 var LB2KG = 0.45359237;                # pounds to kg
 var KG2LB = 1 / LB2KG;