diff --git a/docs/documentation/sizing/initial_sizing/initialSizing.md b/docs/documentation/sizing/initial_sizing/initialSizing.md
index 101b0ac1194aba9cd511ad2d5daefe28731eb2ea..d86785bae284c9d10896db822647b4e0484ca34b 100644
--- a/docs/documentation/sizing/initial_sizing/initialSizing.md
+++ b/docs/documentation/sizing/initial_sizing/initialSizing.md
@@ -45,7 +45,7 @@ For the determination the following parameters are necessary:
 1) acXML:
 
   - Design range  [m]
-  - Crusie flight speed $[\frac{m}{s}]$: automatically calculated from the design machNumber
+  - Crusie flight speed $[\frac{m}{s}]$: automatically calculated from the design mach number
   - Contingency  [-]: percentage for the reserve of the trip fuel (the fuel necessary for the design range without reserves)
   - Cruise flight altitutde  [m]: to calculate the air density