View Single Post
Old 6th Sep 2010, 22:08
  #240 (permalink)  
Join Date: Jan 2005
Location: France
Posts: 2,319
Quick link to Bellerophon's post #66 and photo to save you having to 'leaf' back...
G-BOAE at Mach 2

Originally Posted by Bellerophon
You will see that at FL600 the aircraft had a GS of 1,139 kts whilst flying at M2.00 and an IAS of 429 kts.
Much as I look at that picture, I can't see the groundspeed.....

Ah, oh, ooooops!!!! Of course it's there, in the little window on the top right of the HSI (Horizontal Situation Indicator, the lower one of the two big central instruments).

Shanewhite, in a way, that illustrates that for flying the aircraft things like TAS and GS are not really that important... that's why there are no big instruments indicating TAS or GS, but only IAS and Mach, with only a little digital window for GS, which IS important for navigation (largely handled by the inertial navigation system, which is the system where the GS display comes from), but not for the minute-to-minute handling of the aircraft.

Bellerophon, dumb question from a techie... the 373 miles is presumably just the distance to the next INS waypoint?

ChristiaanJ is offline