Airfly From United Kingdom, joined Mar 2005, 322 posts, RR: 1
Reply 5, posted (10 years 7 months 2 weeks 4 days 16 hours ago) and read 9276 times:
Mach number is a quantity that defines how quickly a vehicle travels with respect to the speed of sound. The Mach number (M) is simply the ratio of the vehicle's velocity (V) divided by the speed of sound at that altitude (a).
Therefore: Mach is the division of Velocity and Altitude.
So above 25000ft use Mach as said before...
I usually do that so the velocity precision is better as the air is much thinner...
If you fly with Knots (IAS) your actual speed would be much faster...
Mir From United States of America, joined Jan 2004, 22868 posts, RR: 53
Reply 6, posted (10 years 7 months 2 weeks 4 days 15 hours ago) and read 9283 times:
I just use my climb speed (300kts) until I get to the mach number I want to cruise at, and then maintain that throughout the rest of the climb (when holding a certain mach number and climbing, IAS will decrease, since the speed of sound decreases with altitude).
7 billion, one nation, imagination...it's a beautiful day