True altitude is height above mean sea level (MSL), crucial for situational awareness and safe flight operations. True altitude calculation involves indicated altitude and temperature; colder ...

Pressure altitude is the height above a standard datum plane (29.92 inHg at sea level), used to calculate aircraft performance in non-standard atmospheric conditions. It's calculated using the formula ...

At last, you’ve arrived in Cuzco, Peru — you’re ready for your dream trek to Machu Picchu. There’s just one problem: You can barely catch your breath, your stomach is churning and, in the morning, ...