CAUTION - DENSITY ALTITUDE!

May 31, 2024

AVIATION 101

SUMMER IS COMING! CAUTION DENSITY ALTITUDE

Your Truckee Tahoe Airport’s (aka KTRK's) airfield elevation is 5,901 feet above Mean Sea Level (MSL), but the Density Altitude signs around the airfield (put up every spring through fall) typically read much higher. Why is that?

The airport has five "Density Altitude" signs strategically placed around the airfield to remind pilots that on warm summer days, their aircraft's performance can be greatly reduced by high density altitudes. This means the aircraft's climb rates, ground speeds, control performance and weight carrying capabilities will all be reduced.

Air density, like air pressure, decreases with increasing altitude. It also changes with variations in temperature and humidity. A higher altitude, low pressure area, with a higher temperature and high humidity all have one result: they lower the density of the air, and as a result - reduce aircraft and engine performance.
At 5,901 feet above sea level, KTRK is already considered a high-altitude alpine airport, which is surrounded by even higher mountainous terrain. The actual air pressure on a hot summer day on the airfield can be as thin as the equivalent air pressure at an elevation of up to 9,000 ft above MSL.

Pilots, as part of their Pre-Flight Planning, need to be diligent in checking their aircraft's performance charts and perform weight & balance calculations prior to departure and “re-plan” if necessary.

(Photos by: Marc Lamb / Taken 5.31.24 at ~10:40am with the temperature at 66 deg F (19C), DA Sign located at the RWY 2 run up area with Northstar Ski Area in the background and Mt Pluto summit elevation at 8,610', and / DA Sign by the 100LL fuel island).