Online Simulators - Altimeter Errors

In the left column enter the indicated altitude and the current altimeter setting that the pilot is flying. The simulator will then assume that your true altitude will be the same as your indicated altitude and will calculate but not display the temperature that this would occur*. Next, in the right column, assume that the conditions of temperature and pressure have changed while the pilot is flying, but the pilot has not entered the new altimeter setting and has not taken in account the temperature change. Enter the new correct altimeter setting (which the pilot has not entered in his altimeter) and the temperature change. The simulator will estimate the true altitude that the aircraft is really flying and display it in the right column. Notice that if you fly from an area of higher pressure to lower and/or fly from an area that is warmer to a cooler one, the true altitude will be lower than what is shown in the altimeter. Hence the saying: "From high to low, hot to cold, look out below".

As mentioned in the introduction note, It is also important to remeber that the altimeters on the left and right side will always indicate the same. The reason there are two is that I wanted to show each situation and condition on each side (scenarios 1 through 2). In this case the pilot is flying a constant indicated altitude on his altimeter therefore both altimeters indicate the same. Yet the aircraft as shown above may actually be at a different altitude (true) than indicated when conditions such as pressure and temperature change. I admit this can cause confusion since you may expect to have some change on the second altimeter. This is not an error with the simulation.

*Please note though that in practice altimeters are only adjusted for pressure but not temperature, so the condition in which indicated altitude equals true altitude only occurs at the airport elevation in which the altimeter setting is obtained.