This is a follow-up to my previous question:

[How does this IMU work and how to convert its output into meaningful information?](https://aviation.stackexchange.com/questions/45039/how-does-this-imu-work-and-how-to-convert-its-output-into-meaningful-information)

for which many people asserted that I need a pitot tube and a static port in order to calculate airspeed and pressure altitude respectively, and errors will build up if I just integrate the accelerometer values.

I'd like to know whether it is possible to **measure airspeed without a pitot tube, accurately**?