Name the sound
 

From the right side "airintake", at start up (cold engine) there is a fan-like sound that can be heard, almost like the same sound you hear when a air plane makes at take-off (almost as if it is building thrust). There is nothing wrong with the sound, I am just curious as to what makes the sound. The mechanical part of it.. after 10 mins it is completely gone.

vacuum pump.

its the impeller spinning that makes the sound. if u listen closely. ... u will hear it spool down ... after around 1-2 mins.... after startup.

Sec air pump? Only at startup?

yes

Thank you :cheers:

I always thought it was the sound of the landing gear retracting, no? ;)

Just sayin'...............

TO

hat tip to you my good sir :cheers: