Noise with engines off?

[dropro]

Just got my spark - really excited!
Charged battery,
Updated the firmware and registered the product.
Now... I notice when I turn the battery on, before the engines rev up, it makes a pretty large whoosh sound, almost as if it has a loud fan inside.
Can anyone else confirm that this is normal? My phantoms do not have any noise when idling...

 

[dcpmark]

Pretty sure my Mavic has internal cooling fans, so no surprise if Spark does as well.

 

[Peter]

It does have a cooling fan that draws air in through one of the top side vents and blows it out of the other..

 

[aviscomi]

Its the fan(s)...mine makes the same noise.

 

[JD4x4]

Here's a link to a page with full disassembly photos. Scroll down a bit. Looks very well thought out and manufactured!