I am oblivious as to what the noises are when a BR715 FIRST Starts. It sounds like card spokes in a bicycle as it slowly starts up. I never notice this on any other engine.
Can ANYBODY please help me figure out what that sound is, and why it is so noisy at first?
It starts at around 0:30. Do any other High-Bypass Turbofans make that noise, or is it specific to the BR700 series?