Hey funderrc,
Just thought I'd let you know about a "roaring vibration" in our AW139. Starts all of a sudden in cruise flight (sometimes!), and carries on until slow down below 100 KIAS. Very noticeably by all on board including the wide-eyed pax. (Offshore config). Thought about nose gear door, but cycling gear had no effect. Start getting worried about roof cowl etc etc. However, finally tracked it down to port side liferaft manual handle canvas flap. Velcro which holds it closed gets worn out (remember AW told us not to open it on pre-flight because it only wears it out!). Anyway the flap starts to resonate like a drum and really gets a good tune going. Repaired it with some duct tape (lasted about 10 minutes) then re-velcroed plus added domes, and sweet as. The only hard bit is taking the whole front liferaft fairing down to the canvas shop to get it sewn up.
So if you are tracking on odd, intermittent loud vibe, check out the liferaft flap.
