Wierd noise on Dash 8

arccosh

Flying home recently and I was on a Flybe Dash 8 with a rather horrid sounding whine coming from under the cabin, about centre to half way back of the plane.
This was there from engine start to shut down, but the higher pictch co-incided with the engines going at a higher rev for take off....

it wasn't service impacting and the flight was fine, just curious as to what it might have been. Is there some of the air circulation equipment around that area?

Tabnabs

I've flown on the Flybe Dash 8 quite a few times and noticed the same, it's a fairly horrible pitch too.

pepe the prawn

I was reading an article over the weekend that addressed this issue as being one due to the movement of air caused by the props..

""As the propellers turn on the Q400’s engines, they push air up against the fuselage. This phenomenon causes the fuselage to experience some flexing which can result in unwanted noise and vibration. The Q400 has engines that deliver nearly twice the power of the PW127M/F engines that are fitted onto the ATR72-500. As a result, there is bound to be more noise and vibration in the cabin...""


It's here in this article which compares the ATR to the Dash8. Good read.
http://theflyingengineer.com/aircraft/proud-to-fly-a-turboprop-q400-vs-atr72/

1012594711

Check out the youtube clips called 'Buzz-saw sound' to see if it's the same noise. The Buzz-saw effect occurs at the points in the flight you mentioned, on certain models of jet and can be annoying but others don't notice it

stopthepanic

Maybe this feature of the Q400 wasn't working:

Active Noise & Vibration Suppression
Passengers enjoy a quieter cabin thanks to the Q400’s unique Active noise and Vibration Suppression system, which results in noise levels lower than those of some jets. The unique ANVS (Active Noise and Vibration Suppression) system renders noise and vibration levels below those of even some jets—technology that represents a leap forward for turboprops. No wonder the “Q” stands for Quiet.

source: https://commercialaircraft.bombardier.com/en/q400/Technology.html

I was on the demo aircraft in Dublin a few years back and they switched this on and off. The difference was quite noticeable.

L1011

I believe it goes inop quite frequently