Originally Posted by
OntimeexceptACARS
After a flight a few years ago on Swiss, I flew LHR-CDG last week on AF on the A220. Love the idea of the latest generation economics and fuel burn and so on, but the noises the thing makes when taxying make the A320 barking dog PTU sound like a Bentley in comparison. Kept thinking 'that can't be oiled properly'! Seemed like the worst creaking door when it moved. Obv all disappeared once rolling and airborne.
I know its a Pratt thing, not the airframe. Why does it sound like it's about to break?
OTEA
Is that the 'cutting wood with a blunt saw and a hammer' sort noise when taxiing? I tried to google that once and the most plausible cause I could find was something hydraulic when taxiing on one engine. I guessed perhaps feeding two circuits from a single pump. I'd be interested to know what it really is.