Strange sound on approach to BNA and BWI?
 

Hello everyone!

Two weeks ago on my STL-BNA-BWI flight (WN 1072 on 6-9-17), I noticed a very strange phenomena while on approach that I have never heard before on a 737-300. I heard a loud humming noise that lasted 1 minute while approaching BNA and about 3 minutes approaching BWI. The whole plane was vibrating My guess was that this was happening when deploying the landing gear.

I have flown on the 733 numerous times, but this was the first time I have heard something like this while flying on the 733. After landing at BWI, I did see what appeared to be a few maintenance workers looking at the plane. I checked the flight status of that plane, and sure enough, it flew the rest of its routes that day, no cancellations. Whatever caused it wasn't serious enough to cancel subsequent legs I suppose.

Have any of you ever seen or heard this? And if so, what caused it?

Flap motor? You could hear this several times in the final 10 minutes of flight. Each time the flaps were extended more.

Bonnaroo?

Nope, doesn't explain BWI.