What causes the 'meow' sound of a jet flying overhead?

Question

I live about 20km from an airport. Usually when jets pass, I hear the familiar rumble of their engines. Every now and then, presumably as they come in for landing, the sound suddenly appears as a long, hollow, meooooow sound that drops in pitch. I know it is probably the Doppler effect, but was wondering if landing gear or flaps being deployed are also responsible ...

Update:

It is quite an eerie sound because there is no build up. It starts suddenly ... more like a sort of KLLLLLLOOOOOOOOOOOWWWWWWWW out of the blue.

! · Accepted Answer

Nah, its just the engine note and the doppler effect.

johnstillness · Answer

It may surprise you but the truth is there are some cats on board most planes.  This is to prevent bird strike as birds are less likely to strike a plane carrying a cat or two.  As the plane slows for landing one cat usually cries out to the other and that sound going through the sound barrier is really loud.  I hope this helps.

? · Answer

Do some research on the Doppler effect.

? · Answer

I think it is due tyres screeching on the asphalt. Similar sound comes when we apply break suddenly on a car.

TJ · Answer

I've never really heard that sound before

What causes the 'meow' sound of a jet flying overhead?

5 Answers