Transponders

[WindSheer]

I have been having a butchers at this site recently:

Watch Air Traffic - LIVE!

It doesn't show prop's.
Given that all the info is taken from transponders, are the prop's squawking in a different mode??

Cheers.

[HEATHROW DIRECTOR]

As the web site notes, it shows only ADS-B equipped aircraft. The vast majority of civil and military prop aircraft, and most "biz jets" do not transmit ADS-B so you won't see them.