Sure sounds like it in the landing in this video!:

http://www.flightlevel350.com/Aircraft_ATR...Video-7415.html

I have heard something that sounds like reverse thrust in other turbo prop videos on this site. But, if they're not as powerfull as turbo fans, then why would they need reverse thrust?

(BTW, I guess I shouldn't hesitate to fly on an ATR-72 in warm weather! They sure sound awesome! )

Yeah they do. Most if not all T-props have a reverse of some sort. The pitch of the blade goes to an angle such that the air flow is reversed and causes the aircraft to slow down quickly. T-props are not as effective as turbo fans no, but the reverse on a T-prop is much more effective than it is on a jet. One reason to have reverse is to save maint. cost in not having to change the brakes as often. The other reason is the most obvious, which is to allow the aircraft to get into smaller strips. Im sure others will be along to share more info...but its late and Im tired. Take it easy...



Tp2

The blades are turned to a negative angle of attack so they actually throw air forward, and not back, as the fan disc rotates.That is the sound you are hearing, the changing of the blade angle. My CT7-9Bs go from a negative 4 degrees in ground idle to negative 13 degrees in full beta (reverse).

In this clip, you can see the blade angle change when max RPM is set for landing, when they enter beta, min RPM after leaving the runway and finally feather:
http://www.flightlevel350.com/Aircraft_Saa...Video-7468.html

http://en.wikipedia.org/wiki/Controllable_pitch_propeller
http://www.auf.asn.au/groundschool/propeller.html

As Tpattyii mentioned, the big reason to do this is the landing distances are greatly reduced, enabling service into very short landing strips.

Yes, Turbo props have some kind of reverse thrust the propeler blades feather meaning that they switch direction that is what you see ont-props when they land that the propeler looks like it is going backwards but it is just feathered

Well, not quite. The propeller blades change pitch. They do not change direction. The props on all planes always turn in the same direction.

When a propeller is feathered that means that it is turned parallel to the direction of flight. I.e. the leading edge of the prop is turned forward. This presents the lowest possible drag when the engine is not providing power and reduces asymetrical drag as much as possible.

The reason a propeller looks like it's turning backwards is because your brain can only process images at about 50 times per second. As you process one image you see the blades at a certain position. The next image your brain processes, about 1/50th of a second later, you see the blade at a position that is just prior to it's position in the previous image in your brain. The blades are turning at a frequency that doesn't coincide with the frequency you are processing their movement. So it appears to be turning backwards.

The degree to which a propeller appears to be turning backwards or forwards depends on it's speed of rotation. Spinning at lower that 50 Hz (50 times/minute) it looks like it's going backwards. Turning faster than 50 Hz and it will appear to be turning forwards (as it actually is).