the capabilities of the super tucano was derived from a specialized Bronco OV-10D NOGS (Night Observation & Gunship). To me this is still the best COIN aircraft ever designed. From a standard OV-10A they installed:
- chin mounted FLIR turret (forward-looking IR)
- M197 3-barrel 20mm rotary canon in an underbelly turret
- the cargo space behind the cockpit which originally can carry 4 paratroops, were converted to carry more fuel and a lot of ammo for the gun turret
- fuel from wing tanks + cargo bay meant longer loiter time
- silenced engine with exhaust pointing upwards to reduce ground IR signature
- titanium bathtub underbelly can take hits up to 23mm shilka rounds

They tested this gunship in a central america rainforest in the mid-80s and put it in auto acquire and destroy mode. The FLIR picked up a lit cigarette through thick foliage at an altitude of some 500 ft. The rotary canon was slaved to the FLIR and opened fire using compressed flechette rounds (like hyper-velocity nails going through tree trunks). The following morning they checked the target area by helo and found all the insurgents with bodies turn into kitchen seives.

The USMC liked it so much that they tried to make a hellfire gunship out of it!
It didn't prosper since the top brass didn't like propeller aircraft and the airframe of the bronco was too old.