A number of other US and Iraqi soldiers were wounded.
"Two UH-60 Blackhawks have crashed while landing at Combat Outpost Ford in Adhamiyah at about 8.55 pm (1755 GMT)," military spokesman, Patrick Evans said.
"One Iraqi army soldier is killed. Two coalition forces and two Iraqi army [soldiers were] wounded," he said, adding that the "situation is under control".
"Emergency services are on the scene," he said.
A Reuters cameraman near the scene said he heard an explosion after the impact,
followed by the sound of shooting.
Local residents said security forces cordoned off the area and did not allow traffic or pedestrians to get through to the crash site.
Army transporter
The UH-60 is the workhorse of the US military and operates in pairs. Each aircraft crew consists of two pilots and two gunners.
The latest US helicopter incident comes 17 days after another US military helicopter crashed in southern Iraq, killing all seven soldiers aboard.
The CH-47 Chinook crashed about 100km west of the main southern port city of Basra as it formed part of a four-aircraft convoy flying from Kuwait to the northern city of Balad.
The US military had said that they did not suspect enemy activity in the September 18 crash too, but investigation findings have not been published.
The worst single crash was on November 15, 2003, when two Blackhawks collided near the main northern city of Mosul, killing 17 soldiers.
In August last year, a Blackhawk transport chopper crashed in northern Iraq, killing 14 US military personnel.
Two American soldiers were hurt when their helicopter crashed south of the Iraqi capital Baghdad in June this year.