A military spokesman in Baghdad said three members of the four-man crew were injured when the aircraft came down hard near the town of Taji, about 20km northeast of Baghdad.
The injuries were not believed to be life-threatening.
No further details were immediately available.
It is the third US helicopter to be brought down in the past two days. On Thursday, two marine Cobra helicopters were hit by groundfire near Falluja.
The two-man crews of both Cobras escaped without serious
injuries after the choppers crash landed and the US military
said the crash sites had been secured.
Damaged US armour
Elsewhere, Aljazeera has learned that three US military vehicles were damaged in an attack by armed men in Hiyt, west of Ramadi.
US tanks are regularly targeted
by anti-US forces
In a videotaped statement made available to Aljazeera, the 1920 Revolution Brigades, the military wing of the National Islamic Resistance in Iraq, claimed responsibility for destroying a US tank in Falluja city.
US military authorities have not commented on the incident but footage aired on Aljazeera clearly showed a US tank along a Falluja road being destroyed by unknown munitions.
There has been no information on its crew, however.
Earlier, The New York Times cited a report from an embedded journalist who described one US tank as being disabled by rocket-propelled grenade fire in the narrow streets of Falluja.
At least 22 US soldiers have been killed and more than 200 wounded since US forces launched their latest assault on Falluja on Monday, a US general said on Friday.
Five Iraqi support troops were killed and some 34 others wounded.
Of those wounded, 40 were treated and returned to duty, Lieutenant-General John Sattler said.
He said about 600 anti-US fighters had been killed but there was no independent confirmation of the figure.