The Marine Corps said yesterday that the V-22 Osprey, a hybrid aircraft with a troubled past, will be sent to Iraq this September, where it will see combat for the first time.

But because of a checkered safety record in test flights, the V-22 will be kept on a short leash.

The Pentagon has placed so many restrictions on how it can be used in combat that the plane — which is able to drop troops into battle like a helicopter and then speed away from danger like an airplane — could have difficulty fulfilling the Marines’ longstanding mission for it.

In Iraq, the V-22 will begin to replace the Vietnam-era helicopters that are increasingly facing enemy fire. The limitations on the V-22, which cost $80 million apiece, mean it cannot evade enemy fire with the same maneuvers and sharp turns used by helicopter pilots.

As a result, the craft could be more vulnerable to attack, and may result in the Marines keeping it out of the thick of battle, using it instead for less dangerous tasks.