Look folks, please try to understand this.
THERE AIN'T NO SUCH THING AS AN INVULNERABLE TANK / HELICOPTER.
The M1, in all it's varients is an extremely capable and survivable tank but it is not invulnerable. The armor is designed to defeat as much as possible whatever is fired at it but it can be penetrated, escpecially from the top, bottom, sides and rear by explosive and kinetic energy weapons. That is specifically why they placed the ammo rack behid a blast door and had blow out panels in the turret over the ammo storage area.
An RPG CAN make a mobility hit on the tank and then make the tank subjetct to more severe attacks by keeping it stuck in one area. The RPG can penetrate the sides of the tank hull and the crew injured from spalling and shrapnell inside the crew compartment. An urban combat environment is extremely hazardous for armored vehicles due to the proximity of enemy gunners and antitank weapons not to mention flanking shots from hide positions. That is one of the reasons that armor does NOT fight alone but is used in a combined arms operation so that each part of the team is supported by the other.
The same goes for the Apache. The running gear was designed to take 20mm hits and continue to work. Take a look at the size differential between a 20mm and a rpg. There is quite a bit more power in the rpg. Remember the experiance in Somalia, given enough rpg rounds launched, someone is going to take a hit that will take down the helicopter. Since the helo's have to support in a close combat environment (urban combat), that places them in reach of the manpads and rpg's that the enemy has.
It isn't a failure of the equipment, it's a failure of the understanding of the limitations of the equipment that leads to news stories complaining about losses of the vehicles. When you put combat equipment into a very hostile environment, particularly one that does not allow the crews to exploit their strengths, there will be losses. Period.
