To: Rich Lee
I do not question the lethality of the Apache. In the view of lethality it is second to none if you don’t consider the A-10 or the C-130 gunship. The point I was making deals with the survivability of the helicopter.
A great deal of effort went into the vulnerability analysis. This consisted of the use of ballistic armor on either side of the pilots, the use of transparent armor between the gunner and the pilot, the use of ballistic armor around the servo systems and the use of “armor “”between the engines.
The main transmission was designed for 30 minutes of flight without any oil in the sump, the use of viscous lubricant in the intermediate and tail rotor gearboxes.
The analysis also consisted of using non-essential components to mask the entry of small arms fire from the ground into the cockpit area.
The main weapon that the Soviet bloc would use against the Apache was the ZSU-23-4 so the Apache had to be invulnerable to one hit of a high explosive incendiary round in one of several places on the helicopter. The ZSU-23-4 shoots around 1200 rounds per minute so if one round hit the Apache it would surely be hit with 20 or more rounds including HEI rounds.
The vulnerability analysis included in the study of the ballistics of small arms ammunition, the effects of being hit by a tumbling 50 cal round fired from a specific distance and the HEI round.
Tests were run to verify that the helicopter could survive in an intensive ballistic arena and I believe the tests, which did not reflect dynamic loading of the elements under test, were successful. I made my comments based on the design requirements specified by the army and, in the fact that small arms rounds downed many of the Apaches.
Oh yes, regarding the ballistic armor that was just inside the skin of the Apache and used to protect the pilots we had a guy in our department that had a hobby of loading his own ammunition. He borrowed a section of the armor and used it as a target at 100 yards. He brought the armor back the following Monday with a hole in it. The armor did not distend in order to absorb the ballistic energy.
Please note that my comments are based on what was during the design phase and some things may have changed.
