To: helmet fire
If you want to make light of what I said that's OK and I do not claim to have an engineering background to perform ballistics design tollerance. However I worked very closely with those engineers that had that capability.
They performed analyses to determine the impact energy of small arms ammunition fired within a specific distance and from various directions. They performed further analyses to determine the impact energy of a tumbled 50 cal. round fired from a specific distance and various directions. From that they were able to design ballistic armor to protect the pilot and gunner.
The also performed analyses regarding the explosive energy released by a 23 mm round as well as a HEI round and from that they designed the transparent armor separating the pilot and the gunner and they also fed this information into the design of the main and other transmissions, the rotorheads and the rotor blades.
After the design was completed they performed live firing exercizes shooting the respective rounds into the respective structures. I do not believe that the components were dynamically loaded so there is a possibility that the respective tests were not truly valid. However the Army accepted the findings.
Here is something that should raise the hackles of a lot of the guys on this forum:
The US Army lied to the pilots of the Apache relative to its’ invulnerability to the ZSU 23-4 weapons system. This was the primary weapon that would be used against the Apache if it were to attack a group of Warsaw Pact tanks.
This weapon was also being supplied to all of the governments that were in league with the Warsaw Pact. The U S Army commissioned a study by a so-called ”Think Tank” to study the effectiveness of the ZSU 23-4 against the Apache. It was their considered opinion that the ZSU 23-4 was inaccurate, It had a low degree of reliability and that if the ZSU 23 did hit the Apache with one round, the pilot would have sufficient time to evade any further hits by dropping below the tree line. The uninitiated reader should understand that the ZSU 23-4 has a rate of fire of 1200 rounds per minute and that if one bullet hit its’ mark, there would be forty or fifty rounds right behind the first round.
When the I was on contract with Agusta helicopters I took a two-week holiday in Yugoslavia. While there, I watched a T V program, which was describing the weaponry of the Warsaw Pact. One of the weapons demonstrated was the ZSU 23-4. In the demonstration the weapon was pointed on a line parallel to a stand of trees. A helicopter popped up from behind the trees and in an instant the weapon acquired the helicopter and was pointed directly at it. The helicopter then dropped below the treetops and at that time the gun was turned off. The helicopter was allowed to fly away and the gun was turned on. It immediately started to fire and it swept an arc approximately 30 to 45 degrees on either side of center. The trees started to explode. It looked like there were hundreds of chain saw wielding loggers in the tree stand felling trees as fast as they could. It appeared to me that if a hail of 23mm bullets didn’t hit the helicopter, a falling tree would destroy it.
The only point of my post was to show that although the Apache was designed with a high level of ballistic tollerance it was brought down by small arms fire. (According to CNN).
