The rule is: you spend all your budget or they'll cut it next year.

Alot of the reasongs for the upgrades insteadojust buying an Apache have to do more with more than just unit cost. As I undserstand it itstill is going to cost less and require less maintenance effort per flight hour for a AH-1Z than a AH-64D. While a lot of off the shelf commercial electronicsare OK for grunt use. The military gets a littl more picky when they start sticking stuff in Aircraft so they have to go with what has gone through the lengthy testing and evaluation process. That is why your newswest miltary aircraft generally uses technology that is about 5 to 10 years old.

As far as I understand the situation: The marines had a lot of AH-1 getting pretty worn and with so cluttered a c@ckpit, the pilots lost situational awareness just strapping in! The obvious choice was a variant of the Apache, but that is a beast that needs pampering and a brain surgeon to get the compass working. So the practical marines decided to tear the AH-1 apart and see if there wasn't a bolt or two, that might be usefull. All helicopters are maintenance-heavy, but the Apache should be in a class all by itself, as far as I've heard.

So why the new main rotor and tail? They 412 rotor could have been used and just strapped on. The new ones are probably more efficient. but is it worth the cost?

another fact to consider: when any aircraft in US service gets a considerable amount of upgrades and improvements (NOT Service Life Extension Programs and refurbishing), it receives a change in its designation. Many of you are right in assuming an upgraded ("maxed out"?) Cobra to be more cost effective than re-equipping the entire USMC logistics system to handle Apaches. And there is the limitied parts commonality between Hueys and Cobras. Although the Cobra is covered in "paper thin" sheet metal, it has been discusses that there is sufficient power in the newer engines to "at a future date" have sufficient Kevlar-type armor sheets installed to give the pilots some small-arms protection. Since they are running out of designation letters, any such modifications would be designated as AH-1Z Block XX(?), kind of like how F-16's are done: one nation's F-16C is not always identical in options to another nation's F-16C. Cobras and Hueys are the same way. I wonder if it would be cost effective for The Corps to have an upgrade that borrows much of the Comanche technology shoehorned into the Cobra, instead of new-build Apaches.

One of the benefits of the AH-1Z/UH-1Y program is th eincreased commonality of parts between the two. I do not know if you would have that same commonality with the 412.

Why a whole new rotor system? In a military environment the 412 rotor system is far too lightweight. The civilian rotor system was not designed to take small arms fire let alone middle weight rounds. The Marines insists on the rotor system being able to survive a large shot from a weapon, hence the need for a new rotor system. Also the new rotor system used newer technology than the 412 rotor. And if that isn't enough to convince you...the 412 rotor system is designed to carry around a roughly 12,000 pound aircraft, the new cobra is going to be more like 18,000. at some point too much weight would make a 412 rotor just break off.

Heard from somebody that the Corpsis going for new UH-1Y instead of just rebuilds of older airframes.