So apparently some use in Spec Op's though doesn't give an idea on how many hour's each air frame has on it. Only so much useful life one will get out of an air frame until it start's costing more to maintain it then to get an entirely new one.
I'd imagine the one's they rebuilding have low hour's, But I'm guessing no one has a rough idea on how many hours our's have?
Firstly I can't see that the Army is going to operate both the new F's and the existing D's side by side, two relatively small fleets of different spec will become a maintenance, logistics and training nightmare, just can't see it happening, but it doesn't mean that the D's can't be 'back traded' to Boeing to either be 'remanufactured' to F standard and returned, or even just back traded and replaced by new or remanufactured F's that are coming off the Boeing production line (our back traded D's would then go into the pool of airframes available for remanufacture by Boeing).
As far as your question about how many hours are on airframes, that really doesn't matter one little bit. Apart from 'new build' F's, the remanufactured F's are basically 'zero timed' when delivered back and the difference in price between the two is only a 'few' million, not 'tens' of millions.
You have to understand that a lot of the D's that are in service around the world today are in fact remanufactured from previous A, B and C models, in fact the D's in Army service today, four were originally C's that were delivered to the RAAF back in 1974 were manufactured in 1973 (what I don't know is if the 12 C's the RAAF received in 1974 if they were 'new' build or 're builds' of previous A or B models), and the additional four D's that were received by the Army from the US were all remanufactured from C's as well, one airframe dates back to 1968!
I've even read an article where a 'current' US National Guard D actually started life as an A back in 1961, the article also talks about the remanufacturing process too (see link below):
National Guard December 2014 Page 28
(Edit update: Try this link, it's easier to read):
http://nationalguardmagazine.com/ar...+‘F’+is+Excellent/1884756/238251/article.html
In the past the journey from A to D saw the same airframe carried through and other components either renewed or replaced (a lot of the 'donor' airframe lived on!), today with the remanufactured F model, the 'whole' of the airframe is replaced with a completely new airframe that has seen a lot of the smaller airframe parts, that were riveted together, replaced with much larger 'single' pieces and it's basically only the very 'large' components such as the transmission that is remanufactured and zero timed, the end result is that a remanufactured D to F results in an almost identical 'new build' F.
In regard to the MH-47G's, I understand that they are all being produced by remanufacturing previous MH-47D's and E's (I haven't read anywhere if Boing is actually making new MH-47G's from scratch, I believe the G's are all remanufactured?).
Anyway, if the Army is going to increase the CH-47F fleet (and possibly look at obtaining MH-47G's for the Special Forces too), it doesn't really matter one bit if they are 'new' or 'remanufactured', the end production is the same.
"Old Chinooks never die! They get reborn over and over, again and again!"