On 16 Dec 2003 23:36:41 -0800, (Tony Williams) wrote:

"Brett" wrote in message ...
"Tony Williams" wrote:
"Brett" wrote in message
...

__Burbage emphasized that both the BK 27 and GAU-12 were able to meet
JSF's lethality requirements, which include probability of kill and
accuracy. He said the GAU-12, which has a higher rate of fire than the
BK 27, was able to meet the requirement by putting more rounds on the
target.
"Performance and affordability are equally important in our selection
process," Burbage said. "If we have two candidates that are comparable
in technical performance, but have significant differences in terms of
affordability, we will pick the one that is more affordable."

Burbage also said there were more technical negatives against the BK 27
than the GAU-12. Cost in three areas, unit recurring fly-away cost,
ammunition, and operational support, tilted the decision in favor of the
GAU-12, he said.

"In all three areas, there was a benefit to the GAU-12," Burbage said.__

see: http://stage.defensedaily.com/VIP/dd...ddi1122.htm#A3

Having studied that article, a couple of interesting points emerge.
The first is that GD withdrew its proposal for the GAU-12/U in
February 2000 "in part due to a belief that the gun did not meet the
necessary requirements." The second is the comment from Burbage that
"We spent a lot of time balancing performance and cost, looking for
best value."

I find it hard to imagine that GD would make such a mistake in
understanding the requirements (in my experience of tendering, it's
more usual for firms to submit non-compliant tenders then argue why
they should be accepted despite that!). Reading between the lines, it
seems most likely that the GAU-12/U did not meet the original
requirements, but when the costs of the BK 27 became an issue, L-M
revisted the requirements and "balanced" them to allow the GAU-12/U to
compete. Or am I just too cynical about the way things work?

"Too cynical", the M61 20mm Vulcan was apparently also considered during the
evaluation and you appear to forget that all the results of the evaluation
would ultimately be judged by the Air Force JSF office.

Which suggests that the initial 'order of merit' after assessing how
well the competitors met the stated requirement was: first, BK 27,
second GAU-12/U, third M61A2.

That raises the interesting question of why the F/A-18E/F and F/A-22
are equipped with the M61A2 instead of the GAU-12/U - I have wondered
about that before. Yes, the M61 is lighter and faster-firing, but the
extra range, reduced shell flight time and much superior hitting power
would have more than compensated, I would have thought. After all, the
USAF originally planned to move to a 25mm gun in the early 1970s (the
GAU-7/A), and would have done so if it wasn't for technical problems
with the combustible-case ammo.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Military gun and ammunition discussion forum:
http://forums.delphiforums.com/autogun/messages/

The F-35 is optimized for air to ground, while the F-18 and F-22 are
optimized for air to air. Different targets, different guns. The GAU-12
is also used in ground to air.

Al Minyard