In message , phil hunt
writes
On Wed, 10 Dec 2003 04:51:34 GMT, Kevin Brooks wrote:

And I suppose designing that feature in and then doing away with it because
of its (relatively slight) increase in unit cost, as was done with the RAF
Typhoon, is not risky?

How much does a Mauser BK 27 cost, I wonder? I bet removing it would
save them no more than the cost of one plane, over the entire
programme.

The official explanation follows...

http://www.publications.parliament.u...cmpubacc/136/1
011710.htm#note12
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Select Committee on Public Accounts Minutes of Evidence
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APPENDIX 2
Supplementary memorandum submitted by the Defence Procurement Agency
00-01/62)

QUESTIONS 264 AND 306. BACKGROUND TO THE DECISION NOT TO EQUIP
EUROFIGHTER WITH A GUN

7. Since the introduction of air-to-air missiles, a gun has been
used in an air-to-air role for very close range engagements where the
target was inside a short-range air-to-air missile's minimum range.
Notably during the early years of the Vietnam war, the probability of
kill in short-range engagements of the air-to-air missiles then
available proved so low that the very modest capability of gun systems
added significantly to overall effectiveness. The probability of success
with guns has advanced little over the years[12]. By contrast, the
performance of air-to-air missiles has improved dramatically. Indeed, in
short-range engagements, the minimum range capability and agility of the
missiles that Eurofighter will carry, together with its planned
helmet-mounted sight targeting system, offers the pilot a shot with a
very high probability of success in almost every conceivable situation.
A gun could be seen as a defence of last resort when all the aircraft's
missiles had been fired. However, even then the gun's usefulness would
be severely limited because of the possibility of engagement by missile
armed aircraft from well outside the gun's range.

8. Firing "warning shots across the bow" with a gun is not an
effective means of coercion in modern operations. The cockpit
environment of modern aircraft is such that the pilot is extremely
unlikely to hear such warning shots and would only see them if they were
tracer rounds. The value of such a display against a civilian aircraft
is dubious and against a military aircraft it may well be misconstrued.

9. Against some threats, missiles may be susceptible to
counter-measures employed by the opposing aircraft. However, ASRAAM has
already proven itself against typical current countermeasure doctrines
and is designed to overcome extreme levels of countermeasures. Even
should an advanced hostile aircraft have decoyed Eurofighter's
air-to-air missiles successfully, there is again little benefit in
adding a gun to Eurofighter's armament. If the UK pilot were then to
close on that hostile target to within the range of the gun, he would be
placing the aircraft—and himself—at unnecessarily high risk of being
shot down by the hostile aircraft's own missiles. Moreover, gun systems
are not completely invulnerable to countermeasures, not least because
most depend on accurate radar range

10. As for air-to-ground combat, it is worth noting that the original
European Staff Requirement, signed by the Chiefs of Air Staffs from the
partner nations in December 1985, specifies the gun only in an
air-to-air role. So, even then, experienced airmen in the partner
nations did not regard the gun as a valuable weapon for ground attack.
It remains the view of experts that it is difficult to justify using the
gun in Eurofighter's offensive support role, owing to:

— the risk of collateral damage resulting from the relative
inefficiency of gun firing from a fixed-wing aircraft, especially in
this age of precision-guided munitions, with which Eurofighter will be
armed; and

— the increased vulnerability of the aircraft because the gun's short
range would leave the aircraft very exposed to surface-to-air missiles
and anti-aircraft gunfire.

11. Overall, therefore, it is clear that the utility of a gun on an
aircraft such as Eurofighter in modern operations is questionable. To
perform its roles effectively, Eurofighter's armament should emphasise
not the very short-range capability that a gun would offer, but the
long-range capability to be offered initially by the Advanced
Medium-Range Air-to-Air Missile (AMRAAM). and later by the Meteor beyond
visual range air-to-air missile.

12. The minimal combat value that the gun does provide is more than
outweighed by the support, fatigue and training cost penalties of
retaining it. Specific disadvantages of the gun include:

— the damaging effects of the shock of its recoil on the electronics
(approximately 4 tons recoil shock 30 times a second);
— the corrosive effects of its exhaust gas;
— the strain which it puts on the airframe, reducing the aircraft's
useful life. (Even the weight of 80kg of ammunition can add well over
half a tonne load at the wing roots of the aircraft when it is subject
to high gravitational pull in manoeuvre. Each aircraft has a finite
design fatigue life. Using up this life much more rapidly would require
us to purchase a greater number of aircraft or to undertake a life
extension programme, the cost and operational penalties of which cannot
be justified by the minimal operational benefits of the gun.); and
— a range of training costs, including the provision of new targets,
the increased demands on the Hawk aircraft towing the targets (which
must shortly be replaced by new aircraft), and the cost of removing
training rounds from the environment.

13. We understand that our partner nations currently intend to retain
the gun on Eurofighter. The American F-14, F-15, F/A-18 all have
internal guns, though the F-117 does not; and the F-22 is planned to
have one. The Russian MiG-29 and the Su-27/31 also have guns as do
Gripen and Rafale. Some of these aircraft types entered service many
years ago when missile technology was far less advanced. However, it is
not currently planned to fit an internal gun to the Short Take-Off and
Vertical Landing variant of Joint Strike Fighter (JSF), although it will
be able to carry an externally mounted gun which can be put on and
removed from the aircraft for particular missions.

14. Our assessment remains that, in the future operational roles for
which we require Eurofighter, the minimal value of a gun is more than
outweighed by its considerable associated costs and disadvantages.
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--
When you have to kill a man, it costs nothing to be polite.
W S Churchill

Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk