“Well that depends almost exclusively on the target.”
Indeed.
“One 500lb GBU-12 hitting a standard tank will destroy it.”
True, if it hits it. Thing is the best tank killer is another tank, and tank plinking may be fun but you only carry a few GBUs, whereas the 1100 rounds from an A-10 means 8-10 passes (not counting the Maverick load-out or its own GBU’s. Again, it is the ability to stay around and shape the battle-space.
“So why would you want to hit it with multiple strafe passes.”
One pass kills it. Move on to the next.
“One 2000lb GBU-10 will replace most buildings with a 50 foot deep crater. You couldn’t get the same effect with 100 strafe passes.”
Never said so. However, a Maverick missile will do some really bad damage, and the A-10 (with its loiter time) can make its own passes with PGMs and move on to the next building.
“What target are you thinking about where your weapon of choice would me a strafe pass over a PGM?”
Armour, armored infantry, infantry, CAS/TIC, even anti-ship (disabling).
It is a matter of flexibility and an ability to serve as a force multiplier.
An A-10 provides a mix of weapons (gun, PGMs), and has the gas to stay on station to provide that level of dedicated support that ensures the battle-space is affected directly.
More than a few times during Gulf War I, I was working a 4-ship of A-10’s as they pounded the pee out of the Iraqi's pass after pass after pass, and then some flight of F-16s shows up and calls only 5-minutes playtime. Great, hold the A-10’s high and dry, call in the Vipers with a GPS designated Tgt, whoosh and then call back the A-10s.
CAS is where the ability to provide precise weapons delivery really counts (and takes time to get eyes on, and also CAS means the friendlies are close and blast/frag means something, and a gun makes all the difference.
Bullets aren’t precision guided munitions. And while A-10’s are accurate strafers, they can’t match the probability of a kill on a strafe pass that they can achieve dropping a laser guided bomb. That is exactly why they now employ the same weapons in the same way as F-16s/15Es/18s/ B-1s/52s etc. and very rarely strafe. Are you aware that in the last decade, a vast majority of CAS has been conducted by aircraft other than the A-10? The argument that if the A-10 goes away, the Army will lose its CAS support has been invalidated by the simple reality that the A-10 has already largely been replaced in the CAS environment. And when it does perform CAS, it almost never does it from low altitude, or uses its gun. There are much better ways to perform CAS now, and all aircraft use essentially the same weapons and tactics to do it.
During Gulf War 1, CAS was conducted almost the same way it was in Vietnam. The only aircraft employing precision guided bombs were F-15Es and A-6s. Now, every aircraft uses them, and employs them with roughly the same targetting pods and tactics. That includes the A-10. In Gulf War 1, one of the most challenging missions was night CAS. You are most likely familiar with A-10s dropping slow burning flares on the ground to create measurement “units” that were then used to talk pilot eyes onto a target that may or may not have been visible under airborne flares floating down in parachutes. With the advent of IR targeting pods, night vision goggles, and IR laser designators, it is now easier to perform CAS at night than it is in daylight. If you were working a CAS mission now, you would pass GPS generated coordinates to the aircraft you were working. You may or may not even have to talk on the radio to do it. You could mark that target with an IR laser and ask the fighters what they see. From an altitude of over 20,000’ agl, those fighters could tell you something like “I see a small two door pickup with a heavy machine gun in the bed. There are four personnel standing near or on the pickup and another doinking a goat behind the bush next to the pickup. The man firing the machine gun is smoking a cigerette” You simply respond, “That’s your target, cleared hot”. 35 seconds later, a 500lb bomb with an accuracy measured in single digit feet, takes out everything including the goat, and you move to the next target. Does that sound anything like the CAS you conducted in Gulf War 1?
Loiter time is a key issue, but moving CAS out of the low altitude environment has significantly increased the loiter time of all aircraft involved. And note that moving CAS out of the low altitude environment didn’t decrease the accuracy of the weapons employed. It increased it. If loiter time is the most important factor, your favorite CAS aircraft should be the B-52. Dozens of laser and GPS guided bombs of all sizes employed using almost the exact same guidance systems as the A-10.
That’s a long way of saying that people who argue the A-10 is the only aircraft that can effectively conduct CAS, have very little idea how CAS is now conducted. Their previous experience (or more commonly, their perception of how CAS is conducted) is obsolete. That’s a good thing, because the technological advances we now use to execute the CAS mission have vastly increased the accuracy of weapons delivered and greatly reduced the time it takes to deliver them.