F-16 vs. A-7 Corsair II ground attack.

[lampshade111]

This isn't about air-to-air as the F-16 clearly has the edge. But which aircraft is superior in the ground attack role? Which has the better range, endurance (loiter time), and accuracy when dropping unguided bombs and even a rare rocket and gun run? What about payload? Should the USAF have pursued the A-7F as an attack aircraft into the '90s and the 21st century?

The reason I ask this is due to the reputation the SLUF has in this area. By most accounts it's avionics raised the bar for bombing accuracy, and it could fly long missions. The F-16 by comparison was originally designed as a pure light-weight fighter and is widely seen as having a short range (althought CFTs can certainly help in that regard.)

[outlaw162]

Except for the PMDS (moving map) in the A-7, the Viper was the preferable aircraft from a pilot standpoint in all ways. Other than the possibility it would have been the size of a silver dollar, why didn’t GD put a moving map in the Viper?

The A-7 may have been able to fly for a looong time on internal fuel, but naturally Vought managed to find the most uncomfortable ejection seat available anywhere for it. The Guard wisely passed on the A-7F to get the Viper.

(The F-4 of course had the talking map.)

OL

[johnwill]

"why didn’t GD put a moving map in the Viper? "

GD did nothing the AF wouldn't pay for, so ask the F-16 SPO why they wouldn't pay for a moving map.

[outlaw162]

Sorry, let me rephrase that.

Why didn't the USAF put a moving map in the F-16?

OL

(It was a rhetorical question anyway)

[lampshade111]

I'm bringing this topic back from the dead I know, but I am curious as to what enabled the A-7's long range and loiter times. The F/A-18 Hornet wasn't able to match the Corsair II in those areas, and I rather doubt a F-16 (without CFTs or external tanks) could fly a similar 2 and 1/2 hour mission with 5,000 pounds of bombs. Yet how much internal fuel did it carry? I can't seem to find a figure anywhere. Surely it's TF30 or TF41 engine wasn't more efficient at mil power than the F100 or F404.

[madrat]

You might PM Gums or Snake-1 for an answer. If I had to guess the lower wing loading, smaller exposed front section, and absence of the afterburner weight would make a difference.

[outlaw162]

A-7D had a little over 9000 lbs internal fuel.

I'll get back here a little later if Gums doesn't jump in first, but your attributing things out of context to the A-7 that it couldn't really do and not taking into account that an F-16 with two bags can fly longer, further, faster and at any time easily outperform a clean A-7 in any part of its envelope.

OL

(Got 1100 in the A-7)

[outlaw162]

Doctor’s waiting rooms all day.

A little hazy perspective on this from an old guy…

The A-7D carried just over 9000 lbs internally; the F-16A carried just slightly less than 7000 lbs internally.

If you compare just the basic clean A-7 to the basic clean F-16A at the same speed and altitude, the F-16 (F-100) will have a lower fuel flow than the A-7 (TF-41) converting those internal fuel values to about the same amount of flying time. For sheer endurance, the A-7 actually might come out ahead by a few minutes at L/D max just based on that 2000+ lbs more fuel. L/D max is generally a useless speed however unless you're holding near the base or running on fumes in the middle of nowhere.

The longest amount of time I ever flew a clean A-7 with no external tanks was 2 hours and 45 minutes from Grissom AFB to Tucson IAP, about 1300 NM. This was at .76 mach and step climbed from 31,000 feet to 39,000 feet. This accomplished absolutely nothing of tactical value and only transported me from point A to point B. I got to Tucson with 1200 lbs of gas so my average fuel flow using about 8000 lbs of gas was right around 2900 lbs/hr. A clean F-16A would have done the same thing at 43,000 feet at .85 mach in 2 hours and 30 minutes with an average fuel flow of around 2400 lbs/hr.

If the A-7 did .85 mach it couldn’t have made it, whereas an F-16 at .76 mach would have probably been fine, except for wasted time, but there was a point you could go too slow.

I’ve cruised a clean F-16A at .95 mach for 700 NM and arrived with over 2000 lbs of fuel. An A-7 was hard pressed to sustain .86 or so, but would of course have more gas left over after 700 NM.

An A-7 without external tanks would not fly for 2½ hours unrefueled with 5000 lbs of ordnance (requiring MER’s or TER’s) in other than a hi-hi-hi tactical scenario. I believe Gums said the USAF flew them with two external tanks and two MER’s (6000 lbs of MK-82’s). They did great work this way.

For what the Guard was generally forecast to be tasked with, the Guard preference was to fly them down low with 6 Mk-82’s on the pylons or 2-4 Mk-84’s. You were good for about 1 hour and 30 minutes at 450-500 KIAS. But you configured based on the tasked mission, sometimes draggy to the point you couldn't get 500 KIAS. The F-16 could fly the same mission profile clean or with externals and have the option of flying it faster. That's the difference, the A-7 really never had the option of doing anything faster.

Usually not this wordy, but I really enjoyed the A-7. I would think Gums could add to this and the current Viper drivers could correct any of my errors.



OL

(Know nothing about the F-18, but suspect with 2 or 3 tanks it will fly longer than an A-7 and still easily outperform it.)

[aaam]

Couple o' notes, remember we're talking about the planes as they existed 20 years ago, not an A-7 of then with an F-16 of today, and only the ground attack role is relevant.

Guard didn't pass on A-7F. AF wouldn't allow the plane to be evaluated. Guard buys what it's told to buy. An A-7F (which would have been a big jump in performance with more fuel and either an F100 or the preferred F110 engine) would have cost about 2/3 of an F-16. AF really wasn't interested in a ground attack plane (remember if it hadn't been for Desert Strom, the A-10 would have been gone in a few years) as it was in more fighters.

With dumb bombs (there weren't that many smart ones yet), the A-7 was the most accurate attack aircraft around, next to the AV-8B (which had the Angle Rate Bombing System).

A-7 had very low loss rate.

A-7s were miserly on fuel. During Desert Storm, the only time both of them were flying the same missions, the A-7Es required far less tanker support than the F/A-18. USN even used them as mini-tankers as well as strikers

[skicountry]

By 1985, the Air Force did not consider the A-7 (or the A-10) to be effective or survivable on the 1990s battlefield. It thought the F-16 could do a better job than either the A-7 or the A-10. The A-7 was judged to lack the thrust and maneuverability to survive against Soviet SAMs and air-to-air threats. Its accuracy and endurance were outstanding, as Gums and Outlaw have reminded us, but the A-7 was a mid-1960s design that was bested by the F-16 in almost every aspect including mud-moving.

The A-7F came about because the Air Force wanted to replace both the A-10 and the A-7D. The A-16 was proposed to replace in the A-10 in the regular force while the A-7F would have replaced the A-7D in the Guard. I know aaam has mentioned the relative cheapness of the A-7F but I’m not sure it wouldn’t have turned out almost as pricey as the F-16/A-16 variants. The whole program was halfheartedly run and there wasn’t all that much analysis put into it, but the last price estimate for a Pratt F100 powered A-7F was $14.2 million (I believe that was in 1988 dollars). Amazingly, that price did not include a new radar or glass cockpit, which the Air Force said it didn’t need right away. It also did not include the price of the LANA night targeting pod (some of which were in stock already) or the cost of replacing suspected rotting wiring that might have added an additional couple of hundred thousand dollars to each aircraft. General Dynamics was claiming at the time that it could convert F-16As to A-16 configuration for around $13 million per aircraft in 1986 dollars.

By the way, the Air Force initially chose the upgrade route (A-16/A-7F) because it desperately wanted to avoid incurring the costs and risks of developing an all-new follow-on design to the A-10. Estimates for an all new program were $2.5+ billion development costs and up to $30 m per aircraft acquisition costs. This threatened the ATF (F-22), ATB (B-2), AMRAAM, and LANITRN programs, all of which had a higher priority for Air Force leadership.

Finally, for what its worth, here is a little schematic comparing the bombing accuracy of different aircraft. I believe it’s sourced from Lou Drendel’s 1982 vintage F-16 book.

[aaam]

Actually, I'm quite familiar with the A-7F program, and I remember this a little bit differently.

For one thing, many were skeptical about AF's (as an organization, not the aircrews) commitment to true CAS, and it was said that CAS-X program & the "A-16" was a ploy for more straight F-16s. I would think that the A-16 conversion was kind of a straw man, because AF naturally didn't want to cut back the total number of "straight" F-16s, so either GD produced new A-16s, or converted early Fs to As and then AF bought more Fs. It should be noted that the specialized "A-16" version disappeared fairly early on during this period and AF said, we'll just use regular F-16s, can we have some more please? This was around the time of the statement (quoted in Armed Forces Journal and elsewhere), "The best thing the Air Force can do for the ground troops is to win the air battle". No, it's been so long I don't remember which AF official said that, but clearly he had never faced a tank coming at him.

AF quickly lost interest in the CAS-X program, which attracted proposals from five companies. Congress, however, directed that the AF evaluate the A-7F, and put a line item in the budget funding and directing just that. It is true that there wasn't much analysis, but I would opine that was because AF simply wasn't interested and was just going through the motions that Congress directed. You know, "OK, we flew it. Now can we have some more F-16s"? They never got far enough along to get to final pricing, because that would depend on what AF would specify in a "production" (acutally all rebuilds) model, but the consistent number was that an A-7F would cost 2/3 of a comparably equipped F-16. With the F100 engine, radius on a Hi-lo-hi with 2 AIM-9s, 6 Mk 82s, FLIR and the gun would be 455 nm on internal fuel alone. This assumed no a/b use, because it wasn't necessary to fly the mission (A-7F on military power alone had far more power than A-7D), but even with 2 min a/b, radius would still match that of the A-7Ds

That is a nice graphic, but whether it is definitive is open to question Depends on the conditions under which each a/c "dropped".

LANA was talked about because it was already there, but LANTIRN would have been mounted when available, if so desired. LANA would have been mounted in a wing pylon, similar to how F-15s are going to be equipped with IRST on the center station.

Regarding the A-7F glass cockpit, again depends on what AF wanted, but here's one of the options:

[skicountry]

Good info aaam. Not much to dispute there. There was a famous political cartoon depicting two Russian tank drivers in a Parisian bar sipping on drinks, with one asking, “By the way Ivan, who ended up winning the air battle?”

I agree that the Air Force, as an organization, was not interested in the CAS mission and was pushing for BAI and preferably outright AI, where it could operate without Army interference. The A-10 couldn’t do that. The F-16 could. The AF has for decades maintained, through its doctrine, official pronouncements and force structure, that the tactical level of war (CAS) is not where its institutional heart lies. Instead, the operational and especially strategic levels are where airpower can be most useful and decisive.

This is in part why the AF joined the Army in its AirLand Battle doctrine. The doctrine’s focus on the second echelon, deep in enemy territory, gave the AF a mission that it truly wanted to do and justified all those fancy and expensive systems that it was so fond of (LANTIRN/Stealth/F-15E/JSTARS/etc). It didn’t need to fly the A-10 anymore because the Hog couldn’t survive a second echelon attack. As we have discussed in an earlier A-16 thread, the mission focus shifted towards BAI with a secondary requirement for CAS, with the Air Force maintaining that a single design, the A-16 or A-7F, could do both. Notably, the Army brain-trust at TRADOC supported the AF on this.

DOD and Congress, on the other hand, were not so sure and constantly interfered in the process worried that the Air Force was going to do as you have suggested – take their A-16s and fly them off the battlefield to do their own thing. The OSD forced the AF to go through the CASADA study and made it jump through all sorts of hoops to justify its forces structure decisions. Feeling the pressure, deputy TAC chief Gen James Brown, retorted, in 1988, that the A-16 was going to be unfailingly dedicated to Army commanders and to prove that, the Air Force was going to “even give it an Army paint scheme.” (that is a direct quote from memory) There was also the famous, and much derided Bob Russ quote, “everything that TACAIR does supports the Army.” The A-16 concept was still on the books in 1989 when the Soviet bloc, and its second echelons, vanished into thin air. With the second echelons gone, it no longer made sense to purchase “specialized” BAI aircraft and regular F-16s were bought instead.

History, as you well might know is quite malleable. I’ve spent a bit of time with my head buried in the archives in Washington, Maxwell and other places, and talked to a few people who were in the heart of this debate. I have found that any number of “personalities” from that period have attempted to shape their legacy after the fact. It really does depend on who you talk to or whose file you open. And just when you think you’ve got a grasp of the subject, Gums helpfully comes along and completely blows your mind and makes you go back to square one (thanks Gums!). All this to say, that while my professional background is in diplomacy and weapons acquisition, I’ve had a great personal interest, and indeed have done grad work, on this exact topic. I am happy to glean anything new on it.

By the way, one of the reasons why the AF chose to upgrade the A-7Ds was the huge amount of airframe life left on them, even after 20 years of flying. The AF estimated its A-7Ds to have a 14,000 hour life – the fleet average in the late 1980s was only 3,400 hrs! The Navy’s A-7Es were in nowhere near that good a shape.

[aaam]

Thanks, skicountry.

Another reason the A-7E was dropped from th upgrade proposal was that AF decided it wouldn't want/need as many CAS-X assets, and to convert the A-7E you'd have to change the refueling system, add bigger brakes and change some radios. Not super-expensive, but more than AF wanted to do.

Again, though, it seems that AF wanted F-16s so they did what Congress directed and no more. They flew the planes and then parked them.

One ended up at the Hill AFB museum, and the last time I saw the other one was in late 2009, baking in the sun at South Base at EDW.