The Myth of High-Threat Close Air Support

June 30, 2016

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Close air support (CAS) is air action by fixed-wing and rotary-wing aircraft against hostile targets that are in close proximity to friendly forces and requires detailed integration of each air mission with the fire and movement of those forces.

Department of Defense Joint Publication 3-09.3

The (eventual) retirement of the A-10 Warthog has been a challenging issue for the Air Force.  The original plan to replace the A-10 entirely with F-35 has fallen by the wayside, buttressed by the reality that the extended combat deployments undergone by the fighter/attack force were never envisioned when the F-35 plan was hatched.  Twenty-five years of continuous conflict, most of it irregular in nature, has highlighted the utility of a relatively slow, heavily armed multirole aircraft.  Our operations over the past decades have been largely very similar to the kind of counterinsurgency demands that led to the requirement for a new attack aircraft (then called A-X) in 1966.

As the Air Force has moved toward the position that a replacement attack aircraft (A-X2 or OA-X) is necessary, one persistent issue continues to arise:  What kind of aircraft might be able to do “high threat” CAS?  In a presumed environment where the air defenses are too lethal for the A-10 to survive, wouldn’t the F-35 be a better alternative?  The question itself is highlights a persistent trend in Air Force concept development — a mythical set of conditions that is highly unlikely, fundamentally not credible, based on a misunderstanding of the air threat, or, in this case, all three.  There is no reasonable case to be made for an aircraft that can survive in a high-threat CAS environment, because there is no credible case to be made that any aircraft can survive in such an environment.  It isn’t that there isn’t a need to apply airpower in such an environment. Rather, it is that having a need doesn’t equate with delivering a capability.  The idea that the Air Force can deliver effective CAS in a highly contested environment is a myth, one that the Air Force would be well served to get rid of.

A Challenging Environment

A high-threat CAS environment involves a situation that is unprecedented in Air Force history.  In this scenario, U.S. ground forces are in need of aerial fire support while under an adversary air defense umbrella.  The air defenses are so severe that legacy aluminum jets are useless. Only stealthy aircraft or standoff munitions can save the day for the beleaguered infantry.  Into this scenario are shoved several potential concepts, including the F-35 in a CAS role, the “weapons-centric CAS” concept, and the ubiquitous use of standoff weapons to provide responsive fires from great distance.  Aside from the fact that this kind of fire support is best provided by long-range artillery, the idea that CAS can be conducted in such an environment fails on two fronts: it is extremely unlikely that we will have ground forces in this condition, and the postulated environment is too lethal for even stealth aircraft.

For more than a decade, the idea that “capabilities-based” threat analysis could provide a valid input to defense planning has held sway.  In the absence of a defined strategy, a planner could simply match adversaries somewhere in the world with capabilities, also available somewhere, to create a new threat against which the defense strategy could be developed.  A lazy approach to strategic planning, it allows for the ludicrous matching of “one from column A and one from column B” adversaries and capabilities.  Reality is more constrained. Only Russia and China have the force structure and design that pose a substantial threat of this nature.  Iran’s air defenses have not largely embraced a mobility doctrine, and if North Korea ever goes on the offense, their radar SAMs will be left where they are.

With that grounding in reality, the follow-on question remains: Under what conditions might we see a demand for CAS?  With respect to China, the answer is easy.  We won’t.  There are no U.S. ground forces stationed in positions where they are in danger of being overrun by the People’s Liberation Army.  We’re not going to ever stage an amphibious landing on the Chinese mainland, and if we did, no amount of CAS is going to save those Marines from rapid annihilation.   The idea that we could push a landing force through an air defense environment is ludicrous on its face, and it’s never been done.  Any expectation that China would replay the Korean War and join a North Korean attack on the south is similarly unlikely.  If we face a high-threat CAS environment, it won’t be against China.

Russia’s resurgence offers a slim reed to grasp for the purveyors of the high threat scenario.  It might be possible for the Russians to overrun one of the U.S. Army brigade combat teams permanently stationed in the Baltics.  Except that there aren’t any.  U.S. Army Europe is so depleted that it lists two stateside divisions on its homepage.  This is justified by the idea that the 3rd and “4th Infantry Division is a regionally allocated force, or CONUS-based force that falls under operational control of USAREUR when deployed to the European theater.” Unfortunately, the 3rd ID (Georgia) and the 4th ID (Colorado) aren’t likely to arrive in time to save the day.  The ground combat power in Europe is limited to the 2nd Cavalry Regiment in Germany and the 173rd Airborne Brigade in Italy.  That’s one regiment and one brigade, neither of which has a land route to the Baltic states.  And let’s face it: Any environment bad enough to prevent aluminum jets from providing CAS isn’t going to allow airlift aircraft through to drop airborne infantry or allow passage of sealift packed to the gunwales with Stryker armored vehicles.

The logical convolutions required to place U.S. forces in a position where CAS is required in a high threat environment are a stretch.  They require the presence of forward-deployed combat forces in danger of being attacked by Russia or China upon short notice or the existence of a joint forcible entry into the teeth of advanced defenses.  Neither condition is credible.

The Evolution of Divisional Air Defense

The Air Force has never done anything that looks like high-threat CAS in a modern environment.  Arguably, it has never done CAS inside an intact air defense environment.  Certainly there have been threats to CAS aircraft. It is a dangerous mission that often involves loitering over enemy ground forces. The largest modern dataset was provided in Operation Desert Storm, where Iraqi Army and Republican Guard formations lost their strategic SAM coverage and most of their few radar systems but continued to pose a threat with IR missiles and anti-aircraft artillery (AAA).

When the A-10 was designed, the primary AAA threat posed by a Soviet motor rifle division was the 14.5 mm heavy machine gun, which was visually aimed.  The 23mm threat was present in small numbers. Each division had four 4-vehicle platoons of the ZSU-23-4 Shilka antiaircraft tank, which had its own fire control radar meshed with four 23mm automatic cannon.  Small numbers of visually-aimed 57mm cannon were also expected, along with SA-7 and SA-9 heat-seeking surface-to-air missiles (SAMs).  SA-6 radar SAMs entered production in 1967, before the A-X concept was formalized.  As has been amply demonstrated in combat, this combination of weapons can and does bring down aircraft, although the A-10 proved remarkably resilient.

But Soviet designers were unimpressed by their own 23mm cannon and by the Gainful missiles of the SA-6.  Even before Egyptian Shilka and SA-6 Kub systems devastated low-flying Israeli jets over the Sinai in 1973, the Soviets were moving towards heavier guns and more lethal SAMs.  The 23mm round was largely abandoned in favor of the 30mm cannon, and the Tunguska was delivered to the Red Army while the A-10 was still in its production run.  The Tunguska was everything the Shilka wanted to grow up to be — it had four 30mm cannon, an acquisition radar to go with the HOT SHOT fire control radar, and four (soon to be eight) SA-19 radar missiles on the sides of the turret.  The optical sighting system incorporated a thermal camera.  A Tunguska gunner was spoiled for choice when it came to weapons selection, and it was blessed with a round that weighed twice that of the 23mm cannon with half again the muzzle velocity.

Similarly, the SA-11 Buk was a substantial improvement on the SA-6, adding more missiles with better capabilities and quadrupling the number of target tracking radars in the battery.  It had longer range, fancier radars, a quicker reload, and an optical night capability that the SA-6 lacked.  It entered service when the A-10 was halfway through its production run.

The air defense threat posed by the Chinese and Russians only got worse after Desert Storm in 1991.  Russian and Chinese designers saw the effect of precision weapons and elected to try and intercept those too.  The Russian SA-15 Tor and the SA-22 Pantsyr advertised anti-munition capability.  The Chinese played another trick by taking naval gun systems designed to defend ships and placing them on trucks.  To add insult to injury, the LD-2000 system is a radar-controlled, seven-barreled Gatling gun derived from the Dutch Goalkeeper — which uses the very came GAU-8A cannon embedded in the A-10.  A cannon designed to bust medium tanks (from the side, anyway) makes a dandy antiaircraft weapon, and with good fire control it is absolutely capable of engaging munitions.  These system examples are not isolated — at least in Russia and China, counter-munition capabilities have become ubiquitous among the air defense units assigned to protect moving ground forces.

Faulty Concepts

Modern high-threat CAS concepts promulgated within the Air Force largely miss the goal because they conceptualize an air defense environment that departs from reality.  If aluminum jets can’t get to the target, neither can aluminum and steel weapons.  Even America’s vaunted stealth capabilities do it absolutely no good at gun range.  The detection range curve for the SA-22 in Figure 1 demonstrates diminishing returns — even reducing the radar cross section to the target to a spectacular one ten thousandth of a square meter (one tenth of a blue-winged locust) still allows the SA-22 radar to track at gun ranges.

Figure 1: Estimated Detection range Curves for the SA-22 (Dr. Carlo Kopp)

The radar stealth issue is itself a red herring.  One U.S. Air Force officer recently claimed that the F-35 would perform CAS using methods that allow it to loiter around the battlefield at medium altitude locating and targeting SAMs “without the threat knowing I’m there”, essentially claiming that he could mix suppression of enemy air defenses (SEAD) and CAS together in an invisible single-seat airplane loitering in hostile airspace.  This in a dark-colored, medium-sized aircraft that has an exhaust hot enough to melt steel decks, and only against SAM operators stupid enough to turn on their radars before they have a target.  SAMs and radar-guided AAA almost always get to attack from ambush, and they can be cued by other radars, optical or heat sensors, or individuals with ears and a pair of Mk 1 eyeballs.  Not all systems are radar-guided and some can only be located by the missile exhaust or muzzle flash — by which time they have already fired.

In Desert Storm, the radar threat was effectively neutered within 72 hours, leaving guns and heat-seeking SAMs functional (they are effectively impossible to suppress) and capable of hitting aircraft.  The vast majority of aircraft hit in Desert Storm were hit in the target area, with most hits being on aircraft loitering over Iraqi ground troops (A-10, OV-10, AV-8 and F-18).

Figure 2: Aircraft lost and damaged by phase of flight, Gulf War

Aircraft that typically loitered looking for targets were treated as being “in the target” area — this covered all Battlefield Air Interdiction (BAI), CAS and Forward Air Control (FAC) taskings, plus interdiction tasked A-10, AV-8B and Marine F/A-18.  Hidden in this data is the fact that most aircraft that were successfully targeted were exposed to hits because they made repeated attacks in a target area or loitered in the threat area near ground troops. This is the reality of the CAS mission — loitering in the vicinity of troops protected by ground-based air defenses.

Expanding the data set to include all NATO fixed-wing combat aircraft for all conflicts since the Falklands reveals that even a benign CAS environment isn’t benign.  CAS and BAI sorties count for more aircraft hit than interdiction sorties, even though interdiction sorties are vastly more common.

Figure 3: Loss and damage by mission, all NATO nations, 1982-1999.

Put simply, aircraft which loiter over dense concentrations of air defense systems are going to get hit. Air defenses are more lethal than ever before.  Therefore, an aircraft performing traditional CAS in an evolved air defense environment is likely to get hit.  At a minimum, this means that it flies home, but against a modern threat, it more likely means that the aircrew walks home.   Russian and Chinese tactical air defenses are entirely capable of hitting loitering targets and their munitions, and targets that get hit will not be able to shrug off the damage.


In certain environments, CAS is not a practical option, be it in a traditional fashion or within a tactically questionable concept where weapons are lofted in from outside.  Even stealthy aircraft, as they currently exist, are not designed for this environment and are at a serious disadvantage against short-range air defenses even if the longer-range SAMs and interceptors are neutralized or suppressed.  This condition presages the conditions that are likely to prevail if directed energy weapons take the field in numbers and where merely flying within view of an air defense energy weapon may be impossible.

Accepting that some missions are effectively impossible is an acceptable outcome, because the conditions under which high-threat CAS might be required are unlikely.  This is one of those cases where even an unabashed airpower advocate like myself may have to admit that there are cases where airpower is not only not the best option, but may not be a practical option at all.  The high-threat environment may, in fact, be the best argument for land or sea-based precision artillery, which flies faster, can be massed more effectively, is less subject to intercept, and is substantially cheaper than any conventional, air-delivered option.  It is absolutely unnecessary for the Air Force to pursue an expensive, technologically challenging, tactically unexecutable, and strategically infeasible capability that unnecessarily duplicates artillery capabilities resident in the other services.  If the Army or Marine Corps believe that they need fire support in an environment where even air-launched weapons are likely to be intercepted, then they should be encouraged to invest in their artillery capabilities.  For the Air Force, making an argument that airpower can be effective in performing high threat CAS is not a credible story and could drive an unnecessary and unproductive diversion of scarce resources.  There are other problems to solve with airpower.


Col. Mike “Starbaby” Pietrucha was an instructor electronic warfare officer in the F-4G Wild Weasel and the F-15E Strike Eagle, amassing 156 combat missions and taking part in 2.5 SAM kills over 10 combat deployments. As an irregular warfare operations officer, Colonel Pietrucha has two additional combat deployments in the company of US Army infantry, combat engineer, and military police units in Iraq and Afghanistan. The views expressed are those of the author and do not necessarily reflect the official policy or position of the Department of the Air Force or the U.S. government.

Image: U.S. Air Force photo, Master Sgt. Lance Cheung

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15 thoughts on “The Myth of High-Threat Close Air Support

  1. As a former CAS Guy (AC-130) I agree and disagree with this article.

    For agree: I appreciate the argument regarding the capability of an F-35 vice more traditional CAS platforms. It cannot be reasonably argued that they both provide similar capabilities. Also, I appreciate the conventional force on force comparison in a high threat environment and agree CAS like that is difficult in a true high threat.

    For disagree: I think the author has two flaws. 1. In a force on force environment you have to consider the complexity and density of the air picture. If a true FEBA/FLOT war happens the skies will be filled with assess from F-16CJs to bombers, air to air combatants and others. There is nothing to say CAS can’t and won’t exist simply because there will be too many targets to strike it all.

    The other part that isn’t considered is the covert action scenario. Picture a newly minted nuclear armed adversary. We launch a SOF strike force to neutralize their facilities. If this unit is discovered well behind enemy lines they will need CAS. Would it be better if they had an A-10, AC-130, little birds or DAPS– sure, but those may not be feasible. An F-35 could provide them some support. No one is arguing that it is as capable as the other platforms, but it is better than nothing. Even if only to break contact and cause a distraction so the ground force can slip away.

    Final thoughts: I am not in anyway arguing that the F-35 is not incredibly over priced or that it doesn’t have flaws. It is an example of how bad government acquisition can be. I am merely stating the argument that a stealth, multi role fighter with CAS capability in some form could be useful in a logical scenario. Also, I believe we need to make strategic decisions based on the war we fight and plan to fight, so the military should be asking congress to fund a next generation Fast Attack aircraft. We all have to be realistic in the financial trade offs as tax payers. We cannot have every toy we would want. The biggest failure here in my opinion is a lack of well defined executive branch QDR strategy that is coordinated with and funded by the legislative branch.

    1. I would say you miss the entire article with your choice of examples. You pick a very specific GIGO mission to highlight the need for a multi billion dollars stealth platform.

      In doing so you totally miss the article and default to the same old AF mantra of air be in he end all be all. One only needs to look to Georgia and the Donbass to see the folly in not bringing the full tool box to the mission and instead falling in love with decades of propaganda of air handling all missions no matter the cost. This has cost us billions when indirect and masses fires could better handle the battle field situation.

      From Vietnam forward leadership has been enamord with air support at a great cost to indirect fire and miss applied the use of air support when 155mm artillery or 5 to 16 inch naval fires were best for the task both for their effect and cost. It’s time to rebalance our approach.

  2. Interesting article and comment above — great analysis.

    Technology is going to shape the battlefield, in whatever form it takes, in ways we hopefully can only imagine — correctly.

    Eventually, one or more of these Guerilla, Insurgent, Terror Groups (or whatever term is in vogue) will obtain shoulder fired or some form of SAM capability as soon as one of the greater powers sufficiently angers another against which it competes – as in Afghanistan or Vietnam of long ago. It will eventually happen.

    Our ground forces seem to go into situations where they are, seemingly by plan, outnumbered and are relying on their fire power and air support to dominate the situation They should, if they already haven’t, begin thinking about how they are going to survive if that Air Support isn’t possible due to technical assets possessed by their opponent on the scene.

    Perhaps, the ground forces should consider whether in the future they will be capable of / or can accept the risks of conducting operations in the manner they have in Afghanistan and elsewhere. As indicated in the article above, they may become far more dependent on their Artillery — and that will change how they maneuver and deploy. Are they going to be able to fly their assets into an area — or will they have to walk or drive?

  3. I’ve seen numerous articles on CAS from the USAF perspective. It’s harder to find offerings from the perspective of the US Army. Here’s what I believe I’ve learned on that score.

    The US Army doesn’t give a damn as to which platform the USAF eventually settles on to provide battlefield CAS.

    The Army simply doesn’t want to have to bother to get the AF on the line in order to ‘request’ CAS, and that’s true whether it eventually comes on in the form of an A10, an AX-2 or an OA-X.

    The Army wants to use its own drones, manned helis, heli-drones, and manned-heli/heli-drone teams.


    End of page.

    End of chapter.

    They’re headed toward a new schema of operations in which the AF takes over up where the atmosphere ends, and the Army handles everything below that.

    1. Agreed and if we were always trying to minute force structures they already have the capablity they need in bot towed and mobile artillery. The issue has always been the corporate mind set of leadership in seeking a lighter smaller force. For some reason it fine to spend a trillion dollars on a new airframe but not ok to spend a few billion on actual manpower.

  4. I always enjoy and usually agree with Col. Pietrucha’s comments on this site. But today’s essay has a few too many “never”s and “won’t”s for comfort. As a student of airpower, Col. Pietrucha certainly knows that risk to airframes isn’t invariably the defining commitment criterion, and if he’s forgotten, any remaining survivors of Operation Pointblank could remind him.

  5. Like Mike Pietrucha, I was an instructor EWO in the F-4G. I think he missed the opportunity to tie in his other articles about the changed overall environment since the first Gulf War. The Air Force has almost eliminated the capability to take out the Integrated Air Defense structure of potential enemies. The limited EW capabilities we currently have and loss of the procedures that were planned to be effective in the event of a major conflict in Europe, as well as the focus on stealth and lack of training at low altitude are the issue. Yes, the threat has improved, as it has throughout history. CAS is a mission, not a platform, and I have no doubt that the Army is planning for the need for CAS in the event of a high threat environment without US air superiority or supremacy.

    1. Agreed we have divested out selves of the SEAD and many other capablities we had 25 years ago after the gulf war as part of the peace dividend. I would argue even more so that this is directly a result of the AF senior leadership being a collection of corporate types and not warriors or great thinkers. We are reaping what we have sowed.

      Hell, we continue to repeated it with our latest of a long line of uninspired Chiefs. You’d think after the hell that has been Welsh we would embrace so inspired intelligent warrior leadership but instead we get Goldfein.

      I truly hope he proves me wrong but afraid we are getting more of the same. Would be nice to have a true leader and someone that can correct the problems of Welsh and James.

  6. I am all about a high threat CAS platform. Chances are you will never need it, but if you did it would be amazing. Our current fighters can operate in high threat areas, and are much more vulnerable then these future stealthies will ever be. If we can make an aircraft that can provide CAS for small teams behind enemy lines, that have a little more survivability, then please make them. There will always be artillery and missile systems being developed to help out as well, so let the grunts worry about that and let the Air Force worry about airpower.

    1. You’re still thinking about the problem wrong. Yes, high threat CAS is mythical for a myriad of reasons. But….if it and unicorns showed up one day there is a way forward. But, it ain’t with airplanes….

    2. Capability comes at a price.

      The price for the stealth capacity necessary to *INADEQUATELY AND TEMPORARILY* survive in the hypothetical environment we have NEVER encountered would be so high we couldn’t afford the aircraft.

      Or, we can design aircraft for *REALISTIC* threat sets, and be able to afford them in sufficient numbers to be useful.

  7. The assessment below :
    “Even America’s vaunted stealth capabilities do it absolutely no good at gun range. The detection range curve for the SA-22 in Figure 1 demonstrates diminishing returns — even reducing the radar cross section to the target to a spectacular one ten thousandth of a square meter (one tenth of a blue-winged locust) still allows the SA-22 radar to track at gun ranges. ”

    show that author has very vagued idea of how CAS and SEAD are done,
    Firstly, the day of getting close to target and using 30 mm cannon to blast them are over, even the A-10 with it’s famous titanium cockpit wont be able to sustain hit from SA-22 or Tor M1, which mean the only 2 advantages that A-10 has over F-35 which is the armor and the big cannon rather irrelevant

    Secondly, the chart created by Carlo Kopp only take into account radar detection range while ignoring factors such as losses and radar jamming , It is very important to remember that jamming has a synergy relationship with stealth, A reduction of RCS 50% will only reduce radar detection range by 9%, but if we take jamming into account, 50% RCS reduction will reduced jamming power requirements by 50% and burn through distance ( the distance where radar power is strong enough to see through jamming) by 25%. And stealth aircraft have their RCS reduced by around 99.99% compared to normal asset like the A-10. In the appearance of jamming most radar won’t even be able to lock on a stealth aircraft at visual range

    Thirdly, author talking about the fact that stealth aircraft can be detected by IR, well, that a well known fact, but the problem is at what distance can these IR system detect F-35? if the distance is less than F-35 weapons and sensor range then it rather irrelevant too, F-35 wasn’t designed to get close and blast the target with it’s 25 mm cannon but rather cruising from afar and attack target by missiles like SPEAR, CUDA, APKWS or bombs like SDB II

    1. I would suggest that the number and type of weapons carried by the A-10 vs the F35 is another substantial advantage. And remember, if the weapon being carried by the F35 is external, then the stealth is greatly compromised.

    2. The author, I might point out, was a SEAD *INSTRUCTOR*, with COMBAT EXPERIENCE taking out air defense threats.

      He might actually know one or two things about his *exact* career field…

    3. The author was referring to the AAA gun range not the aircrafts gun range in his discussion correlating detectable RCS and gun range. Even a low-RCS aircraft will be discoverable and targetable while within the effective envelope of ground based gun systems.