This article was originally posted at The Bar Napkin.
“Even small groups of combatants, such as a handful of enemy troops manning a mortar position, may eventually be deemed worthy of a PGM [precision-guided munition] in some circumstances.”
Though the above statement sounds like some visionary revelation out of Operation Desert Storm, it is not; it’s not even from the 20th century. The above was actually written in a 2005 RAND report on airpower application against terrorism. This statement perfectly captures the essence of how quickly the assumptions surrounding Airpower and PGM employment have changed, and will continue to change. Current aircraft fleet modernization efforts are over-shadowing the need for air-to-ground munitions recapitalization. This effort could modernize the inventory and build partnership capacity, all while defraying some of the cost of doing so.
While in use since World War II, Vietnam War era investments into laser technology lowered the PGM-to-target cost-exchange. This enabled PGMs to invert the paradigm of air interdiction from “sorties per target” to “targets per sortie.” In World War II, a squadron of bombers was often committed to a target area; today a single bomber can hold a plethora of targets at risk.
Senior leaders have now developed an unquenchable appetite for PGMs, and why not? The accuracy of PGMs provides an instantaneous theater-wide risk reduction in collateral damage and potential civilian casualties. PGMs’ performance accuracy relies predominantly on technology, whereas unguided munitions accuracy (and therefore strategic impact) is placed solely in the hands of the aircrew’s ability and performance. In today’s era of social networking and instantaneous news reporting, collateral damage and civilian casualties can have strategic effects like never before. Beyond risk mitigation, the realities of the tyranny of distance coupled with diminishing resources necessitate that if the herculean effort is committed to put Airmen in harm’s way to get an aircraft to a target (or a weapons release point), that weapon employed from the aircraft better hit the target because we almost literally can’t afford to miss. Applied to a high-end fight, PGMs provide a minuscule investment relative to the other support required (logistics, Offensive Counter-Air, tankers, etc.) to increase the probability of achieving desired weapon effects and reducing the risk of follow-on missions (putting more Airmen and resources at risk for an objective). All of this can be summarized in a simple sound bite: In a low-end conflict, PGMs mitigate strategic risk on the ground; in a high-end conflict, PGMs mitigate strategic risk in the air.
Last month, Air Combat Command (ACC) convened its annual Weapons and Tactics (WEPTAC) conference, where managing preferred munitions was a key working group topic. Though the conclusion properly acknowledged that fixing any acquisitions process for PGMs will take at least 24 months, they miss the mark when it comes to harvesting equity in what we already have.
Though the USAF hasn’t employed an unguided bomb during a conflict in over a decade, it still retains nearly 40,000 unguided bomb tail kits. This stockpile currently comprises 21% of the USAF conventional bomb kit inventory. Given the context above, a reevaluation of where unguided weapons fit in today’s arsenal is warranted.
Ninety-six percent of all air-launched weapons bought since 2001 have been short-range, direct attack PGMs such as GPS-guided Joint Direct Attack Munitions (JDAM). No unguided munitions have been bought because only minuscule amounts have been employed. That is not to say they serve no purpose. Unguided munitions do have a place in any country’s arsenal, but more so as a logistical risk mitigation measure, not an operational one. Part of today’s reality is the management of PGMs, consisting of continual tracking of depletion rates, reserve levels, and logistical replenishment time in theater. As a center of gravity, logistical choke-points and chains are vulnerabilities that can effect combat operations if targeted.
At most, the US should retain 10,000 unguided kits as a war reserve materiel (WRM) backstop, permitting a 2.5% critical reserve when accounting for every bomb body in the US arsenal. When compared to weapon tail kits, reducing this inventory would change the unguided weapon apportionment from 21% down to 6% (there are more bomb bodies than weapon kits). The remaining 30,000 kits, valued at $135 million, are occupying 190,000 cubic feet of space within munitions storage areas around the world. That’s the equivalent of 140 20-foot shipping containers. These could be divested through a discounted Foreign Military Sales (FMS) program. Even at a 50% discount compared to current replacement costs, this could generate $67 million, or enough money to purchase over 3,000 JDAM kits (or 50 Joint Air-to-Surface Standoff Missiles.)
A deeper dive into the munitions inventory reveals even greater recapitalization potential. Among the most expensive guided bomb kits in use is the Paveway III GBU-24 laser guided bomb (LGB). Adopted in 1983, GBU-24 was designed to glide below the weather common in Eastern Europe. When the BLU-109 bomb body entered service in 1985, the GBU-24 kit was modified to use the BLU-109, becoming the first guided hard-target penetrating weapon. In 1987, the tail kits were deemed too large to fit inside the still-classified F-117. Instead, engineers swapped in a Paveway II tail kit and reprogrammed the GBU-24 seeker logic, resulting in the infamous GBU-27.
In Operation Desert Storm, all 1,181 GBU-24s employed were from F-111Cs, well before fourth generation fighter’s targeting pods were fielded across the fleet. In 1999, Operation Allied Force finally showcased the GBU-24 in the European theater (and weather) as it was envisioned. The results were less than stellar. Threats restricted aircraft to medium altitude, negating the niche weapon’s primary attribute. Poor visibility led to numerous misses due to the cumbersome mission planning and plethora of considerations. The same poor performances would be observed by F-14s in the opening sorties of Operation Enduring Freedom and F-15Es in Operation Southern Watch. By 2004, the GBU-24 had fallen out of favor with war planners. Today, the GBU-24 is the poster child of a Cold War relic still in use, another distracting from looking forward.
Mission planning, weapons build time, loading simplicity, employment envelope, employment procedures, weather capability, and magazine depth all favor something other than the GBU-24. The weapon is also less optimized for penetration, standoff, and impact conditions than a GBU-31 JDAM. Yet with all of these limitations, it’s not cheaper: at nearly triple the cost of the JDAM, the GBU-24 easily loses the cost-exchange comparison, too.
Yes it can hit moving targets, but so can any bomb with a laser seeker today (the Laser JDAM seeker is more capable yet 10% of the cost). With over 9,000 GBU-24 kits in the inventory, it comprises 18% of the US LGB arsenal and is valued at $550 million (the cost of five F-35s). The kits are occupying an astounding 640 shipping containers of space.
The 2015 USAF Future Operating Concept envisions warfighting in 2035. Does anyone, from Combined Forces Air Component Commander to tactician, realistically foresee a conflict scenario in 2035 with aircraft employing a GBU-24 when a JDAM (Laser JDAM and JDAM-ER included) would do the same job more efficiently, more effectively, and with less risk? What about 2020? What about today? There is a point where everything has served its purpose and is primed for divestment; that time is now for the GBU-24.
Some GBU-24 stalwarts will quickly advocate the weapon’s low-altitude ability. While true the weapon has low-altitude capability (as that was its designed purpose), the GBU-31’s loft capability surpasses the GBU-24 employment impact conditions (velocity and impact angle). Those same loyalists will probably not easily concede that the operational relevancy of manned low-altitude employment has continually diminished since Operation Desert Storm when flying low was halted due to mishaps. Back then, low-altitude employment was preferred to increase unguided bomb accuracy, not threat mitigation as many current tacticians are led to believe. Though we have transitioned from that period, many older aviators who entered service in the 1990s continue to propagate this flawed approach today.
With no realistic plan to use these PGMs, these could be used as an asset for FMS while building partner capacity. Using the most-current year data available, in 2013 the Department of Defense Foreign Military Financing Program waived payments from 71 countries totaling $4.8 billion. Not including the top 3 countries listed, selling these PGM kits would recoup the cost of the remaining 68 countries’ payments that were forgiven ($380 million).
Typically if you drop a bomb today, it’s going to take you two years from now to get the appropriation to replace it, another year or two to actually get it on the shelf. -Gen. Mark Welsh, September 2015
Coalition partners are admittedly running low on PGMs too. Surprisingly, this isn’t a new issue. In 2011’s Operation Odyssey Dawn/Unified Protector, NATO partners were running short on PGMs only three weeks into the campaign. In 2014, the Gulf Cooperation Council members who joined the initial efforts for Operation Inherent Resolve requested munitions transfers from US units in theater after only two days of operations. As recently as September 2015 partner nations were warned that the US military could no longer support them with munitions transfers and they should pursue defense contracts with suppliers. Even worse, there are still partner nations whom are not cleared for Foreign Military Sales of PGMs, which as discussed above induces great risk at strategy while simultaneously making it increasingly difficult to find targets that can be vetted appropriately.
Admittedly, the US is unlikely to divest the entire 9,000 unit stockpile through FMS. However, it should pursue opportunities to deplete these theater munitions and simply not replace them. To augment this, inventory modernization through employment should be pursued. Employing these weapons now in Operation Inherent Resolve, a theater that historically has the best weather and lowest risk, would suspend the depletion rates of GBU-31 JDAM kits and help to shift the weapons allocation portfolio.
The truth is, the USAF is in need of an acquisition/recapitalization success story. PGM recapitalization is a relatively simple way to continue forward progress towards modernization while showing near-term tangible results. The ramp-down of Paveway III and reduction of unguided weapon stockpiles would provide both fiscal and physical space for the ramp-up of emerging munitions such as the Small Diameter Bomb II (SDB II) series and JDAM-ER. In today’s fiscal environment, every bit helps. The time for action is now; the longer the US waits the more irrelevant these commodities become in an evolving world.
Major Mike “Pako” Benitez is an instructor Weapons System Officer in the F-15E Strike Eagle with over 1,000 combat hours spanning multiple deployments. A prior-enlisted Marine and graduate of the US Air Force Weapons School, he has been involved in operational-level crisis action planning in both CENTCOM and EUCOM and has recently completed a Defense Advanced Research Projects Agency (DARPA) fellowship.