Left Behind: Why It’s Time to Draft Robots for CASEVAC


With thousands of air and ground robots in the field, you could be forgiven for thinking that the U.S. military has embraced unmanned systems. The truth is that they are used mostly for niche roles like reconnaissance and bomb disposal. Resistance to expanding their use for more core military missions persists in many corners of the military. As just one example, casualty evacuation is a mission area ripe for unmanned vehicles and yet, perversely, not only is the U.S. military not moving forward in this area, the Army has a policy actively against it. (The policy is unclassified but has not yet been publicly released.)

Almost by definition, casualties are likely to occur in dangerous areas, and manned evacuation missions run the risk of additional casualties. Unmanned vehicles could be used to extract wounded from dangerous areas and evacuate them to safety without risking additional lives. Moreover, because they could be built and operated at lower cost than equivalent manned vehicles, unmanned vehicles could be built in large numbers, so they are readily available on the front lines.

While the value of such a capability seems obvious, cultural barriers to using unmanned vehicles for this mission block their development. The U.S. Army Medical Department Center and School has issued not one or two, but three memoranda — in 2006, 2009, and 2013 — prohibiting the use of unmanned vehicles for casualty evacuation, stating, “… the use of unattended robotic platforms for casualty evacuation [is] unacceptable.” As a result, wounded troops on future battlefields will not have access to a potentially life-saving innovation.

The Army Medical Department Center and School did not respond to multiple requests for comment on its policy, which has two objections to unmanned vehicles. The first is that unmanned vehicles might be less safe than manned vehicles. The second centers on the continuity of care for wounded soldiers. These concerns are not without merit, but a wholesale prohibition on all unmanned casualty evacuation is not a reasonable response. A comprehensive three-year NATO study on casualty evacuation evaluated these concerns and found no rationale for a blanket prohibition, noting that some unmanned vehicles might not be appropriate or safe for casualty evacuation, but that others might be and there was no justification for prohibiting them entirely. Similarly, continuity of care through keeping a medic with a wounded soldier during evacuation is ideal, but if this is not an option, then evacuating a service member on an unmanned vehicle to a place where he or she can receive treatment is certainly preferable to letting him or her die on the battlefield.

The Army medical community is not ignorant to the NATO study’s conclusions. The study was published in 2012 and included 13 U.S. participants, plus another 13 U.S. military or civilian defense officials who were consulted as part of the study. Nevertheless, the Army medical community has continued to sustain its objections to unmanned casualty evacuation. Fully understanding the Army’s objections, and why they don’t hold up, requires a more detailed understanding of the lexicon of taking wounded off the battlefield. Casualty extraction, casualty evacuation, and medical evacuation are all distinct concepts in military lexicon with different policy concerns.

Casualty extraction is the movement of wounded from the point of injury out of immediate harm to a safe location, where they can be treated by a first responder. Medical evacuation (MEDEVAC) is the use of dedicated medical assets, such as MEDEVAC helicopters, to transfer wounded from the battlefield to a higher standard of care at a base. Casualty evacuation (CASEVAC) is the use of field-expedient non-medical assets, like ground combat vehicles or troop-carrying combat helicopters, to transfer wounded back to a base for a higher level of care. Within the Army, the Medical Department controls MEDEVAC assets, while CASEVAC is the purview of ground commanders with whatever assets they have available at the time.

Current Army policy allows the use of unmanned systems for casualty extraction, or movement of wounded out of the line of fire. The most recent memorandum from the Army Medical Department states:

The [unmanned system] can potentially conduct extraction and/or retrieval of combat casualties on behalf of the first responder and deliver the wounded Soldier (within a short distance) to a safer location.

However, the same memorandum prohibits the use of unmanned systems for CASEVAC or MEDEVAC, stating:

The [Army Medical Department] does not support the use of unmanned systems in accomplishing direct medical care tasks or medical evacuation without human accompaniment.

The memo then goes on to detail the Army Medical Department’s concerns. The first is safety:

The safety requirements for putting human beings aboard vehicles or aircraft without an on-board pilot must be at least as stringent and effective as those for piloted vehicles or aircraft.

Safety is undoubtedly a valid concern, and placing wounded personnel onboard an unsafe vehicle or aircraft would not be appropriate. But there is no reason to assume that all unmanned vehicles are inherently unsafe. In fact, autonomously piloted aircraft and ground vehicles have the potential to be much safer than human-piloted vehicles. It would be far more sensible to examine each vehicle individually.

The Army Medical Department’s other principal concern centers on continuity of care:

Medical doctrine with regard to patient evacuation is governed by factors that preclude the use of [unmanned systems] in conducting autonomous medical evacuation/casualty evacuation (CASEVAC). … There are standards of care established that define moral, ethical (Hippocratic Oath), and international conventions that would limit the interaction between wounded Soldiers and unmanned platforms. … To meet these standards, medical personnel must accompany patients.

Continuity of care is a valid concern, and the Army’s objections are not without some merit. Certainly, if a commander placed a wounded soldier on an unmanned vehicle without medical care when there was another option with higher quality care available, then that would be unacceptable. The Army medical community develops and fields dedicated MEDEVAC assets, and for MEDEVAC missions, unmanned vehicles may not be appropriate. If the Army medical community is to invest scarce resources into developing dedicated MEDEVAC assets, then until such time as the standard of care delivered on unmanned vehicles is equal to that delivered with a human medic onboard, then those MEDEVAC resources should remain invested in manned assets. Eventually, this may be possible with the use of through the use of remote trauma pods or other technology, but it is not possible today and so prohibiting unmanned MEDEVAC makes sense.

But that isn’t the Army’s policy. The Army’s policy also prohibits CASEVAC, and here is where it falls apart.

CASEVAC is used when dedicated MEDEVAC assets are unavailable. Under these conditions, it seems insane to prohibit commanders from using unmanned vehicles if that is the best option they have for evacuating wounded from the battlefield. If sending wounded personnel back on an unmanned vehicle means that person cannot be accompanied by a medic, then commanders will have to weigh the benefits of keeping the wounded individual under the medic’s care in the field versus patching up the casualty and speeding him or her to a higher level of care. The best person to make that determination, however, is the commander on the ground. In some situations, it will be better to wait for another mode of transport. In other situations, however, and it isn’t hard to imagine them, sending a wounded soldier back on an unmanned vehicle may be the only option to save that soldier’s life. If the Army trusts its ground commanders to make life-or-death decisions while leading troops in combat, then the Army should trust its ground commanders to make the same calls about evacuating those soldiers.

In fact, it isn’t clear at all if the Army’s policy is even enforceable. It is hard to imagine a ground commander who had an opportunity to save one of his or her soldiers’ lives being deterred by a letter from the Army Medical Department, assuming the commander was even aware of this policy. It isn’t even clear if the Army Medical Department’s letter, which is couched as a “Position Paper,” has any binding authority over ground commanders, since CASEVAC falls outside of the scope of the Army medical community and is the responsibility of the ground commander.

The policy may be contributing to a lack of viable options for casualty evacuation with unmanned vehicles, however. For whatever reason, the Army’s policy has been picked up by the Department of Defense writ large, and is reiterated in the DoD’s most recent Unmanned Systems Integrated Roadmap, FY2013-2038, which states:

Although currently prohibited by policy, future capabilities by unmanned systems could include casualty evacuation and care, human remains evacuation, and urban rescue.

The translation of a position paper by the Army medical community into a DoD-wide policy statement against unmanned CASEVAC is both troubling and careless, and risks a chilling effect in potential investments. Commanders on the ground should have options at their disposal, but if modifications are necessary to existing unmanned vehicles to make them suitable for casualty evacuation, it is hard to imagine how those dollars would be freed up if there is the perception of a DoD-wide policy prohibition. This concern is not merely theoretical. The K-MAX cargo helicopter is currently deployed to Afghanistan, and with the right modifications could serve the dual mission of casualty evacuation in a pinch, potentially saving lives. Additional unmanned cargo helicopters, like the Navy’s autonomous aerial cargo/utility system (AACUS), are likely to enter the force in the not-too-distant future. According to Marine Corps Brig. Gen. Kevin Killea, head of the Marine Corps Future Warfighting Lab and Vice Chief of Naval Research, allowing dual-use casualty evacuation with these systems is a no-brainer: “I don’t see any reason why [AACUS] couldn’t be a future casualty evacuation platform. It makes complete sense.”

The Army’s policy against CASEVAC with unmanned vehicles is backwards and harmful, and the fact that it comes from good intentions doesn’t change its harmful effect. The Army’s position paper cites the “Gold Book” of the Committee on Trauma of the American College of Surgeons when explaining the necessity of human accompaniment for the evacuation of wounded. U.S. wounded personnel deserve the best care, and it would not make sense for the Army medical community to move to a lower standard of care for dedicated MEDEVAC assets. But insisting on applying peacetime civilian standards to the battlefield where commanders may not have the luxury of those choices simply doesn’t make sense.

A sensible policy would have the following components:

  1. Continued authorization of casualty extraction with unmanned vehicles.
  2. A prohibition on developing dedicated unmanned MEDEVAC platforms until such time as the standard of care and safety is equal to or greater than that with human-occupied vehicles, along with research and development into remote surgical pods and other technologies to enable future options.
  3. Explicit authorization of CASEVAC with unmanned vehicles, provided that the vehicle is safe for human transport and that the commander on the ground determines that the temporary loss of direct medical care during transit is outweighed by the benefit of rapid transport to a higher level of care.
  4. Funding for any modifications needed for dual-use unmanned vehicles, such as unmanned cargo helicopters, to allow safe battlefield CASEVAC if necessary.

The quality of care that wounded U.S. service members receive on the battlefield today is light-years beyond what was available in past wars, and the Army medical community is directly responsible for this improved care and the lives that have been saved as a result. It’s time for the Army Medical Department to do the right thing and change its policy. CASEVAC with unmanned vehicles is never ideal, but may save lives. Other countries are developing options to evacuate their wounded with unmanned vehicles, but U.S. troops are being left behind. Ground commanders should have options at their disposal so that they can make the right call for their troops given the situation at the time, and the Army Medical Department should stop standing in their way.


Paul Scharre is a Fellow and Director of the 20YY Warfare Initiative at the Center for a New American Security (CNAS). From 2008-2013 he worked on policies for emerging technologies in the Office of the Secretary of Defense. He is a former Army Ranger and has served in Iraq and Afghanistan. This article is adapted from CNAS’ recent report, “Robotics on the Battlefield – Part I: Range, Persistence and Daring.”


Photo credit: Army Medicine