The Future of Tactical Airlift Is Here and It Is Vertical
Back in 1908, Thomas Edison was asked for his opinion on the Wright brothers’ aeroplane. The electrical wizard pooh-poohed the Wrights’ achievement. “No aeroplane would be good”, he said, “until it could go straight up and down.”
Shot down over the Burmese jungle in a liaison aircraft on April 21, 1944, Technical Sergeant Edward Hladovcak and his three wounded, British ‘Chindit’ passengers had little hope of rescue. They were deep behind enemy lines and expected Japanese soldiers to find them at any minute. American search planes had located them, but — with no runways, roads, or even large clearings nearby — no conventional airplane could land to pick them up. However, the YB-4 “Eggbeater,” a very unconventional, prototype aircraft, and its pilot Lieutenant Carter Harman had just arrived in Burma with the 1st Air Commando Group. Even though Harman only had 36 flight hours in the aircraft that, following the “Y” designation, was still technically experimental, he volunteered to try and retrieve the trapped soldiers. In order to do so, he had to push his helicopter to its limits, including removing the passenger seat to save weight and carrying extra jerry cans of fuel with him in the cockpit. Harman was able to extract the trapped pilot and his passengers one by one — out to safety on a nearby sandbar where they could be picked up by a boat. The effort so strained his aircraft that he had to spend the night on the sandbar himself after the engines overheated. But, it was a success: the first vertical air rescue in history. Ever since, helicopters have been proving their versatility and displacing fixed-wing aircraft.
Despite longstanding trends toward rotary and tilt-rotor aviation, some analysts are revisiting old arguments in favor of acquiring light and superlight, fixed-wing aircraft for tactical airlift. Last year in War on the Rocks, two U.S. airmen made the case for light and superlight tactical airlift in the U.S. military with articles titled “Featherweight Airlift: For Want of a Nail” and “Uplifted: The Case for Small Tactical Airlift.” They argue that light and superlight, fixed-wing aircraft are a cheap and efficient way to both resupply and sustain distributed units in low-intensity operations, and limit dependence on large, vulnerable runways in high-intensity conflict.
Not only are the authors, Mike Pietrucha and Jeremy Renken, citing a capability gap that doesn’t exist, but their arguments are service-centric and myopically focused on the European theater of operations. These arguments largely ignore the past, present, and future of tactical airlift in the military. Fixed-wing tactical and light airlift was phased out in the past for good reasons: Namely, that Army and Marine rotary-wing aircraft and Air Force heavy-lift aircraft could get the job done better. This situation is still the case as both types of aircraft have seen considerable advances in capability since the Air Force retired the C-7 and C-123 after Vietnam without replacement.
New aircraft like those being explored as part of the Army’s Future Vertical Lift program, and unmanned delivery drones will continue to displace other aircraft in airlift roles. These new types of aircraft are faster and more practical than any fixed-wing option. The Air Force has acquired small numbers of CV-22s for its special operations forces. The Navy is in the process of acquiring them to use for resupplying aircraft carriers where they will replace the fixed-wing C2A Greyhound currently used for delivering personnel, mail and other critical supplies at sea. The Marine Corps already flies more than 300 of the tilt-rotor MV-22s. The frontrunner for the Army’s Future Vertical Lift program is the Bell V-280, which is a contender to replace the venerable UH-60 Black Hawk fleet. If the Army acquires it, all four services will operate fleets of tilt-rotor aircraft. Commercial, payload-carrying drones are also increasingly configured for vertical takeoff and landing. These trends make clear that the future of tactical airlift is vertical — a bright spot in U.S. capability.
The Case for Rotary-Wing Aircraft
Rotary-wing and tilt-rotor aircraft are the obvious choice for light and superlight airlift. These platforms have unique capabilities that are ideal for operating at the forward edge of the battlespace. They are uniquely able to hover and land in areas no larger than the width of their rotor blades or on mountaintops and urban roofs. And, while arguments for fixed-wing airlift largely look to past platforms, the capability and versatility of rotary-wing and tilt-rotor aircraft are rapidly growing and include unmanned and optionally manned platforms. Joint Publication 3-17, Air Mobility Operations, clarifies the value of rotary-wing aircraft already in service over fixed-wing aircraft for most tactical lift missions:
The Services and US Special Operations Command also operate rotary-wing and tiltrotor aircraft, such as the UH-1, H-60, V-22, CV-22, CH-46, CH-47, and CH-53, which possess intrinsic intratheater airlift capabilities…. Intratheater airlift operations that might best be filled by rotary-wing aircraft could include large requirement, short distance operations … or routine small-payload operations to sites not co-located with LZs, such as daily courier flights to deployed air defense units.
Air Mobility Operations goes on to list inherent advantages of rotary-wing aircraft, such as the fact that “Their ability to operate at smaller, undeveloped [landing zones] increases their flexibility and often reduces ground-transit times for their loads.” And: “Their ability to sling-load some types of materiel allows them to pick up and deliver loads with minimal ground-handling delays.” But, in a word, their value is utility. They can perform all of the historical roles of light airlifters, light-attack aircraft, and liaison aircraft, and do it from either a hover or without a runway. Rotary and tilt-rotor aircraft are also able to operate from and support many different types of ships, making them much more useful globally, including in the Indo-Pacific, which is the priority theater for the Department of Defense.
Looking Beyond the Air Force
The Army, Navy, and Marine Corps all already operate rotary-wing aircraft tailored for service-specific needs and do not need light airlifters. In fact, the services operate more rotary-wing and tilt-rotor aircraft than all other types of manned, combat aircraft combined. Their helicopters and rotary-wing aircraft exist precisely because the services need responsive airlift tailored to their specific needs — whether it be moving a sling-loaded howitzer across a river, ferrying a platoon of Rangers into a firefight, or delivering the mail to the back of a destroyer at sea.
If there is a light airlift gap in the Air Force, it exists because the other services organically meet their requirements for light airlift. In both articles, Pietrucha and Renken identify a lack of airlift capacity in the military but focus exclusively on their service: the Air Force. The Air Force is not optimized to support soldiers and marines at the forward edge of the battle area. As such, the Army and Marine Corps have traditionally relied on organic assets for “service specific needs.” A RAND study of intra-theater airlift noted that “the current Army concept for future operations does not involve large multi-[brigade combat team] forces operating without a ground line of communication.” This is to say that there is not currently a requirement for the Air Force to provide routine resupply to large and medium-sized ground forces because the Army and the Marine Corps do it themselves. Pietrucha and Renken do not mention Marine Corps aviation at all and make only a single, passing reference to Army rotary-wing aviation. This fact is unfortunate, for the type of tactical airlift they argue does not exist has, in reality, been performed by rotary-wing platforms like the CH-53 Stallion, MV-22 Osprey, UH-60 Black Hawk, UH-1 Huey, and CH-47 Chinook for years.
Pietrucha and Renken also completely neglect the Navy requirement for airlift. Light airlifters sound best when pitched for use in land-centric theaters like Europe and Africa, but they cannot compare to the versatility of rotary-wing and tilt-rotor aircraft that can operate from ships at sea. Carrier onboard delivery is a light airlift mission currently being handed over to tilt-rotor aircraft. Tilt-rotor and rotary-wing aircraft already deliver the mail, critical parts, and personnel on smaller ships. Even some of the smallest warships, like the littoral combat ships and destroyers, can accommodate rotary-wing resupply. This capability is significant because it dramatically expands the reach of tactical airlift if it can be supported at sea. Traditional light airlifters have neither the range to operate effectively in the vastness of the Pacific Ocean nor the vertical capability to operate from smaller warships.
Consider the approximate specifications of the C-7 Caribou light transport aircraft. It is a legacy aircraft often used as an example of the type of aircraft that should be reintroduced to the Air Force for light-lift missions. It can carry approximately 9,000 pounds of cargo, has a cruise speed of 180 miles per hour, and needs a 750-foot runway. A Marine MV-22 can carry 20,000 pounds of cargo if it executes a short takeoff of under 50 feet; or, it can carry 15,000 pounds in a vertical takeoff with a cruise speed of 280 miles per hour. The Stallion, Chinook, Black Hawk, and others can all carry in excess of 5,000 pounds of cargo either inside or “sling loaded” — military lingo for hanging outside. The Marine Corps’ newest helicopter, the CH-53K King Stallion, has a cruising speed that is just faster than that of the C-7 and can carry 36,000 pounds in an external sling load. That carrying capacity is the equivalent of four trips in one of the old C-7s. However, it is a slightly unfair comparison because, if a C-7 was introduced in today’s fight, it would probably feature an upgraded variant of the venerable PT-6A turboprop engines that may allow for higher cruising speeds and potentially increased payload capacity and range.
A more modern airlifter is the C-27J Spartan, a small or medium-sized turboprop airlifter advertised as optimal for “the last tactical mile.” The Spartan can carry 25,000 pounds of cargo — only 20 percent more than an MV-22 and significantly less than a CH-53 — but requires over 2,000 feet of runway for takeoff and over 1,000 feet to land. The C-27 is perhaps the best case study for a light airlifter in the last several decades. Proponents spent years advocating for the acquisition of the aircraft in the face of significant opposition. In the late 1980s, the Government Accountability Office released a report recommending against the U.S. Southern Command’s desire to acquire C-27 light airlift aircraft to meet an intra-theater requirement ferrying personnel and supplies around South America and the Caribbean to remote airfields in support of counter-narcotics operations. Instead, the Government Accountability Office recommended vertical takeoff and landing aircraft, specifically the MV-22 Osprey. The report quoted the House Armed Services Committee’s denial of the request in the 1988 budget:
The Committee does not recommend authorization of the C-27 aircraft to perform the designated mission because of the availability of existing helicopters and the anticipated near-term deployment of the [C]V-22 Osprey aircraft.
The Government Accountability Office then went further, reinforcing the committee’s decision:
The CV-22 … will not be restricted by the condition, length, or width of runways, and thus will offer even greater flexibility than the C-27 aircraft. In addition, the CV-22’s payload and range capabilities will generally parallel the C-27 requirements.
A joint Army-Air Force program actually bought 21 of the C-27 light airlifters, but the mid-2000s program was quickly cancelled after only five years. At the end of the program, C-27s were being delivered directly from the factory to the “boneyard” in Arizona for “non-temporary” storage — that is, permanent storage but with the possibility to be returned to service. Eventually, the services gave 14 planes to the U.S. Coast Guard free of charge. The Air Force ultimately decided, “C-130s could provide nearly all of the Army’s desired capability.” Independent analysis by the Center for Strategic and Budgetary Analyses and the Pentagon’s own 2018 Mobility Capability Requirements Study affirmed, “DoD’s current and planned mobility force structure will be sufficient through 2030.”
Interservice Competition and Tactical Airlift
The competition between fixed- and rotary-wing aircraft for the tactical airlift role largely stems from interservice competition but has continued to color much more recent acquisition discussions over light airlifters. During the Vietnam War, the Army’s forfeiture of light airlifters like the C-7 to the Air Force spurred the Army to field heavy-lift helicopters like the CH-47. If the Army had been permitted to field the hundreds of light airlift aircraft that were called for by the Howze Board report — a Vietnam-era Army study of the desirability and feasibility of creating airmobile units — it is possible that vertical lift programs would have been much more limited. Fallout from the report eventually forced the Army and the Air Force to strike a deal over roles and responsibilities. As part of the deal, the Army was permitted to arm their helicopters for close-air support, which was a compromise of considerable consternation to the Air Force, but had to give up most of their fixed-wing airlift aircraft. Helicopters have since been the preferred close-air support platform for infantrymen because of their longer loiter time and better flexibility in support of ground troops.
Service divisions precluded the Air Force from exploring rotary-wing lift as an update to its light airlift programs that were slowly phased out and replaced by the rugged C-130 and Army rotary-wing aviation. In the 1960s, the Army experimented and fielded regimental and division-sized units intended to be completely supported by helicopters, the “Air Cav” and “Air Assault” units, which have now largely displaced conventional paratroopers in actual combat operations. At around the same time, the Marine Corps rewrote its amphibious doctrine to include helicopters.
Proponents of light aircraft, whether airlifters or attack aircraft, usually note the lower cost of both the airframe and operating the aircraft per hour. However, they fail to consider several other costs. Adding new types of airplanes to the fleet requires new squadrons for operations and training staffed with pilots and aviation technicians who have all passed through their own training pipelines. Such an addition is far more expensive and complicated than just buying new aircraft. Light airlifters offer the promise of cheap and efficient capability, but the true cost of standing up the squadrons and their support structure is yet unknown.
Heavy-lift helicopters like the Army’s CH-47 and the Marine Corps’ CH-53 fill other roles out of reach for fixed-wing aircraft. They can facilitate air bridges over obstacles like rivers with external sling-loading, which no fixed-wing aircraft can do. These helicopters are not only powerful enough to externally lift bridge sections and lower them into place over rivers, canals, and waterways, but also to carry combat and logistics vehicles over obstacles such as giant cranes in the sky, further increasing their value and versatility. Rotary-wing and tilt-wing aircraft can also operate in the complex urban terrain, landing on roofs and flying in between buildings, which will likely be part of any future operating environment.
Toward a Vertical Future
The future of civilian and commercial airlift also increasingly looks vertical. A 2017 RAND report concluded:
Delivery drones may become widespread over the next five to ten years, particularly for what is known as the “last-mile” logistics of small, light items. …In the future, drones could augment, or in some situations even replace, truck fleets.
Of the drones that RAND researched, all but one could take off and land vertically. In the private sector, companies are already employing autonomous “featherweight” airlift drones capable of delivering loads to “locations the size of a doorstep” like Alphabet’s Wing and Amazon’s Prime Air, which are almost exclusively vertical takeoff and lift models. The RAND analysis generally decided to ignore conventional takeoff and landing drones because they were relatively niche and did not perform well against vertical takeoff and landing drones.
Meanwhile, the Marine Corps has developed and deployed to Afghanistan a pair of unmanned helicopters, K-MAX, each capable of lifting 6,000 pounds and performing missions autonomously. The Marine Corps has also tested a fully unmanned version of the UH-1Y Venom utility helicopter. The U.S. Special Operations Command purchased several CQ-10 SnowGoose airlift drones capable of transporting hundreds of pounds of cargo. Bell helicopters has even developed an “air taxi” powered by ducted rotors, a novel form of tilt-rotors for personal transport. AgustaWestland developed a concept for an all-electric, tilt-rotor aircraft. Uber, the ride-hailing company, has also invested in personal-sized tilt-rotor aircraft. These vertical projects, among many others, continue to increase the number of applications for vertical lift.
Rotary-wing aviation is — and continues to be — the priority platform for insertion and extraction “on the X.” It is the priority for casualty evacuation because helicopters can get much closer to wounded soldiers and marines — the intended missions for the MV-22. In a combat zone, helicopters can drop off and pick up, which no fixed-wing aircraft can do. In the words of the helicopter’s inventor, Igor Sikorsky: “If a man is in need of rescue, an airplane can come in and throw flowers on him, and that’s just about all. But a direct lift aircraft could come in and save his life.” Watching the V-280 Valor breeze through testing is a further indication that tilt-rotor aircraft have untapped potential and will take on an even more important role in tactical lift. Other nations have also bought into the tilt-rotor concept; Japan is purchasing MV-22s and Israel may follow suit.
Improving Rotary-Wing and Tilt-Rotor Aircraft
Despite all of their inherent advantages, rotary-wing and tilt-rotor aircraft still aren’t perfect. The services have struggled to arm their MV-22s beyond door-mounted machine guns while the speed and range that make them so valuable have also made it difficult to match them with escorts. Tilt-rotor aircraft are faster than Marine or Army helicopter gunships — but not fast enough to keep up with most jets. In something of an oddball match, the Marine Corps has occasionally paired Ospreys with the venerable A-10 Thunderbolt for escort because they fly at similar speeds. Helicopters, especially tilt-rotors, can also be maintenance-intensive and more sensitive to austere operating environments than light airlifters. Helicopters and tilt-rotors operate at the edge of their performance envelopes in high-altitude environments due to the thinner air in mountainous regions such as Afghanistan and Pakistan. These drawbacks result in helicopters operating with low power margins, especially during vertical or hover operations, that limit payload capacity and increase maintenance costs per hour when compared to their legacy, fixed-wing aircraft peers. To combat soaring maintenance costs and continue experimentation, the U.S. military contracted private companies to use K-MAX helicopters and other rotary-wing aircraft to support U.S. military operations across the Middle East and Africa.
But cost is not everything. All told, rotaries’ ability to take off and land vertically, hover, and carry large amounts of cargo across the battlefield makes them invaluable in modern operations. Between the inter-theater logistical capability offered by the Air Mobility Command to deliver supplies ranging from munitions to paratroopers over thousands of miles, to the helicopters that can deliver supplies over hundreds of miles, or just across the river into a hot landing zone, there is no current capability gap that a featherweight or light airlifter needs to fulfill.
Trust in Rotary
Certainly, commanders will always want more airlift capacity and light airlifters have been effective in the past. However, there are more modern and more capable Marine and Army aircraft filling many of those roles now. The future of tactical airlift is vertical. It’s no coincidence that sci-fi movies like Avatar and Edge of Tomorrow or the Terminator franchise have made a staple out of aircraft with rotating engines — whether they’re rotors or jets spitting out blue-tinted flames. Today, traditional helicopters carry most of the load though the MV-22 has demonstrated what tilt-rotor aircraft are capable of, operating all over the world in support of Marine and now Navy and Air Force operations. The Army is prototyping new tilt-rotor aircraft that have already set records for performance without reaching the edge of their own performance envelopes. In the commercial sector, many companies are developing and commercializing unmanned systems for delivery — almost all of them flying vertically during at least part of their flights. Tactical airlift, far from being under threat, is exploding with possibilities and new capabilities.
Capt. Walker D. Mills is a Marine infantry officer. He is currently serving as an exchange officer with the Colombian Marine Corps. He is also pursuing an MA in international relations and contemporary war from King’s College London.
Lt. Cmdr. Dylan “Joose” Phillips-Levine is a naval aviator. He serves as an instructor in the T-34C-1 “Turbo-Mentor” as an exchange instructor pilot with the Argentine Navy. He has also served as an instructor pilot in the T-6B “Texan II” with VT-6 and has flown the MH-60R “Seahawk” with HSM-46 in support of Operation Enduring Freedom with 5th Fleet and with 4th Fleet in support of counter-narcotics operations.
The views expressed are those of the authors and do not necessarily reflect the official policy or position of the U.S. Marine Corps, the U.S. Navy, or any part of the U.S. government.