In the world of strategic airlifting, the question of which behemoth reigns supreme is a constant source of debate among aviation enthusiasts and military logistics experts. Both the Antonov An-124 Ruslan and the Lockheed C-5 Galaxy, specifically the modernized C-5M Super Galaxy, represent the absolute pinnacle of heavy-lift engineering. In global logistics, size directly dictates an aircraft’s ability to transport oversized cargo, such as power turbines, relief helicopters, or main battle tanks, across oceans in a single trip.

To the casual observer, these two titans look remarkably similar, featuring high-wing designs, four massive engines, and nose/rear-loading capabilities. However, their dimensions and weight capacities tell a story of different design philosophies born from Cold War necessities. This article will explore the specific technical metrics, such as length, wingspan, and payload, to determine which aircraft truly occupies more space in the sky and on the tarmac. It also explores how size in aviation is often a trade-off between physical footprint and the sheer weight an airframe can support.

Battle Of Giants

The Antonov AN-124 Ruslan is generally considered bigger in terms of physical volume, wingspan, and payload capacity, while the C-5 Galaxy is technically longer. If you define size by how much a plane can carry or its total width, the Antonov wins. If you define it by length from nose to tail, the Lockheedtakes the lead by 20 feet.

Specifically, the An-124 boasts a wider fuselage and a wingspan of 73.3 meters or 240 feet 6 inches, which is significantly larger than the C-5M’s 67.9 meters or 222 feet 9 inches. However, the C-5M stretches to 75.3 meters (247 feet 1 inch). In the world of heavy aviation, the Antonov is often the preferred choice for the widest loads, while the Galaxy offers a longer internal cargo floor for longitudinal items.

From a weight perspective, the An-124 is the clear heavyweight champion. Its maximum takeoff weight can reach up to 402,000 kg for the -100M-150 variant, compared to the C-5M’s 381,018 kg. Historically, the An-124 was designed specifically to outclass the original C-5A, and this one-upmanship resulted in a Soviet airframe that can lift roughly 17% more weight than its American counterpart.

Sheer Size Over Flexibility

Determining which giant is bigger involves looking into specific features that lead to the final answer. Physical external dimensions, internal cargo volume, and maximum payload weight are key to clarifying this. Depending on the operation, whether it is carrying a lightweight but voluminous satellite or a dense, heavy generator, one aircraft may feel larger and more capable than the other.

The internal dimensions are perhaps the most telling factor for operators. The An-124 cargo hold is wider with a hold space of 6.4 meters vs 5.8 meters. It is also higher at 4.4 meters vs 4.1 meters when compared to the C-5M, allowing it to accommodate larger industrial components. Conversely, the C-5M has a significantly longer cargo deck at 43.8 meters, which is vital for transporting multiple vehicles or long segments of infrastructure in a single row.

Beyond the airframe, the engines play a role in how these aircraft handle their massive size. Both are quad-engined, but the C-5M utilizes GE CF6 engines and an optimized high-lift wing design, which allows for a much shorter takeoff run of 5,400 feet at MTOW, whereas the An-124, carrying its heavier load on Progress D-18T engines, requires a massive 9,800 feet of runway to get airborne. This means that while the Antonov is bigger in capacity, the Galaxy is arguably more flexible in the airfields it can serve at maximum weight.

Combat Ready

In the specialized world of heavy-lift logistics, experts view the choice between the An-124 and the C-5M not as a competition of size, but as a selection of operation-specific capability. While both are strategic airlifters, the An-124 is the commercial favorite for oversized cargo. According to Volga Dnepr, the Ruslan’s popularity in the private sector is driven by its unique internal systems. Specifically, the aircraft features two onboard bridge cranes capable of lifting up to 30,000 kg each, allowing it to load and unload heavy machinery at airports with virtually zero ground support.

Conversely, the US Air Force maintains that the C-5M Super Galaxy is the superior tool for high-tempo military power projection. A key advantage cited by military loadmasters is the Galaxy’s true drive-through capability. Because both the nose and the rear ramp can be opened simultaneously, vehicles can drive in one end and out the other, a feature that the An-124 mimics but is often noted for being slightly more cumbersome in a combat offload scenario. Additionally, the C-5M’s reliability enhancement and re-engining program has helped address the maintenance nightmare reputation the older C-5A/B models once held but has not been as successful as planned.

The impact of these expert insights is reflected in the current market value of these airframes. The An-124 remains the primary option for the private industry because it was designed with a partially-pressurized cargo hold that prioritizes volume over speed, making it the flying barge of the aerospace world. However, the Air Mobility Command argue that the C-5M’s ability to undergo aerial refueling, a feature the An-124 lacks, gives the American colossus a strategically larger footprint. This capability allows the C-5M to deliver its 127,460 kg payload to any point on the globe without needing to negotiate landing rights at intermediate fuel stops, a massive advantage in geopolitical crises.

Carrying The Torch From A True Icon

While the An-124 and C-5M are the undisputed titans of strategic airlift, they are often compared to the Boeing 747-8F in the commercial sector. The 747-8F is actually recognized as the longest of the three at 76.3 meters or 250 feet 2 inches, surpassing even the C-5M by nearly 3 feet. However, the 747-8F is a nose-only loader for its main deck, which limits its ability to carry the ultra-wide, oversized industrial components that the Ruslan’s wider floor can accommodate.

Another comparative angle involves specialized volumetric freighters like the Airbus BelugaXL and the Boeing Dreamlifter. These aircraft feature massive fuselage diameters, with the BelugaXL’s cargo bay being an incredible 8.8 meters wide, but they are weight-limited. They are designed to transport lightweight aircraft wings and fuselage sections, not the 120+ tonne payloads that the An-124 and C-5M handle. If a battle tank or a heavy locomotive needs moving, the BelugaXL’s 50,500 kg limit makes it an impossible choice, despite its cavernous appearance.

The comparison inevitably touches on the late Antonov AN-225 Mriya, which was essentially a six-engine, scaled-up version of the An-124. Until its destruction in 2022, the Mriya was the only aircraft that could make the An-124 and C-5 look small. In its absence, the An-124 has reclaimed the title as the world’s highest-capacity production freighter. While the C-5M remains the longest active strategic lifter, the aviation community generally accepts the An-124 as the bigger machine because it occupies more total internal volume and offers superior maximum takeoff weight.

A Lack Of Parts

The primary exception to the bigger is better rule is airfield accessibility. A significant drawback for the An-124 is its massive takeoff run. When operating at its maximum takeoff weight of 402,000 kg, it requires nearly 3,000 meters or 9,800 feet of runway. This restricts the bigger aircraft to major international hubs, whereas the C-5M, despite its size, can utilize shorter, more austere runways of roughly 1,645 meters or 5,400 feet thanks to its high-thrust GE CF6 engines.

Maintenance and fleet availability also present major risks. The global fleet of An-124s is aging and increasingly difficult to maintain due to the ongoing geopolitical situation affecting parts production. While the An-124 is physically larger, its reliability rates often lag behind the modernized C-5M. On the other hand, following its RERP upgrades, reliability rates did not increase. For an airline or military, a smaller plane that is actually available to fly is often more valuable than a larger one stuck in a hangar.

An An-124 might be the biggest in terms of what it can carry, but without the C-5M’s aerial refueling capability, its actual utility on long-range operations is limited. If an An-124 has to stop for fuel three times to cross the Pacific, it may be less efficient and thus effectively smaller in operational impact than a C-5M that can fly the distance non-stop.

A New Challenger On The Horizon?

The definitive takeaway is that while both aircraft are engineering icons, the Antonov An-124 Ruslan is physically bigger in nearly every metric that counts for cargo logistics. With a wingspan nearly 18 feet wider than the C-5M Galaxy and a maximum payload of 150,000 kg, the Antonov provides a superior volumetric capacity of 35,800 cubic feet. The C-5M remains the longer aircraft by a notable 20 feet, but in the world of heavy-lift transport, width and weight-bearing capacity are the true measures of a giant.

The choice between these two comes down to a balance of availability and specialized capability. The An-124 remains the accessible workhorse for commercial projects, capable of loading entire train cars and satellites via its internal bridge cranes. Meanwhile, the C-5M Super Galaxy continues to serve as the ultimate tool for rapid military deployment, utilizing its drive-through capability and aerial refueling to project power across the globe.

Looking ahead, the landscape of heavy-lift aviation is set for a transition. With the destruction of the An-225 Mriya and the aging of the current An-124 fleet, the C-5M stands as the most modernized strategic lifter in active service, expected to fly into the 2040s. However, there remains real potential for clean-sheet heavy-lift designs emerging from the United States and Europe that prioritize fuel efficiency and SAF compatibility.