Analysis: Is the C-5 Galaxy in it for the long-haul?

With the C-5 Galaxy as the US Air Force’s (USAF) – and the West’s – only strategic airlifter, Lockheed Martin’s C-5 Galaxy is the de-facto largest military transport aircraft in operational service. As its sole user, the USAF has 52 of the upgraded ‘M’-model plus a smaller number of older stored C-5Bs that could in theory be modernised.

The Galaxy represents the core of the USAF’s strategic airlift capability under Air Mobility Command (AMC), this being defined roughly as aircraft able to carry oversized payloads over transcontinental distances. In this it is supported by the smaller C-17 Globemaster and at a tactical level by the ubiquitous C-130 Hercules.

As a rough comparison, the C-5M has a range of 8,900km with a payload of 54,431kg versus the C-17s highly efficient 71,214kg over 4,480km. Of course, there are ideal numbers and range might drop by 30% or more under operational conditions. Nevertheless, the C-5s plus over 200 C-17s easily represents the largest and most capable air transport force on the planet.

Unlike the F-35 versus F-15EX versus NGAD and the fight over responsibility for the KC-46, strategic airlift isn’t paid much attention. Yet, for obvious reasons, this is an area of critical importance.

The US will fight its next war (or continue its current engagements) at considerable distance not just from CONUS bases but also largely from allied nations – an obvious example being the Pacific. Air mobility is clearly considered vital, and the requirement is unlikely to diminish.

AMC, which also manages the tanker fleet and associated support aircraft, recently saw appointment of a new chief in Gen John Lamontagne. With US involvement in Pacific and European conflict situations, extensive humanitarian operations and the need to keep the force sharp, development of future capability can only be part of his focus.

As with all major organisations, a fresh command team will revisit the core questions of what the force is trying to do, why should it perform this task in any particular way and how this can be evolved and improved.

Given the potential for non-traditional aircraft solutions and approaches, these are not easy questions. The ’what’ seems obvious, but there are subtleties. Moving loads from ‘A’ to ‘B’ is a necessary requirement, but other questions need consideration. What kind of cargoes should fall under AMC purview? Is payload, sorties or range per day the most important?

Additionally, will the aircraft launch from major bases and do they need to land at austere locations – an issue that has long plagued the C-5. Or do modern air defences make transports too vulnerable for operations closer to front lines? The answer is probably ‘Danger: No Landing Here’.

This leads into the question of why the USAF has this mission. Would a combination of ground and sea transport not be more efficient? Aircraft are expensive and fragile and ultimately, large military units have to travel long-distance by sea with supplies to battle taken in trucks or helicopters.

A role for aerial transport clearly exists, but should this not focus on exquisite items such as moving equipment and personnel from rear base to rear base? Vertical-lift, stealthy tactical transports look exciting, but one needs to consider if the vast R&D cost of a larger equivalent can really be justified?

This raises the question of how the force might be optimised. Is an off-the-shelf aircraft to cover a variety of missions not better? Since the end of the Boeing 747 production, nothing approaching the C-5s size is available as a new build aircraft. Standardised design, economies of scale, high availability and operation rate are all greatly valued.

Considering C-5 replacement possibilities

Ultimately, this philosophical, strategic, operational and technological debate can all broken down into one question: does the USAF need a bespoke C-5 replacement?

Clearly there is no simple response to this issue. While many renderings and mockups have been made for a large military transporter, no concrete programme exists. JetZero, Lockheed and Boeing have all been tapped for a blended wing-body design, but enthusiasm seems low.

On the other hand, while civil-based tanker-transports make a lot of sense, most commercial cargo aircraft are not configured for transport of large helicopters, let alone a main battle tank. While the tube-plus-wings is simpler to construct than a blended alternative, the latter might offer higher efficiencies as well as a smaller radar cross-section.

But there is a crucial point that is largely being overlooked. Designing and building something capable of carrying an Abrams tank over 5-10,000km while being radar-shy and able to land at an austere airstrip is missing the real point. No C-5 has ever been deployed where it risked being shot down or has intentionally made a ‘rough-field’ landing.

C-17s have, on occasion, landed at sub-optimal facilities but usually when only absolutely necessary. C-130s and helicopters routinely test their all-terrain capabilities, but statistically even these hardy warriors mostly touch down on concrete.

The tactical delivery notion was issue for the C-5 programme. In retrospect, an aircraft of this size needing the structural integrity for a ‘Khe Sahn approach’ is risible: the ubiquity of MANPADS has excised such operations under all but the direst circumstances.

So, if the CH-47 and C-130 plus their eventual replacements or updates variants can manage the real tactical need, how does bespoke strategic airlift continue? The A400M and C-390 are doing well and fill the useful gap between helicopter and sea transport, but no one is offering anything bigger.

Wilder solutions do exist on paper. The USAF’s 2022 budget asked for $50 million to explore a rocket-based strategic supply system under one of its ‘Vanguard’ programmes. Carrying around 100 tonnes (roughly a C-17 load) it was intended to allow supply of anyone on the planet within an hour. Predictably, this has not progressed far.

The USAF suggests that such a novel solution would exploit ‘rapid launch capabilities from unusual sites, characterisation of potential landing surfaces and approaches to rapidly improve those surfaces and adversary detectability’. Apart from defying reality and common sense, the timeframe for such a development is clearly quite long.

The replacement for a C-130, it transpires, is another C-130. That the replacement for a C-5 is a reusable low earth orbit rocket that operates from unexpected locations is somewhat unlikely.

The pragmatic solution to all of this is a further life extension to the C-5 fleet. It offers an easy answer when set against arguments over other USAF problems and funding would likely be virtually automatic. But even sitting down and thinking about the future of this capability will likely raise questions.

The KC-46 saga has shown how even the simplest developments cause headaches. The proposed KC-Z stealthy tanker would likely have technical elements useful for a new transport but that is a 2050-plus solution. No US ally is likely to help fund a new large aircraft. In the end, hanging on to the C-5 and asking the navy to make good any shortfall seems to be the USAF’s only medium-term strategic lift option.

This analysis article originally appeared in September’s Decisive Edge Air Newsletter. To receive regular updates from Edward Hunt and our team of defence experts visit our Decisive Edge sign up page.

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