Clash of the Titans!

A pair of heavyweight champions are vying to replace the Luftwaffe’s ageing Sikorsky CH-53s. Khalem Chapman details the contenders in Germany’s heavy-lift transport helicopter replacement programme.

Germany is closer in its search for a new heavy-lift, multi-mission transport helicopter fleet, following the candidacy announcements of Boeing’s CH-47F Chinook and Sikorsky’s CH-53K King Stallion for its Schwerer Transporthubschrauber (STH, Heavy Transport Helicopter) programme. The campaign is led by the Bundesamt für Ausrüstung, Informationstechnik und Nutzung der Bundeswehr (BAAINBw, Federal Office for Equipment, Information Technology and Use of the German Armed Forces).

It seeks to replace the nation’s CH-53 Sea Stallion fleet, which entered service with the Deutsches Heeresflieger (German Army Aviation) in 1974. The platform operated with the corps until it was transferred to the Luftwaffe (German Air Force) in early 2013.

According to AirForces Intelligence, as of March, the air arm operates a fleet of 82 Sea Stallions, comprising 16 CH-53G, 40 CH-53GA, six CH-53GE and 20 CH-53GS helicopters. They are employed by Hubschraubergeschwader 64 (HSG 64, Helicopter Wing 64), which is headquartered at Laupheim, Baden-Württemberg, with a subordinate unit at Holzdorf, Brandenburg.

Replacing the Stallions

Germany has been looking to replace its CH-53G fleet for a while, as the Cold War-era workhorse coming to the end of its viable operational life. The platform has also suffered from poor availability in recent years, with age being a significant factor in that.

The STH campaign has its origins in 2018, when the German government released a request for proposal (RFP) and approved the procurement of new heavy-lift helicopters in its parliamentary budget. In June 2019, the BAAINBw published an invitation to tender, which detailed the programme requirements and recommended that the ideal replacement would be the CH-47F or CH-53K.

It noted that the programme seeks to procure between 44 and 60 aircraft for Luftwaffe use. The aircraft must be capable of transporting equipment, personnel and vehicles, with a maximum take-off weight (MTOW) of at least 19.7 tons (20 tonnes). The country is expected to award an acquisition contract – worth roughly €5.7bn (US$6.4bn) – next year, for either the Chinook or the King Stallion. The deal will include the full complement of Germany’s desired platform, type maintenance, repair and overhaul (MRO) and sustainment and training services. Deliveries are scheduled to take place between 2023 and 2031, with the new aircraft being based at Laupheim and Holzdorf, taking over from the CH-53Gs, which are expected to be phased out of service by the end of the decade.

Both Boeing and Sikorsky – a subsidiary of Lockheed Martin – have formally presented their contenders for the STH programme, leaving the BAAINBw to decide on the CH-53G’s successor by 2021. Although the two helicopters follow completely different designs – the Chinook is smaller in size – they have similar performance characteristics, as detailed in the table. They will have the capacity to be air-to-air refuelled, operable with Germany’s future KC-130J Super Hercules tanker/transport fleet – with the Luftwaffe operating three examples in a joint unit with the Armée de l’Air (French Air Force). The air arm also fields several Airbus A400Ms with an air-to-air refuelling capability, which will no doubt also be operable with the CH-47F/CH-53K. Each type will be used to transport personnel, equipment and vehicles, along with supporting humanitarian assistance/disaster relief (HA/DR), medical evacuation (MEDEVAC) and combat search and rescue (CSAR) missions.

Heavyweight Champions

A Proven Powerhouse

Boeing boasts that the CH-47 is the “world’s most proven heavy-lift helicopter”, adding that it has a “record of on-time delivery and first time quality”, combined with low acquisition/operating costs and a technology roadmap that intends to keep the platform relevant over the coming decades.

Development of the twin-engine, tandem rotor helicopter began in the late 1950s, as the US Army sought to replace its Sikorsky CH-37 Mojave fleet. It was originally designed by US-based rotorcraft manufacturer, Vertol, before it was acquired by Boeing in 1960. In line with the army’s tradition of naming aircraft after Native American tribes, the CH-47 was labelled the Chinook after the peoples who lived in the territory now occupied by the states of Oregon and Washington. Other helicopters that have followed this code include the AH-64 Apache and the recently retired OH-58D Kiowa Warrior. The CH-47 first saw operational combat service during the Vietnam War, where it proved its worth as a true heavy-lifting workhorse.

Now at CH-47F-standard, Boeing is still producing the venerable Chinook. Although it shares the same 1950s design, it has greatly developed over time through technological upgrades and the integration of modern systems, keeping it relevant well into the 21st century, as shown with its ongoing export success. As of January 2020, more than 950 examples are in operational service with 20 nations – including eight NATO member states, comprising Canada, Greece, Italy, the Netherlands, Spain, Turkey, the UK and the US.

As the latest in the Chinook family, the CH-47F has been ordered to replace older variants of the platform since the first production model rolled out in June 2006. It employs two upgraded Honeywell T55-GA-714A turboshaft engines, monolithic machined frame components and airframe modifications to reduce vibrations, improving operational support and crew endurance, stability and survivability. Its digital cockpit has been developed around Collins Aerospace’s Common Avionics Architecture System (CAAS), which the company says, “integrates multiple communications, navigation and mission subsystems through its ‘Flight2’ open systems architecture design”. The US Army adds that the CAAS “enables multiservice digital compatibility and interoperability for improved situational awareness, mission performance and survivability, as well as future growth potential”. The aircraft is equipped with a digital automatic flight control system, enabling it to hover in place or land in adverse situations with limited visibility.

Boeing responded to the invitation to tender by officially offering the CH-47F on January 13. Dr Michael Haidinger, president of Boeing Germany, stated that sustainment and training, along with some production work would be performed locally if the nation selected the Chinook. “We will continue to build on and expand our [German] industry team for the H-47 Chinook [STH] competition. In addition, we are committed to bringing high end engineering and production opportunities from across the Boeing enterprise to German industry,” he said.

Michael Hostetter, vice president of Boeing Defense, Space and Security in Germany, said: “We’re pleased to have submitted our response and look forward to working with the BAAINBw and German industry to bring the best value proposition to the German Bundeswehr… The [CH-47F] Chinook is a one-of-a-kind platform, capable of performing missions that other helicopters cannot. It is a proven multi-mission heavy-lift helicopter with advanced technology that meets German requirements.”

Enter the King

According to Beth Parcella, Sikorsky’s CH-53K International Business Development Director, the company is offering “the most efficient, capable and intelligent helicopter, that will deliver the best long-term value to the Bundeswehr through the 21st century.” Sikorsky has taken a different, strategic approach to its bid and has partnered with German defence contractor, Rheinmetall, to offer its CH-53K to the Bundeswehr. The pair have formed a STH project team with local industry, which includes Autoflug, Collins Aerospace, Hensoldt, HYDRO Systems, Liebherr, MTU Aero Engines, Rohde & Schwarz, Vincorion and ZFL. Mike Schmidt, managing director of Rheinmetall Aviation Services, explained that opting for the King Stallion would be significant for both German industry and the CH-53K programme. He said: “This means the creation of many new, long-term jobs for highly qualified employees and an important transfer of know-how… Sikorsky and Rheinmetall prepared the application together over a long period of time; his has strengthened the bonds within our team. We have developed into a highly effective unit.”

To add to this, in November 2019, Rheinmetall announced that it will open a CH-53K Logistics and Fleet Management Centre at Leipzig/Halle Airport, Schkeuditz, in co-ordination with Sikorsky if the King Stallion is selected.

Sikorsky boasts that the CH-53K will provide long-term value to the Bundeswehr in comparison to the CH-47F with regards to life-cycle costs, the fulfilment of mission requirements and its overall capabilities. It argues that the King Stallion will be more interoperable with the Luftwaffe’s A400Ms and future C-130Js. This is due to its use of air transport pallets, allowing for quicker cargo handling when transferring from fixed-wing assets to the CH-53K, which can then be delivered to areas that can’t be accessed by these larger aircraft.

The King Stallion is a complete redesign of the CH-53E Super Stallion, which is currently in service with the US Marine Corps (USMC). It furthers more than half a century of matured manufacturing processes, which started with Sikorsky’s original H-53 Sea Stallion in the mid-1960s. More than 700 examples of all variants were produced since then, serving in the militaries of Austria, Germany, Iran, Israel, Japan, Mexico and the US. The CH-53K has been designed to serve as a direct replacement for the USMC’s Super Stallions and, as of March 2020, just a single aircraft has been delivered to the corps for testing. It is yet to receive any export orders, but the Japanese have shown interest in the type and Israel are running an identical competition to Germany – seeking 20 aircraft to replace its ageing CH-53-2000 Ya’sur/CH-53-2000 Ya’sur 2025 fleet.

Accordingly, the CH-53K is more enhanced than its predecessors, aside from having a 30cm (12in) larger cabin and the capability to carry nearly twice the payload at higher altitudes and in hotter temperatures. Sikorsky states that the aircraft’s internal payload capacity can be substantially increased in the future with only a few, simple modifications made to the helicopter. It also features avionics and digital flight control systems that have been designed to accommodate future software upgrades through a modular open-systems approach (MOSA), which lowers operational costs and allows for the platform to rapidly adapt to new operational mission sets, integrate with the latest technologies and therefore remain relevant to the Luftwaffe for longer. The CH-53K also employs a digital glass cockpit and fly-by-wire flight controls to reduce pilot workload, enable all weather operations and increase the precision of delivering external loads. It is powered by three GE Aviation GE38-1B turboshaft engines and uses a composite seven-bladed main rotor system.

Sikorsky states that the King Stallion’s “versatility” allows it to be used in a variety of mission sets outside of the traditional tactical transport role. It can perform the same tasks as the Chinook, but it can also be employed in aerial firefighting operations. It claims that “no other heavy-lift helicopter in the world can transport more water to fight fires and simultaneously carry material and personnel. The combination of high airspeed, a large water capacity and long mission endurance in operational areas allows the CH-53K to transport up to four times more water than its competitors.” A configuration of the Chinook – the CU-47 – has also been recently developed to conduct aerial firefighting tasks.

The King Stallion has been integrated with sensors to predict and prevent maintenance problems early, with aims to reduce the platform’s time in MRO, thus increasing operational availability rates and reducing life-cycle costs.

Awaiting Coronation

Development of the CH-53K has been turbulent, plagued with delays and problems that Sikorsky has had to solve. Flight testing was expected to start as early as 2011, with deliveries to its launch customer – the USMC – scheduled to begin in 2015 and ending in 2022, with an initial operational capability dated in 2016. The King Stallion didn’t make its first flight until October 2015 and the start of the Initial Operational Test & Evaluation (IOT&E) phase has been pushed back to 2021, with its first USMC operational deployment now planned for 2024.

Problems still cloud the CH-53K. In 2019, the biggest issue for Sikorsky was fixing a gas re-ingestion issue that was discovered during flight testing in 2018. It saw the exhaust gases from the aircraft’s number one and two engines being re-ingested by the second. If left alone, it would cause poor performance, overheating, stalls and result in increased life-cycle costs for the powerplants. The company teamed up with Naval Air Systems Command (NAVAIR) to find a solution, which resulted in additional testing, further development delays and reconstruction. To alleviate the problem, a design change was made to the number one engine’s exhaust duct, air flow into the engine bays was increased, a heat shield was installed and minor alterations were made to the its software. The modifications were made to the second CH-52K prototype, which flew nearly 13 flight test hours across four sorties to validate the changes before the other aircraft were altered. By the end of 2020, each platform is expected to have been modified and sea trials can begin before the IOT&E starts next year. Aside from engine integration issues, the King Stallion has suffered problems with its main gearbox, main rotor damper and had failures in intermediate ground mode during aircraft launch, which can lead to the pilot losing control of the helicopter.

Steve Schmidt, Sikorsky’s CH-53K chief engineer, has praised the platform’s design in overcoming these issues, saying: “This is really where the [aircraft’s] all-digital design really became key… It made it much easier to make these models and run these models.”

A Two Horse Race

The CH-47F and the CH-53K are the only two viable candidates that fit the requirements for Germany’s CH-53G replacement programme, with no real Western alternatives when it comes to heavy-lift transport helicopters with a MTOW of more than 19.7 tons (20 tonnes). This immediately takes the larger medium-lift platforms, such as Airbus Helicopters’ H225 Super Puma/H225M Caracal, Leonardo Helicopters’ AW101 Merlin, NH Industries’ NH90 and Sikorsky’s S-92 out of contention for the contract. The Bell/Boeing V-22 Osprey tiltrotor – although it would fulfil the requirements of the German tender – was likely ruled out of the competition by the BAAINBw to keep within affordability objectives as the Chinook and King Stallion would be cheaper to both acquire and operate. Other contenders could have originated from the east, with the Mil Mi-26T2V – latest incarnation of the ‘Halo’ and largest helicopter in the world. However, similar to those from the West, most helicopters employed fall below Germany’s MTOW requirement, such as the Mil Mi-17.

The Rightful Heir?

Either contender would provide advantages to the Bundeswehr, expanding its heavy-lift rotary mission with modern platforms with new capabilities and technologies, combined with low acquisition and life-cycle costs. Although both aircraft have similar characteristics, the CH-53K’s larger size and additional engine edges out the Chinook in terms of payload capacity, speed and redundancy. Sikorsky’s “for Germany, by Germany” motto also highlights the fact that it is working very closely with local industry – boosting jobs and know-how – to replace its CH-53Gs. Adding to that, the CH-53K will have some degree of commonality with the pilots and ground crew who have worked on its predecessor.

The CH-47F does have advantages over the King Stallion in terms of affordability – it would be the cheaper option of the two – and it’s a capable, combat-proven aircraft that will provide Germany with the opportunity to be more interoperable with fellow NATO member states that are operating the type. The country is also increasing local ties with France, who recently announced its interest in acquiring several CH-47Fs for its own use. The CH-53K’s troublesome development could also point the BAAINBw in favour of selecting the Chinook, preventing it from taking its throne in Germany.

On paper, both contenders would prove to be ideal successors to the Sea Stallions, but with the close performance similarities, will the BAAINBw be swayed by the details – such as Sikorsky/Rheinmetall’s offer to open an in-country CH-53K Logistics and Fleet Management Centre – more than the platforms themselves?