Sikorsky CH-53K King Stallion

The Sikorsky CH-53K King Stallion (Sikorsky S-95)[2] is a heavy transport helicopter designed and produced by Sikorsky Aircraft. The King Stallion is an evolution of the long running CH-53 series of helicopters which has been in continuous service since 1966, and features three up-rated 7,500 shp (5,590 kW) engines, new composite rotor blades, and a wider aircraft cabin than its predecessors. It is the largest and heaviest helicopter in the U.S. military.

CH-53K King Stallion
A CH-53K in transit to Camp Lejeune, May 2022
General information
TypeHeavy transport helicopter
National originUnited States
ManufacturerSikorsky Aircraft
StatusIn production
Primary userUnited States Marine Corps
Number built19 (circa early 2023)[1]
History
Introduction dateMay 2018 (Delivered to USMC)
22 April 2022 (IOC)
First flight27 October 2015
Developed fromSikorsky CH-53E Super Stallion

The United States Marine Corps plans to receive 200 helicopters at a total cost of $25 billion. Ground Test Vehicle (GTV) testing started in April 2014; flight testing began with the maiden flight on 27 October 2015. In May 2018, the first CH-53K was delivered to the Marine Corps. On 22 April 2022, it was declared to have passed initial operational capability.[3] Israel has also reportedly ordered the type; other potential export customers include Japan.

Development

edit

H-53 background

edit

The Sikorsky CH-53 Sea Stallion came out of the US Marine Corps' (USMC) "Heavy Helicopter Experimental" (HH(X)) competition begun in 1962. Sikorsky's S-65 was selected over Boeing Vertol's modified CH-47 Chinook version. The prototype YCH-53A first flew on 14 October 1964.[4] It was designated CH-53A Sea Stallion, delivery of production helicopters began in 1966.[5] The CH-53A was equipped with two T64-GE-6 turboshaft engines, and had a maximum gross weight of 46,000 pounds (21,000 kg).

Variants of the original CH-53A Sea Stallion include the RH-53A/D, HH-53B/C, CH-53D, CH-53G, and MH-53H /J/M. The RH-53A and RH-53D were used by the United States Navy for minesweeping. The CH-53D had a more powerful version of the General Electric T64 engine, used in all H-53 variants, and external fuel tanks.[4] The US Air Force's HH-53B/C Super Jolly Green Giant were for special operations and combat rescue. The Air Force's MH-53H/J/M Pave Low were the final twin-engined H-53s, and had extensive avionics upgrades for all-weather operation.[4]

In October 1967, the USMC issued a requirement for a helicopter with a lifting capacity 1.8 times that of the CH-53D, that could fit on amphibious assault ships. Before this, Sikorsky had been working on an enhancement to the CH-53D, under the company designation "S-80", featuring a third turboshaft engine and a more powerful rotor system. Sikorsky proposed the S-80 design to the Marines in 1968. The Marines considered this a good, quick solution, and funded development of a testbed helicopter.[6] Changes on the CH-53E also included a stronger transmission and a fuselage stretched 6 feet 2 inches (1.88 m). The main rotor blades' material was changed to a titanium-fiberglass composite.[6] A new automatic flight control system was added. The vertical tail was also enlarged, with the tail rotor tilted upwards slightly to provide some lift in hover.[7]

The initial YCH-53E first flew in 1974.[7] Following successful testing, the initial production contract was awarded in 1978, and service introduction followed in February 1981.[6] The US Navy acquired the CH-53E in small numbers for shipboard resupply. The Marines and Navy acquired a total of 177.[6] For the airborne mine countermeasures role, the Navy obtained a CH-53E variant, designated MH-53E Sea Dragon, with enlarged sponsons and fuel tanks for greater fuel storage, in the 1980s.[6][7] The Navy obtained 46 Sea Dragons.[6]

CH-53K

edit
 
A CH-53K prototype during the roll out ceremony in 2014
 
CH-53K on its 6th test flight in 2015
 
A view from below, showing its rear ramp and seven-blade main rotor

The USMC had planned upgrades to retain most CH-53Es, but this effort stalled. Sikorsky proposed a new model, originally designated "CH-53X"; in April 2006, the USMC signed a $18.8 billion contract for 156 "CH-53K" helicopters, with deliveries to be completed by 2021.[8][9][10] The USMC was to begin retiring CH-53Es in 2009, and needed replacements as rotorcraft reached their structural life limits in 2011–12.[8] CH-53K flight testing was expected to begin in 2011.[11] In August 2007, the USMC increased the order from 156 to 227.[12] By that time, the first flight was planned for November 2011 with initial operating capability (IOC) by 2015.[13] The CH-53K will be the USMC's heavy lift helicopter with the MV-22 (medium lift) and UH-1Y (light lift).[14] A 2007 RAND report on seabasing found that a higher ratio of CH-53Ks to MV-22s would reduce ship-based deployment times.[15][16]

In 2008, design work was well underway, along with weight reduction efforts to meet operational requirements; increased engine performance and rotor blade improvements are options to help meet requirements if needed. The rotor mast tilt was decreased and components shifted to ensure the center of gravity does not shift too far rearward as fuel is burned.[17] Design requirements were frozen in 2009–10.[18] On 22 January 2010, Sikorsky opened a $20 million Precision Components Technology Center in Stratford, Connecticut, for producing CH-53K parts, such as the rotating and stationary swashplates, main and tail rotor hubs, and main rotor sleeves.[19] On 3 August 2010, the CH-53K passed its Critical Design Review, reading it for test production.[20][21] However, the IOC fielding date was deferred to 2018.[22] Sikorsky proposed building four pre-production aircraft for evaluation.[23]

On 4 December 2012, Sikorsky delivered the first CH-53K, a Ground Test Vehicle (GTV) airframe. Early tests included fuel system calibration and attaching test sensors across the airframe to record temperature, aerodynamic load, pressure, and vibration. Two additional static GTVs underwent structural testing at the firm's Stratford manufacturing plant.[24] In January 2013, the program had an estimated cost of US$23.17 billion (~$29.9 billion in 2023) after procurement of the planned 200 CH-53Ks.[25] In April 2013, the U.S. Navy program manager stated that work had gone well and it may become operational ahead of schedule.[26] On 31 May 2013, the Navy awarded Sikorsky a $435 million (~$561 million in 2023) contract to deliver four prototype CH-53Ks for evaluation and mission testing;[27] The first two prototypes focused on structural flight loads while the third and fourth validated general performance, propulsion and avionics.[28]

Major subcontractors include Aurora Flight Sciences (main rotor pylon), Exelis Aerostructures (tail rotor pylon and sponsons), GKN Aerospace (aft transition), Onboard Systems International (external cargo hook), Rockwell Collins (avionics management system), Sanmina-SCI Corporation (communications), and Spirit AeroSystems (cockpit and cabin).[29][30][31] In October 2013, Sikorsky gave Kratos Defense & Security Solutions a $8.5 million contract for CH-53K maintenance training aids, such as the Maintenance Training Device Suite (MTDS) and Helicopter Emulation Maintenance Trainer (HEMT). The MTDS is a realistic training and evaluation environment for various avionics, electrical, and hydraulic subsystems. The HEMT is a 3D simulation of multiple scenarios, such as functional test, troubleshoot, fault isolation, removal and installation of 27 subsystems.[32]

On 24 January 2014, the CH-53K GTV ignited its engines, spinning the rotor head without rotors attached. Low-rate production is planned to proceed from 2015 to 2017. Initial operating capability (IOC) was set to occur in 2019, with full-rate production commencing between then and 2022. The USMC intends to have eight active squadrons, one training squadron, and one reserve squadron.[33] In April 2014, testing with blades attached began, system integration followed. Flight testing was set to start in late 2014, each test aircraft flying approximately 500 hours over three years.[34] The maiden flight was delayed, due to issues with the titanium quill shafts in the transmission and gear box.[35][36][37][38]

 
A CH-53K in a hover, 2017

On 5 May 2014, General James F. Amos announced during the official rollout that it will be called the "King Stallion".[39] On 27 October 2015, the CH-53K took its first flight.[40] On 7 March 2018, one lifted a payload of 36,000 pounds (16,000 kg), the maximum weight on the single center point cargo hook.[41][42] The first CH-53K was delivered to the USMC on 16 May 2018; at the time, 18 additional helicopters were in production, and the second was planned for delivery in early 2019.[43]

In December 2018, the CH-53K was projected to not be combat ready as expected in late 2019, due to delivery delays caused by technical flaws found in testing, which resulted in a major program restructuring. Flaws included the engine re-ingesting exhaust gas, limited service life for the rotor gear boxes, late deliveries of redesigned parts, and deficiencies with the tail rotor and driveshaft.[44] It is estimated that the delay will push back delivery of combat-ready CH-53Ks until May 2020.[44]

In 2023, an order was placed with Sikorsky Helicopters for 35 CH-53K helicopters for 2.77 billion USD, as production ramped up at the manufacturing facility to fill orders.[45]

Design

edit
 
Head on view during a 2017 test flight

The CH-53K King Stallion is a heavy lift helicopter, being a general redesign of the preceding CH-53E, the main improvements being the new engines and cockpit layout. It has over twice the lift capacity and radius of action of the CH-53E, and a wider cargo hold to allow it to carry a Humvee internally. A new composite rotor blade system is also used, featuring technology similar to that of the UH-60 Black Hawk helicopter. The CH-53K is powered by the General Electric GE38-1B engine,[46] which was selected over the Pratt and Whitney Canada PW150 and a variant of the Rolls-Royce AE 1107C-Liberty used on the V-22 Osprey.[47] Each of the three T408 engines is rated at 7,500 shp (5,600 kW),[48] and gives the CH-53K the ability to fly 20 knots (37 km/h; 23 mph) faster than its CH-53E predecessor.[49]

 
A CH-53K lifts a Joint Light Tactical Vehicle during a demonstration, 2018

The CH-53K features a new digital glass cockpit with fly-by-wire controls and haptic feedback, HUMS,[50] a new elastomeric hub system, and composite rotor blades to improve "hot and high" performance.[11][51] The split torque gearbox with quill shafts started development around 2007.[52][53][54] The gearbox assembly including rotor hub and rotating control system weighs around 11,650 lb (5,280 kg).[55][56] The split torque gearbox weighs 5,270 lb (2,390 kg).[53] For comparison, the twin-engine Mil Mi-26's split torque gearbox weighs 8,020 lb (3,639 kg).[57]

The CH-53K has an improved external cargo handling system, survivability enhancements, and improvements to extend service life.[11] The cabin will be 30 ft (9.14 m) long by 9 ft (2.74 m) wide by 6.5 ft (1.98 m) tall.[58] Its cabin will be 1 ft (30 cm) wider and 15% larger, but will have new shorter composite sponsons.[11][51] The CH-53K can carry two 463L master pallets, eliminating the need to break apart pallets between airlifter and helicopter.[59][60]

The CH-53K is to surpass the capability of its predecessor by carrying nearly 30% more than the CH-53E's external payload of 27,000 lb (12,200 kg) over the same radius of 110 nmi (204 km).[49] The CH-53K's payload reaches a maximum of 35,000 lb (15,900 kg).[49] The CH-53K's maximum gross weight will be 88,000 lb (39,900 kg),[56] which is increased over the CH-53E's 73,500 lb (33,300 kg). The CH-53K will keep approximately the same footprint as the CH-53E.[29] To this end, it has redesigned composite sponsons that cut overall width for a narrower footprint, which is better for shipboard service.[11]

Operational history

edit

United States Marine Corps

edit
 
CH-53K King Stallion on sea trials in 2023

In May 2018, the first CH-53K King Stallion was delivered to the USMC.[61]

The U.S. Marine Corps received its first CH-53K simulator at Marine Corps Air Station New River in Jacksonville, North Carolina on 1 May 2020. It is a Containerized Flight Training Device (CFTD) built by Lockheed Martin, Sikorsky's parent company.[62]

On 22 April 2022, Lt. General Mark R. Wise, Deputy Commandant for Aviation, declared initial operational capability for the CH-53K.[3]

Israel

edit

In 2009, the Israeli Air Force (IAF) said it would evaluate the new variant after it flies.[63] In August 2015, it formalized a requirement for the CH-53K, listing the type as a "very high priority" item to enable the service to perform missions only the platform is capable of. Israel's current CH-53 "Yasur" fleet is to remain operational until 2025.[64]

The CH-53K competed with the Boeing CH-47F Chinook for an order of approximately 20 helicopters to replace the CH-53 Yasur.[65][66][67] In February 2021, the Israeli Ministry of Defense announced the CH-53K's selection.[68][69] On 31 December 2021, it was announced that Israel had signed a deal to buy 12 CH-53Ks.[70][71]

In August 2023, Sikorsky announced they had been awarded a contract by the US Navy for 35 helicopters at a total cost of $2.77 billion, including eight aircraft for Israel.[72][73][74]

Potential operators

edit

Japan has reportedly shown interest in the CH-53K.[66][67]

Failed bids

edit

In February 2018, Sikorsky signed an agreement valued at around €4 billion with Rheinmetall to team up for the German Air Force's CH-53G heavy lift helicopter replacement program, in which the CH-53K competed against the Boeing CH-47 Chinook. The German Federal Ministry of Defence was expected to issue an official request for information in late 2018, to award a contract in 2020, and for deliveries to begin in 2023 for an expected order of around 40 helicopters.[66][67][75]

On 29 September 2020, the German Ministry of Defense cancelled the "Schwerer Transporthubschrauber" (STH) heavy-lifting helicopter program,[76] it having been judged to be too expensive; instead, the CH-53Gs are still to be replaced after reexamining the project.[77] In 2022, Germany decided to procure the CH-47F Chinook instead, citing interoperability advantages with other European NATO countries—especially the Netherlands—as well as the lower unit cost compared to the CH-53K, which would allow the purchase of more helicopters for the same budget.[78][79][80]

Operators

edit
 
A KC-130 refuels CH-53K-King-Stallion
  United States

Future operators

edit
  Israel

Specifications (CH-53K)

edit
 
The King Stallion makes its international debut at the 2018 ILA Berlin Air Show
 
In flight at ILA 2018
 
Rear view, with all three engine exhausts visible

Data from Sikorsky CH-53K,[82] GE38-1B data,[48] and Flightglobal.com[83]

General characteristics

  • Crew: 4
  • Capacity: 30 passengers or troops, 24 casualty litters, or 35,000 lb (15,876 kg) payload
  • Centre external load hook rating – 36,000 lb (16,329 kg)
  • Fore and aft external load hooks rating – 25,200 lb (11,431 kg)
  • Length: 99 ft (30 m) rotor and tail un-folded
  • Width: 17 ft 6 in (5.33 m) fuselage
  • Height: 28 ft 4.9 in (8.659 m) rotor and tail un-folded
  • Cabin length: 30 ft (9.1 m)
  • Cabin width: 8 ft 7.2 in (2.6 m)
  • Cabin height: 6 ft 6 in (2.0 m)
  • Empty weight: 43,878 lb (19,903 kg)
  • Max takeoff weight: 88,000 lb (39,916 kg) with external load
74,000 lb (33,566 kg) with maximum internal load
  • Fuel capacity:
    • 2,286 US gal (1,903 imp gal; 8,650 L) internal in two cells per sponson (15,545 lb (7,051 kg))
    • 2,400 US gal (2,000 imp gal; 9,100 L) auxiliary internal in three cabin tanks (16,320 lb (7,403 kg))
  • Powerplant: 3 × General Electric T408 (GE38-1B) turboshaft engines, 7,500 shp (5,600 kW) each

Performance

  • Cruise speed: 170 kn (200 mph, 310 km/h)
  • Range: 460 nmi (530 mi, 850 km)
  • Combat range: 110 nmi (130 mi, 200 km)
  • Service ceiling: 16,000 ft (4,900 m) ISA
13,200 ft (4,023 m) ISA +24 °C (75 °F)

See also

edit

Related development

Aircraft of comparable role, configuration, and era

Related lists

References

edit
  1. ^ "Sikorsky Delivers Two More CH-53K® Helicopters to U.S. Marine Corps". Lockheed Martin. 13 February 2023. Archived from the original on 18 December 2023. Retrieved 10 April 2023.
  2. ^ "Sikorsky Builds Marine Corps Heavy Lift". Sikorsky Archives. p. 9. Archived from the original on 19 July 2023.
  3. ^ a b Eckstein, Megan (25 April 2022). "Marine Corps declares its heavy-lift helicopter operational". Defense News. Archived from the original on 11 January 2024.
  4. ^ a b c "Sikorsky Giant Helicopters: S-64, S-65, & S-80". Vector Site. 1 March 2008. Archived from the original on 30 March 2008.
  5. ^ Frawley, Gerard (2002). International Directory of Military Aircraft 2002/03. Motorbooks Intl. p. 148. ISBN 9781875671557.
  6. ^ a b c d e f Goebel, Greg (1 August 2022). "Sikorsky S-80". Air Vectors. Archived from the original on 9 April 2023.
  7. ^ a b c "CH-53A/D Sea Stallion". U.S. Navy. Archived from the original on 6 February 1997.
  8. ^ a b Whittle, Richard (1 January 2007). "Tilton Names New President at MD Helicopters". Aviation Today. Archived from the original on 2 May 2014.
  9. ^ "Sikorsky Awarded $3.0B Development Contract For Marine Corps CH-53K Heavy-Lift Helicopter". Sikorsky. 5 April 2006. Archived from the original on 27 November 2008.
  10. ^ "Sikorsky Aircraft Marks Start of CH-53K Development and Demonstration Phase". Sikorsky. 17 April 2006. Archived from the original on 27 November 2008.
  11. ^ a b c d e Goebel, Greg (1 May 2010). "S-80 Upgrades / CH-53K". Vector Site. Archived from the original on 26 June 2010.
  12. ^ "Marines Up Order for New Heavy Lifter". Aviation Today. 1 August 2007. Archived from the original on 1 July 2012.
  13. ^ "US Marines in desperate need of new CH-53K". FlightGlobal. 21 June 2007. Archived from the original on 12 January 2024.
  14. ^ Fein, Geoff (27 May 2008). "Marine Corps Helicopter Programs Stabilizing, Official Says". Defense Daily. Archived from the original on 11 August 2022.
  15. ^ Button, Robert W.; Gordon IV, John; Riposo, Jessie; Blickstein, Irv; Wilson, Peter A. (2007). Warfighting and Logistic Support of Joint Forces from the Joint Sea Base (PDF). Rand Corporation. ISBN 978-0-8330-4195-1. Archived (PDF) from the original on 31 May 2023.
  16. ^ Bruno, Michael (16 October 2007). "Seabasing study promotes CH-53K, JHSV over MV-22". Aviation Week. Archived from the original on 22 March 2012.
  17. ^ Fein, Geoff (14 May 2008). "Navy, Sikorsky Overcoming Challenges To CH-53K Design". Defense Daily. Archived from the original on 27 January 2022.
  18. ^ Parker, Andrew (28 May 2014). "Sikorsky CH-53K: Pause to Reflect on Obstacle-Filled Road". Aviation Today. Archived from the original on 14 July 2014.
  19. ^ "Sikorsky opens $20M production center". Hartford Business Journal. 22 January 2010. Archived from the original on 12 January 2024. Retrieved 22 January 2010.
  20. ^ "CH-53K helicopter program achieves successful Critical Design review". Shephard. 3 August 2010. Archived from the original on 29 September 2011.
  21. ^ "CH-53K Helicopter Program Achieves Successful Critical Design Review". Sikorsky. 3 August 2010. Archived from the original on 5 July 2011. Retrieved 16 August 2010.
  22. ^ "CH-53K Heavy Lift Helicopter Program Conducts Successful Auxiliary Power Unit "Light-Off"". Sikorsky. 25 August 2010. Archived from the original on 5 July 2011.
  23. ^ "NAVAIR Evaluating New CH-53K proposal From Sikorsky". Fly Away Simulation. 16 April 2012. Archived from the original on 5 May 2012.
  24. ^ "Sikorsky delivers first CH-53K". Star Defense. Archived from the original on 8 February 2013. Retrieved 10 December 2012.
  25. ^ "GAO-15-342SP DEFENSE ACQUISITIONS Assessments of Selected Weapon Programs" (PDF). US Government Accountability Office. March 2015. p. 69. Archived (PDF) from the original on 24 September 2015. Retrieved 15 July 2015.
  26. ^ Majumdar, Dave (10 April 2013). "Sikorsky CH-53K may be operational ahead of schedule". FlightGlobal. Archived from the original on 25 January 2022.
  27. ^ Majumdar, Dave (31 May 2013). "Sikorsky awarded $435 million contract for four CH-53K test aircraft". FlightGlobal. Archived from the original on 17 April 2021.
  28. ^ Drew, James (14 March 2016). "CH-53K project expands to 120kt and two test helicopters". FlightGlobal. Archived from the original on 7 August 2022.
  29. ^ a b "Sikorsky Selects CH-53K Fuselage Supplier Team". Defense-Update. 10 May 2007. Archived from the original on 6 June 2023.
  30. ^ "Sikorsky Aircraft Selects Rockwell Collins to Provide CH-53K Avionics Management System". Vertical Magazine. 29 June 2006. Archived from the original on 12 January 2024.
  31. ^ "Onboard Systems Awarded CH-53K Cargo Hook Program". Onboard Systems. 4 March 2008. Archived from the original on 6 June 2023.
  32. ^ "Sikorsky awards Kratos contract for CH-53K helicopter maintenance training systems". Vertical Magazine. 1 October 2013. Archived from the original on 12 January 2024.
  33. ^ Hemmerdinger, Jon (10 February 2014). "Sikorsky fires up main CH-53K engines". FlightGlobal. Archived from the original on 16 June 2023.
  34. ^ "Sikorsky begins powered ground tests of CH-53K helicopter with rotor blades". Vertical Magazine. 1 May 2014. Archived from the original on 19 January 2022.
  35. ^ Drwiega, Andrew (2 October 2014). "King Stallion Trots Toward Flight Test Program". Aviation Today. Archived from the original on 22 October 2014.
  36. ^ Parsons, Dan (3 December 2014). "Sikorsky CH-53K first flight pushed at earliest to March". FlightGlobal. Archived from the original on 18 January 2022.
  37. ^ Shalal, Andrea (17 June 2015). "Sikorsky tells US ownership change won't affect CH-53K program". Reuters. Archived from the original on 10 April 2023.
  38. ^ Malenic, Marina (14 April 2015). "Sikorsky redesigns CH-53K main gear box components as E-models are kept in service". Jane's. Archived from the original on 19 April 2015.
  39. ^ "Sikorsky Unveils CH-53K Helicopter; U.S. Marine Corps Reveals Aircraft Name". Lockheed Martin. 5 May 2014. Archived from the original on 28 December 2021.
  40. ^ Shalal, Andrea (27 October 2015). "Sikorsky's CH-53K helicopter makes first test flight - Marine Corps". Reuters. Archived from the original on 12 January 2024.
  41. ^ "CH-53K King Stallion Lifts 36,000 Pounds". Military.com. 7 March 2018. Archived from the original on 12 January 2024.
  42. ^ Jennings, Gareth (7 March 2018). "CH-53K marks heavy-lift milestone". Jane's. Archived from the original on 7 March 2018. Retrieved 9 February 2019.
  43. ^ Snow, Shawn (16 May 2018). "The Corps just received its first CH-53K King Stallion". Marine Corps Times. Archived from the original on 9 April 2023.
  44. ^ a b Capaccio, Anthony (19 December 2018). "The $31 Billion King Stallion Helicopter Is the Latest Military Program That Won't Be Combat-Ready on Time". Time. Archived from the original on 13 December 2023.
  45. ^ Eckstein, Megan (24 August 2023). "US Navy awards Sikorsky $2.7 billion for 35 CH-53K helicopters". Defense News. Retrieved 6 April 2024.
  46. ^ "Sikorsky Aircraft Selects CH-53K Main Engines"[permanent dead link]. Sikorsky Aircraft, 22 December 2006.
  47. ^ "CH-53K: The U.S. Marines' HLR Helicopter Program (updated)". Defense Industry Daily. Watershed Publishing LLC. 28 December 2006. Archived from the original on 2 January 2007.
  48. ^ a b General Electric Model GE38 page Archived 20 June 2011 at the Wayback Machine. GE Aviation.
  49. ^ a b c CH-53K brochure Archived 16 February 2012 at the Wayback Machine. Sikorsky.
  50. ^ Head, Elan (2017). "Meet the King". pp. 40–49. Archived from the original on 2 February 2017. Retrieved 22 January 2017.
  51. ^ a b "Prototype Assembly Looms As First Production Parts Arrive for CH-53K Heavy Lift Helicopter" Archived 8 May 2014 at the Wayback Machine. Sikorsky Aircraft, 6 August 2009.
  52. ^ "Marine Corps Prepares New CH-53K for First Flight Archived 24 October 2014 at the Wayback Machine". DefenseTech, 21 October 2014. Accessed: 23 October 2014.
  53. ^ a b He, S., Gmirya, Y., Mowka, F., Leigh, L. "Trade Study on Different Design Configurations of the CH-53K Main Gearbox" Archived 18 November 2015 at the Wayback Machine NASA, 2008
  54. ^ Buzel, Gregory; Gmirya, Yuriy; He, Shulin; Leigh, Leslie. Load Sharing Test of the CH-53K Split Torque Main Gearbox Archived 24 March 2016 at the Wayback Machine AHS International/Sikorsky, 2009
  55. ^ Gmirya, Y., Alulis, M., Palcic, P., Leigh, L. "Design and Development of a Modern Transmission: Baseline Configuration of the CH-53K Drive System Archived 18 November 2015 at the Wayback Machine", NASA, 2011.
  56. ^ a b Parker, Andrew. "CH-53K King Stallion Inches Closer to Sunrise Archived 23 September 2015 at the Wayback Machine" Aviation Today, 6 May 2014. Accessed: 7 May 2014.
  57. ^ Lev I. Chaiko (1990) Review of the Transmissions of the Soviet Helicopters Archived 16 August 2017 at the Wayback Machine, pp. 2, 3, 9. NASA Glenn Research Center NASA Technical Memorandum 10363.
  58. ^ CH-53K Helicopter (click on Attributes tab) Archived 15 November 2015 at the Wayback Machine. Sikorsky.
  59. ^ "CH-53K Helicopter." Archived 8 May 2014 at the Wayback Machine Sikorsky
  60. ^ Vendrasco, Stephanie. "Cargo cabin mockup ready for some heavy lifting." USMC, 20 December 2007.
  61. ^ Werner, Ben (16 May 2018). "Marine Corps Accepts Delivery Of First CH-53K Super Stallion". USNI News. Retrieved 26 May 2024.
  62. ^ Reim, Garrett. "First CH-53K King Stallion simulator delivered to US Marine Corps". Flight Global. Archived from the original on 8 May 2020. Retrieved 10 May 2020.
  63. ^ Egozi, Arie. "Israel drops interest in V-22, eyes CH-53K evaluation." Archived 14 November 2009 at the Wayback Machine Flight International, 12 November 2009.
  64. ^ a b Israeli air force looks for lift from CH-53K Archived 13 January 2017 at the Wayback Machine Flightglobal.com, 10 August 2015.
  65. ^ Ahronheim, Anna (2 August 2018). "Two Defense Companies Compete to Replace Israel's Heavy-Lift Helicopters". The Jerusalem Post. Archived from the original on 7 February 2018.
  66. ^ a b c Shalal, Andrea (15 November 2017). "Lockheed's CH-53K helicopter to make global debut at Berlin air show: sources". Reuters. Berlin. Archived from the original on 14 December 2017.
  67. ^ a b c Shalal, Andrea (5 February 2018). "Lockheed, Rheinmetall team up to bid for German helicopter order". Reuters. Berlin. Archived from the original on 7 February 2018.
  68. ^ "Israel selects CH-53K King Stallion as the IDF's new transport helicopter". timesofisrael.com. Archived from the original on 12 April 2021. Retrieved 25 February 2021.
  69. ^ Zitun, Yoav (25 February 2021). "IDF approves use of CH-53K King Stallion as its new cargo helicopter". ynetnews. Archived from the original on 25 February 2021. Retrieved 25 February 2021.
  70. ^ "Israel signs deal for helicopters, Boeing aircrafts [sic] from US". I24 News. 31 December 2021. Archived from the original on 31 December 2021. Retrieved 31 December 2021.
  71. ^ "Israel – CH-53K Heavy Lift Helicopters with Support | Defense Security Cooperation Agency". www.dsca.mil. Archived from the original on 11 June 2023. Retrieved 11 June 2023.
  72. ^ "U.S. Navy Awards Sikorsky Contract to Build 35 CH-53K® Helicopters". Media - Lockheed Martin. 24 August 2023. Archived from the original on 22 December 2023. Retrieved 22 December 2023.
  73. ^ Katz, Justin (25 August 2023). "Sikorsky awarded $2.7B contract for 35 CH-53K King Stallions, some bound for Israel". Breaking Defense. Archived from the original on 22 December 2023. Retrieved 22 December 2023.
  74. ^ Eckstein, Megan (24 August 2023). "US Navy awards Sikorsky $2.7 billion for 35 CH-53K helicopters". Defense News. Archived from the original on 2 February 2024. Retrieved 22 December 2023.
  75. ^ Stevenson, Beth (6 February 2018). "Sikorsky teams with Rheinmetall for German heavy lift competition". IHS Jane's 360. London. Archived from the original on 7 February 2018.
  76. ^ "Lockheed, Boeing enter Germany's heavy transport helicopter race". 14 January 2020. Archived from the original on 2 February 2024. Retrieved 30 September 2020.
  77. ^ "Germany Axes Plan to Buy Either Sikorsky CH-53K or Boeing CH-47 Helicopters". 29 September 2020. Archived from the original on 13 October 2020. Retrieved 30 September 2020.
  78. ^ Sprenger, Sebastian (1 June 2022). "Boeing wins bid for Germany's multibillion-dollar helo program". Defense News. Archived from the original on 2 February 2024. Retrieved 3 June 2022. ...it would allow Berlin to buy the maximum number of aircraft out of a range previously billed as 45 to 60 copies. ... Officials stressed interoperability benefits with the Netherlands, in particular.
  79. ^ Osborne, Tony (1 June 2022). "Germany To Buy Boeing Chinook Helicopters". Aviation Week & Space Technology. Archived from the original on 17 March 2023. Retrieved 16 March 2023. German officials said other factors in the procurement included the lower per unit price of the CH-47, as well as fewer technical, time and financial risks associated with the platform.
  80. ^ Osborne, Tony (22 June 2022). "Boeing Eyes 2023 Contract Signing For German Chinook Purchase". Aviation Week & Space Technology. Archived from the original on 17 March 2023. Retrieved 16 March 2023. .. the Chinook was chosen because of its affordability and European interoperability. The aircraft already is in use with regional allies Greece, Italy, the Netherlands and the UK.
  81. ^ "US Marine Corps takes delivery of first CH-53K". flightglobal.com. Archived from the original on 18 July 2018. Retrieved 18 May 2018.
  82. ^ "Sikorsky CH-53K The Only Heavy Lift Solution" (PDF). Lockheed Martin. Archived (PDF) from the original on 20 January 2020. Retrieved 28 July 2020.
  83. ^ Hemmerdinger, Jon (21 February 2014). "Sikorsky CH-53K testing continues on schedule". Flightglobal. Archived from the original on 19 December 2019. Retrieved 24 September 2020.
edit