Famille CH-53

CH-53K: The U.S. Marines’ HLR Helicopter Program
12-Jan-2010 10:48 EST



The U.S. Marines have a problem. The CH-53E Super Stallion medium-heavy lift helicopters they rely upon to move troops, vehicles, and supplies off of their ships are wearing out. Fast. Yet the pace demanded by the Global War on Terror is relentless, and usage rates are 3 times normal. Attrition is taking its toll, and CH-53s are being recalled from “boneyard” storage at Davis-Monthan AFB in Tucson, AZ, in order to maintain fleet numbers in the face of recent losses and forced retirements. No flyable spare airframes are left, and by 2012-2015, replacements will be urgently needed.

Enter the Heavy Lift Replacement (HLR) program, also known as the CH-53X and given the formal designation CH-53K in April 2006. The 156-helicopter program will define the future of the US Marine Corps’ medium-heavy lift capabilities. To fulfill that goal, Sikorsky received $3.04 billion for System Development and Demonstration (SDD), to include 4 SDD aircraft, 1 ground test vehicle, and associated program management and test support. Initial Operational Capability isn’t set to happen until 2016, however, which risks a helicopter gap unless other measures are taken.

DID describes the CH-53K’s requirements, covers some of the potential improvements, and notes the treacherous political waters this program will need to survive, in order to wind up delivering US Marines the tools they’ll need to survive. The latest news involves a number of firsts and risk reduction efforts for the program, as it prepares for a critical year in 2010…

•The HLR Program Lifts Off
•The CH-53X / CH-53K [updated]
•HLR Program: Contracts, Events & Milestones [updated]
•Appendix A: Flying Between Scylla and Charbydis: Navigating The Political Shoals (April 2006)
•Appendix B: Interesting Ideas: The CH-53X Skycrane Concept
•Appendix C: Additional Readings & Sources
The HLR Program Lifts Off


On average, existing CH-53E aircraft are more than 15 years old, have over 3,000 flight hours under tough conditions, and are becoming more and more of a maintenance challenge with a 44:1 maintenance man-hours:flight hours ratio. Not to mention the resulting $20,000 per flight-hour cost ratio. According to Jane’s Defense Weekly, a 1999 analysis showed that the existing fleet has a service life of 6,120 flight hours, based on fatigue at the point where the tail folds. The USMC expects that the existing fleet will start to reach this point in 2011, at a rate of 15 aircraft per year.

The HLR program calls for 156 new-build helicopters derived from the CH-53E Super Stallion, with initial flight tests in 2010-2011 and initial operating capability in 2014-2015. US Navy PMA 261 is responsible for the program, and the program manager in February 2007 is Capt. Rick Muldoon.

In an August 2005 decision, the US Navy released an Acquisition Decision Memorandum (ADM) authorizing the HLR program to work toward Milestone B approval in Fiscal Year 2006. If granted by the Pentagon’s Defense Acquisition Board, Milestone B approval authorizes a program to move into the System Development and Demonstration (SDD) phase, the next step required under Department of Defense procurement procedures.

That go-ahead was eventually given. A Dec 22/05 decision by the under secretary of defense for Acquisition, Technology and Logistics gave the estimated $4.4 billion program the green light. In April 2006, a $3 billion April 2006 “Cost Plus Award Fee” contract for the System Development and Demonstration (SDD) phase was signed with Sikorsky. Sikorsky is currently conducting competitions to select suppliers, and is still making awards on that basis.

To date, industrial partners include:

•United Technologies: Program lead (Sikorsky); Integrated secondary power systems, Environmental control system, Computers for the fly-by-wire system, and Primary main and tail rotor actuators (Hamilton Sundstrand); Integrated fuel system, Aircraft hydraulics (Eaton);
•Aurora Flight Sciences: Fuselage – main rotor pylon;
•BAE Systems: Fly-by-wire integration, Cockpit seats and Cabin armor systems;
•Curtiss Wright, Inc.: Fly-by-wire components;
•EDO Corp.: Fuselage – tail rotor pylon & side sponsons;
•GE: GE38-1B engines;
•GKN Aerospace: Fuselage – aft transition;
•Goodrich: Tail drive system, Electrical power generation and distribution system;
•Northrop Grumman: Radar warning receiver;
•Spirit AeroSystems: Fuselage – Cockpit and cabin.
The CH-53X / CH-53K


The CH-53K’s maximum gross weight (MGW) will increase to 88,000 pounds, versus 73,500 pounds for the CH-53E. MGW with internal loads will be 74,000 pounds, compared to 69,750 pounds for the CH-53E. It is being designed to carry a cargo load of 27,000 pounds (13.5 tons) 110 nautical miles, operating at an altitude of 3,000 feet and an ambient temperature of 91.5 degrees Fahrenheit. This is nearly double the capacity of the current CH-53E Super Stallions, all in a helicopter that’s roughly the same size.

Those altitude and temperature qualifications matter, too, because “hot and high” conditions lower aircraft load carrying capabilities and combat radius – especially for helicopters. This reduced performance has recently been a factor during operations in Afghanistan and relief efforts in Pakistan, for instance, and has been a factor with earlier models of the C-130 Hercules as well. Figures for the CH-53K operating entirely around sea level and in cooler temperatures would be higher, but would not be double that of existing CH-53Es.

As an example of these variables at work, Sikorsky’s CH-53K brochure states that the improved CH-53K will have a maximum external load of 16.3t/ 36k lbs. Realistically, in an operation that carries an externally-slung load from sea level to a point 3,000 feet above sea level, with a total range there and back of 220 nautical miles/ 407 km, and 30 minute loiter at the landing zone, that same brochure gives its maximum mission load as only 12.25t/ 27,000 lbs.


Even at sea level, however, increased lift capacity will be important. As the Hummer’s fundamental lack of survivability begins to marginalize it on the battlefield, the Marines are leading the charge to field “MRAP” blast-resistant vehicle designs instead. While an up-armored HMMWV weighs about 9,100 pounds empty, the lightest Category 1 MRAP patrol vehicles check in at weights ranging from 16,000 – 31,000 pounds, and even the “light” JLTVs that will replace a large segment of the Hummer fleet are expected to weigh 14,000 – 20,000 pounds. Those weights mean that tactical operations to airlift mobile forces ashore beyond the beach, or within the zone of operations, will have only one helicopter available that can get the job done: the CH-53.

If the Marines think their existing fleet is seeing heavy use now, just wait.


CH-53K concept
The most important new addition to the CH-53K will be its GE38 engines. The military is hoping for 18% better specific fuel consumption, even though the engine would produce 57% more power than the similarly sized T64 engine. To improve maintenance and reliability, the GE38 is also expected to have 63% fewer parts.

Other technologies under consideration for the CH-53K include a “glass” [digital] cockpit that has high commonality and interoperability with existing Army and Navy helicopters, high-efficiency rotor blades with anhedral tips that are 11% wider, upgraded engines, a cargo rail locking system; external cargo improvements, survivability enhancements, and enhancements designed to extend service life.

The CH-53K program was going to use a “viscoelastic lag damper” for the rotors, in order to minimize vibration and stress. That was removed, in order to speed up deployment. A modified version of standard linear hydraulic dampers will be used instead. The Navy hopes for 2x reliability compared to the existing CH-53Es, but gave up the potential for 4x reliability.

An Affordable Solution To Heavy Lift [PDF] by Lt. Col. James C. Garman, MH-53E pilot in HMH-772 and a Senior Preliminary Design Engineer in the Sikorsky’s New Product Definition Group, describes the basic outlines of many low-risk CH-53X/CH-53K improvements. See also this interview with former HLR program manager Col. Paul Croisetiere. As he put it in a later NAVAIR release:

“Given the CH-53E’s operational costs and maintenance demands, heavy lift has built its reputation for excellence on the backs of our maintainers… We are going to take our maintainers somewhere they’ve rarely been before. Home for dinner.”

Several decades of weapon program history indicates that this is an unlikely goal. Instead, the trend is that these promises are made, but more advanced and complex weapons have more points of failure, and so require even more maintenance. If the CH-53K program can break that cycle, it would represent a landmark success in Pentagon weapons acquisition.

A Critical Design Review and Technology Readiness Assessments are scheduled for 2010. The first CH-53K, a flight test aircraft, is scheduled to make its first flight in FY 2011. Initial operating capability, or IOC, was originally scheduled in FY 2015 and is defined as a detachment of 4 aircraft, with combat ready crews, and prepared to deploy with all required equipment and spares. That is now expected to happen in FY 2016.

• un cockpit numérique avec un système de navigation amélioré dans les norme IFR internationales.
  
• un pilote automatique 4 axes.
  
• des réservoirs auxiliaires dans la cabine portant ainsi l'autonomie à 1200 km.
  
• améliorations des systèmes de communication pour intégrer des missions avec le Tigre et/ou le NH-90.
  
• Intégration d'un FLIR, d'un SATCOM et d'un EWS, système électronique d'autodéfense, d'alerte et d'identification des menaces.
  
• une inspection approfondie de la cellule pour pmorter sa durée de vie de 6000 h à 10000 h.
  
• le remplacement complet de tous les circuits éléectriques.
  

Eurocopter celebrates maiden flight of CH-53GA right on schedule

Donauwörth, February 10,
The CH-53GA medium-lift military transport helicopter successfully completed its maiden flight over the Bavarian town of Donauwörth today before an admiring crowd of approximately 150 guests. Eurocopter test pilot Rene Nater and flight engineer Antoine Van Gent were at the controls. This first flight came just three years after the contract was awarded, and represents a major milestone for the CH-53GA program, as well as for Eurocopter Germany's support centre for the German Army helicopters. Thanks to the new upgrades, the helicopter’s service life has been extended to 2030. Training flights are slated for early 2011, with the first deliveries of the retrofitted helicopters later in the same year. The German Armed Forces will then be able to deploy the CH-53GA with its state-of-the-art equipment for international missions (e.g. Afghanistan).

As Senior Vice-President Ralf Barnscheidt, responsible for German military contracts at Eurocopter Deutschland GmbH, points out: “Over the past 30 years, the Eurocopter support centre for German Army helicopters has completed many important upgrades on the CH-53G transport helicopter, working in cooperation with the Bundesamt für Wehrtechnik und Beschaffung (Federal Agency for Defense Technology and Procurement). I am extremely pleased to see the CH53-GA flying today, as it further demonstrates the successful cooperation we enjoy with the German Armed Forces that has enabled us to complete the program on time and within budget.”

Functional Requirements – Optimized Implementation
The CH-53G is being retrofitted so that the helicopter can be deployed in a wide range of national and international missions. The following major functional requirements for the CH-53GA have been defined and embodied:

• Improved display and flight control systems via state-of-the-art digital avionics
• Advanced accurate navigation system and improved flight capabilities in line with international IFR flight regulations
• Integration of a new automatic flight control systemAFCS/4-axis-autopilot) with automatic hovering
• Installation of auxiliary fuel tanks in the cabin to increase the range to 1,200 km
• Upgrade of communication equipment for joint missions with Tiger and NH90 helicopters
• Integration of a modular mission equipment package including FLIR (Forward Looking Infrared), satellite communication system (SatCom) and a cutting-edge electronic warfare system (EWS) for self-defense and identification of threats

Production work on the CH-53GA is scheduled to start at the Donauwörth plant in 2011 and continue through 2013. The first helicopters will be made available to the German Army before the end of 2011.

The CH-53G in Action – Domestic and International Missions
The CH-53G has been in service for over 35 years, and in the years to come it will continue to form the backbone of the German Army’s deployments in foreign missions. The helicopter is used to harsh conditions. Since entering service it has been the cornerstone of the German Army's versatile troop and equipment transport units as part of the country's NATO obligations, and has also been an important platform for operations in foreign missions in cooperation with other NATO forces. The helicopter has served in conflicts from Kosovo to Kabul since the early 1990s. In addition, it has been deployed in numerous missions to provide aid during national and international catastrophes such as forest fires and floods. The CH53GA will meet the German Army’s need to expand the mission capabilities of its medium-lift transport helicopters for domestic missions and deployment abroad.

Working Closely with the German Army
Eurocopter’s support center for German Army helicopters at Donauwörth is under contract to retrofit a total of 40 medium-lift CH-53G transport helicopters to CH-53GA configuration. The work includes the repair of airframe fatigue due to extensive use and ageing in order to extend the helicopters’ design life from 6,000 to 10,000 flight hours. The entire electrical system, which is nearly 35 years old, will also be replaced. The entire support center for German Army helicopters is involved in the development work on the CH-53GA. The center has experienced substantial growth over the last twenty years; the work force of 69 employees in 1991 has increased to 530 employees today, and still shows an upward trend.

More Power
With its first flight 40 years ago, the Sikorsky CH-53 was off to a magnificent career that made it one of the Western world’s most popular transport helicopters. The German armed forces have been using the twin T64-powered heavyweight for more than three decades. At MTU Aero Engines’ Munich facility, 46 T64s engines are currently being modernized.

The German Federal Office of Defense Technology and Procurement (BWB) had ordered the modernization campaign to adapt the helicopter to extreme climatic and geographic conditions, such as they would be encountered in Afghanistan. The aim was to make the engine work reliably and achieve rated power also in hot and high environments, enabling the helicopter to haul full payloads. The defense ministry also was certain that among other benefits, modernization would lower maintenance costs.

The GE engine is being optimized during regular overhauls. The revamp will give the new T64-100 version 300 kW more power than the baseline T64-7 engine, which delivers maximally 2,929 kW. The power boost is achieved by raising the combustion temperature and using newly developed turbine blades. On hot days, the engine brings 23% more shaft horsepower to the scales than its predecessor model. Also, to alleviate wear from sand ingestion, the helicopters are additionally fitted with sand separators.

“We’re pleased to offer the military an attractive overall package,” says Dr. Stefan Weingartner, who supervises defense programs at MTU. “The package includes everything from the procurement of new parts to overhaul, component modification and test runs.” The project will be completed this year

CH-53G is the basic model.
End of 90s the GS was introduced adding uprated engines, aux fuel tanks, self-defence equipment. Today there are 20 GS. Because these are the ONLY helo assets the Bundeswehr can deploy abroad (e.g. to support ISAF), they are highly stressed and only about 1/3 to 1/2 of those 20 can actually stay in theater (training, rotation). As a result, six additional G are being upgraded to the GE standard due to urgent requirement (GE being GS, just with internal aux fuel tanks to save weight). These are to stay in service until 2020-2025 and be the first to be replaced with the FTH successor h/c.
CH-53GA are the most advanced including avionics upgrades, glass cockpit and are to stay in service until 2035, gradually being replaced by the FTH.
Additionally, 14 G are being upgraded for IFR flight conditions to be flown in Germany and Europe only.

When Sikorsky Aircraft Corp. changed its outsourcing strategy on the CH-53K heavy-lift helicopter, it decided to design and manufacture five of the most complicated rotor parts and gearbox housings in-house. But an aircraft of that size needs space—a lot of space. So Sikorsky carved out a high-tech area in the factory to welcome the newest member of the fleet.
The size and complexity of the aircraft is in the numbers: 330,000 lb. of titanium for the program, five-axis machining centers that will create a 900-lb. rotor hub from a raw titanium part weighing 2,450 lb., automated machining stations with 360 cutting tools . . . and the list goes on. On Jan. 22, Sikorsky opened the doors to its Precision Components Technology Center. “We justified the center based on the [requirements of the] CH-53K, but the idea was to have a place where we could [also] develop new products,” says Brian DeBlasi, Sikorsky’s manager of new product development.
The company has divided its plant into cells, each devoted to a very specific building or machining task. “There was no way to get into the cells to make new product” without disrupting the current workflow, explains DeBlasi, “And the CH-53K is larger than anything we’ve ever built.”
The main rotor hub is 66 in. in diameter and arrives at Sikorsky as a raw, unmachined, 2,450-lb part. The first milling operation machines the hub down to 960 lb. Sikorsky chose the equipment for the Precision Components Technology Center “for torque,” says DeBlasi. The machines are almost as elaborate as the parts they are crafting. One holds 360 different cutting tools, which is twice the number in the largest machine in operation today at Sikorsky.
There are seven main rotor sleeves on the hub, six with different configurations, twisted at angles to accommodate blade fold. A single rotor sleeve weighs 700 lb. in raw forging form, which is then milled down to 450 lb. The CH-53K rotor sleeve is actually three integrated parts: the sleeve, the horn and the damper attachment. “Some people thought we were crazy” to do it this way, says DeBlasi. “I said we need to take the challenge. We had threading problems on all our designs with horn attachments. We got rid of those problems.”
Another way of accommodating complexity was to design the parts around the process, rather than doing the reverse. “We developed complex parts to run through the process we put in place in this center,” says DeBlasi. In the past, “we were always constrained by design.” With the CH-53K, however, “all geometry is based on how we will manufacture [the part].” The anticipated result is a development process that runs more smoothly “than we typically have experienced in the past,” he adds. An in-house integrated product team comprising designers and engineers streamlined the process.
“Our vision was to align manufacturing against our business objectives,” says Mark Cherry, Sikorsky’s vice president for Marine Corps programs. “The size and scale [of the CH-53K] drive the need for the center.”

Sikorsky has opened the assembly facility in West Palm Beach, Florida, where it will build five prototypes for the CH-53K heavylift helicopter development program. The building, formerly home to Pratt & Whitney Rocketdyne, is adjacent to Sikorsky's development flight center, where the CH-53Ks will be tested.


Photo: Sikorsky

Sikorsky was awarded a $3 billion contract in April 2006 to develop the CH-53K to replace US Marine Corps' CH-53Es. First flight has since slipped by two years, and is now planned for fiscal 2013, while initial operational capability in now 2018 - a delay of 40 months from the original goal of September 2015, the US Navy says. At the same time, the Marine Corps has increased the number it plans to buy from 156 to more than 200.

The new-design CH-53K is a heavy helicopter. Although it has the same shipborad footprint as the CH-53E, its maximum gross weight is significantly higher - 74,000lb (vs 69,750lb) with internal load and 88,000lb (vs 73,500lb) with external load. At 27,000lb over 110nm, its lifting capability is almost three times that of the E model.

Sikorsky has delivered the first CH-53K ground test vehicle (GTV) to
the company's flight test team. The airframer is developing the massive
aircraft for the US Marine Corps' heavy lift helicopter requirements as
part of a $3.5 billion contract.

The GTV will be used to wring out the CH-53K's systems in hundreds of
hours of powered ground checks before four flying prototypes are flown
starting in 2014. The checks will cover all of the machine's dynamic
components including the rotors, transmission and engines.

"Extensive ground-based flight checks with Sikorsky and NAVAIR [Naval
Air Systems Command] test pilots at the cockpit controls will confirm
whether these dynamic systems, as well as hydraulic, electrical, and
avionics systems, can meet the requirements established by the Marines
for their next-generation heavy lift helicopter," says Michael Torok,
Sikorsky's CH-53K programme vice president.
According to Sikorsky, flight test engineers will now perform
preliminary acceptance tests which will include calibrating the GTV's
fuel system and attaching sensors. In the coming months, the company
expects the GTV will be fixed to an outdoor test-rig before it is
activated.

By the middle of next year, the aircraft will "light off" when its
three General Electric GE38-1B 7,500shp turboshaft engines are powered
up for the first time. Initially, Sikorsky says, tests will be performed
without rotor blades, but eventually they will be attached.

Meanwhile, two additional static ground test articles are undergoing
airframe structural testing at the company's main manufacturing plant in
Stratford, Connecticut.

Development of the Sikorsky CH-53K is proceeding so well that the
US Navy programme manager says he expects the new heavy-lift helicopter
to become operational ahead of schedule.

"We're going after [2018] like it's cool," says US Marine Corps Col
Robert Pridgen, the Naval Air Systems Command programme manager for the
CH-53K. "[2019] is when the Marine Corps says, 'I need it'. We're trying
to figure out how we can get it here sooner and there are some
opportunities for us to do that."

Pridgen, who was speaking to reporters at the Navy League
Sea-Air-Space Exposition, says that the aircraft is meeting or exceeding
all of its key performance parameters at present. Already, four test
aircraft are being built and Pridgen says he expects to award Sikorsky a
contract to build a further four operational test aircraft by May.

He adds that he does not expect budget cuts and the current fiscal
turmoil in the US government to delay or derail the programme.

If all goes as planned, Pridgen says he expects the first flight of
the CH-53K to be in late 2014. Low rate initial production is expected
to start in 2015, with two more lots to follow in 2016 and 2017. Full
rate production should start around 2019 or 2022, Pridgen says.

This phase of testing – conducted without rotor blades – began under auxiliary power in December with safety-of-flight test pilots at the aircraft's controls.

The GTV is in two-year ground test programme with Sikorsky and US Marine Corps test pilots. The testing, being conducted at Sikorsky’s West Palm Beach facility, will measure the 44,000-pound GTV aircraft’s ability to operate safely under its own power.

Mike Torok, vice president, CH-53K Program, Sikorsky, said: ‘GTV main engines powered 'on' is a significant step for the CH-53K helicopter programme. Having independently tested the aircraft's many components and subsystems, including electrical and avionics, hydraulics and flight controls, landing gear, propulsion, transmissions and rotors; now we have begun testing these critical functions as an entire system powered by the GTV aircraft's three GE 7,500 shaft horsepower class engines.’

Once Bare Head testing is completed, Sikorsky will mount seven main rotor blades and four tail rotor blades onto the GTV. During this second test phase, Sikorsky will conduct extensive aircraft system checks leading to a formal Pre-Flight Acceptance Test required to clear the first flight aircraft for flight testing.

Four additional test aircraft are being prepared for flight test, commencing in late 2014. During the three-year flight test programme, Sikorsky will continue to evaluate the GTV for long-term endurance of the engines and dynamic components, survivability, and maintenance practices.

Col. Robert Pridgen, US Marine Corps Program Manager for Heavy Lift Helicopters, said: ‘We have entered a much anticipated phase in this developmental programme. We have experienced significant learning at the sub-system and component level, which continues to build our confidence in the capabilities of the 53K. We look forward to the initial validation and discovery at a full system level.

Stratford, Connecticut - Sikorsky Aircraft Corp., a subsidiary of United Technologies Corp. (NYSE:UTX), has begun full system testing of the U.S. Marine Corps’ CH-53K heavy lift helicopter with all seven main rotor blades and four tail rotor blades attached for the first time to a non-flying prototype called the Ground Test Vehicle (GTV). Powered “Light-Off” with rotor blades spinning follows a “Bare Head” (without blades) test phase of the GTV aircraft’s systems powered by its three GE 7,500 horsepower class engines, and begins a rigorous two-year test program of the rotor blades, transmission, engines, and all subsystems while the GTV is anchored to the ground.


“This is another key milestone in our building block approach to maturing the aircraft system,” said Mike Torok, Sikorsky’s CH-53K Program vice president, of the April 17 event. “The aircraft is now fully configured to proceed to the next series of system integration tests that will further validate the aircraft systems, such as rotors, drive, electrical, hydraulic, avionics and flight controls – all leading to operational acceptance testing that will clear the flight aircraft for flight operations. The preliminary results maintain our confidence in meeting first flight of the initial flight test helicopter in late 2014.”

The GTV will play a key role for Sikorsky and the U.S. Marine Corps during hundreds of hours of powered ground tests as the CH-53K team prepares for first flight and the subsequent three-year flight test program. By accumulating operational experience ahead of the four flight test aircraft — currently in final assembly — the GTV can measure and verify the ability of the drive system, transmissions and engines to fly the CH-53K helicopter safely and efficiently across multiple flight scenarios up to its 88,000-pound (39,916 kg) maximum gross weight with an external load.

During the next 250 hours of operation, the GTV will continue to assess the helicopter’s subsystems and the structural integrity and whirl characteristics of the rotors, blades and drive train.

The first of the four flight test helicopters — known as Engineering Development Models — is scheduled to take to the skies in late 2014. During the three-year flight test program, each flight test aircraft is expected to accumulate approximately 500 flight test hours. To ensure safety of flight, the GTV will continue to accumulate hundreds of operational endurance hours ahead of the flight aircraft.

“First flight is driven by the current ground test vehicle (GTV) test events,” says Kelly Burdick, a spokesman for the navy’s programme executive office for aviation. “The GTV is currently undergoing powered ground tests to measure and verify the ability of the drive system, transmissions and engines and flight control system to safely fly the CH-53K helicopter across multiple flight scenarios.”

Engineers at NAVAIR and Sikorsky have made adjustments to the CH-53K’s main rotor gearbox to improve load distribution and have been retesting the fix “to ensure optimal performance prior to the flight test phase”, Burdick says

Poncho (Admin) a écrit:Petit soucis sur la boite de transmission du CH53K aux essais qui décale le premier vol

http://www.flightglobal.com/news/articles/sikorsky-ch-53k-first-flight-pushed-at-earliest-to-march-406718/

Il parait que les essais sont fait pour ça (oui OK ! mais les planning faut croire qu'il ne le savent pas !)
On passe de juillet août 2014 à mars - mai 2015. Comme ça !

“First flight is driven by the current ground test vehicle (GTV) test events,” says Kelly Burdick, a spokesman for the navy’s programme executive office for aviation. “The GTV is currently undergoing powered ground tests to measure and verify the ability of the drive system, transmissions and engines and flight control system to safely fly the CH-53K helicopter across multiple flight scenarios.”

Engineers at NAVAIR and Sikorsky have made adjustments to the CH-53K’s main rotor gearbox to improve load distribution and have been retesting the fix “to ensure optimal performance prior to the flight test phase”, Burdick says

J'espère qu'Orion ne cramera pas en redescendant sur terre ce soir...

• 14 March, 2016
  
• BY: James Drew
  
• Washington DC
  

Sikorsky's first CH-53K King Stallion has achieved speeds of 120kts as the heavy-lift helicopter development project presses forward with flight envelope expansion and adds a second test aircraft to the mix.
The Lockheed Martin-owned rotorcraft manufacturer says its second triple-engine giant achieved flight on 22 January, and the two developmental aircraft have logged 35 flight hours since CH-53K flying began on 27 October.
Operating from Sikorsky’s flight test centre in West Palm Beach, Florida, the first engineering development model (EDM) recently flew 120kts, just 21kts sky of its advertised speed of 141kts.

First CH-53K test aircraft achieves 120kts in West Palm Beach, Florida

Sikorsky

The programme, which entered development in October 2005, will deliver 200 "super-heavy-lift" helicopters to the US Marine Corps as a replacement for the CH-53E Super Stallion, which the service plans to phase out by 2027.
Powered by three General Electric Aviation T408-400 turboshaft engines, the King Stallion will introduce fly-by-wire controls, “fourth-generation rotor blades” with anhedral tips, and increase the payload capacity threefold. It will haul 12.2t (27,000lbs) over 110nm – 1.4t (3,000lbs) less than the original target set in 2005 but still significantly more than the Sikorsky CH-53E.

6,000ft density altitude at a temperature of 35°C