features A Heavy Lift

With decades of service left, the U.S. Army is weighing upgrades to the CH-47F against other modernization priorities.
Avatar for Dan Parsons By Dan Parsons | August 26, 2021

Estimated reading time 14 minutes, seconds.

With the 60th anniversary of its first flight coming up in September and no plans to replace it for another several decades, the U.S. Army is wrestling with how to keep the Boeing CH-47 Chinook operationally relevant and how to pay for necessary performance upgrades. 

Two U.K. Royal Air Force Chinooks during Exercise Decisive Manoeuvre in 2019. U.K. Ministry of Defence Photo

Boeing has come up with and is perfecting a suite of structural and performance enhancements called the Chinook Block II that add speed and lift to the venerable airframe. But the Army has held Boeing at bay for three years by continually refusing to fund the effort for its fleet of 400 or so CH-47F Chinooks. 

The service’s budget request for the 2022 fiscal year for the fourth time has no funding for production of Block II kits, though testing on elements of the upgrade package continue. Boeing has said that Block II is essential for keeping its Philadelphia, Pennsylvania, production line open and has a relatively rosy attitude about the outlook of it being funded by Congress.

U.S. Army 19th Special Forces Group soldiers of the Utah Army National Guard, Royal Moroccan Army Paratroopers, and Royal Moroccan Navy commandoes conduct fast rope training out of an MH-47 Chinook in Tifnit, Morocco on June 14, 2021. U.S. Army Sgt. Jacob Jespersen Photo

“The U.S. Army’s budget request for fiscal year 2022 did not include funding for the CH-47F Block II,” a Boeing spokesperson told Valor in an email. “However, the Army has stated that it needs the capabilities offered by the CH-47F Block II upgrades. As a result, they included the Block II program on their unfunded requirements list submitted to Congress.” 

“As we continue to look forward, we know that the Department of Defense is going to make difficult decisions with regards to budgets, specifically regarding how they balance funding new development while still supporting the operational needs of today,” the spokesperson added. “For the Army, CH-47F Block II is offers a clear answer: an affordable, low-risk, multi-domain operations enabler, especially as FVL [Future Vertical Lift] Heavy is still undefined.”

Chinook was not a lone bill payer for the Army’s modernization priorities. The Boeing AH-64 Apache and Sikorsky UH-60 Black Hawk programs both took hits to protect coveted Future Vertical Lift projects, especially the Future Attack Recon Aircraft (FARA) and the Future Long Range Assault Aircraft (FLRAA).

Getting to Block II

The Army in 2018 jettisoned plans to upgrade its 473 F-model Chinooks while sticking to its desire for 69 Special Operations versions of the aircraft. Three MH-47G Block II of 24 on order have delivered to Special Operations Command (SOCOM), according to Andy Builta, Boeing’s H-47 program manager. 

South Carolina National Guard soldiers with Det. 1 Company B, 2-238th General Support Aviation Battalion, complete gunnery training with a CH-47F Chinook helicopter at Poinsett Range Complex, South Carolina, May 10, 2021. U.S. Army National Guard Sgt. 1st Class Roby Di Giovine Photo

Still, engineering and manufacturing development of the Block II aircraft progressed. Three EMD test aircraft have been built, one of which is in the Army’s hands and undergoing testing at Redstone Arsenal in Alabama. The other two instrumented aircraft are at Boeing’s test facility in Mesa, Arizona. 

Boeing paused testing briefly “at the direction of the Army” in early 2021 so it could move one of those test aircraft from the F-model to the MH-47G program, Builta said. Following about three-and-a-half months of gathering data in support of the SOCOM aircraft, flight test resumed in April on the CH-47F Block II testing, Builta said. 

“We’re really excited about where we are with the overall progress of the program,” Builta said. “Like any developmental test program there is always some discovery and learning along the way. We’ve been working very closely with the Army as those learnings occur and laying out a path forward to completion.” 

“The flight test program will continue . . . likely through early next year,” Builta added. “That is primarily focused on capturing all of the test points necessary to support the program.”

Moroccan Special Forces alongside U.S. Army Special Forces soldiers of the Utah Army National Guard prepare to land their Chinook helicopters during a high value target training at Tifnit, Morocco on June 17, 2021. U.S. Army Sgt. James Garvin Photo

While there are plans for two new aircraft under the Future Vertical Lift program, there are no plans to develop a new heavy-lift rotorcraft, referred to as capability set, or “cape set,” four in Army parlance. The Future Attack Recon Aircraft that will replace the retired Bell OH-58D Kiowa Warrior satisfied capability set one while the Future Long Range Assault Aircraft that will replace Black Hawk was previously referred to as capability set two. 

Senior U.S. Army officers for years were cagey about whether the service would or should pay to upgrade its entire Chinook fleet to Block II configuration. But recently, some of the service’s highest-ranking officials have begun climbing the effort.

The Army’s top uniformed official, Chief of Staff Gen. James McConville, recently told a House appropriations subcommittee on defense that “where we’re at, from my point, we want to get to Block II.”

An instrumented CH-47 Block II aircraft undergoes slingload testing as part of the engineering and development effort. Boeing Photo

“If you don’t get to Block II, then you have a different discussion,” McConville said. “But you need to get that aircraft to Block II. That’s what we’re supporting. . . . That will put that aircraft in a much better place. The decision that is going to need to be made is what do we do with those aircraft as we move into the future.”

“There is no plan right now for a cape set four or five and the Army has been pretty consistent in saying that,” Gen. John Murray said May 12 at the annual MacAleese/Credit Suisse Defense Programs Conference. “The FARA — Future Attack Reconnaissance Aircraft — and the Future Long Range Assault Aircraft are the two plans, programs we have working right now. There is nothing working for a replacement for the CH-47.”

RAF Odiham CH-47 Chinook helicopters from 18 and 27 squadrons flying in formation heading to Sennybridge Training Area as part of Exercise Black Maruader. U.K. Ministry of Defence Photo

“The CH-47 is a critical capability,” Murray added. “We started the CH-47, specifically the Block II, years ago. The CH-47 Block II is actually being fielded to our special operators today . . . so we’re absolutely committed to that and we’re absolutely committed to working with Congress and industry to make sure we can deliver that capability.”

New blades

Central to the Chinook Block II design is the advanced Chinook rotor blade (ACRB), a drop-in composite replacement for existing fiberglass rotor blades that Boeing promised could deliver at least a 1,500-pound (680-kilogram) increase in lift. The ACRB has undergone multiple redesigns during developmental testing of the Block II package because the initial blade design did not provide the power improvements predicted by computational models, though they were more stable than later iterations. 

But a January report from the Defense Department chief of weapon testing found that the new blades produce excessive vibration that poses a risk to crewmembers. During flight testing, the ACRB produced “excessive vibrations in various flight profiles across the Block II’s performance envelope,” according to the annual weapon systems report published in January by the U.S. Defense Department’s director of test and evaluation (DOT&E).

“The most recent ACRB design produces excessive vibrations in ground, hover, and forward flight that may cause a safety of flight risk,” the report said. “Aircrews reported prolonged fatigue and other physiological conditions due to excessive vibrations following a developmental test flight using the redesigned ACRBs.” 

The Army’s heavylift program office has examined the issue and decided to delay limited user testing (LUT) scheduled for later in 2021. A decision was made in March not to proceed with the testing using the classic fiberglass blades and instead wait until tweaks to the ACRBs are qualified, according to Brig. Gen. Robert Barrie, the Army’s aviation acquisition chief. 

The decision to delay limited user test was “due to challenges seen in the ACRB,” Barrie told reporters in a recent roundtable discussion. He would not elaborate on when a timeline for rescheduling the LUT, saying it is “pre-decisional.” 

“We have some work still to do and we are working with Boeing, our prime, to characterize the remaining technical challenges that we have on ACRB,” Barrie said. “We’re confident that we will be able to execute it, but I think we’d be pre-decisional to give you a timeframe for that.” 

As of mid-April, Boeing had proven all the key performance characteristics promised by the Block II package through more than 450 flight hours. Builta said Boeing “absolutely” plans to address and correct the vibrations identified in Army testing, but said that process is a normal one for a developmental aircraft design that incorporates new blades and a lighter, stiffer airframe. 

U.S. Army soldiers assigned to the 19th Special Forces Group (Airborne) fast-rope out of a 160th Special Operations Aviation Regiment MH-47G Chinook in Tifnit, Morocco, during African Lion 2021. U.S. Army Spc. Rhianna Ballenger Photo

“Vibration is not unique to Chinook,” Builta said. “It’s a common characteristic in all helicopters and all helicopters have some sort of vibration mitigation system. . . . The Block II Chinook vibrates at different frequencies than prior Chinooks and that’s a combination of different factors to include the new rotor blade, as well as the lighter, stiffer structure.”

The “Advanced Chinook Rotor Blades are not a safety-of-flight risk, but we do believe we need to mitigate and go fix the vibrations,” Builta said. “But again, this is common with any developmental test program to identify the specific frequencies you would observe from a vibration standpoint in a platform and then go and develop a specific tuning of a mitigation system to dampen out those vibrations.”

Future Baseline

Boeing and the U.S. Army will mark the 60th anniversary of the Chinook’s first flight on Sept. 21. Since it first left the ground, the aircraft has been continually upgraded but has lost lift capacity as new weapons and equipment have been added. New longer-range fuel tanks, ballistic protection, electronic equipment and other capability-enhancing gear have been added especially in the last two decades of nearly continual combat in Iraq, Afghanistan and elsewhere.

With no plans for replacement until perhaps 2060, the Army will likely need capability improvements in its heavy lift fleet. There is hope that Congress will again reinstate funding for Block II production in the 2022 budget and Army officials have said they intend to award a Lot One contract for five CH-47F Block IIs by the end of the year using funds Congress allotted in the current budget, but none of that is certain.

Aside from the U.S. Army, Boeing has hopes that international Chinook operators will come in with orders for Block II upgrades and new aircraft. A major development was the recent $599 million foreign military sale to the U.K. Air Force of 14 CH-47F Block II aircraft. The sale was announced just after the U.K. hit the 40th anniversary of its operating the tandem rotor. The United Kingdom will be the first international operator of a Block II Chinook. Deliveries are scheduled to start in 2026.

Heather McBryan, director of global sales and marketing, said the Block II is “critical to both Philadelphia production line and the defense industrial base — our suppliers — to include 20,000 total jobs over 200 suppliers in 38 states.”

“The Army fleet, which is 470-plus Chinooks, makes up a significant percentage of the Chinooks we build,” McBryan said. “Both Boeing and our suppliers have planned production schedules around the Army’s initial desire for Block II and some of our suppliers have a significant amount of business tied into the Chinook program.”

Members of the 152nd Security Forces Squadron disembark off a Nevada Army National Guard CH-47 Chinook helicopter during Operation Resolute Hunter in Dixie Valley, Nevada, June 22, 2021. U.S. Air National Guard Airman First Class Thomas Cox Photo

Builta said that regardless of the Army’s ultimate decision on Block II, “it is the future of the Chinook.”

“It is absolutely going to be our baseline going forward,” he said. “The exact point at which we transition from the prior configuration to this configuration is really dependent on what a specific customer’s need might be.”

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1 Comment

  1. The RAF’s new “H-47(ER)” will be MH-47G’s without the refuelling probe, not CH-47Fs.

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