THE CHINOOK TURNS 60: A PILOT’S PERSPECTIVE ON THE OLD ‘WORKHORSE OF THE SKY’
By Eric Edwards
U.S. Army
In August of 1962, a unique, new helicopter—the CH-47 Chinook—took to the skies for the U.S. military. Possessing an unprecedented combination of power, speed, stability, and payload capacity, the Chinook quickly became the Army’s primary heavy-lift rotorcraft, a title it’s continued to hold for the past 6 decades. The so-called “Workhorse of the Sky” has not only ferried millions of tons of equipment, personnel, and even other vehicles back and forth across the globe, but it’s also helped change the standards and expectations of all U.S. military helicopters that have followed. Moreover, the aircraft has proven its suitability and effectiveness not just for its primary cargo and troop transport duties but also for many other specialized missions, including medical evacuation, search and rescue, parachute drops, aircraft recovery, special operations, disaster relief, firefighting, and construction support. It’s thus no wonder that the aircraft is now flown by more than 20 militaries around the world [1].
In recognition of the Chinook’s 60-year milestone, we recently asked CW4 Mark Chamberlin (pictured in Figure 1)—a retiring CH-47 pilot and subject-matter expert from the Joint Combat Assessment Team (JCAT)—to provide a pilot’s perspective on this iconic warbird, its remarkable capabilities, and its likely future.
Figure 1. CW4 Chamberlin in the Driver’s Seat.
How long have you been flying Chinooks?
“I’ve been flying the Chinook for 18 years, and in pretty much every condition imaginable. This includes one deployment in Iraq to support the Marines and two Afghanistan deployments. And between the aircraft itself and its crew, the helicopter has always brought me home safely. Most people don’t realize it, but without the work of the flight engineers and crew chiefs that run the back half of the aircraft, we couldn’t perform our mission as pilots.”
What other aircraft have you flown?
“I flew the Bell Jet Ranger (also known as the TH-67) in flight school at Fort Rucker, AL. I then transitioned to the CH-47D. As you can imagine, going from an aircraft that has a max gross weight of 5,500 lbs to carrying that in just fuel is pretty amazing. The center of gravity of a TH-67 is also very sensitive. Because the CH-47 is basically hung from two rotor systems, its center of gravity is very hard to throw out of balance.”
As Boeing’s longest-running continual-production program, the Chinook is one of only two U.S. military aircraft developed in the 1960s that are reportedly still in production and service after 60 years [1]. How do you explain the aircraft’s ongoing longevity?
“The progression of the Chinook has been filled with trials and tribulations, but ever since its time in Southeast Asia, the helicopter has proven itself to be a battle-tested, versatile workhorse that doesn’t know the meaning of quit. Having the ability to leverage the entire airframe for carrying cargo or personnel makes the Chinook a perfect platform for everything from air assaults to resupply missions. And that isn’t going to change any time soon.”
U.S. Air Force Photo by Gary Emery
What are the main features of the CH-47 that sets it apart from other similar helicopters?
“The Chinook has a current max gross weight of 50,000 lbs, compared to the Blackhawk’s 22,000. This makes the Chinook an extremely capable aircraft for humanitarian and military operations. In addition, having a dual-rotor system allows the Chinook to apply all 100% of its power to lift; no power is lost to a tail rotor. The aircraft also has three hooks, which allows it to sling multiple objects in a single lift. So, the ability to simultaneously sling external loads while also carrying internal cargo or personnel continues to make the Chinook an unmatched asset for the battlefield commander.”
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How has the aircraft changed since it first entered service?
“The Chinook has been a game-changer in virtually every conflict the world has seen during its lifetime—including Vietnam, Iran, Libya, the Falklands, Iraq, and Afghanistan. When the -47A model appeared in 1962, it had a maximum gross weight of 33,000 lbs. Then, in 1966, the aircraft received a much-needed upgrade to the -47B, integrating the T55-I-7C turboshaft engines and an improved airframe, which increased the maximum gross weight to 40,000 lbs. The -47B also featured a blunted rear rotor pylon, redesigned asymmetrical rotor blades, and strakes along the rear ramp and fuselage to improve aerodynamics [2].
U.S. Army Photo by Barbara Romano
A year later, the -47C was Boeing’s response to the Army’s request for the ability to transport 15,000 lbs 30 nautical miles on a 95° day at 4,000 ft. It was powered by T55-I-11 engines, which brought the maximum gross weight up to 46,000 lbs. All three of these early Chinook models were flown in Vietnam [2].
After Vietnam, 472 of the previous models underwent massive upgrades, which led to the CH-47D. Introduced in 1979, the -47D had larger engines (the T55-l-712 and, later, the T55-l-714), with more than 5,000 hp/engine at contingency power. This upgrade allowed for the tremendous payloads and maximum gross weight of >50,000 lbs that we see today [2].
Finally, the upgrades that were made to bring the 40-yr-old -47D into the 21st century were earth-shattering. Beginning around 2006, we went from doing landings with forward airspeed (“crash and bangs”) to hovering down in a complete brown-out with the ability to Position Hold the aircraft within a 3-ft circle.
Another major upgrade going from the -D to the -F model was having the ability to constantly update the performance charts. As altitudes change and temperatures adjust, the aircraft will automatically tell you if you are about to hit a limit or time-limited operation. It’s just another great feature to ensure we’re getting the best performance out of this heavy-hitter.”
It’s been said that the Chinook is faster than the Apache. Is that true?
“As the Chinook has progressed in design and performance, it’s become an extremely fast and nimble aircraft. On paper, the Chinook is actually the slowest aircraft of the big three—the Chinook, the Apache, and the Black Hawk—with a maximum recommended speed of 170 knots. However, during an air assault in which we’re just carrying an assault force, the Chinook will often outrun its security element. Multiple times I’ve been asked to slow down so the fully loaded Apaches can keep up. And you never want to outrun your security.”
What do you like most about flying the current Chinook?
“The CH-47F (which replaced the -D model) is one of the most advanced aircraft the Army has the luxury of owning, giving the Warfighter the capability to fight around the globe in any environment and in any conditions. With a new avionics suite comprising the Common Avionics Architecture System (CAAS) and the Digital Advanced Flight Control System (DAFCS), the aircraft has the capability to use an extremely advanced Flight Director for every mission set. Once you set up the mission and flight route at your desk or in the cockpit, engaging the Flight Director allows for autonomous flight to your destination, including the approach and any holding or deviations you might have programmed or need to adjust to in flight.”
What do you like least about flying the current Chinook?
“The thing I like least about the Chinook also happens to be one of its biggest upgrades, the Flight Director and DAFCS. As amazing as these systems are, having all of them requires quite some time for the pilot to bring the aircraft up to operating speed and puts us at risk for newer threats on the battlefield and increased start-up times. You can start a -47F in the same amount of time as a -47D, but you’d be departing with quite a few systems offline.”
U.S. Army Photo by John Pennell
What can you say about the Chinook’s overall survivability?
“The Chinook is an extremely survivable aircraft, and it wasn’t all done completely on purpose. Most of the components are in very survivable locations, and almost everything is redundant. Because of its sheer size, most of the critical components (and backup systems) are separated enough that it would likely take multiple engagements to bring down the aircraft. Even when hit multiple times, the Chinook has very low vulnerability, as the secondary or emergency systems are often on the opposite side of the aircraft. With my years being part of JCAT-Army, I’ve done multiple assessments on damaged Chinooks, and almost every time the aircraft makes it back to its home base without issue.”
U.S. Army Photo
What can you say about the Chinook’s ability to transport personnel?
“When it comes to personnel movement, the CH-47 is by far the preferred carrier among our customers. One of my favorite sayings in our community is, ‘How many personnel can a Chinook carry?’ The answer is always ‘one more.’ The main cabin can officially hold up to 33 fully equipped troops (plus 3 crew members); and when the helicopter is used for medical evacuation, the cabin can accommodate 24 litters (stretchers). However, in the final days of the Vietnam War, one Chinook was said to have transported 147 refugees in a single lift.”
How does the CH-47’s handling compare to other helicopters in the fleet?
“I often get asked, ‘What’s it like to not think about torque?’ This is something our sister airframes, such as the Black Hawk and Apache, have to think about often—How much gas can I take, Do I need to trade fuel for ammo, How many passengers can I carry, Can the VIP bring his entire entourage, etc.? In short, the Chinook has more than enough power to get the mission done. That’s not to say, of course, that we don’t think about power performance. I have carried everything from M113’s to M198’s under my aircraft. When you ferry equipment back and forth, you just want to consider which load is the heaviest, so you can take it last and burn off some of the aircraft’s 6,000 lbs of fuel first.”
Photo by Cpl Rob Travis and SAC Nicholas Egan, RAF Odiham
What’s a pinnacle landing like?
“Pinnacle landings are something we practice starting in flight school. I’ve done air assaults where the terrain was so challenging that we could only get one wheel on the ground and with just enough room for the passengers to get off the ramp. This is where trusting the crew comes into play. I don’t have the ability to look over my shoulder and back up the aircraft like you would a car in the driveway. So, the crew members in the back of the aircraft have to tell me how far forward and how high I am from landing. Obviously, the more proficient the crew is, the easier it is to do, but it takes a lot of trust and experience to do it slow and steady.”
What is your most memorable moment flying a Chinook?
“When I was first deployed to Afghanistan, we flew multiple missions to a place called Barg-e Matal. It’s a small village north of the Kunar Valley. The mountains and rivers in that area are so beautiful that it reminded me of flying in Alaska. It wasn’t a very friendly area, however, so we didn’t go there that often. But when we did, I always tried to get on that flight. Between the scenery and the fresh air, you often forgot you were in Afghanistan.”
What is your scariest moment in a Chinook?
“During a particular mission where we were going after a high-value target, the illumination from the moon was about 98%, which is great if you are trying to do some night-vision goggle (NVG) work at home station but not so great down range. The simple rule of thumb is, if you can see your sister-ship unaided (without NVGs), so can the enemy. So, as we were about to touch down in the landing zone (LZ), I heard and felt a loud explosion. My NVGs whited out, and I realized we’d been shot at by a large weapon system. My door gunner calmly announced ‘RPG left gun’; it was his calmness and professionalism that snapped me back into reality. Without thinking, I pulled max power and kept it there until we were out of harm’s way. As we were departing the LZ, four more RPGs were launched in our direction, with most hitting the sides of the mountain and casting shadows of our aircraft on the surrounding landscape as we made our escape. We landed at a nearby combat out post (COP) and made sure the aircraft was still flyable. We didn’t get a scratch; the ramp gunner saw the RPG gunner fire, but the round missed the aircraft and hit the bolder out our left door.”
U.S. Air Force Photo by SrA. Anthony Leclerec
The Future Vertical Lift Program is supposed to start replacing the current Army helicopter fleet in the 2030s. The initial focus is said to be on medium-lift helicopters, which may keep the Chinook in service beyond 2060 (and its 100-year anniversary) [3]. What do you think is the future of the aircraft?
“Reportedly, the Chinook is supposed to stay in use until 2075. That will make the airframe 113 years old. At that time, it will be very interesting to see what replaces it. Hopefully, I’ll still be around to see the progression of this amazing aircraft (but I may be pretty old).”
What will you miss most about flying the Chinook?
“The thing I already miss most about flying the Chinook is the feeling of freedom when you’re in the open air in it. Even though it’s a big airframe, once you become one with it, you don’t even know it’s there. The aircraft is so dynamic and nimble, it feels like an extension of your body.”
Photo by Hamish Burke, Courtesy of Wikimedia Commons
References
[1] Hynes, Rod. “33 Things You Probably Don’t Know About the CH-47 Chinook.” Honeywell Aerospace, https://aerospace.honeywell.com/us/en/learn/about-us/blogs/33-things-you-probably-do-not-know-about-chinook-ch47, accessed March 2022.
[2] Boeing. “H-47 Historical Snapshot.” https://www.boeing.com/history/products/h47-chinook. page, accessed March 2022.
[3] Trimble, Stephen. “US Army Outlines CH-47F Upgrades for 100-Year Lifespan.” FlightGlobal, https://www.flightglobal.com/helicopters/us-army-outlines-ch-47f-upgrades-for-100-year-lifespan/116403.article, 30 March 2015, accessed March 2022.
