The Boeing-Vertol CH-47 Chinook
is a versatile,
twin-engine, tandem rotor
. Its top speed of
) was faster than
utility and attack helicopters of the 1960s and even many of today.
Its primary roles include troop movement, artillery emplacement and
battlefield resupply. It has a wide loading ramp at the rear of the
fuselage and three external-cargo hooks.
The Chinook was designed and initially produced by Boeing Vertol
in the early 1960s.
The helicopter is now produced by Boeing Integrated Defense
. Chinooks have been sold to 16 nations; the largest
users are the U.S. Army
and the Royal Air Force
, see Boeing Chinook
Design and development
Late in 1956 the Department of the Army announced plans to replace
the CH-37 Mojave
, which was powered by
piston engines, with a new, turbine-powered aircraft. A design
competition was held and, in September 1958, a joint Army-Air Force
source selection board recommended that the Army procure the
helicopter. However, the necessary funds to proceed with full-scale
development were not available and the Army vacillated in its
design requirements. Some in the Army felt that the new helicopter
should be a light tactical transport aimed at the mission of the
old H-21s and H-34s and, consequently, sized for approximately
fifteen troops. Another faction believed that the new transport
should be much larger to serve as an artillery prime mover and have
minimum interior dimensions compatible with the Pershing Missile
System. This "sizing" problem was a critical decision.
Vertol began work on a new tandem rotor helicopter designated
Vertol Model 107 or V-107 in 1957. In June 1958, the US Army
awarded a contract to Vertol for the aircraft under the YHC-1A
designation. The YHC-1A was tested by the Army to derive
engineering and operational data. Three aircraft were built with a
maximum troop capacity of twenty. However, the YHC-1A was
considered by most of the Army users to be too heavy for the
assault role and too light for the transport role. The decision was
made to procure a heavier transport helicopter and at the same time
upgrade the Huey as a tactical troop transport. This decision was
to determine the pattern of airmobile operations for the next
decade. As a consequence, the Army concept of air assault operations
differed from the Marines
because, among many reasons, the very nature of the equipment
demanded different methods of employment. The YHC-1A would be
improved and redesignated CH-46 Sea
HC-1B in flight being tested and
The Army then ordered the larger Model 114 under the designation
HC-1B. The pre-production Boeing
YCH-1B made its initial hovering flight on September 21,
1961. In 1962 the HC-1B was redesignated the
under the 1962
United States Tri-Service aircraft designation system
. The name
"Chinook" alludes to the Chinook people
the Pacific Northwest
The Chinook is powered by two turboshaft
engines, mounted on either side of the helicopter's rear end and
connected to the rotors by driveshafts. The counter-rotating rotors
eliminate the need for an anti-torque vertical rotor, allowing all
power to be used for lift and thrust. If one engine fails, the
other can drive both rotors.
The "sizing" of the Chinook was directly related to the growth of
the Huey and the Army's tacticians' insistence that initial air
assaults be built around the squad. There was a critical stage in
the Huey program when the technicians insisted not to go beyond the
UH-1B model with Bell; that there should be a new tactical
transport "between" the Huey and medium transport helicopter. By
resolutely pushing for the Huey and the Chinook, the Army
accelerated its airmobility program by years.
Improved and more powerful versions of the CH-47 have been
developed since it entered service.
A commercial model of the Chinook, the Boeing-Vertol Model
, is used worldwide for logging, construction, fighting
forest fires and supporting petroleum exploration operations.
December 15, 2006 Columbia
Helicopters, Inc. of Aurora, Oregon has purchased the Type
Certificate of the Model 234 from Boeing.
company is seeking FAA
issuance of a Production
Certificate to produce parts with eventual issuance of a Production
Certificate to produce aircraft.
Chinook was also built under license by Elicotteri Meridionali (Agusta) in Italy and Kawasaki in Japan.
U.S. troops board CH-47 Chinooks and UH-1 Hueys during
Operation Crazy Horse
, Vietnam, 1966.
The Army finally settled on the larger Chinook as its standard
medium transport helicopter and as of February 1966, 161 aircraft
had been delivered to the Army. The 1st Cavalry Division
had brought their organic Chinook battalion with them when they
arrived in 1965 and a separate aviation medium helicopter company,
the 147th, had arrived in Vietnam on 29 November 1965. This latter
company was initially placed in direct support of the 1st Infantry
The most spectacular mission in Vietnam for the Chinook was the
placing of artillery batteries in perilous mountain positions
inaccessible by any other means, and then keeping them resupplied
with large quantities of ammunition. The 1st Cavalry Division found
that its Chinooks were limited to 7,000 pounds payload when
operating in the mountains, but could carry an additional 1,000
pounds when operating near the coast. The early Chinook design was
limited by its rotor system which did not permit full use of the
installed power, and users were anxious for an improved version
which would upgrade this system.
As with any new piece of equipment, the Chinook presented a major
problem of "customer education". Commanders, pilots and crew chiefs
had to be constantly alert that eager soldiers did not overload the
temptingly large cargo compartment. It would be some time before
the using troops would be experts at sling loads and educated in
such minor details as removing the gunner's sight from the
artillery pieces. The Chinook soon proved to be such an invaluable
aircraft for artillery movement and heavy logistics that it was
seldom used as an assault troop carrier. The early decision to move
to a helicopter of this size proved to be indisputably sound.
The Chinooks were generally armed with a single 7.62 millimeter M60
machine gun on a pintle mount on either side of the machine for
self-defense, with stops fitted to keep the gunners from firing
into the rotor blades. Dust filters were also added to improve
engine reliability. At its peak employment in Vietnam, there were
22 Chinook units in operation.
Of the nearly 750 Chinooks in the U.S. and Republic of Vietnam
fleets, about 200 were lost in combat or wartime operational
accidents. US Army supplied Chinooks to the Australian Task Force
After an agreement signed between Boeing and Elicotteri
Meridionali, the Imperial Iranian Air Force (IIAF) purchased 20
Elicotteri Meridionali built CH-47Cs in 1971. The Imperial Iranian
Army Aviation (IIAA) purchased 70 CH-47Cs from Elicotteri
Meridionali during the period of 1972-1976. In late 1978, Iran
placed an order for an additional 50 helicopters with Elicotteri
Meridionali, but that order was canceled immediately after the
On or about 21 July 1978, four Iranian CH-47C Chinooks penetrated
15–20 km into Soviet airspace in the Turkimenistan Military
District. They were intercepted by a MiG-23M, shooting down one
Chinook, killing eight crew members and forcing a second one to
Iran lost at least 8 Chinooks during the 1980-1988 war with Iraq.
On 15 July 1983, an Iraqi Mirage F-1 destroyed three Iranian CH-47s
flying low to deliver marines to the front line.
The Chinook was used both by Argentina and the United Kingdom
during the Falklands War
in 1982. The
Argentine Air Force
deployed four CH-47C
(two each) which were widely used in general transport duties. Of
the Army's airframes one was destroyed on ground by a Harrier
whilst the other was captured (and
reused after the war) by the British. Both Air Force helicopters
returned to Argentina and remained in service until 2002.
Iraq and Afghanistan
Approximately 163 CH-47Ds served in Kuwait and Iraq during
Operations Desert Shield and Desert Storm in 1990-91.
is currently seeing wide use in Operation Enduring Freedom in
Afghanistan and Operation
Iraqi Freedom in Iraq.
Chinook is being used in air assault
missions, inserting troops into fire bases
and later bringing food, water, and ammunition. It is also the
casualty evacuation (casevac) aircraft of choice in the British
Army. It is typically escorted by attack helicopters such as the
for protection. The CH-47D was
particularly useful in the mountainous terrain of Afghanistan where
high altitudes and temperatures limited the use of the Black Hawk
Dutch Chinooks have been used in operations like Kosovo, Iraq and a
number of CH-47Ds were sent to Afghanistan. Australian Chinooks
participated in the in Afghanistan War.
The all-weather, medium-lift CH-47A Chinook was powered initially
by Lycoming T55
-L-5 engines rated at
but then replaced by the T55-L-7 rated at engines or T55-L-7C
engines rated at . The CH-47A had a maximum gross weight of .
Initial delivery of the CH-47A Chinook to the US Army was in August
1962. A total of 349 were built.
The ACH-47A was originally known as the Armed/Armored CH-47A (or
A/ACH-47A). It was officially designated ACH-47A by US Army—Attack
Cargo Helicopter—and unofficially "Guns A Go-Go"). Four CH-47A
helicopters were converted to gunships by Boeing Vertol in late
1965. Three were assigned to the 53rd Aviation
Detachment in South Vietnam for testing,
with the remaining one retained in the U.S. for weapons
By 1966, the 53rd was redesignated the 1st Aviation
Detachment (Provisional) and attached to the 228th Assault Support
Helicopter Battalion of the 1st Cavalry Division (Airmobile). By
1968, only one gunship remained, and logistical concerns prevented
more conversions. It was returned to the United States, and the
The ACH-47A carried five M60D
7.62x51 mm machine guns or M2HB
.50 caliber machine guns,
provided by the
armament subsystems, two M24A1
20 mm cannons, two XM159B/XM159C
rocket launchers or sometimes two
, and a single M75
40 mm grenade launcher in the
armament subsystem (more commonly seen on the UH-1 series of
helicopters). The surviving aircraft, Easy Money, has been
restored and is on display at Redstone Arsenal, Alabama.
The CH-47B was an interim solution while Boeing worked on a more
substantially improved CH-47C. CH-47B was powered by two Lycoming
T55-L-7C 2,850 shp (2,130 kW) engines. It featured a blunted
rear rotor pylon, redesigned asymmetrical rotor blades, and strakes
along the rear ramp and fuselage to improve flying characteristics.
It could be equipped with two door-mounted M60D 7.62 mm NATO machine
on the M24 armament subsystem and a ramp-mounted M60D
using the M41 armament subsystem. Some CH-47 "bombers" were
equipped to drop tear gas
from the rear cargo ramp onto NLF
Việt Cộng) bunkers. The CH-47 could be equipped with a hoist and
cargo hook. The Chinook proved especially valuable in "Pipe Smoke"
aircraft recovery missions. The "Hook" recovered about 12,000
aircraft valued at over $3.6 billion during the war. 108
The CH-47C featured more powerful engines and transmissions. Three
versions of the "C model" were built. The first had Lycoming
T55-L-7C engines delivering . The "Super C" included Lycoming
T55-L-11 engines delivering , an upgraded maximum gross weight of
and a pitch stability augmentation system (PSAS). Due to
difficulties with the T55-L-11 engines, which were hurriedly
brought to war to increase payload, they were temporarily removed
from the "Super C" prior to 1970 and the very reliable Lycoming
T55-L-7C's were installed until the L-11 engine difficulties could
be quantified and corrected. This L-7C engine configuration was
affectionately referred to as the "baby C" although it was still a
Super C. It distinguished itself from the "C" in that it had PSAS
and an uprated maximum gross weight. The CH-47 A, B, and all
variants of the C were not able to receive certification from the
FAA for civil use due to the non-redundant hydraulic flight boost
system drive. A redesign of the hydraulic boost system drive was
incorporated in the CH-47D which allowed that model to achieve FAA
certification as the Boeing Model 234. 233 CH-47Cs were
The CH-47A, B, and all versions of the C saw wide use during the
Vietnam war. They replaced the H-21
in the combat assault support role.
The Royal Air Force
variant of the
CH-47C is known as the Chinook HC1
The export version of the CH-47C Chinook for the Italian Army was
designated "CH-47C Plus".
The CH-47D was originally powered by two T55-L-712 engines, but
most are now fitted with the T55-GA-714A. Models CH-47A, CH-47B,
and CH-47C, all used the same airframe, but later models featured
upgraded engines. With its triple-hook cargo system, the CH-47D can
carry heavy payloads internally and up to 26,000 pounds - for
example, bulldozers and containers - externally, at speeds over
155 mph (250 km/h). In air assault operations, it often
serves as the principal mover of the 155 mm M198 howitzer
, 30 rounds of ammunition, and an
11-man crew. Like most US Army
helicopters, the Chinook has advanced avionics and electronics,
including the Global
Nearly all of the Army production CH-47D models were conversions
from previous US Army A, B, and C models. The last US Army D model
built was delivered to the U.S.
Army Reserve, located at Fort Hood,
Texas, in early 2002.
The Royal Air Force
versions of the
CH-47D are known as the Chinook HC2
HC2A. The CH-47SD is a modified variant of the CH-47D, with
extended range fuel tanks and higher payload capacities.
It is in
use by the Republic of
Singapore Air Force, Greek Army and
the Republic of
The CH-47DG is an upgraded version of the
CH-47C for the Greek Army. The CH-47D is an upgraded version of the
CH-47LR for the Republic of Korea Army.
The MH-47D variant was developed for special forces
operations and has in-flight
refueling capability, a fast-rope rappelling system and other
upgrades. The MH-47D was used by US Army 160th
Special Operations Aviation Regiment
. 12 MH-47D helicopters
were produced. 6 were conversions from CH-47A models and 6 were
conversions from CH-47C models.
The current model used by US Army Special Operations is the MH-47E.
Beginning with the E model prototype manufactured in 1991, there
were a total of 26 Special Operations Aircraft produced. All
aircraft were assigned to 2-160th SOAR(A)"Nightstalkers", home
based at Fort Campbell Kentucky. E models were conversions from
existing CH-47C model airframes. The MH-47E has similar
capabilities as the MH-47D, but includes an increased fuel capacity
similar to the CH-47SD and terrain following/terrain avoidance
In 1995, the Royal Air Force
, effectively a low cost version of the MH-47E for the
special forces operations role. They were delivered in 2001 but
never entered operational service due to technical issues with
fit, unique to the HC3. In
2008, work started to downgrade the HC3s to HC2 standard, to enable
them to enter service.
The CH-47F, an upgraded D model, first flew in 2001. The first production
model was rolled out on June 15, 2006 at the Boeing facility in
Park, Pennsylvania, and had its maiden flight on October 23,
The CH-47F was designed to extend the service life of
the Chinook class beyond 2030. Among its upgrades are new 4,868
Honeywell engines, improved avionics, and an upgraded airframe with
larger single-piece sections to reduce part count and need for
fasteners. The new milled construction will reduce vibrations,
eliminate points of joint flexing, and reduce the need for
inspections and repairs, and reduce maintenance costs. It is also
expected to increase service life. The CH-47F can fly at speeds of
over with a payload of more than . The improved avionics include a Rockwell Collins Common Avionics
Architecture System (CAAS) cockpit, and BAE Systems' Digital Advanced Flight Control System
Boeing has delivered 48 F-model helicopters to the United States Army
; on August 26, 2008,
Boeing announced that the Army has signed a five-year contract,
worth over $4.8 billion for 191 more, plus 24 options. In February
2007, the Netherlands were the first international customer to
order the F model; six helicopters were ordered to expand their
current fleet to 17. These six helicopters will be equipped with an
upgraded version of the Honeywell Avionics Control Management
System (ACMS) cockpit.
The MH-47G Special Operations Aviation (SOA) version is currently
being delivered to the U.S. Army. It is similar to the MH-47E, but
features a more sophisticated avionics including a digital Common
Avionics Architecture System (CAAS). The CAAS is common glass
cockpit used by different helicopters such as MH-60K/Ls, CH-53E/Ks,
and ARH-70As. The MH-47G will also incorporate all of the new
sections of the CH-47F.
operational experience in Afghanistan, the CH-47 was found to be an effective substitute
for the UH-60 Black Hawk as an
With its larger payload, range, and
higher operating speed, one Chinook can replace up to five UH-60s
in this role as an air assault transport.
On November 9, 2006, the HH-47, a new variant of the Chinook based
on the MH-47G, was selected by the U.S. Air Force
as the winner of the Combat Search and Rescue (CSAR-X) competition.
Four development HH-47s will be built, with the first of 141
production aircraft to enter service in 2012. However, as of
February 2007 this contract award has come under scrutiny by the
and the USAF may recompete the CSAR-X
Other export models
The CH-47J is a medium-transport helicopter for the Japan Ground Self Defence
, and the Japan
Air Self Defence Force
. The CH-47JA is a long range version of
the CH-47J, fitted with enlarged fuel tanks. Both versions are
built under license in Japan by Kawasaki
. The HH-47D is a search
and rescue version for the Republic of Korea Air
Eight CH-47C Chinooks were delivered to the Canadian Forces
in 1974. The Chinooks were
in Canadian service from 1974 to 1991; they were designated
"CH-147". These aircraft were subsequently sold to the Netherlands
and are now operated by the Royal Netherlands Air Force
CH-47Ds. In April 2009, the Australian government requested a
possible sale of seven CH-47F helicopters. Additional orders are
expected from Italy and the United Kingdom. Plans are to upgrade
the current fleet of CH-47Ds to the F-model standard and eventually
enlarge the fleet to 20 aircraft, pending funding.
On August 10, 2009, Canada signed a contract to purchase 15 CH-47Fs
for delivery in 2013-14.
- Model 234LR (Long Range) - Commercial
transport helicopter. The Model 234LR can be fitted out as an
all-passenger, all-cargo, or cargo/passenger transport
- Model 234ER (Extended Range) - Commercial
- Model MLR (Multi Purpose Long Range) -
Commercial transport version.
- Model 234UT (Utility Transport) - Utility
- Model 414 - The Model 414 is the international
export version of the CH-47D. It is also known as the
CH-47D International Chinook.
In the 1970s, the Army contracted Boeing to design a "Heavy Lift
Helicopter (HLH)", designated XCH-62A
. It appeared to be a scaled-up
CH-47 without a conventional body, in a configuration similar to
the S-64 Skycrane
), but the project was soon canceled.
It was given a second examination in the 1980s and was again
rejected. The scaled up model of the HLH was scrapped
at the end of 2005 at Fort Rucker, Alabama.
- : see Boeing
- : captured ex-VNAF Chinooks
Former civil operators are marked by italics
- Taiwan National Fire Administration (currently operates three
234s and nine CH-47SD)
Notable accidents and incidents
September 11, 1982, at an airshow in
Germany a United States Army Chinook (serial number
74-22292) carrying parachutists crashed,
killing 46 people. The crash was later found to be
caused by an accumulation of ground walnut
shells that had been used to clean the machinery.
November 6, 1986, a British International
crashed on approach to Sumburgh Airport, Shetland Islands
resulting in the loss of 45 lives and the withdrawal of the Chinook
from crew servicing flights in the North Sea.
- Major Marie Therese Rossi
Cayton was the first American woman to fly in combat during
Desert Storm in 1991. She was killed when her Chinook helicopter
crashed on 1 March 1991.
- On 2
June 1994 an RAF Chinook HC2 (registration ZD576, call sign F4J40)
crashed on the Mull of Kintyre, Scotland, killing all twenty five passengers and all four
- On 29
May 2001 a ROK Army CH-47D installing a sculpture onto a bridge in Seoul, South Korea
failed to unlatch the sculpture. The helicopter's rotors
struck the monument then the fuselage hit. The helicopter broke
into two. Half crashed onto the bridge in flames and the other half
fell into the river. All three crew members on board died.
Turboshaft engine on the rear of a CH-47
Soldiers wait for pickup from two
Chinooks in Afghanistan, 2008.
- Origins: Vertol V-107 & V-114, Vectorsite.net,
July 1, 2004.
- Spenser, Jay P. Whirlybirds, A History of the U.S.
Helicopter Pioneers. University of Washington Press, 1998.
- Chinook Information and diagrams about the
- boeing-vertol CH-47C Chinook in argentina comando de
aviacion de ejercito argentino
- US Army CH-47A / CH-47B / CH-47C / CH-47D / SOA
Chinooks. Vectorsite.net, 1 July 2004.
- Boeing CH-47D model Chinook helicopters.
- Boeing MH-47D model Chinook helicopters.
- Boeing MH-47E model Chinook helicopters.
- "New Boeing CH-47F takes flight", Aerotech News and
Review, November 3, 2006, p. 3.
- "Boeing's New CH-47F Chinook Helicopter Begins Operational
Test Flights with U.S. Army", Boeing, February 19, 2007.
- Holcomb, Henry, "New Look Chinook", Philadelphia
Inquirer, August 17, 2007. archive link
- "Boeing Awarded US Army Contract for 191 CH-47F
Chinook Helicopters", Boeing, August 26, 2008.
- "Boeing Signs Contract for Dutch Chinooks",
Boeing, February 15, 2007.
- Warwick, Graham. "Chinook: CAAS unites rotorcraft cockpits".
Flight International, 1 April 2008.
- MH-47E/G Special Operations Chinook product page.
- Air Transportation: Chinook Replaces Blackhawk in
-  Boeing News Release
-  Global Security.org
- Bowing To GAO, USAF Likely To Recompete CSAR-X
28 February 2007
- "Australia - CH-47F Chinook Helicopters". DSCA,
23 April 2009.
- "Chinooks will fly too late for
- XCH-62 with photo
- Canadian military acquiring new helicopters,
- Boeing: History - Products - Boeing Model 234
- SP-3300 Flight Research at Ames, 1940-1997
- Description of crash of Chinook 74-22292,
- Air show safety in the spotlight, BBC, 27 July
- Ursula J. Schoenborn v. The Boeing
Company, 769 F.2d 115 (3d Cir. 1985) - a case in the U.S.
Court of Appeals for the Third Circuit
- Report No: 2/1988. Report on the accident to Boeing
Vertol (BV) 234 LR, G-BWFC 2.5 miles east of Sumburgh, Shetland
Isles, 6 November 1986
- "Marie Therese Rossi Cayton" Arlington National Cemetery
- "S. Korean Helicopter Crashes Into Bridge, 3
Killed". People's Daily, 30 May 2001. archive page on Google.com