User:Fnlayson/CH-xx

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1 CH-46
2 CH-47

[edit] CH-46

Main article: CH-46 Sea Knight

[edit] Development

Unused: ^[1] ^[2]

...

Production of the improved CH-46D followed with deliveries beginning in 1966. Its improvements included modified rotor blades and more powerful T58-GE-10 turboshaft engines^[1] rated at 1,400 shp (1,040 kW) each. The increased power allowed the D-model to carry 25 troop or 7,000 pounds (3,180 kg) of cargo. A total of 266 CH-46Ds were produced. Also, approximately 12 CH-46As were upgraded to CH-46Ds. The Navy received 10 UH-46Ds for ship resupply.^[2]

The Marines also received 174 CH-46Fs from 1968 to 1971. The F-model retained the D-model's T58-GE-10 engines but revised the avionics and included other modifications. The CH-46F was the final production model with the last helicopter being the 524th H-46 produced.^[1] The Sea Knight has undergone upgrades and modifications. Most USMC Sea Knights were upgraded to CH-46E standard. The CH-46E features fiberglass rotor blades, airframe reinforcement, and further uprated T58-GE-16 engines producing 1,870 shp (1,390 kW) each. Some CH-46Es have been given doubled fuel capacity.^[2]

(try to use other sources for CH-46D, F content)

The H-46 Sea Knight Block Upgrade provides(d?) for installation of stub wings with increased fuel capacity and an emergency helicopter flotation system.^[1]

TEXT 4

The first of the CH-46As flew on 16 October 1962, and testing continued into late 1964, with the first US Marine squadrons taking these aircraft into service in early 1965. Since then a number of versions have been built, these including the CH-46D for the USMC, generally similar to the CH-46A, but with 1044kW T58-GE-10 turboshaft engines; the CH-46F for the USMC, generally similar to the CH-46D, but with additional avionics; the UH-46A Sea Knight, similar to CH-46A, procured by the US Navy with first deliveries to Utility Helicopter Squadron 1 in July 1964; and the UH-46D for the US Navy, virtually the same as the CH-46D. The US Marine Corps has updated 273 of its Sea Knights to CH-46E standard, with 1394 kW General Electric T58-GE-16 turboshafts and other improvements.

In 1965, Kawasaki in Japan acquired from Boeing Vertol the worldwide sales rights for the Model 107-II, and in 1981 continued to produce these helicopters under the designation KV-107/IIA. A number of versions have been built and remain in production, and these are listed below.

D.Donald "The Complete Encyclopedia of World Aircraft", 1997

[edit] Design

The CH-46 has tandem contrarotating rotors that were powered by two GE T58 turboshaft engines. The engines are mounted on each side of the rear rotor pedestal with a driveshaft to the forward rotor. The engines are coupled so either could power both rotors in an emergency. The rotors feature three blades and could be folded for on-ship operations.^[2]

The CH-46 has a cargo bay with a rear loading ramp that could be removed or left open in flight for extended cargo or for parachute drops. A belly sling hook could be attached for carrying external cargo. It has a crew of three. A pintle-mounted 0.50 in (12.7 mm) Browning machine gun was mounted on each side of the helicopter for self-defense.^[2] Service in southeast Asia resulted in the addition of armor with the guns.^[1]

The CH-46 has fixed tricycle landing gear, with twin wheels on all three units. The gear configuration causes a nose-up stance to facilitate cargo loading and unloading. The main gear are fitted in rear sponsons that also contained fuel tanks with a total capacity of 350 US gallons (1,438 L).^[2]

TEXT 1

The sponsons and the nose-up attitude of the CH-46 on the ground gave the appearance of a frog ready to hop, and so the Marines nicknamed the type the "Frog". Although there was initial suspicion of the type since the Marines were accustomed to Sikorsky helicopters, the Frog quickly proved itself in Vietnam after its introduction into the theater in March 1966, though the CH-46 fleet was grounded for a time in 1967 when a few of them were lost in accidents. The Frogs acquitted themselves well, particularly during the siege of Khe Sanh in early 1968.

Boeing Sea Knight & Chinook

TEXT 2

... Following a design competition, Boeing/Vertol was selected to build its model 107M as the HRB-1, early in 1961. It retained the general configuration of its predecessors, including the aft sponsons carrying the fixed main gear, a fixed nose gear and built-in emergency flotation provisions so it could land and take off from the water in light seas. Special features included power-operated blade folding, integral cargo handling provisions, a rear loading ramp that could be left open in flight, personnel recovery and rescue equipment, and provisions for hoisting 10,000 pounds externally. These and other features marked a significant step forward in helicopter capability in the time period.

US Navy History CH-46 page

[edit] Operational history

TEXT 1

The Sea Knight has proven very long-lived in service. Since Vietnam it has seen action with the Marines in Lebanon, Grenada, and elsewhere. ...

The Marines are now looking to replace the Sea Knight with the Bell-Boeing "MV-22 Osprey" tilt-rotor transport, but the Osprey is an ambitious machine and the program has run into various snags. As a result, Marine Frogs are still in service, and in fact after the US invasion of Iraq in the spring of 2003, the USMC implemented an upgrade program, replacing metal armor with a new lightweight armor to increase the helicopter's lift capacity. The first upgrades are expected to go into service in 2005.

The US Navy, confronted with rising costs for keeping the service's venerable UH-46s in the air, is now phasing them out, replacing them with the Sikorsky MH-60S Knighthawk, a new variant of the Sikorsky Blackhawk / Seahawk family. The UH-46 should be generally out of service in 2004 or 2005.

Boeing Sea Knight & Chinook

TEXT 2

The early A models now serve as search and rescue HH-46As. CH-46s equip Marine Reserve squadrons, and conversion of earlier aircraft to the new CH-46E version was completed with fiberglass blades slated added to its other improvements.

US Navy History CH-46 page

TEXT 3

The first U.S. Marine Corps Sea Knight was delivered in 1964 and began military service during the Vietnam War a year later, carrying troops and cargo to and from Navy ships in the China Sea.

By 1968, the Sea Knight had flown 75,000 hours on 180,000 missions, including 8,700 missions rescuing wounded Marines, and had carried 500,000 troops.

Between 1964 and 1990, Boeing Vertol delivered over 600 Sea Knights. The passenger version of the Sea Knight, the Model 107-II, entered service with the New York Airways in July 1962. During the 1980s and 1990s, Boeing developed modification kits and upgrades to modernize the Sea Knights.

Boeing CH-46 history page

[edit] Variants

Several variants have been produced including the CH-46A for the Marines (160); the UH-46A Sea Knight for the US Navy (24); the CH-46D with an uprated engine for the Marines (266); the UH-46D for the US Navy (10); the UH-46B for evaluation by the USAF; the RH-46E minehunters for the US Navy, and the CH-46F for the Marines (174), which is similar to the CH-46D but with improved electronics. Seven civil aircraft were used by New York Airways from 1962, while 18, designated CH-113, were ordered by the Canadian Air Force and 14, designated HPK-4, by Sweden.

The Model 107 has also been built under license in Japan by Kawasaki Heavy Industries in civil and military versions: the KV-107/11-2 commercial version for passenger transport adopted by Kawasaki, the Thai government and New York Airways; the KV-107/11-3 minehunters; the KV-107/11-4 for tactical transport, 59 of which have been built for the Japanese Ground Self-Defense Force; the KV-107/11-5 rescue version for the Japanese Air Self-Defense Force and the Swedish Navy (38 built); the KV-107/11-7 six-eleven-seat VIP transport version, only one of which has been built for the Thai government; and the KV-107/IIA version for hot climates and high altitudes.

G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984

[edit] External links

Sea Knight & Chinook on Vectorsite.net
CH-46 page on Aviastar.org (for info only)

[edit] CH-47

Main article: CH-47 Chinook

The Boeing CH-47 Chinook is a versatile, twin-engine, tandem rotor heavy-lift helicopter. The counter-rotating rotors eliminate the need for an anti-torque vertical rotor, allowing all power to be used for lift and thrust. Its top speed of 170 knots (196 mph, 315 km/h) 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. There is a wide loading ramp at the rear of the fuselage and three external-cargo hooks. It has replaced the CH-54 Tarhe as a lifter.

Chinooks have been sold to 16 nations, the largest users are the U.S. Army and the Royal Air Force (see Boeing Chinook (UK variants)). The H-47 is now sold by Boeing Integrated Defense Systems.

A commercial model of the Chinook, the Boeing-Vertol Model 234, is used worldwide for logging, construction, fighting forest fires and supporting petroleum exploration operations. As of December 15, 2006 Columbia Helicopters, Inc of Aurora, Oregon has purchased the Type certificate of the Model 234 from Boeing.^[3] Currently the company is seeking FAA issuance of a Production Certificate to produce parts with eventual issuance of a PC to produce aircraft.

[edit] Development

The Army then ordered the larger Model 114/HC-1B. The pre-production Boeing Vertol YCH-1B made its initial hovering flight on September 21, 1961. In 1962 the HC-1B was redesignated the CH-47A under the 1962 United States Tri-Service aircraft designation system.

TEXT 1

In 1956, Vertol began studies for a new medium-lift helicopter, with the general configuration of the company's "HUP-1 Retriever / H-25 Mule" helicopter and based on the rotor system of the company's "H-21 Flying Banana", but fitted with new lightweight turboshaft engines then in development. The new machine was given the company designation of "Vertol Model 107 (V-107)", and company management decided to go ahead with development using their own funds.

Construction of the V-107 prototype began in May 1957. The prototype was powered by two Lycoming T53 turboshaft engines, each with 640 kW (860 SHP) and lent by the US Army. Initial flight of the prototype was on 22 April 1958. The machine was then put through an intensive program of flight demonstrations in the US and overseas. In June 1958, the Army awarded a contract to Vertol for ten production aircraft designated "YHC-1A".

The Army also issued a request to industry for a larger helicopter, and so Vertol began design work on what amounted to a scaled up version of the V-107, designated the "V-114". The V-114 won the Army competition in March 1959, and Vertol was awarded a contract for a mockup and five prototypes, to be designated the "YHC-1B".

Vertol was now busy trying to develop two helicopters at the same time, which severely strained the company and led to the Boeing buyout. The number of YHC-1A prototypes was reduced to three to free up resources for YHC-1B development. The first flight of the initial YHC-1B prototype was on 21 September 1961.

The Army had lost interest in the smaller YHC-1A, but Boeing Vertol still felt there was a market for it and continued development. The US Marine Corps was impressed by the machine and awarded the company a production contract in February 1961. The Marines originally wanted to give the V-107 the military designation of "HRB-1", but in September 1962, the Pentagon introduce a new "tri-service" uniform designation scheme. The HRB-1 became the "CH-46A Sea Knight", while the HC-1B became the "CH-47A Chinook". The five V-114 prototypes became "YCH-47As".

Initial delivery of the CH-47A Chinook to the US Army was in August 1962. The Chinook had a similar configuration to the Sea Knight, with the same contrarotating tandem-rotor configuration and turboshaft engines mounted on each side of the the rear rotor pedestal. As with the Sea Knight, a driveshaft ran up the top of the fuselage to the forward rotor and one engine could drive both rotors in a pinch.

Initial CH-47A engine fit consisted of two Lycoming T55-L-5 turboshafts with 1,640 kW (2,200 SHP) each. These were presently changed in production to T55-L-7 turboshafts with 1,795 kW (2,650 SHP) each. The three-bladed rotors were set high enough to allow personnel to walk under them safely under normal circumstances. The rotors could be manually folded.

The Chinook had a rear loading ramp that could be set to any level to allow loads from truckbeds or other platforms, and which could be opened in flight for dropping paratroops or parachute loads. A winch system was provided in the cargo bay to help handle loads, which were secured with deck tie-point points. A single sling attachment was fitted in the belly.

Of course, the Chinook was bigger than the Sea Knight, boxcar-size rather than schoolbus-size. Fairings containing the fuel tanks ran most of the length of the fuselage, and there were four fixed landing gear, rather than three. Fuel capacity of the CH-47A's self-sealing tanks was 2,350 liters (621 US gallons). There were dual wheels on the front gear, which bore most of the load, and single wheels on the back. The rear wheels were steerable. As with the Sea Knight, the wheels could be fitted with skis for operation on snow or marshy ground. The machine could land on calm waters in an emergency.

Crew consisted of pilot, copilot, and loadmaster or combat commander. There were emergency exit doors on each side of the cockpit, and a split-section personnel door behind the cockpit on the left side. The personnel door had built-in steps on the lower half. An auxiliary power unit provided ground power and operations from remote sites, and the cargo bay included a heater-blower system to keep the occupants warm.

The CH-47A could carry 33 fully-equipped troops on sidewall seating, though more could be carried by fitting center seats; or 24 casualty litters with two attendants; or 2,720 kilograms (6,000 pounds) of internal cargo. Almost 6 tonnes (13,000 pounds) of cargo could be lifted externally, though with much reduced range for very heavy loads.

354 CH-47As were built for the US Army. The Chinooks were generally armed with a single 7.62 millimeter 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.

CH-47A production was followed by manufacture of 108 "CH-47Bs" for the US Army, with initial flight of a prototype, a modification of one of the five original YCH-47A prototypes, on 9 September 1966. Initial service delivery was in May 1967, and the type arrived in Vietnam in February 1968. The CH-47B featured Lycoming T55-L-7C turboshafts with 2,125 kW (2,850 SHP) each, as well as slightly longer, redesigned rotor blades. Strakes were fitted alongside the rear loading ramp to improve flight stability, a feature retained in later Chinook models.

The CH-47B was an interim solution while Boeing worked on a more substantially improved Chinook, the "CH-47C", which was the last major new production variant for the US Army.

The CH-47C featured Lycoming T55-L-11 turboshafts with 2,800 kW (3,750 SHP) each and a more robust power transmission system to support the greater power. One of the main drivers for the development of the CH-47C was that the earlier versions of the Chinook had troubles carrying the Army's M198 155 millimeter howitzer any distance. The CH-47C could not only handle the big howitzer, the machine also had substantially greater speed than its predecessors.

In addition, the CH-47C had greater fuel capacity of 4,273 liters (1,129 US gallons). Additional fuel bladders could be carried in the cargo bay for long ferry flights, giving the C-47C the capability to cross the Atlantic and self-deploy to Europe.

270 CH-47Cs were built, with the first flying on 14 October 1967. Initial deliveries to the US Army began in the spring of 1968, with the variant going into service in Vietnam in September of that year.

The Chinook has been upgraded to keep it in service. A glass-fiber rotor blade was introduced in 1969, and 182 CH-47Cs were retrofitted with the improved blades. The CH-47C fleet was also fitted with "crashworthy" fuel tanks beginning in 1973.

403 US Army Chinooks, including CH-47As, CH-47Bs, and CH-47Cs, were later upgraded to the "CH-47D" specification. The CH-47D features a refurbished airframe with some composite assemblies; single-point pressure refueling; an improved rotor transmission; fiberglass rotor blades; and improved Textron Lycoming (now Garrett) T55-L-712 turboshafts providing 2,800 kW (3,750 SHP) each.

Lift capacity was increased to 6,300 kilograms (13,900 pounds) internally or 10,340 kilograms (22,800 pounds). The CH-47D could even lift a Cat D-5 bulldozer. One nice new feature was fit of three sling hooks, which made it much easier for the machine to lift unstable cargoes, or balance multiple loads. This was one of those ideas that in hindsight should have been implemented at the start, and it is now standard on all Chinooks.

About 32 CH-47Ds were updated to the "CH-47D Special Operations Aircraft (SOA)" configuration for support of the US Army Special Operations Command (Army SOC). These machines were fitted with improved navigation and communications gear, including satellite communications links; countermeasures systems; and pintle-mounted machine guns. Introduction to service was in 1985.

The Army went on to obtain improved SOA Chinooks. The CH-47D SOA was followed by a dozen "MH-47D SOA" machines, with deliveries beginning in the mid-1980s. These rotorcraft were similar to the CH-47D SOA variant, but added nose radar; a forward-looking infrared (FLIR) camera mounted in the nose; a glass cockpit; inflight refueling probe; and other refinements. One crashed in 1989.

The next step was the "MH-47E SOA", which built on the MH-47D by adding a Texas Instruments AN/APQ-174 terrain-following radar in a pod on the left side of the machine; a night vision goggle (NVG) compatible cockpit; and oversized fairings with a huge fuel capacity, along with additional internal fuel tanks. 26 MH-47Es were rebuilt from other Chinook models, with initial flight of a prototype on 1 June 1990 and service delivery in early 1994. Two MH-47Es was lost in crashes, one in 1996 and the second in 2002. The CH-47Ds have been been returned to conventional Chinook transport configuration, but the MH-47Ds and MH-47Es remain in service.

All MH-47Ds and MH-47Es will be upgraded to the MH-47G configuration, and the Army may buy a few used Chinooks on the international market for upgrade as well. The remainder will be new production.

The Chinook is still going strong and shows no signs of fading out of service, making it one of aviation's major success stories. CH-47Ds are now being upgraded for the 21st century in the form of the "Model 414-100 CH-47SD Super D" for export, and the "CH-47F" for the US Army.

The CH-47SD features twin AlliedSignal T55-L-714A turboshafts, with 3,040 kW (4,075 SHP) each. These engines provide greater fuel economy; are "marinized" with corrosion protection to allow operation in a salt-water environment; and are fitted with FADEC.

External cargo load has been increased to 12,700 kilograms (28,000 pounds) on the center sling hook, or 9,070 kilograms (20,000 pounds) each on the forward and aft cargo hooks. Larger fuel tanks have been fitted, giving the Super D twice the range of the CH-47D, and the airframe has been given structural changes and reinforcement. The CH-47SD has a glass cockpit with color displays and digital map, a Global Positioning System (GPS) navigation system, and nose radar. Countermeasures kit is optional.

Initial flight of the Super D prototype was on 25 August 1999. The initial announced customer was Taiwan, with deliveries of three machines beginning in 2001. These machines were designated "Model 234MLR" after an earlier unbuilt commercial variant to give them a "civilian" designation and avoid the wrath of the mainland Chinese.

As mentioned, Singapore is also buying six Super Ds to increase their Chinook fleet to twelve, and is considering upgrade of their current International CH-47Ds to the Super D standard.

The upgrade program was launched in May 1998 as the "Improved Cargo Helicopter (ICH)" effort, and will reduce operating costs by about 20% compared to the CH-47D. The machines will be run through depot level maintenance to be given structural reinforcements to renew service life and reduce vibration, and will also be fitted with new rotorheads; T55-714A turboshafts; an extended-range fuel system; a partial glass cockpit; other improved avionics, and a MIL-STD 1553 data bus.

The CH-47F is essentially a subset of the CH-47SD. There has been some grumbling among the Army helicopter aviation faction that the full Super D fit wasn't that much more expensive and is clearly superior, particularly with regards to a full glass cockpit and many more corrosion-proof composite assemblies, and that the CH-47F effort has been "penny wise and pound foolish". In fact, by the spring of 2004 Army program management seemed to be agreeing and was having discussions with Boeing for production CH-47F machines that would be largely new and have a more sophisticated cockpit layout.

Initial CH-47F prototype flight was in June 2001. Two prototypes are still in evaluation.

Chinook on Vectorsite

[edit] Operational history

The Chinook went to Vietnam in 1965, where it served with distinction, particularly in retrieving thousands of downed aircraft from field locations. It was also useful for carrying stores, ammunition, and artillery pieces to remote firebases. The Chinooks were generally armed with a single 7.62 millimeter 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.

The large Chinook fleet in US Army service remains the backbone of the service's medium-lift capability, serving in most of America's campaigns since Vietnam. Not only has the big helicopter proven useful and reliable, but it has an enviable flight safety record. It has been used for a wide range of roles, including fire-fighting with a sling-carried kit, and even for transporting the Apollo Lunar Module, used to land on the Moon, from the Grumman manufacturing plant in Tulsa, Oklahoma, to Cape Canaveral in Florida.

The CH-47D program was initiated in 1976, with first flight of a prototype on 14 May 1979. The first flight of a production CH-47D was on 26 February 1982, with the variant going into service that May. The CH-47D has gone on to provide excellent service in the Gulf War and other campaigns.

26 MH-47Es were rebuilt from other Chinook models, with initial flight of a prototype on 1 June 1990 and service delivery in early 1994. Two MH-47Es was lost in crashes, one in 1996 and the second in 2002. The CH-47Ds have been been returned to conventional Chinook transport configuration, but the MH-47Ds and MH-47Es remain in service.

Following the American intervention in Afghanistan in late 2001, the US Army's special operations helicopter fleet was very heavily committed, and the service is now interested in expanding the fleet from 35 machines to 72 in expectation of further service in the American "war on terror". They will all be the new "MH-47G SOA" variant, which will essentially provide MH-47E-style enhancements to the new "CH-47F" variant, described in a later section, plus an improved defensive countermeasures suite.

The US Army hopes to convert at least 300 of their current fleet of CH-47Ds to the CH-47F standard. The CH-47Fs are expected to remain in service until 2033 at earliest, at which time the Chinook will have been in US Army service for over 70 years.