Chinook Headline News: Chinooks helicopter grounded for transmission checks

Chinook Headline News

Boeing Troop Helicopters Grounded For Checks

Monday, 9 August 1999

The Army said Monday it had grounded its 466 CH-47 Chinook troop helicopters made by Boeing Company and advised other militaries to halt flights worldwide after a crack was found in a transmission gear of a British CH-47.

   The twin-engine workhorse Chinook, first introduced in the early 1960s and updated several times since, can carry 33 fully-equipped soldiers and a crew of three.

   Army officials said the halt for safety checks was ordered late Friday and that Boeing would help inspect transmission gear assemblies, including those in more than 300 CH-47s bought by the militaries of other countries. The grounding affects only CH-47D and derivative models that have entered service since 1982.

   Officials said the ''prudent'' stand-down was made because failure of the

transmission gears could have catastrophic consequences during flight. The Army stressed that the gear problem had not caused any accidents, however.

About 10 countries outside the United States fly CH-47s including Britain, Egypt, Greece and Singapore.

The cracked engine transmission gear was found recently in a CH-47 second stage planetary gear assembly during a routine check by the British Royal Air Force.

A subsequent Boeing investigation discovered three more cracked gear assemblies in the company's factory inventory.

Jack Satterfield, a Boeing spokesman, said the worldwide fleet was grounded until the company can determine exactly which helicopters contain the suspect gear assembly made by an unidentified supplier.

Once Boeing determines exactly which gear assembly units are affected, it will recommend that those helicopters be returned to a major maintenance base, where their transmissions can be taken apart and inspected.

"If they don't contain parts from this manufacturer ... what we're going to need to do is evaluate those and probably clear those aircraft to return to flight status,'' Satterfield said.

He said Boeing was working with the supplier to determine how many gear assembly units were in the affected production lot, a process that will take several days.

In addition to the gears in the lot in question, Boeing was investigating the condition of gears in other manufactured lots, the Army said.

"We want to make a very thorough check to make sure that the problem is addressed,'' said Dan O'Boyle, a spokesman at the U.S. Army's Program Executive Office for Aviation at Redstone Arsenal in Alabama.

Army Grounds Fleet of Helicopters

Monday, 9 August 1999

The Army announced Monday it was temporarily grounding its entire fleet of CH-47 Chinook transport helicopters after a crack was found in a transmission gear in one being used by the British Royal Air Force.

The fleet is grounded. It's a precautionary measure,'' said an Army spokeswoman, Nancy Ray.

She said that 466 helicopters in the Army fleet were involved in the temporary grounding.

''In an overhaul, the Royal Air Force discovered a cracked gear. That gear has been traced diligently,'' Ray said. She said Boeing was working with the Army Aviation Center to see if the problem affected any of the Army Chinooks.

The twin-rotored Chinook helicopter is the military's medium lift tactical transport.

Meanwhile, the British Ministry of Defense said Monday that it has grounded its fleet of Royal Air Force Chinooks also pending safety checks.

The Boeing Company, which manufactures the helicopter at its Philadelphia plant, requested the suspension of flights by about 20 operators around the world to allow inspection of their transmissions, said company spokesman Jack Satterfield.

Boeing's subsidiary, Boeing Precision Gear in Chicago, manufactured the type of gear used in the aircraft, Satterfield said.

''All the models should be suspending flight operations pending a check of records to determine if the aircraft contained gears from the suspect production lines,'' he said.

The US Army has the largest fleet of Chinooks. Between 300 to 400 Chinooks are used in other countries, including Australia, Argentina, Spain, Italy, Greece, Morocco, Egypt, Taiwan and Japan, Satterfield said.

Army Allows Helicopters To Fly

Friday, 27 August 1999

The Army announced Friday that half its fleet of CH-47 Chinook transport helicopters will return to limited flight while tests continue of suspect transmission gears.

The Army grounded its entire fleet of 466 Chinooks on August 9th after the discovery of a cracked transmission gear during an aircraft overhaul.

Army units continue to work with the Boeing Company, which manufactures the helicopter in its Philadelphia plant, to locate all gears of the suspect type and design, the Army said.

The Army also stated that no accidents or mishaps have been attributed to cracked gears.

The Army said it hoped to get the entire fleet back into full flight operations as soon as possible.

Boeing Settles Lawsuit Over Bad Gears

Thursday, 5 April 2001

DETROIT -- A six-year investigation recently ended when the Boeing company agreed to pay the government almost $62 million to settle a lawsuit filed after two CH-47 Chinook helicopters crashed, allegedly due to faulty transmission gears.

A Boeing supplier, SPECO, which manufactures the helicopter transmission gears, also paid the government nearly $16 million under an earlier settlement.

At least $32 million so far in monies, inventory, tooling and equipment has been awarded directly to the Army as a result of the case, officials said.

The investigation was handled in part by an arm of the Army Criminal Investigation Command, the Detroit Fraud Resident Agency. Special Agent William Janiga of the DFRA had a significant role in the joint investigation, along with Special Agent Conrad Swensen of the Defense Criminal Investigative Service in Dayton, Ohio.

The investigation began in November 1994 when information was received that transmission gears manufactured by the SPECO Corporation were responsible for at least two accidents involving CH-47 Chinook helicopters. The gears were believed to have a defect known as "continuous inter-granular carbide networking." When the gears failed, one aircraft was destroyed and another received major damage.

The investigation resulted in a civil lawsuit being filed under the False Claims Act. The trial attorneys were Dennis Phillips and Paul Wogaman, Civil Division, Department of Justice, Washington, D.C. The settlement with SPECO was reached in December 1996. In the recent settlement with Boeing, an additional $14 million is pending appeal.

Even more important than the money, officials said, is the resulting identification of a safety issue and the removal of gears manufactured by SPECO from the Army and Boeing inventories and all CH-47 aircraft.

Read an Info Sheet about the Lawsuit [PDF Format]

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