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Ferry chopper ditches in Atlantic with 18 on board

Gee Dany, did you forget about "ABC" already?

Karma's a bitch.......
 
FAA orders flight manual change after crash off Newfoundland
Last Updated: Wednesday, June 17, 2009 | 7:04 AM NT The Canadian Press

The U.S. Federal Aviation Administration has issued a directive to change the rotorcraft flight manual for the Sikorsky 92-A chopper, the same model involved in a deadly crash off Newfoundland earlier this year.

The American regulator says the change to the manual is required because some normal and emergency procedures involving the main gearbox may be unclear following the March 12 crash that killed 17 people.

The regulator says changes to the manual procedures are intended to clarify those procedures to give crew members the best available information in the event of any main gearbox failure.

Shortly after the crash, the regulator issued an emergency directive stating that the titanium mounting studs on the main gearbox filter assembly must be replaced with steel ones before the Sikorsky 92-As could fly again.

A month ago, those choppers resumed carrying workers to Newfoundland's offshore oil platforms.

The Transportation Safety Board is investigating the crash

LINK: http://www.cbc.ca/canada/newfoundland-labrador/story/2009/06/17/faa-cp-sikorsky-cougar-617.html
 
TSB releases update on Cougar crash 
The Telegram



The Transportation Safety Board says the floats on Cougar Helicopters’ Flight 491 did not deploy when the aircraft crashed into the Atlantic Ocean March 12.
“The Sikorsky S-92A flotation system activation switch was found in the armed position after recovery, said a TSB release issued Thursday morning.
“The helicopter experienced significant forces during the impact with the water, and examination of the inflation bottles indicates that they had not released their compressed gas to inflate the flotation collars.”
The TSB investigation into factor contributing to the crash continues.
The Sikorsky S-92A helicopter crashed into the ocean off Newfoundland killing 17 of the 18 people on board as they headed to offshore oil platforms on the Grand Banks.
The board also says the helicopter’s tail rotor drive gears had also stopped working prior to the crash.
“The examination of the MGB (main gearbox) also revealed that the tail rotor drive gears had been severely damaged, resulting in a loss of drive, causing it to stop producing thrust,” said the TSB release.
“Further examination is being carried out by the TSB engineering laboratory to determine the cause and sequence of this loss of tail rotor drive.”


Update: Faulty tail rotor, inflation system in deadly chopper crash, probe finds 
BY TARA BRAUTIGAM
The Canadian Press


A helicopter that crashed off Newfoundland’s east coast earlier this year, killing 17 people, lost control because of a faulty tail rotor and its inflation collar system did not work when it slammed into the Atlantic Ocean, federal investigators said Thursday.
The federal Transportation Safety Board released an update into its probe in the deadly March 12 crash and found that while the main rotor blades continued to rotate when the chopper crashed, the tail rotor drive gears were severely damaged.
The pilots of the Sikorsky S-92A, which was ferrying workers to offshore oil platforms, lost steering control in the flight’s final moments because of the tail rotor failure, lead Transportation Safety Board investigator Mike Cunningham said in an interview.
“Without that tail rotor drive, your directional control ability is much more difficult,” Cunningham said.
“In other words, the nose is going up, then the nose is going down and it’s rolling to the left and it’s rolling to the right.”
In addition to steering control, the tail rotor plays a supplementary role in keeping the helicopter in the air, Cunningham said.
Investigators also found that when Cougar Flight 491 crashed, its inflation collar system did not work as it was supposed to.
“The helicopter experienced significant forces during the impact with the water, and examination of the inflation bottles indicates that they had not released their compressed gas to inflate the flotation collars,” the agency said in its update.
“The reason the collars failed to inflate is still under investigation.”
The flotation collars are intended to keep the helicopter afloat in the event of a landing on water.
Investigators also found that the titanium oil filter attachment studs “revealed fatigue cracking in the studs as well as evidence of thread damage.”
The Transportation Safety Board said investigators were still trying to determine the origin of the fatigue cracks in the studs. It has previously said that the titanium mounting studs that attach an oil filter bowl assembly to the main gearbox broke during the flight.
The studs have since been replaced with steel under a directive issued by the U.S. Federal Aviation Administration.
The helicopter, piloted by two crew members, crashed about 65 kilometres southeast of St. John’s as it was carrying workers to two offshore oil platforms.
One man, Robert Decker, survived the crash.
 
Tail rotor failure
Transportation Cougar pilot attempting controlled landing when tail rotor lost power
MOIRA BAIRD
The Canadian Press



Cougar Helicopters Flight 491 lost power in its tail rotor drive - but not its main rotor - about a minute before it crashed into the ocean off Newfoundland on March 12 killing 17 of the 18 people on board.

The Transportation Safety Board (TSB) says the pilots were making a controlled descent to land in the water. The helicopter was about 500 feet above sea level when its tail rotor failed. Three seconds later, the pilot switched off the engines to attempt an "engines-off landing," a procedure also known as an autorotative landing.

"What it's showing us is that there was control remaining and the guys were doing their best to get the helicopter down on the surface," said Mike Cunningham, TSB investigator-in-charge, in an interview Thursday.

On Wednesday, the TSB updated the families of the crash victims on the progress of its investigation.

Without a working tail rotor, Cunningham says controlling the direction of a helicopter is difficult. The tail rotor also helps the helicopter stay in the air.

"It is one of the more serious emergencies that a helicopter pilot can experience.

"It will rock around and the nose will go up and down, and the pilot is, at that point, just attempting to get the thing down on the ground or the surface of the water, as in this case, as quick as he can."

The flight data recorder stopped working after 800 feet, but investigators were able to piece together information from the aircraft's onboard computer.

They determined the helicopter struck the water at a "moderate" speed.

"Initially, there were some reports that the aircraft had struck the water at a high speed," said Cunningham. "Now, with this data that we have available to us, we know that the forward speed had been slowed down."

He couldn't pinpoint the exact speed, though, saying TSB engineers are continuing their analysis of the data.

The pilot may have also flared the helicopter - a manoeuvre used to slow the rate of descent without the use of power. The pitch of the helicopter is adjusted nose high, which increases rotor revolutions per minute and decreases forward airspeed.

Despite this, the helicopter hit the water with a significant impact - nose upward and banking slightly to the right.

All three of its flotation devices failed as the helicopter hit the three-metre seas.

"The damage that was done to this aircraft during the impact was so significant that ... it might be unreasonable to expect that this (flotation) system could have even operated," said Cunningham. "And would it have made any difference, if it did, is pretty hard to say."

The TSB says the cylinders didn't release compressed gas to inflate the collars that are supposed to keep the helicopter afloat.

"One of the flotation bags was ripped right out of the housing," said Cunningham.

The failure of the flotation collars is in still under investigation.

The TSB also says a metallurgical examination of the titanium mounting studs revealed fatigue cracking and thread damage.

The board is still trying to determine the origin of the fatigue cracks.

During its examination of the helicopter wreckage in March, the board discovered two of the three mounting studs that attach the oil filter assembly to the main gearbox had broken in flight.

A U.S. Federal Aviation Authority directive then ordered the titanium mounting studs be replaced with steel studs. It said "the broken studs resulted in rapid loss of oil."

Without oil in the main gearbox, which powers both the main rotor and the tail rotor, there is no lubrication of rotor gear teeth.

That directive grounded the worldwide fleet of Sikorsky S-92As, including Cougar Helicopter aircraft, until the studs were replaced.

Sheldon Peddle, the president of a union that represents 700 workers on the Hibernia and Terra Nova oil platforms, remains wary of the steel studs.

"I'm not totally convinced that these steel studs are going to be any better in the long run," he said.

mbaird@thetelegram.com
 
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