Helicopter crashes off Canada coast, 17 missing

[sindeewell]

TORONTO (Reuters) – Seventeen people are missing in the frigid waters off Canada's Atlantic coast after a helicopter crashed while ferrying workers to an offshore oil platform, a search and rescue spokeswoman said on Thursday.

The helicopter was on its way to the platform when it went down about 47 nautical miles southeast of the Newfoundland and Labrador capital of St. John's, said Jeri Grychowski of the Rescue Co-ordination Center in Halifax, Nova Scotia.

"There were 18 people on board. One has been taken out of the water," she said.

"There is a life raft in the water, but at this particular time we don't have any indication if there's anybody in it."

She said the helicopter regularly ferries people between

St. John's and the Hibernia platform.

Images on CBC TV showed a rescue helicopter landing in St. John's and a person on a stretcher being wheeled to an ambulance.

A Hercules aircraft, two Cormorant rescue helicopters, and two surface ships were actively searching the site, Grychowski said.

She said water temperatures were just above freezing, with waves of up to three meters (nine feet).

The aircraft is owned by Cougar Helicopters of St. John's, which plans to hold a press conference later on Thursday, the company said.

The Hibernia platform is owned by Petro-Canada, Exxon Mobil Corp. with 33.125 percent, Chevron Corp., Murphy Oil Corp. with 6.5 percent, StatoilHydro, and the government of Canada.

http://news.yahoo.com/s/nm/20090312/ts_nm/us_crash

[Frankie]

http://en.wikipedia.org/wiki/Cougar_Hel ... _Flight_91

[sindeewell]

Hearses bring nine bodies pulled from N.L. chopper wreckage for examination

By Tara Brautigam, The Canadian Press


ST. JOHN'S, N.L. - Under the dark of night, nine bodies pulled from the mangled wreckage of a downed helicopter were taken in hearses to a St. John's hospital for examination early Monday as investigators came closer to concluding their recovery mission.


The unidentified bodies came ashore in St. John's aboard the Atlantic Osprey offshore supply vessel dispatched to retrieve as many of the bodies as possible from 178 metres of water.


"They were located inside the fuselage," RCMP Sgt. Wayne Newell said. "We do believe that there's other bodies aboard the wreckage."


Newfoundland and Labrador's chief medical examiner, Dr. Simon Avis, was expected to begin examining the bodies later Monday.


The Osprey docked at the Canadian Coast Guard base in this port city and was greeted by several emergency vehicles. Police cordoned off the area as the bodies were unloaded from the vessel.


The ship then left a few hours later to return to the crash site to retrieve more bodies. Eventually investigators will also try using it to recover the damaged fuselage of the Sikorsky S-92, owned by Cougar Helicopters, which crashed into the North Atlantic as it ferried workers to two offshore oil platforms.


Newell identified the pilot as Matthew Davis, 34, of St. John's.


Meanwhile, friends and relatives of 26-year-old Allison Maher were preparing to mourn her death at a funeral service Monday in the small Avalon Peninsula town of Fermeuse. Her body was the first to be recovered.


In all, 18 people were aboard the chopper when it crashed last Thursday. So far, 10 bodies have been recovered.


The lone survivor - Robert Decker - remains at the Health Sciences Centre in St. John's.


Remote controlled cameras have revealed that the chopper's cockpit area was damaged, the fuselage cracked and the tail boom broken off after the crash, said lead investigator Mike Cunningham.


"Obviously (the) aircraft is busted up pretty good, which would indicate a fairly significant impact," he said Sunday.


Investigators are aiming to retrieve the wreckage by possibly using a large basket to scoop it.


Cunningham said they will draw upon their experience with recovering the remnants of Swissair Flight 111 that crashed near Peggy's Cove, N.S., in September 1998.


"If we can retrieve 95 per cent of a large airliner, which was basically in tiny little pieces, I'm pretty confident - unless there's something I don't know about - we'll be able to retrieve what's down there."


Various debris, including personal belongings, have been collected from the crash site about 65 kilometres southeast of St. John's.


The upper and lower parts of the helicopter's main entrance door, the aft cargo door and one of the emergency exit doors have also been recovered.

The chopper wreckage likely contains vital clues, including the data recorders, as to what caused it to plunge into the icy waters.

Transport Canada's aviation database had reported the pilot of the helicopter declared a mayday "due to a main gearbox oil pressure problem," though officials have not elaborated on the significance of that yet.

The gearbox is located on the top of the fuselage under the main rotor head and serves as a link between the engines and transmission.

[VectorForFood]

Not knowing much about helos, I am purely parlour talking, but on such a flight I would assume they operate at a relatively low altitude, one would think an auto-rotation would be easier from low altitude than from high altitude?

I haven't heard if they were still in radar contact yet, but there is at least an SSR radar site in St.John's and I believe a PSR as well but I'm not sure.

[Ed]

...flight I would assume they operate at a relatively low altitude, one would think an auto-rotation would be easier from low altitude than from high altitude?

I don't know why they would inherently operate at low altitude.

I am pretty sure it is the other way around from what you described for auto-rotation, although you have not defined what you mean by high and low altitude.

I used to watch the twin hueys do auto-rotations at YFC out of Gagetown. The impression I got was that they had to be high enough to get some vertical momentum, and rotate at the last second. It looked like a terrifying procedure.

I have a lot of respect for helicopters.

[Giles]

Not knowing much

no argument here.

I am purely parlour talking

concur

one would think an auto-rotation would be easier from low altitude than from high altitude

no

[Sir Gallivant]

A helicopter certainly needs a certain amount of altitude in order to stabilize during autorotation. Once autorotation has commenced, additional altitude will give the pilot more time to find a suitable landing spot. It is the timing of the flare that is very critical as you only get one chance.

Autorotation is indeed a very impressive manoeuvre, I had the opportunity to be onboard a helicopter with a pilot training all kinds of emergency procedures, and I learned a lot about the possibilities a helo-pilot has in case of losing engine power or the tail rotor.

In this case it seems the main rotor has been disabled, if the gear box seize up and the main rotor stops turning, no amount of training will save a helicopter as it loses it lift and it will drop like a stone.

[rattler]

...one would think an auto-rotation would be easier from low altitude than from high altitude?...

The opposite is true.

Rattler

[rattler]

I do not now what helo was involved, but as Cougar Helos only operate 332 SuperPumas or - according to the link provided - Sikorskis 92, both models would be twin engine.

If there was not tail rotor incident (as reported), a question to the ppl in the know: What are the chances (and the probable reasons) for both turbines failing at the same time apaprt from Murphy predicting it? I have my own ideas, but I would like to hear out the real experts...?

Rattler

[ZeroAltitude]

...one would think an auto-rotation would be easier from low altitude than from high altitude?...

The opposite is true.

Rattler

It can't be wrong to have more time (=altitude) to stabilize things and do some corrections on the controls.

[Procede]

If there was not tail rotor incident (as reported), a question to the ppl in the know: What are the chances (and the probable reasons) for both turbines failing at the same time apaprt from Murphy predicting it? I have my own ideas, but I would like to hear out the real experts...?

Both engines were probably fine, up to the moment the gearbox failed. If your gearbox fails, I would guess your engines would be damaged due to extreme loads (standing still instantly), whilst your rotor will probably break free from the gearbox. I would think you would still have collective control and thus should be able to perform an auto-rotation.

[Sir Gallivant]

Transport Canada's aviation database had reported the pilot of the helicopter declared a mayday "due to a main gearbox oil pressure problem," though officials have not elaborated on the significance of that yet.

The gearbox is located on the top of the fuselage under the main rotor head and serves as a link between the engines and transmission.

A non-turning tail-rotor is bad enough, but you really don't need it until speed decays and lose aerodynamic longtitudal stability of the helicopter. Misjudging a landing in 3m waves might wreck the aircraft when it starts to rotate around itself, but forward speed will be low at this time.

A non-turning main rotor will leave the helicopter with no lift, and that is of course a bad situation if the altitude is anything other than Zero.

[Dmmoore]

Depending on the gearbox failure, autorotation may not have been possible. If the failure was the output shaft, the rotor system may have started to seize.

[flyboy2548m]

You know, I look at just about any helicopter and I think to myself "what could possibly NOT go wrong here?"

[Dmmoore]

Definition of "Helicopter":
10,000 moving parts flying in close formation.

[VectorForFood]

Definition of "Helicopter":
10,000 moving parts flying in close formation.

Definition of a Canadian Forces SeaKing:

1,000,000 moving parts flying in formation

[Gabriel]

one would think an auto-rotation would be easier from low altitude than from high altitude?

Check the Dead Man's Curve:


Nice explanation here:
http://aerosafe.com.au/page/newsletter_ ... _2008.html

Scroll down to the article titled "The Dead Man's Curve – what is it really?"

[Sir Gallivant]

A helicopter does not achieve flight by aerodynamic lift - it beats the air into submission.

A helicopter flies because it is such an ugly craft the Earth repels it.

[3WE]

Gabriel:

Could you please explain how a helicopter deals with the fact that when it's moving forward that one blade swings forward and therefore has more airspeed, while the blade moving back has less airspeed, and how the helicopter compensates for that, and then deals with the blade being long and thin and thus flexible and how that flexibility comes into play as the blade is twisted to higher and lower AOA's fairly rapidly, and harmonics, and twisting, and then how metal fatigue affects linkages and the blade....

(Mod's you will need some more server space in about 3 days)

[Ancient Mariner]

Gabriel:

Could you please explain how a helicopter deals with the fact that when it's moving forward that one blade swings forward and therefore has more airspeed, while the blade moving back has less airspeed, and how the helicopter compensates for that, and then deals with the blade being long and thin and thus flexible and how that flexibility comes into play as the blade is twisted to higher and lower AOA's fairly rapidly, and harmonics, and twisting, and then how metal fatigue affects linkages and the blade....

(Mod's you will need some more server space in about 3 days)

I can answer that. It doesn't.
You're welcome, Gabriel.
Per

[3WE]

It ususally does, but often it doesn't.

Fixed

[flyboy2548m]

Gabriel:

Could you please explain how a helicopter deals with the fact that when it's moving forward that one blade swings forward and therefore has more airspeed, while the blade moving back has less airspeed, and how the helicopter compensates for that, and then deals with the blade being long and thin and thus flexible and how that flexibility comes into play as the blade is twisted to higher and lower AOA's fairly rapidly, and harmonics, and twisting, and then how metal fatigue affects linkages and the blade....

(Mod's you will need some more server space in about 3 days)

Oh, for the love of God, no!!!!

[OldSowBreath]

Gabriel:

Could you please explain how a helicopter deals with the fact that when it's moving forward that one blade swings forward and therefore has more airspeed, while the blade moving back has less airspeed, and how the helicopter compensates for that, and then deals with the blade being long and thin and thus flexible and how that flexibility comes into play as the blade is twisted to higher and lower AOA's fairly rapidly, and harmonics, and twisting, and then how metal fatigue affects linkages and the blade....

(Mod's you will need some more server space in about 3 days)

Oh, for the love of God, no!!!!

And what if the helicopter were on a vertical conveyor-belt?

[Peter_K]

Gabriel:

Could you please explain how a helicopter deals with the fact that when it's moving forward that one blade swings forward and therefore has more airspeed, while the blade moving back has less airspeed, and how the helicopter compensates for that,

The backward moveing blade has a higher angle of attack than the forward moveing blade.

[Ancient Mariner]

Gabriel:

Could you please explain how a helicopter deals with the fact that when it's moving forward that one blade swings forward and therefore has more airspeed, while the blade moving back has less airspeed, and how the helicopter compensates for that,

The backward moveing blade has a higher angle of attack than the forward moveing blade.

Thank you, that will suffice. Thread locked.
Sorry, Gabriel just file it.
Per