Aesir,

The S-76 has a rotor brake which allows the pilot to start the engines and then engage the rotor. If there is significant tail wind, the brake should not be used, as engine exhaust can be turned upward by that wind and impinge on the blades, perhaps causing local hot spots that could bubble. The operating instructions explain all this.

If that had happened, replacing the blades (which would show obvious overheat damage on the lower surface) would eliminate this as pertinent information relative to the accident.

any news ... ?
 

This accident already seem to be forgotten on the news. I for one have not.

Anyone know when the preliminary accidentreport will be official ? Anyone heard or read anything new ?

Regards

RS

Source: Helsingin Sanomat
Link: http://www.helsinginsanomat.fi/engli.../1101980643479


--------------------------------------------------------------------------------

Post mortem results indicate helicopter crash victims died from drowning

http://www.helsinginsanomat.fi/kuvat...980606025.jpeg
A CCTV image of the Sikorsky S-76C+ helicopter in Tallinn, shortly before it took off on its fatal flight.

The cause of death of the victims in last Wednesday's Copterlines helicopter crash was drowning, according to the Estonian State Prosecutor's Office. Post mortem examinations had been carried out on most of the victims by Tuesday afternoon.
Twelve passengers and two crew members died when the helicopter plunged into the sea on Wednesday afternoon, a few minutes after take-off on a scheduled flight from Tallinn to Helsinki. The body of one of the two Finnish pilots is still missing, but all thirteen of the other victims apparently died in their seats.

Final results of the forensic examinations will be published in September. An Estonian police official stated that the bodies had been in remarkably good condition considering the nature of the accident, and the Finnish forensic odontologist Helena Ranta, who was among those sent over to help in the identification process, said that there had been no problems in identifying the deceased.
The cause of the crash remains a mystery, and a commission of inquiry has been set up to examine the incident. The onboard flight recorder is to be sent for analysis in Great Britain.

According to investigation commission member Tonu Ader, Tallinn radar recording shows that shortly after take off the helicopter deviated 20- 30 degrees from course and changed course several times. After that it turned back towards south then to west. Shortly after that it turned to north. While this happened its speed decreased fast and it lost altitude rapidly from 1000 ft. All this took about 30 seconds.

The preliminary report is expected at 10th of September.

From Svenska dagbladet

Apparantly the pilots tried to transmit several emergency calls before ditching. The reason for the mayday calls not beiing received anywhere is under investigation in connection with the analysis of the CVR.

The engines were running at the time of crash and the weather is not considered to be factor, also a birdstrike is ruled out.

One pilot is still missing.

All flights were cancelled monday due to spare parts awaiting delivery from the manufacturer for the remaining S76.

http://www.svd.se/images/ettan2005/0...ikopter339.jpg

Amplification of Aesir's earlier post.

Crew of ill-fated helicopter tried to send emergency message

Pilots understood something was wrong 35 seconds before crash

The pilots of the Copterline passenger helicopter, which crashed into the Gulf of Finland soon after takeoff while en route from the Estonian capital Tallinn to Helsinki tried to send an emergency message shortly before the crash.

On Monday, a week and a half after the crash, in which all 14 people on board were killed, the Estonian Ministry of the Economy and Transport announced its findings after the helicopter's flight recorder was returned from Britain to Estonia.
"The crew knew that something was wring 35 seconds before the helicopter splashed into the water", said Taivo Kivistik in Tallinn on Monday at a press conference reporting on the findings from the flight recorder.

Kivistik said that there was not much of a conversation going on in the helicopter. The voice recorder revealed that one of the pilots repeated the word "mayday" three times.

However, the call was not heard at air traffic control. "I cannot say if there was a technical fault, or if the pilots failed to push the right button", Kivistik said.
He added that the successful sending of an emergency message would not have speeded up the rescue operation, which was launched immediately.

The voice recordings in the flight recorder of the US-made Sikorsky S-76+ model helicopter did not reveal any obvious causes for the crash.
"Nothing in the examination of the wreckage or the black box indicates that there would have been a collision with a bird or a flock of birds", Kivistik says.

An act of terror is considered unlikely, but not completely impossible. So far, nothing in the evidence suggests any such event.
The flight recorder reveals that the engines functioned until they came into contact with water. The engines have been sent to France, the country where they were manufactured, for additional investigations.

One of many possible causes under investigation is a fault in the gear transmission between the engine and the rotor. The transmission mechanism is also under investigation. The possibility that a fault in the rear rotor would have caused the crash is also under investigation.

The wreckage of the helicopter has been taken to Tallinn Airport, and is being examined by investigators of Estonia's criminal police. The commission of inquiry has promised its initial report on the 10th of September. A final report could take a year.

Copterline had to cancel all of its flights between Helsinki and Tallinn on Monday because of a delay in the delivery of a spare part from the United States.

Copterline still has one helicopter operating on the Helsinki-Tallinn route. The spare part was expected to arrive on Tuesday morning.

initial report
 

Hello rotorheads!

Any news on the initial report of the accident that was scheduled for the 10th of september ?

If anyone has read it, please post a summary here.

Best regards

RotorSwede

I can’t find anything in English but Helsingin Sanomat has fresh news in finnish so here’s simple translation. I'm sure more presice news in english will follow tomorrow.

The chopper had just reached it’s cruising altitude at 130 kt when its nose suddenly raised up and it turned first left then right and started to spin (13 times before it hit water). When the spinning started captain asked for more power witch was followed by noise level increase and a mayday call (3 maydays). During the spinning co-pilot asked “did we lose our tail”. Everything happened in 37 seconds.

Speed was too fast so floats did not inflate properly. With the floats it is possible that the chopper might not have sunk but turned upside down.

The preliminary rapport rules out metal fatigue, braking in the air, problems with main transmission etc. According to Suomen tietotoimisto, preliminary rapport rules out pilot error and pilots were not able to prevent the accident. Control systems and some other systems are still under investigation.

The reason why this rapport is not public is because lawyer for one of the Estonian victim(s family) asked that it would not be published. New decision will be made in a few days.

Also the missing captain was found by some voluntary divers some time ago.

Final rapport is expected next august.

regards,

xano

This was on the "S92s grounded" thread!

Anyone have any more info about that?

autorotation with TR problem
 

From what I've heard, if the S-76 would lose tailrotor controll the fin would not be able to prevent the ship from starting to spin. Not even at maximum speed. Correct me if I'm wrong.

My question is, if you lose your tailrotor, start to spin uncontrollably and then shut off both your engines and enter autorotation, would you be able to regain controll off the machine ? Let's say from 1000 feet AGL and you loose the tail in about 130 kt speed? Maybe someone has done this in a sim?

Best regards

RotorSwede

Aesir:

Check the UK AAIB site for details of the formal report into the loss of G-BJVX.

RotorSwede,

In a past life, I flew simulators of the same helicopter type but built by different manufactures. The failed tail rotor situation was controllable in one simulator but almost un-controllable in the other!!

In one you could fly, with a lot of lateral cyclic, to a suitable area to carry out an EOL but in the other simulator, if you did not enter auto, and shut off the engines, immediately, you spun!

Simulation depends partly on software engineers.

FLI

Preliminary report is expected to be published on Wednesday 14.9 according to Estonian finance and transportation ministry.

Accident of helicopter Sikorsky S76 C+: Preliminary report

http://www.mkm.ee/index.php?id=2787

Aser

A link to an English language version of the report here.

Could someone briefly describes what this report says ? From where I'm it's difficult to download. I'm very interested since I use to fly this type of bird....by the way I have heard another one went down recently, with a successfull ditching in GOM...is it true ? have you got more infos about it ?
Thanks.

cpt:

In essence, no real cause found at the moment.

The tail rotor appears to have been intact at the time the aircraft hit the water, the blade roots are still attached, and the other blade portions have been recovered.

All in all, it took something like 37 seconds from the initial problem to hitting the water.

cpt:

************************************************************ ********************
** Report created 9/16/2005 Record 1 **
************************************************************ ********************

IDENTIFICATION
Regis#: 90421 Make/Model: S76 Description: S-76, H-76, AUH-76, Spirit, Eagle (HE-24
Date: 09/06/2005 Time: 2105

Event Type: Accident Highest Injury: None Mid Air: N Missing: N
Damage: Destroyed

LOCATION
City: SABINE State: TX Country: US

DESCRIPTION
N90421, A SIKORSKY S-76 ROTORCRAFT STRUCK THE WATER, CAUGHT FIRE AND SANK,
THE TWELVE PERSONS ON BOARD WERE RECOVERED AND SUSTAINED UNKNOWN INJURIES,
GULF OF MEXICO 23 MILES SOUTH OF SABINE, TX

INJURY DATA Total Fatal: 0
# Crew: 2 Fat: 0 Ser: 0 Min: 0 Unk: Y
# Pass: 10 Fat: 0 Ser: 0 Min: 0 Unk: Y
# Grnd: Fat: 0 Ser: 0 Min: 0 Unk:

WEATHER: METAR KGLS 2152UTC 08015KT 10SM CLR 31/20 A3005

OTHER DATA

Departed: Dep Date: Dep. Time:
Destination: SABINE PASS, TX Flt Plan: Wx Briefing:
Last Radio Cont:
Last Clearance:

FAA FSDO: HOUSTON, TX (SW09) Entry date: 09/08/2005

HOUSTON, Sep 07, 2005 (BUSINESS WIRE) --
Rowan Companies, Inc. (NYSE:RDC) reported today that a Sikorsky S-76 helicopter carrying 10 passengers and two crew members crashed in the Gulf of Mexico yesterday afternoon. All 12 persons aboard, including eight Rowan employees, were rescued last night by the U. S. Coast Guard and transported to nearby hospitals. Six Rowan employees have been treated for minor injuries and released. The other two employees remain hospitalized for treatment and observation. Neither appears to have suffered any life-threatening injuries.

The helicopter had departed Rowan's jack-up rig, the Bob Keller, located in High Island Block 346 at approximately 3:45 PM (CT), en route to the Company's Sabine Pass, Texas facility. At just after 4:00 PM, a distress signal was received by the Federal Aviation Administration. The helicopter was found approximately 23 miles south of Sabine Pass.

Rowan Companies, Inc. is a major provider of international and domestic offshore contract drilling services. The Company also operates a mini-steel mill, a manufacturing facility that produces heavy equipment for the mining and transportation industries, and a drilling products division that has designed or built about one-third of all mobile offshore jack-up drilling rigs, including all 24 operated by the Company. The Company's stock is traded on the New York Stock Exchange and the Pacific Exchange - Stock & Options. Common Stock trading symbol: RDC.

SOURCE: Rowan Companies, Inc.

Rowan Companies, Inc., Houston William C. Provine, 713-960-7575 www.rowancompanies.com

Thank you NR Fairy an Mars....
A bit concerning actualy ! I just hope the actual cause will be found soon now....at least the "baltic case"

The first indication of anything going wrong is the collective going to full up, followed by a lot of aft cyclic movement. Considering that control movements can usually fit in a matchbox the amount of control travel of both the collective and cyclic could be considered extreme.

Full collective up pulls the engines through blowaway power after the NR droops from 107 to 101, then the NR continues to droop down to about 70% NR. Starting at 130 knots, this would quickly lead to retreating blade stall, accounting for the roll to the left.

Low RPM, the tailrotor is ineffective, airspeed is low and the aircraft yaws to the right since the engines are still trying to get the rotor back to 107 and the torque would be significant.

Thirteen turns to the water at 2.5 seconds per turn, or about 150 degrees per second, similar to a flat spin in an airplane. They kept it upright and pulled the throttles off, not sure why it would have kept rotating and they were unable to regain airspeed.

So why did the collective get pulled all the way up and was left there until the rotor drooped so far? Hydraulics? Servos? Autopilot? Evasive action by the pilots?