Aircraft Accident Investigation Commission Ministry of Economic Affairs and Communications Estonia FINAL REPORT AIRCRAFT ACCIDENT INVESTIGATION COPTERLINE OY SIKORSKY S-76C+ In Tallinn Bay, Estonia on 10 August 2005 6 August 2008 Intentionally blank cover page’s photo: copyright Alexander Laich Photo 1 on page 7: copyright Janne Laukkonen TABLE OF CONTENTS ABBREVIATIONS............................................................................................................................VI FOREWORD ...................................................................................................................................IX SYNOPSIS ......................................................................................................................................XI 1. FACTUAL INFORMATION....................................................................................................... 1 1.1 History of the flight ........................................................................................................... 1 1.1.1 Observations by eyewitnesses................................................................................ 1 1.2 Injuries to persons............................................................................................................ 2 1.3 Damage to aircraft ........................................................................................................... 2 1.4 Other damage.................................................................................................................. 2 1.5 Personnel information...................................................................................................... 2 1.5.1 Pilot-in-command..................................................................................................... 2 1.5.1.1 Pilot – Licences and ratings ................................................................................ 2 1.5.1.2 Pilot – Training records with Copterline .............................................................. 3 1.5.1.3 Pilot – Flight and duty time.................................................................................. 3 1.5.2 Co-pilot .................................................................................................................... 4 1.5.2.1 Co-pilot – Licences and ratings........................................................................... 4 1.5.2.2 Co-pilot – Training records with Copterline......................................................... 5 1.5.2.3 Co-pilot – Flight and duty time ............................................................................ 5 1.6 Aircraft information........................................................................................................... 6 1.6.1 General information................................................................................................. 6 1.6.2 S-76 helicopter description...................................................................................... 6 1.6.3 Minimum Equipment List (MEL) .............................................................................. 8 1.6.4 Mass and balance ................................................................................................... 8 1.6.5 Maintenance of the helicopter ................................................................................. 8 1.6.5.1 General................................................................................................................ 8 1.6.5.2 S-76 maintenance program................................................................................. 8 1.6.5.3 Checks and maintenance performed.................................................................. 9 1.6.5.4 Helicopter log books.......................................................................................... 10 1.6.5.5 Airworthiness Directives and Alert Service Bulletins ........................................ 11 1.6.5.6 Reliability and trend monitoring......................................................................... 11 1.6.5.7 Major repairs and alterations............................................................................. 11 1.6.5.8 S-76 hydraulic system maintenance................................................................. 11 1.6.6 Description of the main rotor flight control system................................................ 12 1.6.6.1 General.............................................................................................................. 12 1.6.6.2 Description of the main rotor hydraulic actuators ............................................. 13 1.6.6.3 Operation and maintenance of the main rotor actuators .................................. 14 1.6.6.4 Examination of the main rotor actuators ........................................................... 16 1.6.6.4.1 Forward actuator......................................................................................... 16 1.6.6.4.2 Aft actuator.................................................................................................. 17 1.6.6.4.3 Lateral actuator ........................................................................................... 18 1.6.7 Examination of the tail rotor actuator .................................................................... 18 1.6.8 Examination of the engines................................................................................... 18 1.7 Meteorological information............................................................................................. 19 1.7.1 General weather.................................................................................................... 19 I 1.7.2 Weather reports..................................................................................................... 19 1.7.3 Conditions at sea................................................................................................... 19 1.7.4 Weather necessary for creation of a waterspout .................................................. 20 1.8 Aids to navigation .......................................................................................................... 20 1.9 Communications............................................................................................................ 20 1.9.1 Radio communications.......................................................................................... 20 1.9.2 Radio panel settings.............................................................................................. 21 1.10 Heliport information........................................................................................................ 21 1.10.1 Linnahalli ............................................................................................................... 21 1.10.2 Radar data............................................................................................................. 21 1.11 Flight recorders.............................................................................................................. 21 1.11.1 Description of the flight recorder ........................................................................... 21 1.11.2 CVR and FDR synchronization ............................................................................. 22 1.11.3 The flight data recorder ......................................................................................... 23 1.11.4 The audio recorder ................................................................................................ 23 1.12 Wreckage and impact information................................................................................. 24 1.12.1 Initial examination of the helicopter wreckage under water.................................. 24 1.12.2 Recovery of the helicopter wreckage from the sea............................................... 24 1.12.3 Detailed examination of the helicopter.................................................................. 25 1.12.3.1 Main rotor blades .......................................................................................... 25 1.12.3.2 Main rotor head............................................................................................. 26 1.12.3.3 Tail rotor system............................................................................................ 27 1.12.3.4 Fuselage........................................................................................................ 27 1.12.3.5 Cockpit and flight controls............................................................................. 28 1.12.3.6 Landing gear ................................................................................................. 30 1.12.3.7 Emergency Locator Transmitter ................................................................... 30 1.13 Medical and pathological information............................................................................ 30 1.14 Fire................................................................................................................................. 30 1.15 Survival aspects............................................................................................................. 30 1.15.1 Passenger safety briefings.................................................................................... 30 1.15.2 Helicopter emergency equipment and flotation devices ....................................... 31 1.15.3 Search and rescue operation...............................................................................