Chronology of events: offshore helicopter Cougar Flight 491

This draft chronology of events has been compiled from informationprovided by the Transportation Safety Board of Canada.

Times arein Universal Time Co-ordinated , or UTC, (roughly equivalent to Greenwich Mean Time).

11:48:07 Cougar Flight CHI91 departs St. John's.

12:05:52 CHI91 advises Gander Area Control Centre (ACC) that they have levelledoff at 9,000 feet and that their estimated time of arrival at the Hibernia platform is 13:10. Speed is 110 knots.

12:15:05 Rapid loss of main gearbox oil pressure occurs. No abnormal indications of any kind recorded on flightdata recorder prior to this event.

12:15:19 CHI91 begins a right turn.

12:15:24 Main gearbox oil pressure decreases to approximatelyfive psi.

12:15:27 CHI91 issues mayday call to Gander ACC and begins descent from 9,000 feet. They are 53 nautical miles from St. John's.

12:15:32 CHI91 advises Gander ACC that they have main gearbox oil pressure problems and requests immediate clearance to return to St. John's.

12:15:43 CHI91 heads back to the coast. Their heading is 290 degrees and their speed is 120 knots.

12:17:04 Main gearbox oil pressure reaches 0 psi.

12:17:25 CHI91 advises Gander ACC that they are heading for nearest land. Their heading is 292 degrees and their speed is 122 knots.

12:17:42 CHI advises Gander ACC that they have lost all main gearbox oil pressure. CHI91 is descending through an altitude of 5,740 feet.

12:18:25 Gander ACC advises CHI91 that they are 42 miles from Cape Spear.

12:19:10 Gander ACC advises CHI91 that search and rescue has been notified.

12:19:18 CHI91 advises Gander ACC that Cougar dispatch has been advised and that another helicopter is being readied.

12:22:20 CHI91 levels off at approximately 800 feet. Their heading is 292 degrees and their speed is 133 knots.

12:24:44 A power interruption to the Flight Data Recorder/Cockpit Voice Recorder occurs.

12:25:36 CHI91 advises Gander ACC that they are preparing to ditch.

12:25:52 St. John's radar records CHI91 at 800 feet. CHI91 subsequently descends to 300 feet in approximately 29 secondswhich equates to an approximate rate of descent of 1,000 feet per minute.

12:26:26 St. John's radar records the last radar return of CHI91 at 300 feet.

12:26Gander ACC advises search and rescue that CHI91 has ditched. Cougar dispatch confirms the ditching with search and rescue, and advises that they will launch Cougar 61 as a rescue helicopter.

12:42 A Provincial Airlines patrol aircraft arrives atcrash site and observes two people in orangeimmersion suits in the water.

13:07 Cougar rescue helicopter departs St. John's.

13:25 Cougar rescue helicopter arrives atcrash site and spots two people (one of whom is later confirmed dead), two rafts and helicopterdebris.

13:33Cougar rescue helicopter lowers a rescue person toward the people in the water.