12 fatalities

1977-01-14: De Havilland DHC-6 Twin Otter (C-GNTB) — Northern Thunderbird Air - NT Air — Terrace, Canada

Terrace, CanadaLanding (descent or approach)

On January 14, 1977, a De Havilland DHC-6 Twin Otter (registration C-GNTB) operated by Northern Thunderbird Air - NT Air was involved in an aviation accident near Terrace, Canada during landing or approach. 12 people were killed. Investigators recorded the probable cause as: The following findings were identified: - The ceiling and visibility were reported to be below published minima for landing when the approach was initiated. - The Flight crew carried out a non-standard abbreviated approach. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 4 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781228444Data APIEditorial standards

An aircraft crashed on final approach to Terrace Airport, killing all 12 occupants. The approach was initiated while weather was below published minima, and the crew conducted a non-standard abbreviated approach, descending below the minimum altitude.

Background

The aircraft departed Prince Rupert at 1654 PST bound for Prince George, with scheduled stops at Terrace and Smithers. The flight proceeded normally until the approach to Terrace.

Sequence of Events

At 0117, the pilot contacted Terrace Aeradio, reporting they were about 8 minutes from the range and requesting weather. Terrace Aeradio issued the latest weather, which indicated that the ceiling and visibility were below published minima for an approach and landing. Despite this, at 0118 the flight contacted Terrace Operations, advising they would be overhead in 5 minutes and on the ramp 11 minutes later.

At 0131, the flight reported by the range inbound, and a final wind check was given and acknowledged. No further transmissions were received from the aircraft. When it became evident that the aircraft had not landed, the Rescue Coordination Centre was alerted at 0146. A search was initiated, and at 0515 the wreckage was found scattered along the eastern slope of Little Herman Mountain.

The aircraft had crashed on the final approach track to the runway, 3 miles short of the threshold at latitude 54° 25' N longitude 128° 34' W. The airplane was destroyed, and all 12 occupants were killed.

Findings

The official investigation identified the following findings: the ceiling and visibility were reported to be below published minima for landing when the approach was initiated; the flight crew carried out a non-standard abbreviated approach; the flight crew descended below the published minimum altitude of 1,620 feet MSL; the captain was at the controls throughout the approach; and the approach was continued below the authorized minimum altitude for undetermined reasons.

Probable cause

The following findings were identified: - The ceiling and visibility were reported to be below published minima for landing when the approach was initiated. - The Flight crew carried out a non-standard abbreviated approach. - The Flight crew descended below the published minimum altitude of 1,620 feet MSL. - The Captain was at the controls throughout the approach. - The approach was continued below the authorized minimum altitude for undetermined reasons.