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Last updated: 6 December 2021
Status:Definitief
Datum:donderdag 25 juni 2015
Tijd:12:16
Type:Silhouette image of generic DH3T model; specific model in this crash may look slightly different
de Havilland Canada DHC-3T Vazar Turbine Otter
Luchtvaartmaatschappij:Promech Air
Registratie: N270PA
Constructienummer: 270
Bouwjaar: 1958
Motoren: 1 Pratt & Whitney Canada PT6A-135A
Bemanning:slachtoffers: 1 / inzittenden: 1
Passagiers:slachtoffers: 8 / inzittenden: 8
Totaal:slachtoffers: 9 / inzittenden: 9
Schade: Vernield
Gevolgen: Written off (damaged beyond repair)
Plaats:nabij Ella Lake, Misty Fjords National Monument, AK (   Verenigde Staten)
Fase: Kruisvlucht (ENR)
Soort vlucht:Binnenlandse charter
Vliegveld van vertrek:Rudyerd Bay, AK, Verenigde Staten
Vliegveld van aankomst:Ketchikan Harbor Seaplane Base, AK (WFB), Verenigde Staten
Beschrijving:
The float equipped DHC-3T Turbine Otter aircraft, operated by Promech Air, was destroyed when it impacted steep, mountainous tree-covered terrain about 25 miles northeast of Ketchikan above Ella Lake in the Misty Fjords area of Alaska. The pilot and eight passengers were killed.
The accident airplane was the third of four Promech-operated float-equipped airplanes that departed at approximate 5-minute intervals from a floating dock in Rudyerd Bay. The accident flight and the two Promech flights that departed before it were carrying cruise-ship passengers who had a 12:30 "all aboard" time for their cruise ship that was scheduled to depart at 13:00. The sightseeing tour flight, which the cruise ship passengers had purchased from the cruise line as a shore excursion, overflew remote inland fjords; coastal waterways; and mountainous, tree-covered terrain in the Misty Fjords National Monument Wilderness.
Promech pilots could choose between two standard tour routes between Rudyerd Bay and Ketchikan, referred to as the "short route" (which is about 52 nautical miles, takes about 25 minutes to complete, and is primarily over land) and the "long route" (which is about 63 nm, takes about 30 minutes to complete, and is primarily over seawater channels). Although the long route was less scenic, it was generally preferred in poor weather conditions because it was primarily over water, which enabled the pilots to fly at lower altitudes beneath cloud layers. Route choice was at each pilot's discretion based on the pilot's assessment of the weather. The accident pilot and two other Promech pilots (one of whom was repositioning an empty airplane) chose the short route for the return leg, while the pilot of the second Promech flight to depart chose the long route.
The accident flight encountered deteriorating weather conditions with terrain becoming obscured by overcast clouds with visibility restricted in rain and mist.
Although the accident pilot had climbed the airplane to an altitude that would have provided safe terrain clearance had he followed the typical short route (which required the flight to pass two nearly identical mountains before turning west), the pilot instead deviated from that route and turned the airplane west early (after it passed only the first of the two mountains). The pilot's route deviation placed the airplane on a collision course with a 1,900-ft mountain, which it struck at an elevation of about 1,600 ft mean sea level. In the final 2 seconds of the flight, the airplane pitched up rapidly before colliding with terrain. The timing of this aggressive pitch-up maneuver strongly supports the scenario that the pilot continued the flight into near-zero visibility conditions, and, as soon as he realized that the flight was on a collision course with the terrain, he pulled aggressively on the elevator flight controls in an ineffective attempt to avoid the terrain.

Probable Cause:

The National Transportation Safety Board determines that the probable cause of this accident was
(1) the pilot’s decision to continue visual flight into an area of instrument meteorological conditions, which resulted in his geographic disorientation and controlled flight into terrain; and
(2) Promech’s company culture, which tacitly endorsed flying in hazardous weather and failed to manage the risks associated with the competitive pressures affecting Ketchikan-area air tour operators; its lack of a formal safety program; and its inadequate operational control of flight releases.

Accident investigation:
cover
Investigating agency: NTSB
Status: Investigation completed
Duration: 1 year and 10 months
Accident number: NTSB/AAR-17/02
Download report: Final report

Bronnen:
» NTSB
» FAA
» ADN.com


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Foto's

photo of DHC-3T-Vazar-Turbine-Otter-N270PA
accident date: 25-06-2015
type: de Havilland Canada DHC-3T Vazar Turbine Otter
registration: N270PA
photo of DHC-3T-Vazar-Turbine-Otter-N270PA
accident date: 25-06-2015
type: de Havilland Canada DHC-3T Vazar Turbine Otter
registration: N270PA
photo of DHC-3T-Vazar-Turbine-Otter-N270PA
photo of DHC-3T-Vazar-Turbine-Otter-N270PA
photo of DHC-3T-Vazar-Turbine-Otter-N270PA
photo of DHC-3T-Vazar-Turbine-Otter-N270PA
photo of DHC-3T-Vazar-Turbine-Otter-N270PA
accident date: 25-06-2015
type: de Havilland Canada DHC-3T Vazar Turbine Otter
registration: N270PA
 

Kaart
Deze kaart geeft het vliegveld van vetrek weer en de geplande bestemming van de vlucht. De lijn tussen de vliegvelden geeft niet de exacte vliegroute weer.
De afstand tussen Rudyerd Bay, AK en Ketchikan Harbor Seaplane Base, AK bedraagt 66 km (41 miles).
Accident location: Approximate; accuracy within a few kilometers.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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