ANC25LA027

NTSB accident investigation · Pilatus PC-12/45 · Sleetmute, AK · March 8, 2025

Accident · No injuriesClass 3 · LimitedPreliminary report
Date
March 7, 2025, 17:40 local (Mar 8, 2025, 02:40 UTC)
Place
Sleetmute, AK
Injuries
10 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N304PTPilatus PC-12/45
Defining event
Enroute: Part(s) separation from AC
Weather
Instrument (IMC) · Day
Status
Investigation ongoing
Investigation class
Class 3
NTSB office
Alaska Regional Office
Parties
FAA
FAA report
20250307001849A
Case key
199893

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Preliminary report

What NTSB knew early in the investigation. It may change in the final report.

On March 7, 2025, about 1740 Alaska standard time, a Pilatus PC-12 airplane, N304PT, sustained substantial damage when it was involved in an accident near Sleetmute, Alaska. The pilot and nine passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 135 on demand charter flight. The airplane had departed the Scammon Bay Airport (PACM) at 1635 with nine passengers onboard on an instrument flight rules (IFR) flight plan, en route to the Ted Stevens International Airport (PANC), Anchorage, Alaska. After departure the airplane climbed to 27,000 ft and about 1 hour and 23 minutes into the flight the pilot observed and heard the left side of the windscreen crack. The pilot immediately reduced power and began a gradual descent. About a minute later, as the airplane passed through 24,000 ft, the left side windscreen blew completely out of the airplane. See Figure 1 Figure 1. N304PT depicting missing left side windscreen (Photo provided by operator) The pilot diverted to the Sleetmute Airport (PASL) and landed without incident. An examination of the window frame is pending.

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.

Aircraft

Registration
N304PT
Reported as
Pilatus PC-12/45
Category
Airplane
Serial number
304
Built
2000
Damage
Substantial damage
Flight
Business · Part 135
Operator
Trygg Holdings, LLC, doing business as Trygg Air
Registered owner
Trygg Holdings, LLC
Departed
PACM · Scammon Bay Airport, AK
Destination
PANC · Anchorage, AK
Flight plan
IFR
Airport
SLQ · Sleetmute

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Weather

Conditions
Instrument (IMC) · Day
Visibility
10 statute miles
Lowest ceiling
6,000 ft overcast
Temperature
34 °F, dew point 25 °F
Altimeter
29.56 inHg
Observed at
PANI, 68 nm away
METAR
PANI 080156Z AUTO VRB05KT 10SM OVC060 01/M04 A2956 RMK AO2 SLP013 T00061039 FZRANO $

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.