Bombardier DHC-8-401Horizon Airlines
Medford, OR, USA · 2003-01-09·N409QX
What happened
NTSB summary, verbatimThe aircraft, which was on a downwind for a night visual approach, impacted a flock of Lesser Scaups (diving ducks). The nose structure of the aircraft and the windshield directly in front of the captain received multiple bird strikes. Some of the birds penetrated the aircraft's skin, but there was no direct penetration of the windshield. Although the windshield was not penetrated, hundreds of small pieces of glass were ejected from the most inner of the windshield's three panes, and approximately 70 of these pieces imbedded themselves in the face, forehead, and scalp of the captain. The first officer ultimately completed a successful landing, while using backup flight instruments. The investigation determined that the windshield certification process defined in Part 25 of the Federal Aviation Regulations and the Canadian Aviation Regulations does not take into account the effects of multiple bird strikes on the same windshield.
Photographs
2the aircraft, and what the investigators foundPhotographs are NTSB docket attachments — works of the US government, in the public domain. Captions are the Board’s own.
Probable cause
the Board's determinationThe fracture and spalling of the inner-most pane of the aircraft's port side windshield while on a downwind for a night visual approach due to an imposed load beyond that required for windshield certification (multiple bird strikes). Factors include a dark night, and a flock of ducks (Lesser Scaups) flying in the location of the visual traffic pattern.
Sequence of events
9 timed eventsfrom the FDR factual report · claude-sonnet-5- SRN 97029 secondsDescentp.2Approximate time of the bird strike; airplane was descending through a pressure altitude of 3922 feet, with the autopilot engaged and an airspeed of 241.5 knots.
- approximately SRN 97033 seconds (about four seconds after bird strike)Descentp.2Autopilot was disengaged and the airplane continued to descend.
- SRN 97042 secondsDescentp.2Vertical acceleration values began to fluctuate, reaching 1.152 g's.
- SRN 97047 secondsDescentp.2Airplane descended to a pressure altitude of 3496 feet for two seconds before pressure altitude began to increase.
- SRN 97072 secondsClimbp.2Pressure altitude increased over the previous 25 seconds, reaching 3754 feet.
- after SRN 97072 secondsDescentp.2Pressure altitude then decreased for the remainder of the recording.
- SRN 97087 secondsDescentp.2Power lever angles for engines 1 and 2 increased to 48.2 degrees and 48.4 degrees, respectively.
- SRN 97095 seconds (eight seconds after 97087)Descentp.2Power lever angles increased again to 51.3 degrees and 51.4 degrees, respectively.
- SRN 97098 secondsDescentp.2FDR stopped recording data. During the last second of recorded data, the airplane was descending through a pressure altitude of 3400 feet, while at an airspeed of 175.5 knots.
NTSB analysis
from the final reportThe aircraft, which was on a downwind for a night visual approach, impacted a flock of Lesser Scaups (diving ducks). The nose structure of the aircraft and the windshield directly in front of the captain received multiple bird strikes. Some of the birds penetrated the aircraft's skin, but there was no direct penetration of the windshield. Although the windshield was not penetrated, hundreds of small pieces of glass were ejected from the most inner of the windshield's three panes, and approximately 70 of these pieces imbedded themselves in the face, forehead, and scalp of the captain. The first officer ultimately completed a successful landing, while using backup flight instruments. The investigation determined that the windshield certification process defined in Part 25 of the Federal Aviation Regulations and the Canadian Aviation Regulations does not take into account the effects of multiple bird strikes on the same windshield.