Pilot Debrief

MCDONNELL DOUGLAS DC-9-83 near Los Angeles Intl Airport, CA — 2008-12-26

Final reportDCA09FA022
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Date
2008-12-26
Location
Los Angeles Intl Airport, CA, USA
Airport
LAX
Aircraft
MCDONNELL DOUGLAS DC-9-83
Registration
N9617R
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Taxi

Probable cause

The first officer's unannounced advancement of the left engine throttle, which led to a sustained application of high thrust that caused the airplane to impact the tug.

NTSB narrative

The first officer indicated that he advanced the left engine throttle during the airplane's taxi in order to clear what he suspected was a stuck bleed air valve. Although he suspected that he had only moved the throttle "about an inch", FDR data revealed it had been advanced to and remained at an extremely high power setting for approximately 28 seconds. This action, which occurred without the knowledge of the captain or the tug operator and without application of the parking brakes, resulted in a substantial increase in thrust that overwhelmed the tug's resistance until the airplane impacted the tug.

Analysis

Primary failure mode
Human factors
First missed decision gate
Captain should have ensured throttle was not moved during pushback.

NTSB coding

Evidence available

  • CVR
  • FDR / data
  • Photos
  • 12 docket documents
View NTSB final reportView NTSB docket

Docket documents12

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