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Cases › IAD00IA032 · Part 121 airline

Boeing 767-332 DELTA AIRLINES

NEW YORK CITY, NY, USA · 2000-03-31·N182DN

0
fatal
0
serious
No injury
highest injury
—
damage
AnalyseThe analystOne timeline · precedents · ask the docket · what the record saysGenerateInvestigation briefFacts, cause, recorder extremes, sequence, sourcesSourceNTSB docket11 documents on data.ntsb.gov

What happened

NTSB summary, verbatim

During climb out at night over water, the airplane was straight and level and heading towards an intersection. The first officer was hand flying the airplane and the auto-pilot was not engaged. While climbing through 6,500 feet, the airplane rolled to the right and reached a maximum of 65.5 degrees. The first officer used left aileron, followed by left rudder input and returned to level flight. The crew declared an emergency, dumped 20,000 pounds of fuel and landed uneventfully at the departure airport. The captain reported there were no traffic collision avoidance system alerts or engine indication and crew alerting system warnings. The captain reported there was a thin deck of clouds at 6,500 feet, and it was a dark night with no moon. The international relief pilot stated there was no discernable horizon, and the first officer stated there was no horizon, stars, or moon, and all he saw was darkness. An examination of the airplane's systems revealed there were no mechanical or computer related discrepancies. The digital flight data recorder data revealed the rolls to the right were initiated by control wheel input.

Probable cause

the Board's determination
The first officer's failure to maintain control of the airplane during climb out over water at night, which was a result of spatial disorientation. Factors in the incident were the cloud layer and dark night.

Sequence of events

9 timed eventsfrom the FDR factual report · claude-sonnet-5
  1. 1:24:10Climbp.2
    The airplane began a 20° left wing down (LWD) roll as altitude values increased through 3,200 feet
  2. 1:24:20Climbp.2
    Flight Management System (FMS) mode changed from Heading Select to Lateral Navigation (L-NAV)
  3. 1:24:58 (approx 1:24:5g)Climbp.2
    The 20° LWD bank was maintained for the next 38 seconds until the airplane rolled wings level on a heading of approximately 90°
  4. 1:24:58 to 1:25:28Climbp.2
    Heading maintained between 90° and 100° as altitude values steadily increased from 5,100 feet to 6,300 feet
  5. 1:25:29Roll eventp.2
    Control wheel and aileron parameters indicate start of right roll control inputs; the airplane began to roll right; right control wheel input increased over next 3.5 seconds to peak value of 63.7°, roll angle reached 38.4° RWD
  6. 1:25:33Roll eventp.2
    Control wheel values switched from right to left control wheel inputs [63.7° RWD at 1:25:32.5 to 20° LWD at 1:25:33]; peak control wheel value of 34° LWD recorded at 1:25:33.5; control column and elevator parameters became active with 2° ANDinput; roll angle reached 48° RWD at 1:25:33.5
  7. 1:25:34Roll eventp.2
    Control wheel values switched to RWD and over next 3 seconds varied between 18.8° RWD and 40.7° LWD, trending toward LWD by end of period; roll values increased from 62.9° to 65.5° RWD during this period
  8. 1:25:37.3Recoveryp.2
    First indication of a left rudder application recorded; over next 6 seconds rudder values changed from steady 1.6° Rt. to 4.9° Lt. as roll angles decreased from 65.5° RWD to approximately wings level; control wheel values varied between 3.4° and 34.1° LWD; with application of ANU control inputs, pitch attitude values increased from 5° AND to 0.9° ANU and decrease in altitude values stopped
  9. remainder of flightCruise/remainder of flightp.2
    The parameters did not display any unusual or anomalous characteristics during the remainder of the flight

NTSB analysis

from the final report

During climb out at night over water, the airplane was straight and level and heading towards an intersection. The first officer was hand flying the airplane and the auto-pilot was not engaged. While climbing through 6,500 feet, the airplane rolled to the right and reached a maximum of 65.5 degrees. The first officer used left aileron, followed by left rudder input and returned to level flight. The crew declared an emergency, dumped 20,000 pounds of fuel and landed uneventfully at the departure airport. The captain reported there were no traffic collision avoidance system alerts or engine indication and crew alerting system warnings. The captain reported there was a thin deck of clouds at 6,500 feet, and it was a dark night with no moon. The international relief pilot stated there was no discernable horizon, and the first officer stated there was no horizon, stars, or moon, and all he saw was darkness. An examination of the airplane's systems revealed there were no mechanical or computer related discrepancies. The digital flight data recorder data revealed the rolls to the right were initiated by control wheel input.