BOMBARDIER CL600 — Charleston, WV, USA, 2010-01-19

NTSB summary

Cockpit voice recorder (CVR) information revealed that the flight crew began a personal conversation (that is, a conversation not pertinent to the operation of the airplane) during departure delay. The flight crewmembers continued the nonpertinent conversation throughout the entire taxi, which was not in accordance with company procedures and Federal regulations regarding sterile cockpit. CVR information also revealed that, although the flight crew completed all of the required checklist items during the taxi, each item was read and responded to in a very quick and routine manner. About 1609, the captain called for flaps 20 and then for the Taxi checklist. Flight data recorder (FDR) data indicated that, 1 second later, the flaps moved from the flaps 0 to the flaps 8 position. Further, while conducting the checklist, the first officer stated, “flaps 8” and “eight degrees,” indicating that he had selected the flap handle to the flaps 8 position, not to the flaps 20 position as called for by the captain. However, the captain responded, “set” and “eight,” respectively, indicating that he did not notice the incorrect flap setting. The rapid and perfunctory manner in which the flight crew conducted the Taxi checklist resulted in the captain not visually comparing the airplane’s flap position with the aircraft communications addressing and reporting system data, which was his normal practice. After rapidly completing the Taxi checklist, the flight crew continued the nonpertinent conversation until the captain called for the Before Takeoff checklist. After the flight crew rapidly conducted this checklist, without including a proper takeoff briefing, the flight was cleared for takeoff. The takeoff was normal until the airplane reached an airspeed of about 120 knots. At this time, FDR data showed the flaps beginning to move from the flaps 8 to the flaps 20 position. Shortly thereafter, the first officer stated, “V one [the takeoff decision speed],” which was 127 knots. The CVR then recorded the sound of the airplane master caution and flaps and spoilers configuration aural alerts. The captain initiated a rejected takeoff (RTO) about 5 seconds after he started moving the flaps and when the airplane was at an airspeed of about 140 knots, which was 13 knots above V1. Bombardier computed the total distance required for the incident airplane to accelerate stop using data from the FAA-approved Airplane Flight Manual and the planned takeoff performance data (including configuration, weight, altitude, and reduced thrust takeoff). The calculations indicated that the airplane would have stopped about 5,730 feet from the beginning of the takeoff roll if the deceleration had been initiated at the planned V1 (127 knots). Given that the runway was 6,300 feet long and that FDR data indicated a normal deceleration during the RTO, sufficient runway distance would have existed for the airplane to stop on the runway surface if the captain had initiated the RTO immediately after he identified the misconfigured flap setting instead of reconfiguring the flaps. The captain should have called for an RTO as soon as he recognized the flaps were in the wrong position. As a result of the captain’s decision to attempt to reconfigure the flaps and delay the RTO, the airplane overran the runway end and entered the engineered materials arresting system (EMAS) at an airspeed of about 50 knots. The airplane stopped 128 feet into the EMAS arrestor bed with about 277 feet of arrestor bed remaining. Before the installation of the EMAS in September 2007, the runway end safety area for runway 23 was only 120 feet long. If this incident had occurred before the installation of the EMAS, the airplane most likely would have traveled beyond the length of the original safety area and off the steep slope immediately beyond its end.

Probable cause

(1) The flight crewmembers’ unprofessional behavior, including their nonadherence to sterile cockpit procedures by engaging in nonpertinent conversation, which distracted them from their primary flight-related duties and led to their failure to correctly set and verify the flaps; (2) the captain’s decision to reconfigure the flaps during the takeoff roll instead of rejecting the takeoff when he first identified the misconfiguration, which resulted in the rejected takeoff beginning when the airplane was about 13 knots above the takeoff decision speed and the subsequent runway overrun; and (3) the flight crewmembers’ lack of checklist discipline, which contributed to their failure to detect the incorrect flap setting before initiating the takeoff roll. Contributing to the survivability of this incident was the presence of an engineered materials arresting system beyond the runway end.

Flight data recorder

— 4,929 samples, 98 parameters, 16:12:35.0 to 16:13:60.0.

Sequence of events (FDR factual report)

Cockpit voice recorder

350 transcribed utterances from 14:32:14 to 16:36:34, 21 sources. Final entries:

Recorder documents in the docket

Docket: data.ntsb.gov/Docket/?NTSBNumber=DCA10IA022. This brief is an analytical aid assembled from public records; it is not an investigative finding.