BOEING 737-524CONTINENTAL AIRLINES INC
Denver, CO, USA · 2008-12-21·N18611
What happened
NTSB summary, verbatimThe Safety Board's full report is available at http://www.ntsb.gov/publictn/A_Acc1.htm. The Aircraft Accident Report number is NTSB/AAR-10/04. On December 20, 2008, about 1818 mountain standard time, Continental Airlines flight 1404, a Boeing 737-500, N18611, departed the left side of runway 34R during takeoff from Denver International Airport (DEN), Denver, Colorado. A postcrash fire ensued. The captain and 5 of the 110 passengers were seriously injured; the first officer, 2 cabin crewmembers, and 38 passengers received minor injuries; and 1 cabin crewmember and 67 passengers (3 of whom were lap-held children) were uninjured. The airplane was substantially damaged. The scheduled, domestic passenger flight, operated under the provisions of 14 Code of Federal Regulations Part 121, was departing DEN and was destined for George Bush Intercontinental Airport, Houston, Texas. At the time of the accident, visual meteorological conditions prevailed, with strong and gusty winds out of the west. The flight operated on an instrument flight rules flight plan.
Photographs
78the 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 captain’s cessation of right rudder input, which was needed to maintain directional control of the airplane, about 4 seconds before the excursion, when the airplane encountered a strong and gusty crosswind that exceeded the captain’s training and experience. Contributing to the accident were the following factors: 1) an air traffic control system that did not require or facilitate the dissemination of key, available wind information to the air traffic controllers and pilots; and 2) inadequate crosswind training in the airline industry due to deficient simulator wind gust modeling.
Occurrence sequence
3 stepsNTSB coding · CICTT taxonomy- 1 · TakeoffOther weather encounter
- 2 · TakeoffLoss of control on ground
- 3 · TakeoffRunway excursiondefining event
Findings
8 causal · 2 contributing- CAUSEAircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control — Not attained/maintained
- CAUSEAircraft › Aircraft oper/perf/capability › Performance/control parameters › Crosswind correction — Not attained/maintained
- CAUSEEnvironmental issues › Conditions/weather/phenomena › Wind › Crosswind — Response/compensation
- CAUSEPersonnel issues › Action/decision › Action › Incomplete action — Pilot
- CAUSEPersonnel issues › Task performance › Use of equip/info › Aircraft control — Pilot
- CAUSEEnvironmental issues › Conditions/weather/phenomena › Wind › Crosswind — Availability of related info
- CAUSEOrganizational issues › Management › Communication (organizational) › Between groups/organizations — ATC
- CAUSEOrganizational issues › Support/oversight/monitoring › Training — Not specified
- FACTORAircraft › Aircraft systems › Equipment/furnishings — Damaged/degraded
- FACTORAircraft › Aircraft systems › Equipment/furnishings › Buffet/galleys — Damaged/degraded
Safety recommendations
20 issuedwhat changed because of this accidentTO THE FEDERAL AVIATION ADMINISTRATION: Conduct research into and document the effects of mountain wave and downslope conditions at airports, such as Denver International Airport, that are located downwind of mountainous terrain (including, for example, airports in or near Colorado Springs, Colorado; Anchorage, Alaska; Salt Lake City, Utah; and Reno, Nevada), identify potential mountain-wave-related hazards to ground operations at those airports, and disseminate the results to pilots and airport air traffic control personnel to allow for more informed runway selection decisions.
TO THE FEDERAL AVIATION ADMINISTRATION: Archive all low-level windshear alert system (LLWAS) data obtained from Denver International Airport and other airports that experience similar wind conditions and make these data available for additional research and the potential future development of an improved LLWAS algorithm for crosswind and gusty wind alerts on air traffic control tower ribbon display terminals.
TO THE FEDERAL AVIATION ADMINISTRATION: Modify Federal Aviation Administration Order 7110.65 to require air traffic controllers at airports with multiple sources of wind information to provide pilots with the maximum wind component, including gusts, that the flight could encounter.
TO THE FEDERAL AVIATION ADMINISTRATION: Review the required documentation for all low-level windshear alert system (LLWAS)-equipped air traffic control towers to ensure that a letter to airmen has been published and is easily accessible describing the location and designation of the remote sensors, the capabilities and limitations of the system, and the availability of current LLWAS remote sensor wind information on the request of a pilot, in compliance with Federal Aviation Administration Order 7210.3.
TO THE FEDERAL AVIATION ADMINISTRATION: Require air traffic control towers to locally develop and implement written runway selection programs that proactively consider current and developing wind conditions and include clearly defined crosswind components, including wind gusts, when considering operational advantage with respect to runway selection.
TO THE FEDERAL AVIATION ADMINISTRATION: Gather data on surface winds at a sample of major U.S. airports (including Denver International Airport) when high wind conditions and significant gusts are present and use these data to develop realistic, gusty crosswind profiles for use in pilot simulator training programs.
TO THE FEDERAL AVIATION ADMINISTRATION: Require 14 Code of Federal Regulations Part 121, 135, and 91K operators to incorporate the realistic, gusty crosswind profiles developed as a result of Safety Recommendation A-10-110 into their pilot simulator training programs.
TO THE FEDERAL AVIATION ADMINISTRATION: Once realistic, gusty crosswind profiles as asked for in Safety Recommendation A-10-110 are developed, develop a standard methodology, including pilot-in-the-loop testing, for transport-category airplane manufacturers to establish empirically based, type-specific maximum-gusting-crosswind limitations for transport-category airplanes that account for wind gusts.
TO THE FEDERAL AVIATION ADMINISTRATION: Once a methodology as asked for in Safety Recommendation A-10-112 has been developed, require manufacturers of transport-category airplanes to develop type-specific, maximum-crosswind takeoff limitations that account for wind gusts.
TO THE FEDERAL AVIATION ADMINISTRATION: Until the actions described in Safety Recommendation A-10-113 are accomplished, require manufacturers of transport-category airplanes to provide operators with interim crosswind takeoff guidelines that account for wind gusts.
TO THE FEDERAL AVIATION ADMINISTRATION: Work with U.S. airline operators to review and analyze operational flight data to identify factors that contribute to encounters with excessive winds and use this information to develop and implement additional strategies for reducing the likelihood of wind-related runway excursions.
TO THE FEDERAL AVIATION ADMINISTRATION: Require cockpit crew seats installed in newly manufactured airplanes that were type certificated before 1988 to meet the crashworthiness standards contained in 14 Code of Federal Regulations 25.562.
TO THE FEDERAL AVIATION ADMINISTRATION: Require operators to perform periodic inspections on the Burns Aerospace model 2501-5 jumpseats for fatigue cracks within the jumpseat structure and replace the jumpseat if fatigue cracks are found.
TO THE FEDERAL AVIATION ADMINISTRATION: Require that operators of transport-category airplanes that use galley latches or latch plates secured solely by adhesives that may degrade over time modify the latches to include mechanical fasteners.
TO THE FEDERAL AVIATION ADMINISTRATION: Modify the design and test requirements for the attachment points of passenger service units to account for the higher localized loading that results from the relative motion of the attachment structure.
TO THE FEDERAL AVIATION ADMINISTRATION: Require that the installation design for overhead bins and passenger service units (PSU) manufactured by Boeing and installed in Boeing 737NG series airplanes be modified so that the PSUs remain attached to the bins or are captured in a safe manner during survivable accidents.
TO THE FEDERAL AVIATION ADMINISTRATION: Review the designs of manufacturers other than Boeing for overhead bins and passenger service units (PSU) to identify designs with deficiencies similar to those identified in Boeing’s design, and require those manufacturers, as necessary, to eliminate the potential for PSUs to separate from their attachments during survivable accidents.
TO THE FEDERAL AVIATION ADMINISTRATION: Develop test criteria and performance measures for negative-g strap assemblies to better evaluate their real-world loading capability during accident sequences.
TO THE FEDERAL AVIATION ADMINISTRATION: Once test criteria and performance measures are established as recommended in Safety Recommendation A-12-4, amend 14 Code of Federal Regulations Part 25, as appropriate, to include the newly developed test criteria and performance measures for negative-g strap assemblies.
TO THE FEDERAL AVIATION ADMINISTRATION: Require that negative-g strap attachment brackets manufactured by Ipeco be retrofitted with stronger brackets.
Sequence of events
1 timed eventsfrom the FDR factual report · claude-fable-5-1 (in-session)- 18:17:32-18:18:29 MSTtakeoffp.4Attempted takeoff covered by the two OQAR plots, aligned with the FDR: engine N1/N2, FCC master lights, flight path accelerations, flight spoilers 2 and 7, EFIS ground speed, heading and total pressure
NTSB analysis
from the final reportThe Safety Board's full report is available at http://www.ntsb.gov/publictn/A_Acc1.htm. The Aircraft Accident Report number is NTSB/AAR-10/04. On December 20, 2008, about 1818 mountain standard time, Continental Airlines flight 1404, a Boeing 737-500, N18611, departed the left side of runway 34R during takeoff from Denver International Airport (DEN), Denver, Colorado. A postcrash fire ensued. The captain and 5 of the 110 passengers were seriously injured; the first officer, 2 cabin crewmembers, and 38 passengers received minor injuries; and 1 cabin crewmember and 67 passengers (3 of whom were lap-held children) were uninjured. The airplane was substantially damaged. The scheduled, domestic passenger flight, operated under the provisions of 14 Code of Federal Regulations Part 121, was departing DEN and was destined for George Bush Intercontinental Airport, Houston, Texas. At the time of the accident, visual meteorological conditions prevailed, with strong and gusty winds out of the west. The flight operated on an instrument flight rules flight plan.