Status: | Accident investigation report completed and information captured |
Datum: | woensdag 11 september 1991 |
Tijd: | 10:03 |
Type: | Embraer EMB-120RT Brasilia |
Operated by: | Britt Airways |
On behalf of: | Continental Express |
Registratie: | N33701 |
Constructienummer: | 120077 |
Bouwjaar: | 1987 |
Aantal vlieguren: | 7229 |
Aantal vluchten: | 10009 |
Motoren: | 2 Pratt & Whitney Canada PW123 |
Bemanning: | slachtoffers: 3 / inzittenden: 3 |
Passagiers: | slachtoffers: 11 / inzittenden: 11 |
Totaal: | slachtoffers: 14 / inzittenden: 14 |
Schade: | Vernield |
Gevolgen: | Written off (damaged beyond repair) |
Plaats: | Eagle Lake, TX ( Verenigde Staten)
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Fase: | Kruisvlucht (ENR) |
Soort vlucht: | Binnenlandse lijnvlucht |
Vliegveld van vertrek: | Laredo International Airport, TX (LRD/KLRD), Verenigde Staten |
Vliegveld van aankomst: | Houston-Intercontinental Airport, TX (IAH/KIAH), Verenigde Staten |
Vluchtnummer: | 2574 |
Beschrijving:Embraer 120 N33701 was pulled into the Continental Express hangar at Houston around 21:30 for scheduled maintenance which included removal and replacement of both left and right hand horizontal stabilizer deice boots. The second shift mechanics started working on the right hand deice boot. Although planned for the third shift, the 47 screws from the top of the left leading edge assembly for the horizontal stabilizer were already removed by the second shift. The third shift mechanics finished the replacement of the right hand deice boot but did not have time to replace the left hand boot as well.
The first flight was a 07:00 scheduled flight from Houston to Laredo.
Flight 2574 departed Laredo for the return leg to Houston at 09:09. The cruise portion of the flight was uneventful and at 10:03 the aircraft was descending through 11800 feet to 9000 feet when the air loads caused the left horizontal stabilizer leading edge to bend downward and separate. A sudden severe nose down pitchover occurred and the wings stalled negatively. A negative g of 3.5 was recorded by the FDR. Eyewitnesses reported a bright flash and saw the aircraft breaking up while descending in a flat left spin until impact.
Probable Cause:
PROBABLE CAUSE: "The failure of Continental Express maintenance and inspection personnel to adhere to proper maintenance and quality assurance procedures for the airplane's horizontal stabilizer deice boots that led to the sudden in-flight loss of the partially secured left horizontal stabilizer leading edge and the immediate severe nose-down pitchover and breakup of the airplane. Contributing to the cause of the accident was the failure of the Continental Express management to ensure compliance with the approved maintenance procedures, and the failure of FAA surveillance to detect and verify compliance with approved procedures."
NTSB board member John K. Lauber filed a dissenting statement on the investigation report, believing the probable cause should read as follows:
"1) The failure of Continental Express management to establish a corporate culture which encouraged and enforced adherence to approved maintenance and quality assurance procedures, and 2) the consequent string of failures by Continental Express maintenance and inspection personnel to follow approved procedures for the replacement of the horizontal stabilizer deice boots. Contributing to the accident was the inadequate surveillance by the FAA of the Continental Express maintenance and quality assurance programs."
Accident investigation:
|
Investigating agency: | NTSB |
Status: | Investigation completed |
Duration: | 10 months | Accident number: | NTSB/AAR-92-04 | Download report: | Final report
|
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Bronnen:
» NTSB Safety Recommendations A-92-79 and -80
» Air Safety Week 4 January 1993 (p. 4)
» Flight International 18-24 September 91
» ICAO Adrep Summary 1/95
» NTSB/AAR-92/04
Veiligheidsmaatregelen
NTSB issued 4 Safety Recommendations
Issued: 28-FEB-1992 | To: FAA | A-92-6 |
ENHANCE FLIGHT STANDARDS SURVEILLANCE OF CONTINENTAL EXPRESS, TO INCLUDE SUFFICENT DIRECT OBSERVATION OF ACTUAL MAINTENANCE SHOP PRACTICES TO ENSURE THAT SUCH PRACTICES CONFORM TO THE CONTINENTAL EXPRESS GENERAL MAINTENANCE MANUAL AND APPLICABLE FEDERAL AVIATION REGULATIONS. (Closed - Acceptable Action) |
Issued: 28-FEB-1992 | To: FAA | A-92-7 |
ENHANCE FLIGHT STANDARDS PROGRAMS GUIDELINES, INCLUDING THE NATIONAL AVIATION SAFETY INSPECTION PROGRAM, TO EMPHASIZE HANDS-ON INSPECTION OF EQUIPMENT AND PROCEDURES, UNANNOUNCED AND INTERNAL AUDIT FUNCTIONS, IN ORDER TO EVALUATE THE EFFECTIVENESS OF AIR CARRIER MAINTENANCE PROGRAMS RELATED TO AIRCRAFT CONDITION, THE ADHERENCE TO APPROVED AND PRESCRIBED PROCEDURES, AND THE ABILITY OF AIR CARRIERS TO IDENTIFY AND CORRECT PROBLEMS FROM WITHIN. (Closed - Acceptable Action) |
Issued: 14-AUG-1992 | To: FAA | A-92-79 |
IN COOPERATION WITH AIRCRAFT MANUFACTURERS AND AIRLINES, CONDUCT A REVIEW OF THE REGULATIONS, POLICIES, AND PRACTICES RELATED TO ESTABLISHING REQUIRED INSPECTION ITEMS (RIIS) FOR AIRLINE MAINTENANCE DEPARTMENTS WITH THE VIEW TOWARD DEVELOPING MORE SPECIFIC IDENTIFICATION OF RIIS. (Closed - Acceptable Action) |
Issued: 14-AUG-1992 | To: FAA | A-92-80 |
REQUIRE THAT AIRLINES OPERATING UNDER 14 CFR PARTS 135 AND 121 STUDY THE FEASIBILITY OF DEVELOPING A MEANS TO ADVISE FLIGHTCREWS ABOUT RECENT MAINTENANCE, BOTH ROUTINE AND NONROUTINE, ON THE AIRPLANES THAT THEY ARE ABOUT TO FLY, SO THAT THEY HAVE THE OPPORTUNITY TO BE ALERT TO DISCREPANCIES DURING PREFLIGHT INSPECTIONS AND POSSIBLY TO MAKE AN ADDITIONAL INSPECTION OF CRITICAL ITEMS, SUCH AS REQUIRED INSPECTION ITEMS (RIIS), THAT MAY AFFECT THE SAFETY OF FLIGHT. (Closed - Acceptable Action) |
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Foto's
accident date:
11-09-1991type: Embraer EMB-120RT Brasilia
registration: N33701
Kaart
Deze kaart geeft het vliegveld van vetrek weer en de geplande bestemming van de vlucht. De lijn tussen de vliegvelden geeft
niet de exacte vliegroute weer.
De afstand tussen Laredo International Airport, TX en Houston-Intercontinental Airport, TX bedraagt 482 km (301 miles).
Accident location: Exact; as reported in the official accident report.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.