Accident Embraer EMB-120RT Brasilia N33701, Wednesday 11 September 1991
ASN logo
 

Date:Wednesday 11 September 1991
Time:10:03
Type:Silhouette image of generic E120 model; specific model in this crash may look slightly different    
Embraer EMB-120RT Brasilia
Owner/operator:Continental Express, opb Britt Airways
Registration: N33701
MSN: 120077
Year of manufacture:1987
Total airframe hrs:7229 hours
Cycles:10009 flights
Engine model:Pratt & Whitney Canada PW123
Fatalities:Fatalities: 14 / Occupants: 14
Other fatalities:0
Aircraft damage: Destroyed, written off
Category:Accident
Location:Eagle Lake, TX -   United States of America
Phase: En route
Nature:Passenger - Scheduled
Departure airport:Laredo International Airport, TX (LRD/KLRD)
Destination airport:Houston-Intercontinental Airport, TX (IAH/KIAH)
Investigating agency: NTSB
Confidence Rating: Accident investigation report completed and information captured
Narrative:
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: "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:
cover
  
Investigating agency: NTSB
Report number: NTSB/AAR-92-04
Status: Investigation completed
Duration: 10 months
Download report: Final report

Sources:

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

History of this aircraft

Other occurrences involving this aircraft

25 August 1990 N33701 Britt Airways 0 College Station, TX non

Statistics

  • 29th worst accident in 1991
  • 8th worst accident of this aircraft type
  • 3rd worst accident of this aircraft type at the time

Location

Images:


photo (c) 32 Bit; 1988

Revision history:

Date/timeContributorUpdates

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org