# NTSB DCA91MA052: Embraer 120, N33701, Eagle Lake, TX, September 11, 1991 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 1 · Major · Final report - Date: September 11, 1991, 10:03 local (15:03 UTC) - Place: Eagle Lake, TX - Location: 29.5873° N, 96.3286° W: Placed by OpenAirDocs: center of Eagle Lake, TX, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=29.5873&lon=-96.3286&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 14 fatal - Status: Completed, report December 9, 1993 - Report: Board-adopted at Board Meeting - Investigation class: Class 1 - NTSB office: Major Investigations Division - Safety recommendations: Yes - NTSB case key (mKey): 10966 - NTSB case page: https://www.ntsb.gov/investigations/Pages/DCA91MA052.aspx - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10966/pdf - Board report AAR9204 (PDF): https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR9204.pdf - Page: https://openairdocs.org/ntsb/DCA91MA052 ## 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 CONTINENTAL EXPRESS MANAGEMENT TO ENSURE COMPLIANCE WITH THE APPROVED MAINTENANCE PROCEDURES, AND THE FAILURE OF THE FAA SURVEILLANCE TO DETECT AND VERIFY COMPLIANCE WITH APPROVED PROCEDURES. (NTSB REPORT AAR-92/04) ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, descent - normal - horizontal stabilizer surface - not secured (cause) - maintenance - improper, company maintenance personnel (cause) - inadequate surveillance of operation, company/operator mgmt (contributing factor) - inadequate surveillance of operation, faa(organization) (contributing factor) - horizontal stabilizer surface - separation - In flight collision with terrain/water, descent - uncontrolled ## Analysis THE AIRPLANE BROKE UP IN FLIGHT WHILE DESCENDING FROM FL240. THE HORIZONTAL STABILIZER, OR TOP OF THE T-TYPE TAIL, HAD SEPARATED FROM THE FUSELAGE BEFORE GROUND IMPACT. EXAMINATION REVEALED THAT THE 47 SCREW FASTENERS THAT WOULD HAVE ATTACHED THE UPPER SURFACE OF THE LEADING EDGE ASSEMBLY FOR THE LEFT SIDE OF THE HORIZONTAL STABILIZER WERE MISSING. THEY HAD BEEN REMOVED THE NIGHT BEFORE DURING SCHEDULED MAINTENANCE. INVESTIGATION REVEALED THAT THERE WAS A LACK OF COMPLIANCE WITH THE FAA-APPROVED GENERAL MAINTENANCE MANUAL PROCEDURES BY THE MECHANICS, INSPECTORS, AND SUPERVISORS RESPONSIBLE FOR ASSURING THE AIRWORTHINESS OF THE AIRPLANE THE NIGHT BEFORE THE ACCIDENT. IN ADDITION, ROUTINE SURVEILLANCE OF THE CONTINENTAL EXPRESS MAINTENANCE DEPARTMENT BY THE FAA WAS INADEQUATE AND DID NOT DETECT DEFICIENCIES, SUCH AS THOSE THAT LED TO THIS ACCIDENT. ## Factual narrative SEE NATIONAL TRANSPORTATION SAFETY BOARD BLUE COVER REPORT AAR- 92/004. ## Aircraft - Registration: [N33701](https://openairdocs.org/deregistered/N33701-1992-11-06), registration cancelled 1992-11-06, S/N 120077 (OpenAirDocs) - Reported make and model: EMBRAER 120 - Registry model: [Embraer EMB-120RT](https://openairdocs.org/model/embraer-emb-120rt) (registry code 3260202) (OpenAirDocs) - Category: Airplane - Serial number: 120-L77 - Airframe hours: 7229 - Engines: P&W turbo prop - Damage: Destroyed - Fire: Both - Flight: Part 135 - Operator: Continental Express - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, September 10, 1991 - Departed: LRD, LAREDO, TX - Destination: IAH, HOUSTON, TX - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 4,243 total, 2,468 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 7 knots - Visibility: 6 statute miles - Lowest ceiling: 3,000 ft broken - Temperature: 82 °F, dew point 73 °F - Altimeter: 30.00 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19910911039219A](https://openairdocs.org/incident/19910911039219A), Sep 11, 1991: Emb EMB120RT, Eagle Lake, TX, Destroyed, 14 fatal. On descent ,breakup in flight and fire. Left horizontal stabilizer leading edge failed. Improper maintenance. ## Other investigations on N33701 (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB FTW90IA169](https://openairdocs.org/ntsb/FTW90IA169), Aug 25, 1990: Embraer EMB-120 (N33701), College Station, TX, incident, no damage. Probable cause: PROPELLER AND ENGINE (POWERPLANT) OVERSPEED. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.