# NTSB FTW95IA013: Gates Learjet 35A, N46TJ, San Antonio, TX, October 11, 1994 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: October 10, 1994, 19:00 local (Oct 11, 1994, 00:00 UTC) - Place: San Antonio, TX - Coordinates: 29.540988, -98.490882 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.5410&lon=-98.4909&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 16, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 19257 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW95IA013 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19257/pdf - Page: https://openairdocs.org/ntsb/FTW95IA013 ## Probable cause THE UNCONTAINED FAILURE OF THE TURBINE WHEEL. A FACTOR WAS THE RESULTANT LOSS OF HYDRAULIC POWER. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, climb - turbine assembly,turbine wheel - disintegrated (cause) - reason for occurrence undetermined - hydraulic system,line - cut/severed (contributing factor) - Loss of control - on ground/water, landing - roll - directional control - not possible, pilot in command - Overrun, landing - roll ## Analysis DURING A CLIMB THROUGH FL200, THE CREW HEARD A NOISE, FOLLOWED BY THE LOSS OF POWER FROM THE RIGHT ENGINE AND A YAW. THEY SECURED THE RIGHT ENGINE AND CONTINUED ON TO THEIR DESTINATION. AN INSPECTION OF THE RIGHT ENGINE REVEALED THAT THE NUMBER 3 TURBINE WHEEL HAD FAILED AND THAT THE FAILURE WAS UNCONTAINED. THE FAILURE ALSO SEVERED THE HYDRAULIC LINES IN THE EQUIPMENT BAY AND SEPARATED THE BAY DOOR. THE PIECES OF THE TURBINE WHEEL WERE NOT RECOVERED. DURING THE LANDING ROLL THE CREW EXITED ON A TAXIWAY BUT DID NOT HAVE SUFFICIENT CONTROL TO STAY ON THE TAXIWAY. THE AIRPLANE CAME TO REST IN THE GRASS. ## Factual narrative On October 10, 1994, approximately 1900 central daylight time, a Gates Learjet Corp. 35A, N46TJ, received minor damage during an uncontained engine failure climb. The airplane, owned by a Mexican corporation and flown by two commercial pilots, was on a cross country positioning flight. An IFR flight plan was filed and in effect and visual meteorological conditions prevailed. Neither pilot was injured. In their written report the crew reported that they were en route from Laredo, Texas, to Dallas, Texas, and climbing through FL200, when they "heard a noise, right engine suddenly stopped, and the airplane began to yaw." They secured the right engine, executed the emergency check list, and requested to divert to San Antonio. During the descent, the crew noticed they had no hydraulic pressure and that activation of the hydraulic pump did not restore pressure. During the ensuing landing, the crew was "unable to stay on the taxiway and came to a stop a few yards beyond the taxiway in the grass." Initial examination revealed that the right engine cowling had punctures from the inside out. After the cowling was removed there was physical evidence that the number 3 turbine wheel had experienced a failure and that the failure was uncontained. Pieces of the turbine wheel had also penetrated the fuselage in the area of the equipment bay. The pieces entering the equipment bay also severed the hydraulic lines and separated the bay door. All pieces of the number 3 turbine wheel were lost following the uncontained failure resulting in no metallurgical testing being performed. ## Aircraft - Registration: N46TJ (not matched to a registry record) - Reported make and model: Gates Learjet 35A - Category: Airplane - Serial number: 077 - Engines: GARRETT TFE-731-2 3500 lbs thrust turbo fan - Damage: Minor damage - Flight: Positioning, Part 91 - Registered owner: Aeroservicos Demex, S.A. - Airworthiness certificate: Standard, Transport - Departed: LRD, LAREDO, TX - Destination: DAL, DALLAS, TX - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 47; commercial; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 5,504 total, 208 in this make and model, 5,000 as pilot in command, 160 in the last 90 days, 60 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 39 °F - Altimeter: 30.00 inHg - Observed at: SAT, 60 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19941010040859I](https://openairdocs.org/incident/19941010040859I), Oct 10, 1994: Lear 35A, San Antonio, TX, Substantial damage. Reported problems with aircraft systems caused runway overrun. Hot substantiated since violation reported. 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.