# NTSB ERA12IA582: Learjet 60, N862PA, Teterboro, NJ, September 28, 2012 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: September 28, 2012, 12:15 local (16:15 UTC) - Place: Teterboro, NJ - Coordinates: 40.849998, -74.056388 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.8500&lon=-74.0564&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 12, 2013 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 85163 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12IA582 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/85163/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=85163 - Page: https://openairdocs.org/ntsb/ERA12IA582 ## Probable cause Failure of the nosewheel steering computer strut servo for reasons that could not be determined or replicated during postincident testing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: nose/tail landing gear](https://openairdocs.org/ntsb-findings/01023220): Aircraft › Aircraft systems · Related operating info (probable cause); cases with it: [Learjet 60, 1 case](https://openairdocs.org/ntsb-findings/01023220/cases.md?model=5170707), [All aircraft, 185 cases](https://openairdocs.org/ntsb-findings/01023220/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Learjet 60, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=5170707), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Learjet 60, 2 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=5170707), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Learjet 60, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=5170707), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Takeoff-rejected takeoff: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Learjet 60, 3 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=5170707), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis After pretakeoff checks revealed no anomalies, the pilots taxied the airplane to the runway for takeoff. Shortly after beginning the takeoff roll, they received an aural warning, and the nosegear steering disconnect light illuminated on the master caution panel. The airplane veered left, and the pilots aborted the takeoff. The airplane’s nose landing gear and left main landing gear exited the left side of the runway, where the airplane came to rest undamaged. During postincident maintenance and troubleshooting, the airplane’s nosewheel steering computer was replaced, and subsequent taxi tests confirmed normal operation of the steering. The removed nosewheel steering computer was sent to the manufacturer’s facility for further testing, where it performed within specifications. The unit’s history log indicated repeated attempts to calibrate the unit and ultimately a failure of the strut servo. However, the failure could not be replicated in postincident tests. ## Factual narrative On September 28, 2012, approximately 1215 eastern daylight time, a Learjet Inc 60, N862PA, departed the left side of the runway following an aborted takeoff from Teterboro Airport (TEB), Teterboro, New Jersey. The two certificated airline transport pilots on board were not injured, and the airplane was not damaged. Instrument meteorological conditions prevailed, and an instrument flight rules flight plan was filed for the flight, which was destined for Lehigh Valley International Airport (ABE), Allentown, Pennsylvania. The positioning flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The two pilots each provided written statements to a Federal Aviation Administration (FAA) inspector, and their accounts of the incident were similar. They reported that all pre-taxi and pre-takeoff checks were completed normally with no anomalies noted. After positioning the airplane on the runway for takeoff, the engine throttles were advanced to takeoff power. The pilots released the brakes, and shortly after beginning the takeoff roll, they received an aural warning and the nose gear steering disconnect light illuminated on the master caution panel. The airplane veered left, and the pilots aborted the takeoff while attempting to maintain directional control by rudder application and differential braking. The airplane's nose landing gear and left main landing gear exited the left side of the runway, where the airplane came to rest undamaged. During post-incident maintenance and troubleshooting, the airplane's nose wheel steering computer was replaced, and subsequent low- and high-speed taxi tests confirmed normal operation of the nose wheel steering. According to FAA and company records, the airplane was manufactured in 1993. Its most recent approved inspection program (AAIP) inspection was completed on March 1, 2012. The removed nose wheel steering computer was sent to the manufacturer's facility for further testing, where it performed within specifications. The unit’s history log contained 22 power supply out-of-tolerance conditions, indicative of repeated attempts to calibrate the unit. The recorded data ended with one “strut response incorrect” fault code, and one “strut inputs disagree” fault code, consistent with a failure of the strut servo at the time of the event. The failure, however, could not be replicated in post-incident tests, and no repairs were required to return the unit to service. ## Aircraft - Registration: [N862PA](https://openairdocs.org/deregistered/N862PA-2016-08-01), registration cancelled 2016-08-01, S/N 014, built 1993 (OpenAirDocs) - Reported make and model: LEARJET INC 60 - Registry model: [Learjet 60](https://openairdocs.org/model/learjet-60) (registry code 5170707) (OpenAirDocs) - Registry engine: [Pratt & Whitney PW300 series](https://openairdocs.org/engine/pratt-whitney-pw300-series) (registry code 52128, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 014 - Airframe hours: 6598 - Engines: P & W PW305A 4600 lbs thrust turbo fan; P & W PW305A 4600 lbs thrust turbo fan - Damage: No damage - Flight: Positioning, Part 91 - Operator: Delta Private Jets - Registered owner: Pointe Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, March 1, 2012 - Departed: TEB, Teterboro, NJ - Destination: ABE, Allentown, PA - Flight plan: IFR - Airport: TEB, Teterboro Airport, runway 24, 6,013 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; flight engineer, airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review July 28, 2012; seat: left; flight hours: 14,541 total, 4,233 in this make and model, 12,193 as pilot in command, 41 in the last 90 days, 23 in the last 30 days - Co-pilot; age 42; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review June 29, 2012; seat: right; flight hours: 4,922 total, 377 in this make and model, 4,026 as pilot in command, 33 in the last 90 days, 27 in the last 30 days ## Weather - Conditions: Instrument (IMC), Day - Wind: 10° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: 800 ft overcast - Temperature: 66 °F, dew point 64 °F - Altimeter: 30.01 inHg - Observed at: TEB ## 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 20120928022919I](https://openairdocs.org/incident/20120928022919I), Sep 28, 2012: Learjet Inc 60, Teterboro, NJ, No damage. Immediately after brake release, during takeoff, nose steering warning sounded, followed by immediate yaw left. Crew promptly executed abort, but left main and… ## Docket (5 files) The files NTSB released with the investigation on June 17, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=85163. 1.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 882 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40393948&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statements (item 2, .PDF, 349 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40393950&FileExtension=.PDF&FileName=Pilot%20Statements-Redacted.PDF - Maintenance Log Excerpt (item 3, .PDF, 316 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40394718&FileExtension=.PDF&FileName=Maintenance%20Log%20Excerpt%20-Redacted.PDF - Steering Computer Teardown Report (item 4, .PDF, 184 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40394720&FileExtension=.PDF&FileName=Steering%20Computer%20Teardown%20Report-Redacted.PDF - Photo 1 - Airplane as it came to rest (Courtesy of Delta Private Jets) (item 5, .PDF, 203 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40393949&FileExtension=.PDF&FileName=Photo%201%20-%20Airplane%20as%20it%20came%20to%20rest%20(Courtesy%20of%20Delta%20Private%20Jets)-Master.PDF 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.