# NTSB NYC99IA239: Israel Aircraft Industries 1124, N666K, Nantucket, MA, September 26, 1999 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: September 26, 1999, 11:03 local (15:03 UTC) - Place: Nantucket, MA - Location: 41.2714° N, 70.0959° W: Placed by OpenAirDocs: center of Nantucket, MA, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=41.2714&lon=-70.0959&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report April 6, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 47581 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC99IA239 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47581/pdf - Page: https://openairdocs.org/ntsb/NYC99IA239 ## Probable cause A fractured turbine wheel. ## 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 - fractured (cause) ## Analysis While in a climb after departure, the left engine failed. All procedures were accomplished to secure the engine and the airplane landed uneventfully. Examination of the airplane revealed extensive damage to the left engine nacelle and turbine section. The first stage low pressure turbine rotor disk was found separated from the low-pressure turbine shaft, and had penetrated the inner stage transition liner. The engine was removed from the airplane and disassembled. The disassembly revealed the first stage low-pressure turbine (LPT) had a piece of the web and rim, missing outboard of the curvic coupling. Metallurgical examination of the ruptured first stage LPT disk revealed a high cycle fatigue failure that originated from the subsurface location. The disk's dimensions adjacent to the fracture and the disk's material properties conformed to engineering specifications. ## Factual narrative On September 26, 1999, about 1100 Eastern Daylight Time, an Israel Aircraft Industries IA-1124, N666K, experienced an uncontained failure of the left engine while climbing from the Nantucket Memorial Airport (ACK), Nantucket, Massachusetts. The certificated airline transport pilot, co-pilot, and two passengers were not injured. Visual meteorological conditions prevailed, and an instrument rules flight plan was filed for the personal flight conducted under 14 CFR Part 91. According to the pilot, approximately 7 minutes after departure from ACK, the left engine failed. All procedures were accomplished to secure the engine and an emergency was declared. The airplane was then landed uneventfully at the Barnstable Municipal-Boardman/Polando Airport, Hyannis, Massachusetts. Examination of the airplane by a Federal Aviation Administration inspector revealed extensive damage to the left engine nacelle and turbine section. The first stage low pressure turbine rotor disk was found separated from the low-pressure turbine shaft, and had penetrated the inner stage transition liner. The engine was removed from the airplane, shipped to AlliedSignal, Phoenix, Arizona, and disassembled in the presence of a Safety Board investigator on October 26, 1999. The disassembly revealed the first stage low-pressure turbine (LPT) had a piece of the web and rim, missing outboard of the curvic coupling. The pieces were not recovered after the accident. Metallurgical examination of the ruptured first stage LPT disk revealed a high cycle fatigue failure that originated from the subsurface location. The disk's dimensions adjacent to the fracture and the disk's material properties conformed to engineering specifications. The engine was an AlliedSignal TFE731-3-1G, serial number P77382. The engine's maintenance records revealed that the engine had a total time of 9,157.6 hours and 6,575 cycles, and time and cycles since a major periodic inspection of 452.4 hours and 348 cycles, respectively. Additionally, the records revealed that new 1st and 2nd stage low-pressure turbine disks were installed in the engine by a maintenance facility on January 16, 1998, during the major periodic inspection. ## Aircraft - Registration: N666K (not matched to a registry record) - Reported make and model: Israel Aircraft Industries 1124 - Category: Airplane - Serial number: 316 - Airframe hours: 9635 - Engines: Garrett TFE-731-3-1G 3700 lbs thrust turbo jet - Damage: Minor damage - Flight: Personal, Part 91 - Registered owner: Aero Jet Inc - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, September 15, 1999, 10 hours before - Departed: ACK, NANTUCKET, MA - Destination: GAI, GAITHERSBURG, MD - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 6,500 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 54 °F - Altimeter: 30.00 inHg - Observed at: ACK, 2 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 19990926032239I](https://openairdocs.org/incident/19990926032239I), Sep 26, 1999: Israel 1124, Hyannis, MA, Minor damage. (-23) Pilot declared an emergency due to loss of #1 engine. Aircraft diverted to Hyannis and landed safely. Maintenance inspection revealed an uncontained #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. --- 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.