# NTSB MIA94IA040: Israel Aircraft Industries 1124, N74JM, Melbourne, FL, December 19, 1993 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: December 19, 1993, 00:15 local (05:15 UTC) - Place: Melbourne, FL - Coordinates: 28.139211, -80.710159 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.1392&lon=-80.7102&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 9 uninjured - Status: Completed, report September 13, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 37438 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA94IA040 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37438/pdf - Page: https://openairdocs.org/ntsb/MIA94IA040 ## Probable cause WAS INADEQUATE QUALITY CONTROL BY THE ENGINE MANUFACTURER WHICH RESULTED IN FAILURE OF THE SECOND STAGE LOW PRESSURE TURBINE DISK DUE TO A MACHINING ANOMALY AND REDUCED FATIGUE STRENGTH DUE TO SUB STANDARD HEAT TREAT PROCESSING. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - inadequate quality control, manufacturer (cause) - turbine assembly,turbine wheel - previous damage (cause) - turbine assembly,turbine wheel - fatigue (cause) - turbine assembly,turbine wheel - failure,total (cause) ## Analysis The flight experienced an uncontained failure of the number two engine while in cruise flight. An uneventful landing was made. Examination of the number two engine indicated the second stage low pressure turbine disk experienced separation of a small segment near the disk rim. Metallurgical examination indicated the separation was due to a machining anomaly and reduced fatigue life due to sub standard heat treat of the disk material. ## Factual narrative On December 19, 1993, about 0015 eastern standard time, a Israel Aircraft Industries 1124, N74JM, registered to Turnberry Charters, Inc., experienced an uncontained failure of the no. 2 engine while in cruise flight near Melbourne, Florida, while on a 14 CFR Part 91 corporate flight. Visual meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed. The aircraft received minor damage and the two pilots and seven passengers were not injured. The flight originated at Daytona Beach, Florida, on December 19, 1993, about 0000. The first officer stated that shortly after they leveled at 29,000 feet and set cruise engine power they felt severe vibration and heard unusual noises. They observed the no. 2 engine had lost power. They shut down the no. 2 engine and diverted to Orlando, Florida. Postlanding examination of the aircraft by an FAA inspector indicated the no. 2 engine had sustained damage in the turbine section and that a component had exited the engine through the turbine case, engine cowling, and tail pipe. The third stage low pressure turbine wheel (LPT-3)was recovered from inside the roof of a house in Melbourne, Florida. Examination of the no. 2 was conducted at Allied Signal Engines, Phoenix, Arizona. Examination revealed "the second stage low pressure turbine wheel (LPT-2) experienced a separation of a small segment of the disk near the rim. The separation resulted in rotational unbalance of the low pressure turbine rotating group and expulsion of the LPT-3 wheel overboard. Metallurgical analysis of the LPT revealed the rim separation of the 2nd LPT to be primary with all other damage secondary. The 2nd LPT separated due to a machining anomaly in a blade slot in combination with sub standard heat treat process resulting in reduced fatigue life." See attached Allied Signal Engines report. ## Aircraft - Registration: N74JM (not matched to a registry record) - Reported make and model: ISRAEL AIRCRAFT INDUSTRIES 1124 - Category: Airplane - Serial number: WW-1124A - Airframe hours: 3723 - Engines: GARRETT TFE-731-3-1G 3700 lbs thrust turbo fan - Damage: Minor damage - Flight: Executive/Corporate, Part 91 - Registered owner: Turnberry Charters, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, October 18, 1993, 37 hours before - Departed: DAB, DAYTONA BEACH, FL - Destination: FLL, FORT LAUDERDALE, FL - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 4,500 total, 2,400 in this make and model, 3,325 as pilot in command ## Weather - Conditions: Instrument (IMC), Night/dark - Wind: 290° at 5 knots - Visibility: 0.5 statute miles - Temperature: 55 °F, dew point 55 °F - Altimeter: 30.00 inHg - Observed at: MLB, 3 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 19931219051299I](https://openairdocs.org/incident/19931219051299I), Dec 19, 1993: Israel 1124, Melbourne, FL, Minor damage. Preliminary report missing. Approach engine malfunction inflight. Diverted to Melbourne. Faulty turbine wheel. 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.