# NTSB LAX96LA280: Mitsubishi MU-2B, N999FA, Scottsdale, AZ, July 20, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 20, 1996, 08:57 local (15:57 UTC) - Place: Scottsdale, AZ - Coordinates: 33.609806, -111.889656 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.6098&lon=-111.8897&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 25, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 29515 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX96LA280 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29515/pdf - Page: https://openairdocs.org/ntsb/LAX96LA280 ## Probable cause an uncontained failure of the second stage turbine wheel due to fatigue. Factors were: obstructions in the forced landing area and the inability of the airplane to climb after the turbine wheel failure. ## 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, takeoff - initial climb - 1 engine - turbine assembly,turbine wheel - fatigue (cause) - turbine assembly,turbine wheel - separation - misc,engine uncontained failure - Forced landing, emergency landing after takeoff - On ground/water collision with object, landing - flare/touchdown - object - utility pole (contributing factor) - object - vehicle (contributing factor) - maneuver to avoid obstructions - performed, pilot in command - object - wall/barricade (contributing factor) ## Analysis The right engine lost power after an uncontained engine failure during the initial takeoff climb. The airplane would not climb and the pilot was forced to land. The pilot selected a street for a forced landing area. The pilot landed gear up while maneuvering to avoid hitting street light poles and automobiles. After touchdown, the airplane slid into a block wall. A fire erupted as a result of a postimpact fuel leak in the left wing. The airplane's engines were examined at the manufacturer's facilities. The right engine exhibited evidence of an uncontained separation of the second stage turbine rotor disk. Examination of the disk fragments revealed a low cycle fatigue fracture mode. The fatigue initiated from multiple areas at and adjacent to the inside diameter bore surface near the aft side of the disk. According to the engine manufacturer, the multiple indication areas were associated with uninspectable size porosity and the primary carbides in the cast material. There were no material or casting defects detected on any of the fractures through the wheel. ## Factual narrative On July 20, 1996, at 0857 hours mountain standard time, a Mitsubishi MU-2B, N999FA, landed off the airport after a loss of power during the initial takeoff climb from the Scottsdale Municipal Airport, Scottsdale, Arizona. The airplane was subsequently destroyed by fire and the airline transport pilot was not injured. The airplane was being operated as a business flight under 14 CFR Part 91 when the accident occurred. The airplane was destined for the Phoenix Sky Harbor International Airport, Phoenix, Arizona. Visual meteorological conditions prevailed at the time. The pilot told the Safety Board that the right engine sustained an uncontained engine failure after lift-off while the landing gear was being retracted. After the loss of power, the airplane would not climb. The pilot selected a street about 2 miles northwest of the airport for a forced landing area. The pilot elected to land gear up, while maneuvering to avoid hitting street light poles and automobiles. After touchdown, the airplane slid into a block wall. A fire erupted as a result of a postimpact fuel leak in the left wing destroying the airplane. The airplane's engines were examined by the Federal Aviation Administration at manufacturer's facilities in Phoenix, Arizona. According to the manufacturer, the left engine damage was indicative of engine rotation and operation at the time of impact. The right engine exhibited evidence of an uncontained separation of the second stage turbine rotor disk. Three fragments of the disk remained inside the engine and numerous other fragments exited. Not all of the fragments were recovered. Examination of the three disk fragments revealed a low cycle fatigue fracture mode. The fatigue initiated from multiple areas at and adjacent to the inside diameter bore surface near the aft side of the disk. According to the engine manufacturer, the multiple indication areas were associated with uninspectable size porosity and the primary carbides in the cast material. During the examination, there were no material or casting defects detected on any of the fractures through the wheel. According to the manufacturer, the rest of the damage to the right engine was secondary resulting from the fatigue separation of the second stage turbine wheel. ## Aircraft - Registration: [N999FA](https://openairdocs.org/deregistered/N999FA-1997-04-09), registration cancelled 1997-04-09, S/N 676 (OpenAirDocs) - Reported make and model: Mitsubishi MU-2B - Registry model: [Mitsubishi MU-2B-36](https://openairdocs.org/model/mitsubishi-mu-2b-36) (registry code 5780412) (OpenAirDocs) - Category: Airplane - Serial number: 676 - Airframe hours: 8878 - Engines: Garrett TPE-331 715 horsepower turbo prop - Damage: Destroyed - Fire: On-Ground - Flight: Business, Part 91 - Operator: D & D Aviation - Registered owner: Med Arizona, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, July 7, 1996, 5 hours before - Departed: SDL - Destination: PHX, PHOENIX, AZ - Airport: SDL, Scottsdale Municipal, runway 21, 8,251 × 75 ft ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 4,559 total, 81 in this make and model, 4,437 as pilot in command, 48 in the last 90 days, 15 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 7 knots - Visibility: 60 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 95 °F, dew point 48 °F - Altimeter: 29.00 inHg - Observed at: FFZ, 15 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). - [Accident 19960720019079A](https://openairdocs.org/incident/19960720019079A), Jul 20, 1996: Mtsbsi MU2B36, Scottsdale, AZ, Destroyed. Right engine blew on climbout. Landed on street. Hit rock wall. Turbine rotor disk failed. 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.