Beech B100 incident near Bakersfield, California, July 17, 2014
On July 17, 2014 at about 4:30 am local time, a 1980 Beech B100, registered N6756P, suffered minor damage in an incident during enroute (cruise) near Bakersfield, California (Meadows Field Airport). It was a business flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The failure of the 2nd-stage turbine wheel due to an improper repair of the 2nd-stage stator assembly, which the manufacturer does not consider a repairable item. Contributing to the incident was the designated engineering representative's approval of the repair process.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 17, 2014 · about 4:30 am local time
- Place
- Bakersfield, California · Meadows Field Airport · map
- Type
- Incident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech B100 NO SERIES, built 1980 · all B100s on the register
- Registration
- N6756P · no longer on the register · serial BE-92
- Damage
- Minor damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, while in cruise flight, the left engine of the twin turboprop airplane lost power. The pilot secured the left engine and performed an uneventful single-engine landing at an airport. Examination revealed damage to the left nacelle and external damage to the left engine, consistent with an uncontained engine failure. Further examination of the left engine revealed an overload failure of the 2nd-stage turbine wheel. The investigation determined that a repair to a brazed joint on the 2nd-stage main nozzle casting support baffle and outer flange had failed. This baffle directs cooling air to the aft face of the 1st-stage turbine wheel and knife-edge seal ring. Once the baffle failed and cooling air was lost, the temperature of the knife-edge seal ring cavity increased, which precipitated its fracture. Once the seal ring fractured, it sprang open slightly from normal internal stresses, became loose in the cavity, and then migrated axially aft until it contacted the rotating 2nd-stage turbine wheel web and started to machine the web material, weakening it until the overload failure occurred. According to the engine manufacturer, without the cooling air, metal temperatures of the knife-edge seal ring at the forward and aft ends were estimated to be 1446°F and 1263°F, respectively. Intergranular fractures were initiated after exposure to these high temperatures. The nominal cavity temperature should be 1060°F. A review of the repair history of the 2nd-stage stator assembly revealed that the forward braze joint had been repaired about 5 years before the accident using a repair process specification that was not applicable for the assembly part being repaired. Further, the engine manufacturer does not consider the part a repairable item and advises that it be removed from service. However, the Federal Aviation Administration designated engineering representative had approved the repair process and did not include technical substantiation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of engine power (total) during enroute (cruise) defining event
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Turbine section › Failure
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Turbine section › Incorrect service/maintenance
- factor Organizational issues › Support/oversight/monitoring › Oversight › Oversight of reg compliance › FAA/Regulator
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 5,000 hours in all; 1,000 in this make and model; 50 in the last 90 days; 15 in the last 30 days
- Last flight review: October 1, 2013
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 7,807 hours
- Last inspection: continuous airworthiness programme, May 5, 2014
- Maximum gross weight: 11,800 lb
- Seats: 10
- Landing gear: retractable
- Engine 1: Garret TPE331-6 (turboprop); 7,807 hours total
- Engine 2: Garret TPE331-6 (turboprop); 7,807 hours total
The flight
- Departed from: KTVL S. Lake Tahoe CA at 3:30 am
- Destination: KCRQ Carlsbad CA
- Flight plan: none
Weather at the time
- Light: night
- Wind: from 300° at 11 knots
- Visibility: 5 statute miles
- Sky: clear
- Temperature: 84°F (29°C), dew point 55°F (13°C)
- Altimeter: 29.86 inHg
- Observation at 3:54 am from KBFL
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR14IA297.