Cessna 501 incident near Opa Locka, Florida, December 31, 2020
On December 31, 2020 at about 10:15 pm local time, a Cessna 501, registered N75TL, suffered minor damage in an incident during takeoff (rejected takeoff) near Opa Locka, Florida (Opa Locka Executive Airport). It was a personal 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).
The NTSB's probable cause their words, unchanged
An uncontained left engine failure caused by a low cycle fatigue crack that originated from a manufacturing machining groove on the high pressure compressor impeller aft face. Contributing to the incident was service bulletin borescope inspection criteria that was insufficient to detect the presence of machining grooves on the high pressure compressor impeller at the time the incident engine was inspected in May 2004.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 31, 2020 · about 10:15 pm local time
- Place
- Opa Locka, Florida · Opa Locka Executive Airport · map
- Type
- Incident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 501 CITATION · all 501s on the register
- Registration
- N75TL · registry record · serial 5010016
- Damage
- Minor damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The No. 1 (left) engine high pressure compressor (HPC) impeller developed a low cycle fatigue (LCF) crack that originated from a machining feature (groove) on the aft face of the impeller. The machining groove was created during the part manufacturing process. The LCF crack progressed to overload and resulted in an uncontained HPC impeller failure and secondary impact damage throughout the engine gaspath. Pratt & Whitney Canada (PWC) released a service bulletin (SB) in May 2003 that recommended a one-time borescope inspection of the HPC impeller aft face to check for evidence of machining grooves. The borescope inspection was subsequently mandated by Transport Canada and Federal Aviation Administration (FAA) airworthiness directives (AD). The incident engine was inspected in accordance with the SB inspection instructions in May 2004, with no HPC impeller machining anomalies noted. Following the incident, the HPC impeller fragments were inspected at the PWC facility in Bridgeport, West Virginia in accordance with the overhaul manual procedures. Aside from impact damage created during the incident event, the machining grooves present on the HPC impeller aft face would have passed inspection criteria. It is unlikely the machining grooves would have been visible during the SB borescope inspection performed in May 2004, particularly given the technology available at the time. A crack striation count was performed as part of the materials laboratory analysis of the incident HPC impeller. Assuming each crack striation correlates to one engine cycle, a 1/32 inch crack (thumbnail shape) would have formed on the HPC impeller aft face surface at approximately 1,970 engine cycles. The engine had accumulated 6,803 cycles since new when the HPC impeller borescope inspection was performed in May 2004. The crack would have been detectable by fluorescent penetrant inspection as outlined in the recently released corrective actions discussed in the factual section of this report.
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
- Uncontained engine failure during takeoff (rejected takeoff) defining event
- Powerplant sys/comp malf/fail during takeoff (rejected takeoff)
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Compressor section › Failure
- Organizational issues › Development › Manufacture/production › Document/info production › Manufacturer
- Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Compressor section › Inadequate inspection
- Organizational issues › Development › Manufacture/production › Equipment manufacture › Manufacturer
The aircraft
- Landing gear: retractable
- Engine 1: Pratt & Whitney Canada JT15D-1A (turbofan); 0 hours total
- Engine 2: Pratt & Whitney Canada JT15D-1A (turbofan); 0 hours total
- Operator: Interstellar Air LLC
The flight
- Departed from: OPF Opa Locka FL at 10:15 pm
- Destination: X60 Willston FL
- Flight plan: IFR
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 77°F (25°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 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 ENG21LA011.