Columbia Aircraft Mfg LC41 550FG incident near Chandler, Arizona, August 1, 2017
On August 1, 2017, a 2006 Columbia Aircraft Mfg LC41 550FG, registered N8725, suffered minor damage in an incident during enroute near Chandler, Arizona. It was a business flight under general aviation rules (Part 91). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The over-tensioning of the accessory belt, which resulted in damage to the starter adapter and subsequent loss of oil that led to oil starvation and catastrophic engine failure.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 1, 2017
- Place
- Chandler, Arizona · map
- Type
- Incident
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Columbia Aircraft Mfg LC41 550FG, built 2006 · all LC41 550FGs on the register
- Registration
- N8725 · registry record · serial 41605
- Damage
- Minor damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During the flight the pilot reported a loss of oil pressure followed by a decrease in manifold pressure. The pilot declared an emergency and requested landing clearance, however, the engine lost total power and he initiated a forced landing to a field where the airplane sustained minor damage. Postincident examination of the airplane revealed that the lower side of the fuselage was covered in oil and a hole was discovered in the engine’s crankcase. The examination of the engine revealed damage to the starter adapter assembly, which included the starter pulley, bearing, seal, and shaft, that was consistent with the over-tensioning of the accessory belt, which resulted in an excessive side-load. The damaged starter adapter assembly components ultimately resulted in the loss of engine oil and subsequent failure of several connecting rods due to oil starvation. A manufacturer Critical Service Bulletin provided instructions for an inspection of the starter adapter for indications of oil leakage at the shaft oil seal, however, review of the airplane maintenance records show that the service bulletin was not complied with.
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 defining event
The NTSB's findings
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng rear section › Damaged/degraded
- Personnel issues › Task performance › Inspection › Scheduled/routine inspection › Maintenance personnel
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng oil sys › Damaged/degraded
- Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng rear section › Incorrect service/maintenance
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 1,215 hours in all; 288 in this make and model; 79 in the last 90 days; 20 in the last 30 days; 1,215 as pilot in command
- Last flight review: August 1, 2016
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Passenger
- Seat: rgt
- Injury: no injuries
Passenger
- Seat: rear
- Injury: no injuries
Passenger
- Seat: rear
- Injury: no injuries
The aircraft
- Airframe total time: 478.2 hours
- Last inspection: 100-hour inspection, July 21, 2017; 4.2 hours since
- Seats: 4
- Landing gear: fixed
- Engine: Cont Motor TSIO-550-C (piston); 478 hours total
The flight
- Departed from: NYL Yuma AZ
- Destination: 5AZ3 Queen Creek AZ
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 250° at 5 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 8,000 ft
- Temperature: 102°F (39°C), dew point 61°F (16°C)
- Altimeter: 29.80 inHg
- Observation at 10:47 pm from KCHD, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 3 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
6 documents, released by the NTSB on February 16, 2021. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 2 | Critical Service Bulletin Csb 02-2C | PDF, 4 pages | View Download |
| 3 | Cmi Component Examination Report-starter Adapter | PDF, 4 pages | View Download |
| 4 | Cmi-component Examination Report-oil Pump | PDF, 2 pages | View Download |
| 5 | Cmi Engine Field Inspection Report | PDF, 38 pages | View Download |
| 6 | Statement of Party Representatives to NTSB Investigation-continental Motors | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.