Beech A45 accident near Boulder City, Nevada, June 23, 2013
On June 23, 2013 at about 9:43 pm local time, a Beech A45, registered N434M, was substantially damaged in an accident during enroute (descent) near Boulder City, Nevada (Boulder City airport). It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot/mechanic's loss of control during an emergency descent following a loss of engine power while in cruise flight. Contributing to the accident was the pilot/mechanic's incorrect assembly of the No. 6 cylinder at the last cylinder change, which resulted in a separation of the cylinder and the loss of engine power.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 23, 2013 · about 9:43 pm local time
- Place
- Boulder City, Nevada · Boulder City · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Beech A45 · all A45s on the register
- Registration
- N434M · registry record · serial G-756
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot, who was also the mechanic for the airplane, had replaced all six cylinders on the engine during the airplane's annual inspection; he reported that, 3 days before the accident, the engine was operated and ran well. On the day of the accident, he was returning the airplane to its home base following a maintenance inspection on the wings. The pilot was near the end of the flight when he contacted approach control and requested priority handling because an engine chip light had illuminated. Shortly thereafter, the pilot stated that the engine had lost power on a cylinder, and he declared an emergency. When the airplane was at 9,500 ft mean sea level, the pilot said that he was going to attempt to land at a nearby airport (elevation 2,201 ft). Before switching to the airport's common traffic advisory frequency (CTAF), the pilot reported to the approach controller that the airplane was at 3,800 ft with the landing gear down and that the situation was under control. The pilot did not contact approach control again and did not broadcast over the CTAF. The airplane collided with terrain in a nose- low attitude about 1 mile west of the airport. Postaccident examination of the airframe revealed no evidence of mechanical anomalies that would have precluded normal operation. Postaccident examination of the engine revealed that the No. 6 cylinder had separated, and no nuts were located on its through bolts. Magnified examinations of the bolt threads found the thread profiles intact and only locally distorted, consistent with the nuts not being present during the No. 6 cylinder separation, which appeared to be the result of the incorrect assembly of the cylinder at the last cylinder change. Fretting damage on the mounting pad was observed, which indicates looseness and movement between the cylinder and the case that resulted from inadequate preload in the fasteners either through insufficient initial torque or loss of torque during operation. Considering the short time since cylinder installation, it is likely that the cylinder fasteners, or at least some of them, were not correctly torqued at installation.
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
- Powerplant sys/comp malf/fail during enroute (cruise)
- Loss of engine power (partial) during enroute (cruise)
- Loss of control in flight during enroute (descent) defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- factor Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Incorrect service/maintenance
- factor Personnel issues › Task performance › Maintenance › Replacement › Maintenance personnel
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: airplane single-engine; instrument: airplane; rotorcraft: balloon; rotorcraft: helicopter
- Flight time: 945 hours in all
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: frt
- Injury: fatal
The aircraft
- Seats: 2
- Landing gear: retractable
- Engine: Cont Motor IO-550-B23B (piston); 0 hours total
- Operator: Jet Test And Transport LLC
The flight
- Departed from: Chandler AZ
- Destination: VGT North Las Vegas NV
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 140° at 25 knots, gusting 30
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 95°F (35°C), dew point 27°F (-3°C)
- Altimeter: 29.67 inHg
- Observation at 9:35 pm from KBVU, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 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 WPR13FA284.