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Accidents · NTSB DEN05FA126 · Final report

Cessna 425 accident near Lone Tree, Colorado, August 14, 2005

On August 14, 2005 at about 2:20 am local time, a Cessna 425, registered N425SG, was destroyed in an accident near Lone Tree, Colorado. It was a personal flight under general aviation rules (Part 91). 4 people were killed. The weather was instrument conditions (cloud, fog or low visibility).

The NTSB's probable cause their words, unchanged

The pilot's failure to properly execute the published instrument approach procedure, which resulted in controlled flight into terrain.

Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.

What the record shows

Date
August 14, 2005 · about 2:20 am local time
Place
Lone Tree, Colorado · map
Type
Accident
Injuries
4 people were killed.
Weather
instrument conditions (cloud, fog or low visibility)
Aircraft
Cessna 425 · all 425s on the register
Registration
N425SG · no longer on the register · serial 425-0166
Damage
Destroyed
Flight
Personal flight · general aviation rules (Part 91)

The NTSB's narrative final · quoted from the NTSB record

During an ILS approach in night instrument meteorological conditions, the airplane impacted terrain and was destroyed by impact forces and postcrash fire. Prior to departure, the pilot obtained a weather briefing, which reported light rain, mist, and instrument meteorological conditions at the destination airport. After approaching the terminal area, the pilot received radar vectors to intercept the localizer for the Runway 35R ILS approach. The pilot's keying of the microphone and the timing of his speech exhibited decreased coordination during the approach phase of flight. After crossing the outer marker and at altitude of 7,700 feet, the pilot asked the controller what the current ceilings were at the airport, and the controller stated 500 feet. With the airplane at an altitude of 6,800 feet, the controller informed the pilot of a "low altitude alert" warning, at which the pilot responded, "Yeah, I am a bit low here." Approximately 20 seconds later, the pilot stated, "I'm back on glideslope." No further communications were received from the accident airplane. The controller issued another low altitude warning, and the radar target was lost. The accident site was located on a hilly, grass field at an elevation of 6,120 feet approximately 2.6 nautical miles from the runway threshold near the extended centerline of the runway. At 2027, the weather conditions at the airport were reported as wind from 360 degrees at 10 knots, visibility 2 statute miles with decreasing rain, scattered clouds at 500 feet, broken clouds at 1,100 feet, and an overcast ceiling at 2,800 feet. An acquaintance of the pilot, who had flown with him on other occasions, provided limited information about the pilot's proficiency, but stated, "a night ILS in IFR conditions would not be [the pilot's] first choice if he had an option." The pilot's logbooks were not located. The pilot did not hold a valid medical certificate at the time of the accident, and post-accident toxicological test revealed the presence of unreported prescription medications. No anomalies were noted with the airframe and engines. Ground inspection and flight testing of the airport's navigational equipment revealed that the equipment functioned satisfactorily.

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

Pilot

  • Certificate: private
  • Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
  • Flight time: 5,000 hours in all; 1,450 in this make and model
  • Last flight review: November 1, 2004
  • Medical certificate: None
  • Seat: left
  • Injury: fatal

The aircraft

  • Airframe total time: 4,003.9 hours
  • Last inspection: continuous airworthiness programme, May 1, 2005
  • Maximum gross weight: 8,275 lb
  • Seats: 6
  • Landing gear: retractable
  • Engine: Pratt & Whitney Canada PT6A-135A (turboprop); 0 hours total
  • Fire on the ground

The flight

  • Departed from: SZT Sandpoint ID at 11:27 pm
  • Destination: APA Englewood CO
  • Flight plan: IFR

Weather at the time

  • Light: night
  • Wind: from 010° at 9 knots
  • Visibility: 2 statute miles
  • Sky: overcast at 2,800 ft; scat at 500 ft
  • Temperature: 54°F (12°C), dew point 54°F (12°C)
  • Altimeter: 30.21 inHg
  • Observation at 2:27 am from APA, 2 miles away

Injuries

FatalSeriousMinorNone
Crew1
Passengers3

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.

Other NTSB records under N425SG the same tail number, which may have belonged to a different aircraft at the time

2003-05-31DEN03LA095 · accident near Pueblo, CO · substantial damage · no injuries

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.