# NTSB WPR25FA277: Lawson Thomas O Lancair Super ES, N905ET, Mount Hamilton, CA, September 12, 2025

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Class 3 · Field · Preliminary report
- Date: September 12, 2025, 14:21 local (21:21 UTC)
- Place: Mount Hamilton, CA · NE Lick Observatory on hillside
- Coordinates: 37.39495, -121.58826
- Nearby events: https://openairdocs.org/map.md?lat=37.3950&lon=-121.5883&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-descent: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Investigation ongoing
- Investigation class: Class 3
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 200993
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR25FA277
- NTSB preliminary report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/200993/pdf
- Page: https://openairdocs.org/ntsb/WPR25FA277

## Preliminary report

On September 12, 2025, about 1421 Pacific daylight time, an experimental amateur-built Lancair Super ES, N905ET, was destroyed when it was involved in an accident near Mount Hamilton, California. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot’s sister reported that the pilot was due to depart from Ryan Field Airport (RYN), Tucson, Arizona, with the intended destination of the Norman Y Mineta San Jose International Airport (SJC), San Jose, California. Hunters near the accident site reported observing the airplane circling their location at high speed about 1,000 ft above them. During a subsequent circling pattern, the airplane had descended to about 300 ft above ground level, then made a sharp right turn overflying their location. The airplane continued to bank to the right and “went straight down into the hillside at what sounded like full engine power.” The recorded ADS-B flight track showed that at 1300:12, the airplane was on a northeast heading at an altitude of about 8,900 ft mean sea level (msl). ADS-B contact was lost about 242 miles southwest of the accident site. Examination of the accident site revealed that the airplane impacted mountainous terrain along the western edge of a valley about 5 miles northeast of Mount Hamilton. The first identified point of contact (FIPC) was a 12 ft tall tree that had damaged limbs near the top of the tree. The debris path was oriented on a heading of about 250° magnetic and was about 90 ft in length from the FIPC. Various portions of airplanes flight control surfaces, and propeller fragments were observed throughout the debris path. The fuselage came to rest inverted on a heading of about 250° magnetic at an elevation of 2,148 ft msl.

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Enroute-descent: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Lawson Thomas O LANCAIR SUPER ES, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=056200A), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Enroute-descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Lawson Thomas O LANCAIR SUPER ES, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=056200A), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Aircraft

- Registration: [N905ET](https://openairdocs.org/aircraft/N905ET), registered now, S/N 148 (OpenAirDocs)
- Reported make and model: LAWSON THOMAS O LANCAIR SUPER ES
- Registry model: [Lawson Thomas O LANCAIR SUPER ES](https://openairdocs.org/model/lawson-thomas-o-lancair-super-es) (registry code 056200A) (OpenAirDocs)
- Registry engine: [Continental IO-550 series](https://openairdocs.org/engine/continental-io-550-series) (registry code 17042, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 148
- Year built: 2006
- Airframe hours: 566
- Damage: Destroyed
- Flight: Personal, Part 91
- Airworthiness certificate: Special, Experimental (Special)
- Departed: RYN, Tucson, AZ
- Destination: SJC, San Jose, CA
- Equipment: Unknown

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 5 knots, gusting 14
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 57 °F
- Altimeter: 29.95 inHg
- Observed at: KRHV, 12 nm away
- METAR: KRHV 122047Z 31005G14KT 10SM SKC 26/14 A2995

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20250912015629A](https://openairdocs.org/incident/20250912015629A), Sep 12, 2025: Lawson Thomas O LANCAIR SUPER ES, Mt Hamilton, CA, Destroyed, 1 fatal. [privacy data omitted]. [privacy data omitted] [privacy data omitted]. [privacy data omitted] [privacy data omitted]

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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