Lake LA 4 accident near Byron, California, July 25, 2017
On July 25, 2017 at about 8:10 pm local time, a 1969 Lake LA 4, registered N7628L, was substantially damaged in an accident during landing (flare/touchdown) near Byron, California (Byron airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s failure to activate the hydraulic system during the approach, and his failure to ensure that the landing gear was down and locked before touchdown. Contributing to the accident was the pilot's decision to operate the airplane with an inoperative landing gear position indicator light.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 25, 2017 · about 8:10 pm local time · cases in 2017
- Place
- Byron, California · Byron · cases near this airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Lake LA 4 UNDESIGNAT, built 1969 · all LA 4s on the register
- Registration
- N7628L · registry record · serial 401
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
During landing, the nose landing gear and right main landing gear collapsed, and the airplane veered off the runway. The pilot stated that it was likely that he switched the hydraulic pump off during the accident flight. Although both the hydraulic switch position and checking the hydraulic system pressure were included in his before-landing checklist, he could not recall their position and indication, respectively, during the accident approach. The pilot also reported that he had been experiencing issues with the landing gear microswitches, and the airplane's landing gear indicator light was inoperative as a result. Postaccident examination of the airplane and landing gear system revealed no evidence of mechanical malfunctions or anomalies that would have precluded normal operation. It is likely that the pilot's failure to properly configure the hydraulic switch, and his subsequent failure to recognize the error during his before-landing check, resulted in inadequate hydraulic pressure to extend and lock the landing gear. The airplane's inoperative landing gear indicator light likely contributed to the pilot's failure to recognize that the landing gear was not fully extended and locked before landing.
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
- Landing gear collapse during landing (flare/touchdown) defining event
- Runway excursion during landing (landing roll)
The NTSB's findings
- Aircraft › Aircraft systems › Hydraulic power system › Hydraulic, main system › Incorrect use/operation other cases naming the heating, ice protection and utility systems
- Aircraft › Aircraft systems › Landing gear system › Gear position and warning › Not serviced/maintained other cases naming the landing gear
- Personnel issues › Task performance › Use of equip/info › Use of equip/system › Pilot
- Personnel issues › Action/decision › Info processing/decision › Decision making/judgment › Pilot
- Aircraft › Aircraft systems › Landing gear system › (general) › Incorrect use/operation other cases naming the landing gear
Pilot
- Certificate: private
- Ratings: single-engine land; single-engine sea
- Flight time: 790 hours in all
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Passenger
- Seat: rgt
- Injury: no injuries
The aircraft
- Landing gear: retractable
- Engine: Lycoming O-360 (piston); 0 hours total
The flight
- Departed from: LVK Livermore CA at 8:00 pm
- Destination: C83 Byron CA
- Flight plan: none
- Runway 30, 4,500 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 210° at 9 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 81°F (27°C), dew point 52°F (11°C)
- Altimeter: 29.92 inHg
- Observation at 7:53 pm from KLVK, 12 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Photographs from the investigation 5 pictures from the NTSB's docket, as the NTSB released them
Photo 1 – Accident site.
Photo 2 – Accident site.
Photo 3 – Accident Site
Photo 4 – Right main landing gear position switch.
Photo 5 – Left main landing gear position switch.The NTSB's photographs with the NTSB's captions, at screen size. Open a picture to see it full size or to report one that should not be shown.
Documents from the investigation the NTSB's docket: the evidence folder behind the report
3 documents, released by the NTSB on January 5, 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 | FAA Examination Notes | PDF, 3 pages | View Download |
| 2 | Pilot Statement | PDF, 5 pages | View Download |
| 3 | Photo Array | PDF, 5 pages · our copy | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N7628L on the register today · the tail number may have moved to another aircraft since
- Lake LA-4 137 registered today · the model family and its accident history
- Lake 137 aircraft on the register
- Engine: Lycoming O-360 1,069 aircraft carry this series today · as the NTSB recorded it
- Byron Airport · nearest airport
- Livermore Municipal · departed from
- Accidents and incidents in California 9,080 since 1982 · 1,097 in the last ten years
- California 27,897 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/WPR17LA165.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.