Grumman American Avn. CORP. AA-5B accident near Lone Pine, California, August 19, 2023
On August 19, 2023 at about 2:10 am local time, a 1979 Grumman American Avn. CORP. AA-5B, registered N4537Y, was substantially damaged in an accident during maneuvering (low-alt flying) near Lone Pine, California. It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured and 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's inability to maintain altitude after encountering a downdraft, which resulted in collision with terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 19, 2023 · about 2:10 am local time
- Place
- Lone Pine, California · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Grumman American Avn. CORP. AA-5B, built 1979 · all AA-5Bs on the register
- Registration
- N4537Y · no longer on the register · serial AA5B1292
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that, while conducting a low pass over an off-airport landing strip at an altitude of 100 ft above the ground, the airplane encountered a downdraft. The pilot felt the airplane was unable to climb out of the valley without stalling, so he maintained airspeed, but the airplane descended and impacted the ground. The airplane subsequently rebounded and came to a rest in an upright position, which resulted in substantial damage to both wings, fuselage, and empennage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.
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
- Other weather encounter during maneuvering (low-alt flying)
- Low altitude operation/event during maneuvering (low-alt flying) defining event
The NTSB's findings
- Personnel issues › Action/decision › Info processing/decision › Identification/recognition › Pilot
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Climb rate › Capability exceeded
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Not attained/maintained
- Environmental issues › Physical environment › Terrain › Mountainous/hilly terrain › Effect on operation
- Environmental issues › Conditions/weather/phenomena › Wind › Downdraft › Ability to respond/compensate
- Environmental issues › Conditions/weather/phenomena › Wind › Downdraft › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land; rotorcraft: glider
- Flight time: 1,097 hours in all; 16 in this make and model; 70 in the last 90 days; 32 in the last 30 days; 1,023 as pilot in command
- Last flight review: August 10, 2023
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: left
- Injury: minor injuries
Passenger
- Seat: rgt
- Injury: serious injuries
The aircraft
- Airframe total time: 2,209.8 hours
- Last inspection: annual inspection, July 11, 2023; 25 hours since
- Maximum gross weight: 2,400 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming A4K (piston); 2,225 hours total
The flight
- Departed from: KSMO Santa Monica CA at 6:11 pm
- Destination: KSMO Santa Monica CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 140° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 97°F (36°C), dew point 36°F (2°C)
- Altimeter: 29.92 inHg
- Observation at 11:56 am from KNID, 40 miles away
Weather report (METAR): KNID 181856Z AUTO 14005KT 10SM CLR 36/02 A2992 RMK AO2 SLP102 T03560017 $
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on November 30, 2023. 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 | Photos | PDF, 3 pages | 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.