Amateur-built AC 4C accident near Front Royal, Virginia, February 9, 2020
On February 9, 2020 at about 6:20 pm local time, a 2002 amateur-built AC 4C (glider), registered N912ES, was substantially damaged in an accident during approach (VFR pattern downwind) near Front Royal, Virginia (Front Royal-Warren County airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's exceedance of the glider’s critical angle of attack while maneuvering for landing, which resulted in an aerodynamic stall and subsequent loss of control.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 9, 2020 · about 6:20 pm local time
- Place
- Front Royal, Virginia · Front Royal-Warren County · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built AC 4C No Series, built 2002
- Registration
- N912ES · no longer on the register · serial 002K
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Prior to the flight, the pilot told a fellow soaring club member that he was going to practice speed control in the traffic pattern. The panel-mounted radio in the glider was not working, so the pilot had to use a handheld radio to communicate. However, no witnesses recalled hearing any communications from the pilot after he disconnected from the tow plane. About 1 hour after the pilot departed, a club member saw his glider on downwind for runway 28. The glider appeared to have a nose-up attitude, was moving "slower than normal," and appeared to be at "minimum sink" speed. At this time, another club glider had just executed a practice premature termination of tow (PTT) maneuver from runway 28 and was landing in the opposite direction on runway 10. The club member thought that the accident pilot had slowed down to wait for that glider to clear the runway, and due to spacing, the accident pilot might have to fly over the top of them and land. The club member turned his attention away from the accident glider and did not see the accident. The flight instructor who had just completed the PTT maneuver said that they had just finished their landing rollout on runway 10 when he looked up and saw the glider in a fully involved spin toward the ground. The glider impacted wooded terrain about a 1/2 mile northwest of the airport. Postaccident examination of the glider revealed no mechanical anomalies that would have precluded normal operation prior to the accident. An index card with airspeeds written on it was found in the wreckage. According to the airspeeds listed, the glider's minimum sink speed was 39 knots, and the stall speed was 37 knots. The pilot's handheld radio was found stowed in a storage pouch that was attached to the right side of the cockpit wall. The radio exhibited some impact damage to the battery section and was inoperable. It was not determined why the pilot was not using his handheld radio to communicate. The club's duty officer who was monitoring the airport's traffic frequency the accident pilot was always meticulous with making radio calls, and it was unlike him not to do so on the day of the accident. Since the pilot stated that he was going to practice speed control in the pattern and was observed flying slower than normal and near minimum sink speed on the downwind leg of the traffic pattern, he may have been distracted by traffic on the runway. It is likely the pilot exceeded the glider's critical angle of attack and entered an aerodynamic stall at an altitude that was too low to recover.
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
- Loss of control in flight during approach (VFR pattern downwind) defining event
- Aerodynamic stall/spin during approach (VFR pattern downwind)
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Not attained/maintained
Pilot
- Certificate: airline transport pilot, commercial pilot, flight engineer
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: glider
- Flight time: 18,800 hours in all; 16.5 in this make and model
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: ctr
- Injury: fatal
The aircraft
- Airframe total time: 120.4 hours
- Last inspection: condition inspection, February 13, 2019
- Maximum gross weight: 485 lb
- Seats: 1
- Landing gear: fixed
- Engine: (none); 0 hours total
The flight
- Departed from: FRR Front Royal VA at 5:25 pm
- Destination: FRR Front Royal VA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 250° at 7 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 46°F (8°C), dew point 27°F (-3°C)
- Altimeter: 30.40 inHg
- Observation at 6:35 pm from FRR, 1 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
10 documents, released by the NTSB on January 26, 2022. 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 | NTSB Record of Conversation - Witness (Preflight) | PDF, 1 page | View Download |
| 2 | NTSB Roc - Witness (Traffic Pattern) | PDF, 1 page | View Download |
| 3 | NTSB Record of Conversation - Flight Instructor | PDF, 1 page | View Download |
| 4 | NTSB Record of Conversation - Tow Pilot | PDF, 1 page | View Download |
| 5 | NTSB Record of Conversation - Duty Officer | PDF, 1 page | View Download |
| 6 | Photos | PDF, 7 pages | View Download |
| 7 | Maintenance Record | PDF, 1 page | View Download |
| 8 | Toxicological Report | PDF, 1 page | View Download |
| 9 | Memorandum - Medical and Pathological Information | PDF, 1 page | View Download |
| 10 | Release of Aircraft Wreckage and Ecf | PDF, 2 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.
