Let L-23 SUPER BLANIK accident near Sterling, Massachusetts, July 31, 2021
On July 31, 2021 at about 4:58 pm local time, a 2000 Let L-23 SUPER BLANIK (glider), registered N373BA, suffered minor damage in an accident during landing (flare/touchdown) near Sterling, Massachusetts (Sterling Airport). It was an instructional flight under general aviation rules (Part 91). 1 person was seriously injured; 1 other was unhurt. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The flight instructor’s lack of remedial action, which resulted in an aerodynamic stall in the landing flare and a hard landing.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 31, 2021 · about 4:58 pm local time
- Place
- Sterling, Massachusetts · Sterling Airport · map
- Type
- Accident
- Injuries
- 1 person was seriously injured; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Let L-23 SUPER BLANIK, built 2000 · all L-23 SUPER BLANIKs on the register
- Registration
- N373BA · registry record · serial 008713
- Damage
- Minor damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The flight instructor reported that student pilot was flying the glider as it approached to land with the air brakes in the fully extended position. As the student pilot attempted to flare, the glider pitched up and stalled several feet above the runway, resulting in a hard landing. During the hard landing, the glider sustained minor damage and the student pilot was not injured; however, the flight instructor was seriously injured. The flight instructor added that there were no preimpact mechanical malfunctions with the glider and he should have had his hands in close proximity to the controls to be ready to prevent any abrupt inputs and take control if required.
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
- Hard landing during landing
- Aerodynamic stall/spin during landing (flare/touchdown) defining event
The NTSB's findings
- Personnel issues › Action/decision › Action › Lack of action › Instructor/check pilot
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Pitch control › Not attained/maintained
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Capability exceeded
Flight instructor
- Certificate: commercial pilot
- Ratings: instructor: glider; rotorcraft: glider
- Flight time: 733 hours in all; 80 in this make and model; 11 in the last 90 days; 5 in the last 30 days; 695 as pilot in command; 37 on instruments
- Last flight review: August 30, 2020
- Medical certificate: None
- Seat: rear
- Injury: serious injuries
Dual student
- Certificate: student
- Flight time: 12 hours in all; 2 in this make and model; 3 in the last 90 days; 1 in the last 30 days; 0 as pilot in command
- Medical certificate: None
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 2,545 hours
- Last inspection: annual inspection, August 17, 2020
- Maximum gross weight: 1,124 lb
- Seats: 2
- Landing gear: retractable
The flight
- Flight plan: none
- Runway 34, 3,086 ft by 40 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 270° at 10 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 46°F (8°C)
- Altimeter: 29.93 inHg
- Observation at 12:52 pm from FIT, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 | 1 |
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number ERA21LA327.