Alexander Schleicher GMBH & CO ASW 27-18 accident near Sterling, Massachusetts, July 15, 2021
On July 15, 2021 at about 8:00 pm local time, a 2012 Alexander Schleicher GMBH & CO ASW 27-18 (glider), registered N129MG, was substantially damaged in an accident during takeoff near Sterling, Massachusetts (Sterling airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s failure to maintain the glider’s stability in the roll axis during the takeoff roll, which resulted in a dragged wingtip and ground loop.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 15, 2021 · about 8:00 pm local time
- Place
- Sterling, Massachusetts · Sterling · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Alexander Schleicher GMBH & CO ASW 27-18, built 2012
- Registration
- N129MG · registry record · serial 29081
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot, there was a slight depression in the narrow, paved strip used for glider takeoffs, and that during the takeoff roll, the left wing “flexed” and “dipped” such that the wingtip contacted the turf which created the pivot point around which the glider “ground-looped” which fractured the empennage aft of the cockpit. The pilot added that there had been “3 weeks of heavy rain” prior to the day of the accident and that the grass on either side of the takeoff strip was longer than usual, which reduced his wingtip clearance. He stated that while he had successfully departed the strip earlier that day, a lower grass height would have lowered his risk exposure during the takeoff run. The pilot reported that there were no pre-accident mechanical malfunctions or anomalies 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
- Loss of control on ground during takeoff defining event
The NTSB's findings
- Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Lateral/bank control › Not attained/maintained
- Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land; rotorcraft: glider
- Flight time: 3,216 hours in all; 435 in this make and model; 63 in the last 90 days; 21 in the last 30 days; 323 as pilot in command
- Last flight review: July 15, 2020
- Medical certificate: None
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 472 hours
- Last inspection: annual inspection, November 1, 2020
- Maximum gross weight: 1,322 lb
- Seats: 1
- Landing gear: retractable
The flight
- Flight plan: none
- Runway 34, 2,800 ft by 10 ft
Weather at the time
- Light: daylight
- Wind: from 230° at 9 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 88°F (31°C), dew point 61°F (16°C)
- Altimeter: 30.04 inHg
- Observation at 3:52 pm from KFIT, 8 miles away
Weather report (METAR): KFIT 151952Z AUTO 23009KT 10SM CLR 31/16 A3004 RMK AO2 SLP171 T03060161 TSNO=
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
4 documents, released by the NTSB on May 4, 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 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 11 pages | View Download |
| 2 | Pilot's Statement | PDF, 2 pages | View Download |
| 3 | Memorandum for Record A�� Telephone Interview, Pilot | PDF, 1 page | View Download |
| 4 | Photos | 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.