# NTSB ERA25LA287: Grob-Werke Twin Astir, N103GV, Franconia, NH, July 24, 2025 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: July 24, 2025, 16:00 local (20:00 UTC) - Place: Franconia, NH · Field - Coordinates: 44.17493, -71.764361 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.1749&lon=-71.7644&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of lift](https://openairdocs.org/ntsb-events/500) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 20, 2025 - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 200709 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA25LA287 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/200709/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=200709 - Page: https://openairdocs.org/ntsb/ERA25LA287 ## Probable cause The pilot’s failure to detect the inadvertent deployment of the spoilers, which resulted in a prolonged, excessive descent rate. Contributing to the accident was the pilot’s decision to conduct a downwind approach versus a straight in approach to the diversionary airport, which resulted in an off-airport landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Grob-Werke TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=1660309), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) - [Flight control system: drag control system](https://openairdocs.org/ntsb-findings/01022760): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Grob-Werke TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-findings/01022760/cases.md?model=1660309), [All aircraft, 10 cases](https://openairdocs.org/ntsb-findings/01022760/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Grob-Werke TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1660309), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Grob-Werke TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-events/500/sequence.md?model=1660309), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Grob-Werke TWIN ASTIR, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=1660309), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot of the glider was being towed to altitude near mountainous terrain when the glider encountered turbulence and rotor wave activity. The pilot reported that, after releasing from tow, he noted that the glider was in “some bad sink.” The pilot initially turned back to the airport but continued to lose altitude quickly. He then noticed that the spoilers were extended, retracted them, and attempted to reach a diversionary airport; however, the glider continued to descend rapidly. The pilot said he entered the airport traffic pattern rather than making a straight-in landing approach, but realized he had insufficient altitude to clear trees, and landed in a nearby field. Upon landing, the glider ground looped when it contacted tall grass resulting in substantial damage to the tail boom. The pilot said there were no mechanical malfunctions or failures of the glider that would have precluded normal operation. ## Aircraft - Registration: [N103GV](https://openairdocs.org/aircraft/N103GV), registered now, S/N 3069 (OpenAirDocs) - Reported make and model: GROB-WERKE TWIN ASTIR - Registry model: [Grob-Werke TWIN ASTIR](https://openairdocs.org/model/grob-werke-twin-astir) (registry code 1660309) (OpenAirDocs) - Category: Glider - Serial number: 3069 - Airframe hours: 3205 - Engines: None none - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 15, 2024 - Departed: 1B5, Franconia, NH - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 49; injuries: none; private; last flight review October 20, 2024; seat: rear; restraint: 4-point; flight hours: 253 total, 14.2 in this make and model, 171.2 as pilot in command, 24.7 in the last 90 days, 14.8 in the last 30 days, 1.4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 8 knots, gusting 19 - Visibility: 10 statute miles - Temperature: 88 °F, dew point 63 °F - Altimeter: 29.98 inHg - Observed at: HIE, 15 nm away - METAR: KHIE 241952Z AUTO 23008G19KT 200V270 10SM FEW050 31/17 A2998 RMK AO2 SLP149 T03110172 ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20250724010089A](https://openairdocs.org/incident/20250724010089A), Jul 24, 2025: Grob-Werke TWIN ASTIR, Franconia, NH, Substantial damage. On Thursday July 24, 2025, the pilot of a Grob Twin Astir with one passenger in the front seat departed from 1B5 (Franconia NH) at around 1530, PIC launched… ## Docket (2 files) The files NTSB released with the investigation on November 20, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=200709. 2.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19152177&FileExtension=pdf&FileName=6120_1_Redacted-Rel.pdf - Investigation photo (item 2, PDF, 2 pages, 1 photo, 234 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19150762&FileExtension=pdf&FileName=Investigative%20Photo-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.