NYC99LA102 · Glaser-Dirks DG-400
Glaser-Dirks DG-400 · Accident: airframe, component or system failure en route
From 22B · BURLINGTON, CT to an unrecorded destination
Event
- NTSB case
- NYC99LA102
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Glaser-Dirks DG-400
- Aircraft type
- Glaser Dirks DG-400
- Category
- Glider
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N400FJ
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 22B · BURLINGTON, CTTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Manufacturer › Material defect(inadequate quality of material)
- Wing, wing attachment fitting › Debonded
Approximate · Estimated position: the centre of New Milford, CT, the place the record names. Not the accident site.
NTSB narrative
While in flight, at an indicated airspeed of 60 knots, a 'loud bang' was heard and the gear warning alarm began to sound. The pilot looked to the left and observed the left wing displaced 20 degrees up from its normal position. The glider began to descend and control inputs by the pilot were unresponsive. In the decent, as the glider's speed began to increase, the pilot elected to egress from the glider. The glider broke apart in flight and descended to the ground. A piece of the glider's fiberglass skin that contained a residue of an adhesive on the inside surface was removed and examined. The adhesive area would have attached spar pin-lock assembly, which secured the wing spar pins. The surface of this epoxy layer contained impression marks similar to a cross-weave pattern found on the surface of fiberglass. The cross-weave pattern on the surface of the epoxy was consistent with a fracture that traveled between the UD-glass fabric tape and the epoxy layer. This separation was characterized as an adhesive separation. The surface of the epoxy layer also contained exposed voids. No bonding between the epoxy and UD-glass fabric tape was observed in the void areas.
Probable cause
The manufacturer's use of inadequate adhesive material which resulted in the de-bonding and subsequent failure of the wing spar pin-lock assembly.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC99LA102
- Event ID
- 20001212X18857
- Case number
- NYC99LA102
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: b70bb086767b3a0727d572f8bd23042de47dfeb7fbd104b69292a550cef407e2; retrieved 2026-09-21T20:33:21.158Z.