# NTSB CHI93LA334: Burkhart Grob G103, N422BG, Hinckley, IL, August 22, 1993

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 22, 1993, 11:10 local (16:10 UTC)
- Place: Hinckley, IL
- Coordinates: 41.759162, -88.640296 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.7592&lon=-88.6403&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report October 20, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 9290
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI93LA334
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9290/pdf
- Page: https://openairdocs.org/ntsb/CHI93LA334

## Probable cause

the failure of the cockpit canopy.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, approach - vfr pattern - final approach
  - window,canopy - failure,total (cause)
- Hard landing, landing - flare/touchdown

## Analysis

THE SOLO STUDENT PILOT WAS ON FINAL APPROACH FOR LANDING WHEN HE HEARD A LOUD CRACK AND SOMETHING STRUCK HIM IN THE FACE AND KNOCKED HIS GLASSES OFF. HE THEN NOTICED THAT THE COCKPIT CANOPY WAS BROKEN AND OPEN, AND THAT THE NOSE OF THE SAILPLANE WAS LOW. HE PULLED THE NOSE UP JUST AS THE SAILPLANE LANDED HARD. A NEARBY WITNESS REPORTED SEEING SOMETHING FLY OFF THE SAILPLANE JUST BEFORE THE HARD LANDING. POSTACCIDENT INSPECTION FAILED TO DISCOVER WHY THE CANOPY BROKE/OPENED.

## Factual narrative

On August 22, 1993, about 1110 central daylight time, a Grob G103 sailplane, N422BG, sustained substantial damage during a hard landing at Hinckley Airport, Hinckley, Illinois.  The solo student pilot incurred minor injury. Visual meteorological conditions existed for the local, instructional flight.  The flight originated about 1059 without flight plan and operated under 14 CFR 91.

The pilot stated that while on final approach for landing, at an estimated altitude of 20', he heard a loud crack and was struck in the face by something that knocked his glasses off.  He then noticed that the canopy was open and broken, and that the sailplane was in a nose low attitude. He said he was pulling the nose up as the sailplane landed hard.

A witness on the ground approximately 300 feet away, saw an object coming off the nose of the sailplane as the Grob was on final approach to land.

A postaccident examination of the canopy and sailplane failed to discover why the canopy opened/broke in-flight.

## Aircraft

- Registration: [N422BG](https://openairdocs.org/aircraft/N422BG), registered now, S/N 3711, built 1982 (OpenAirDocs)
- Reported make and model: Burkhart Grob G103
- Registry model: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g103-twin-astir) (registry code 1660202) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 3711
- Airframe hours: 2190
- Engines: unknown
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Hinckley Soaring
- Registered owner: Hinckley Soaring
- Airworthiness certificate: Special, Provisional (Special)
- Last inspection: Annual, June 25, 1993, 60 hours before
- Airport: 0C2, Hinckley, runway 27, 2,600 × 300 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; student; medical: unknown; seat: front; flight hours: 15 total, 1 in this make and model, 6 as pilot in command, 1 in the last 90 days, 1 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: 10,000 ft overcast
- Temperature: 75 °F, dew point 64 °F
- Altimeter: 30.00 inHg

## 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 19930822030119A](https://openairdocs.org/incident/19930822030119A), Aug 22, 1993: Grob G103ATWINII, Hinckley, IL, Substantial damage. On landing approach canopy came open. Debris knocked pilots glasses off. Hard landing. Undetermined cause of canopy

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.

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