# NTSB CHI07CA233: Schweizer SGS 1-35C, N135EX, Northfield, MN, July 20, 2007

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: July 20, 2007, 14:30 local (19:30 UTC)
- Place: Northfield, MN
- Coordinates: 44.560714, -95.980636 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.5607&lon=-95.9806&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 30, 2007
- Report: Approved by Office Director
- NTSB case key (mKey): 66343
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI07CA233
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66343/pdf
- Page: https://openairdocs.org/ntsb/CHI07CA233

## Probable cause

The pilot's failure to maintain adequate airspeed, which resulted in a stall during the off-airport landing.  A factor contributing to the accident was the dirt/rock pile.

## Sequence of events

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

- In flight collision with terrain/water, landing
  - terrain condition - rock(s)/boulder(s) (contributing factor)
  - airspeed - not maintained, pilot in command (cause)
  - stall - encountered, pilot in command
  - terrain condition - open field

## Analysis

The glider was substantially damaged during an off-airport landing.  The pilot stated that as he was returning from a flight about 7 miles west of the departure airport, he encountered heavy sink and found himself at 1,100 feet above ground level.  The pilot then elected to make an off-airport landing to a cow pasture.  He stated that his approach was "somewhat high, and [he] had to lose altitude while rapidly approaching the upslope terrain with a dirt/rock pile at the far end."  The pilot stated that he pitched up to either lose speed, or avoid the dirt/rock pile, causing the glider to balloon.  The glider then stalled about 5 to 10 feet above the ground and bounced "very hard."  The glider's fuselage was subsequently found to have damage to the bulkhead and skins.

## Factual narrative

The glider was substantially damaged during an off-airport landing.  The pilot stated that as he was returning from a flight about 7 miles west of the departure airport, he encountered heavy sink and found himself at 1,100 feet above ground level.  The pilot then elected to make an off-airport landing to a cow pasture.  He stated that his approach was "somewhat high, and [he] had to lose altitude while rapidly approaching the upslope terrain with a dirt/rock pile at the far end."  The pilot stated that he pitched up to either lose speed, or avoid the dirt/rock pile, causing the glider to balloon.  The glider then stalled about 5 to 10 feet above the ground and bounced "very hard."  The glider's fuselage was subsequently found to have damage to the bulkhead and skins.

## Aircraft

- Registration: [N135EX](https://openairdocs.org/aircraft/N135EX), registered now, S/N 72, built 1977 (OpenAirDocs)
- Reported make and model: Schweizer SGS 1-35C
- Registry model: [Schweizer SGS 1-35C](https://openairdocs.org/model/schweizer-sgs-1-35c) (registry code 8050151) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 72
- Airframe hours: 876
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Clear Sky LLC
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 1, 2007
- Departed: SYN, Stanton, MN

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; injuries: none; private; airplane ratings: single-engine land; medical: class 3, unknown; last flight review August 1, 2006; seat: single; flight hours: 328 total, 22 in this make and model, 275 as pilot in command, 15 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 110° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 48 °F
- Altimeter: 30.18 inHg
- Observed at: SYN, 4 nm away

## 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 20070720019869A](https://openairdocs.org/incident/20070720019869A), Jul 20, 2007: Scwzer SGS135C, Stanton, MN, Substantial damage. (-23) The pilot airman [privacy data omitted] encountered unexpected aerial downdrafts, which led to an off field glider landing, 4 miles from the intended…

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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