# NTSB CEN12LA490: Smith Applebay Zuni II, N1ZV, Gregory, MI, July 29, 2012

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: July 29, 2012, 13:43 local (17:43 UTC)
- Place: Gregory, MI
- Coordinates: 42.441944, -84.064445 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.4419&lon=-84.0644&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach-VFR pattern base: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report July 30, 2014
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA Detroit FSDO
- NTSB case key (mKey): 84491
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA490
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84491/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84491
- Page: https://openairdocs.org/ntsb/CEN12LA490

## Probable cause

The glider pilot’s failure to maintain sufficient altitude and airspeed while turning to the base leg of the traffic pattern, which resulted in a stall/spin and impact with trees and terrain.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Smith Mike APPLEBAY ZUNI, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=05675CB), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Smith Mike APPLEBAY ZUNI, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=05675CB), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Smith Mike APPLEBAY ZUNI, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05675CB), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach-VFR pattern base: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Smith Mike APPLEBAY ZUNI, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=05675CB), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md)
- [Approach-VFR pattern base: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Smith Mike APPLEBAY ZUNI, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05675CB), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that the takeoff and tow to 3,000 feet above ground level (agl) was normal. The pilot released the glider from the tow airplane about 2 miles northwest of the airport. He was unable to achieve the necessary lift, and, as the glider lost altitude, he started flying back toward the airport and proceeded toward the initial point for landing on the runway. As the pilot flew the glider on the downwind pattern leg, he realized that he was not going to be able to complete the traffic pattern. He attempted to clear the tree line that crossed the downwind leg, but the glider hit the trees and subsequently impacted terrain. A witness reported that the glider's altitude was about 125 to 150 feet agl when it was on the downwind leg and that its airspeed was too low. The witness added that the glider continued to slow as it turned to the base leg, at which point, the left wing stalled, and then the glider pitched down nearly vertical and completed about 1/2 spin before it disappeared behind the trees. A postaccident examination of the airframe revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

## Factual narrative

On July 29, 2012, at 1343 eastern daylight time, an experimental Smith Applebay Zuni II glider, N1ZV, sustained substantial damage when it impacted trees and terrain while on the downwind leg to runway 36 at the Richmond Field Airport (69G), Gregory, Michigan. The pilot, the sole occupant, received serious injuries. The glider was registered to and operated by the pilot under the provisions of the 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the local flight which originated from 69G at 1329. The pilot reported that he completed the pre-takeoff checklist, which included a positive control check of the flight controls. He reported that the takeoff and tow to 3,000 feet above ground level (agl) was normal. The pilot released the glider from the tow airplane at 3,000 feet agl about 2 miles northwest of 69G. The pilot was unable to find the necessary lift, and as the glider lost altitude, he started flying back toward the airport. Still not finding the needed lift, he proceeded toward the initial point for landing on runway 36. As the pilot flew the downwind pattern leg, he realized that he was not going to be able to complete the pattern. He attempted to clear the tree line that crossed the downwind leg, but the glider hit the trees and subsequently impacted the terrain. A witness located at the airport reported that he observed the glider on the downwind leg. He reported that the glider's altitude was low – about 125 to 150 feet agl, and it was in close to the airport and flying "somewhat slowly." The glider seemed to slow down even more as it began to turn to the base leg. He reported that the left wing stalled and the glider pitched down nearly vertical. It completed about 1/2 spin before it disappeared behind the trees about 2,000 feet away. Another witness at the airport also reported that the glider was too low on the downwind leg. He reported that the glider went down as it turned to shorten the pattern. A Federal Aviation Administration inspector examined the glider wreckage. Flight control cable continuity was confirmed from the flight controls to their respective attach points on the flight control surfaces. The inspection of the glider did not reveal any evidence of pre-impact failure or malfunction.

## Aircraft

- Registration: [N1ZV](https://openairdocs.org/deregistered/N1ZV-2014-04-01), registration cancelled 2014-04-01, S/N 30, built 1983 (OpenAirDocs)
- Reported make and model: SMITH APPLEBAY ZUNI II
- Registry model: [Smith Mike APPLEBAY ZUNI](https://openairdocs.org/model/smith-mike-applebay-zuni) (registry code 05675CB) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 30
- Airframe hours: 184
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Wasilewski Stephen G
- Registered owner: Wasilewski Stephen G
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Condition, May 1, 2012
- Departed: 69G, Gregory, MI
- Destination: 69G, Gregory, MI
- Airport: 69G, Richmond Field Airport, runway 36, 2,471 × 100 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 66; injuries: serious; commercial; last flight review April 12, 2012; seat: single; flight hours: 163 total, 15 in this make and model, 130 as pilot in command, 3 in the last 90 days, 2 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: variable at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 82 °F, dew point 50 °F
- Altimeter: 30.09 inHg
- Observed at: LAN, 26 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 20120729019399A](https://openairdocs.org/incident/20120729019399A), Jul 29, 2012: Smith Mike APPLEBAY ZUNI, Gregory, MI, Destroyed. An eye witness stated, "I observed the zuni sailplane traveling southbound on a downwind leg, he was very low, maybe 125 - 150 above the ground in close to the…

## Docket (2 files)

The files NTSB released with the investigation on June 26, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84491. 5.7 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40413688&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Unadilla Township Police Report (item 2, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40413689&FileExtension=.PDF&FileName=Unadilla%20Township%20Police%20Report-Redacted.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.

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