# NTSB WPR09CA368: Schweizer SGU 2-22CK, N3907A, Ephrata, WA, July 24, 2009

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Data collection · Final report
- Date: July 24, 2009, 06:00 local (13:00 UTC)
- Place: Ephrata, WA
- Coordinates: 47.304721, -119.51667 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.3047&lon=-119.5167&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: Glider tow event](https://openairdocs.org/ntsb-events/510)
- Highest injury: Minor injuries
- Injuries: 1 minor, 1 uninjured
- Status: Completed, report October 19, 2009
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration FSDO
- NTSB case key (mKey): 74366
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09CA368
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74366/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74366
- Page: https://openairdocs.org/ntsb/WPR09CA368

## Probable cause

The premature launch signal given by the wing walker.

## Findings

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

- [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Ground crew (probable cause); cases with it: [Schweizer SGU 2-22CK, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=8050610), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md)

## Sequence of events

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

- [Takeoff: Glider tow event](https://openairdocs.org/ntsb-events/510) (defining event); cases with it: [Schweizer SGU 2-22CK, 1 case](https://openairdocs.org/ntsb-events/510/sequence.md?model=8050610), [All aircraft, 45 cases](https://openairdocs.org/ntsb-events/510/sequence.md)

## Analysis

The certified flight instructor (CFI) and student pilot were onboard the glider readying it for an automobile tow launch. The CFI reported giving the 'take up slack' command to the wing walker, who was steadying the wings. Before the slack was taken up by the tow vehicle driver, the wing walker prematurely gave the launch signal. The tow driver then accelerated and the glider was suddenly launched into the air. The CFI attempted to control the glider by applying full forward elevator and simultaneously attempting to release the tow line. The glider struck the ground with the line still attached and was again launched into the air as the tow truck continued to accelerate. The tow line then released and the nose of the glider struck the ground. The glider sustained substantial damage to the aft fuselage structure during the accident sequence.

## Factual narrative

The certified flight instructor (CFI) and student pilot were onboard the glider readying it for an automobile tow launch. The CFI reported giving the 'take up slack' command to the wing walker, who was steadying the wings. Before the slack was taken up by the tow vehicle driver, the wing walker prematurely gave the launch signal. The tow driver then accelerated and the glider was suddenly launched into the air. The CFI attempted to control the glider by applying full forward elevator and simultaneously attempting to release the tow line. The glider struck the ground with the line still attached and was again launched into the air as the tow truck continued to accelerate. The tow line then released and the nose of the glider struck the ground. The glider sustained substantial damage to the aft fuselage structure during the accident sequence.

## Aircraft

- Registration: [N3907A](https://openairdocs.org/aircraft/N3907A), registered now, S/N 66, built 1973 (OpenAirDocs)
- Reported make and model: SCHWEIZER SGU 2-22CK
- Registry model: [Schweizer SGU 2-22CK](https://openairdocs.org/model/schweizer-sgu-2-22ck) (registry code 8050610) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Glider
- Serial number: 66
- Airframe hours: 2190
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Civil Air Patrol Inc
- Registered owner: Civil Air Patrol Inc
- Airworthiness certificate: Standard, Normal
- Departed: EPH, Ephrata, WA
- Destination: EPH, Ephrata, WA
- Airport: EPH, Ephrata Municipal Airport, runway 29, 3,843 × 60 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 71; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 11, 2009; seat: rear; flight hours: 3,274 total, 230 in this make and model, 2,735 as pilot in command, 69 in the last 90 days, 60 in the last 30 days, 2 in the last 24 hours
- Student pilot; age 15; injuries: minor; student; seat: front; flight hours: 0 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 280° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 68 °F, dew point 52 °F
- Altimeter: 29.95 inHg
- Observed at: EPH

## 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 20090724012819A](https://openairdocs.org/incident/20090724012819A), Jul 24, 2009: Scwzer SGU222CK, Ephrata, WA, Substantial damage. (-23) During a prematurely initiated vehicle towed glider launch wherein the vehicle driver misunderstood signals, while the flight instructor was still in the…

## Other investigations on N3907A (1)

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.

- [NTSB SEA92LA172](https://openairdocs.org/ntsb/SEA92LA172), Jul 31, 1992: Schweizer SGU 2-22CK (N3907A), Ephrata, WA, substantial damage. Probable cause: THE PILOT MISJUDGED THE LANDING FLARE. FACTORS INCLUDE A LACK OF TOTAL PILOT EXPEREINCE.

## Docket (1 files)

The files NTSB released with the investigation on August 31, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74366. 518 KB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 518 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40317606&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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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