# NTSB SEA84LA159: Applebay Sailplanes Zuni II, N22HL, Ephrata, WA, July 3, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 3, 1984, 14:00 local (21:00 UTC)
- Place: Ephrata, WA
- Coordinates: 47.270294, -119.589164 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.2703&lon=-119.5892&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 39959
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA84LA159
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39959/pdf
- Page: https://openairdocs.org/ntsb/SEA84LA159

## Sequence of events

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

- Midair collision, maneuvering
  - visual lookout - inadequate, pilot in command (cause)
  - clearance - not maintained, pilot in command (cause)
  - visual lookout - inadequate, pilot of other aircraft (cause)
  - clearance - not maintained, pilot of other aircraft (cause)
- Midair collision, maneuvering
  - visual lookout - inadequate, pilot in command (cause)
  - clearance - not maintained, pilot in command (cause)
  - visual lookout - inadequate, pilot of other aircraft (cause)
  - clearance - not maintained, pilot of other aircraft (cause)

## Analysis (aircraft 2)

THE TWO GLIDERS COLLIDED WHILE THERMALING IN VICINITY OF EACH OTHER WHILE ENGAGED IN A CONTEST. ACCORDING TO THE PLTS THEY LOST SIGHT OF EACH OTHER WHILE SPIRALING IN THE LIFT. BOTH ACFT LANDED SAFELY. THE COLLISION WAS NOSE TO TAIL.

## Aircraft 1

- Registration: [N22HL](https://openairdocs.org/deregistered/N22HL-2019-10-05), registration cancelled 2019-10-05, S/N 26, built 1981 (OpenAirDocs)
- Reported make and model: APPLEBAY SAILPLANES ZUNI II
- Registry model: [Applebay Sailplanes ZUNI II](https://openairdocs.org/model/applebay-sailplanes-zuni-ii) (registry code 0130230) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Engines: unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: William G Hill
- Departed: EPH, EPHRATA, WA

## Aircraft 2

- Registration: [N20UZ](https://openairdocs.org/aircraft/N20UZ), registered now, S/N 20016, built 1978 (OpenAirDocs)
- Reported make and model: SCHLEICHER ASW-20
- Registry model: [Schleicher ASW-20](https://openairdocs.org/model/schleicher-asw-20) (registry code 3801506) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 20016
- Airframe hours: 289
- Engines: unknown
- Damage: Minor damage
- Flight: Personal, Part 91
- Registered owner: Ronald K. Ferguson
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, October 29, 1983
- Departed: EPH, EPHRATA, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot, aircraft N22HL; age 42; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 4,750 total, 750 in this make and model, 4,597 as pilot in command, 102 in the last 90 days, 8 in the last 24 hours
- Pilot, aircraft N20UZ; age 32; commercial, private, flight instructor; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 876 total, 156 in this make and model, 817 as pilot in command, 55 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 8 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 46 °F
- Altimeter: 30.00 inHg
- Observed at: EPH, 9 nm away

## FAA reports on this event (2)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19840703029582A](https://openairdocs.org/incident/19840703029582A), Jul 3, 1984: Amtr ZUNI2, Ephrata, WA, Substantial damage. Glider was struck from behind while thermaling in the same thermal with another glider N2OUZ.
- [Accident 19840703029581A](https://openairdocs.org/incident/19840703029581A), Jul 3, 1984: Schler ASW20, Ephrata, WA, Minor damage. Glider struck another glider while thermaling the same thermal. N22HL.

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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