# NTSB SEA84FA172: Schempp-Hirth Ventus A, N17KS, Ephrata, WA, July 12, 1984

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 12, 1984, 14:50 local (21:50 UTC)
- Place: Ephrata, WA
- Coordinates: 47.270782, -119.590415 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.2708&lon=-119.5904&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal, 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 39814
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA84FA172
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39814/pdf
- Page: https://openairdocs.org/ntsb/SEA84FA172

## Sequence of events

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

- Midair collision, maneuvering
  - visual lookout - inadequate, pilot of other aircraft (cause)
  - total, pilot of other aircraft (cause)
  - remedial action - not performed, pilot in command (cause)
- Midair collision, maneuvering
  - visual lookout - inadequate, pilot in command (cause)
  - improper use of procedure, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - stall

## Analysis (aircraft 2)

A 'GAGGLE' OF ABOUT 7 GLIDERS WERE MANEUVERING IN A CLIMB WHEN N919R CLIMBED INTO THE GROUP. THE PLT OF N17KS SAID HE SAW N919R CLOSING AND INCREASED HIS ANGLE OF BANK TO ABOUT 100 DEGREES TO TRY AND AVOID A COLLISION. THE LEADINGEDGE OF THE LEFT WING OF N919R CONTACTED THE TRAILING EDGE OF N17KS RIGHT WING. N17KS WENT INTO A VERTICAL DIVE BUT RECOVERED AND LANDED AT THE AIRPORT ABOUT 3 MILES AWAY. N919R WENT INTO AN INVERTED SPIN AND CRASHED STILL INVERTED. NO PARACHUTE WAS OBSERVED TO DEPLOY.

## Analysis (aircraft 1)

A 'GAGGLE' OF ABOUT 7 GLIDERS WERE MANEUVERING IN A THERMAL WHEN N919R TRIED TO JOIN THE GROUP. THEIR AIRSPEED WAS ABOUT55 KTS AND HIS WAS ESTIMATED AT ABOUT 80 KTS. N919R COLLIDED WITH N17KS AND ENTERED AN INVERTED SPIN FROM WHICH IT DID NOT RECOVER. N17KS MADE A SUCCESSFUL LANDING WITHOUT FURTHER INCIDENT AT THE ARPT OF DEPARTURE.

## Aircraft 1

- Registration: N17KS (not matched to a registry record)
- Reported make and model: Schempp-Hirth VENTUS A
- Category: Glider
- Serial number: 6
- Engines: NONE NONE unknown
- Damage: Minor damage
- Flight: Personal, Part 91
- Registered owner: Lawrence M. Rogers
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, August 4, 1983
- Departed: EPH, EPHRATA, WA

## Aircraft 2

- Registration: N919R (not matched to a registry record)
- Reported make and model: SCHLEICHER ASW 20 B
- Category: Glider
- Serial number: 20621
- Engines: NONE NONE unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Karl H Striedieck
- Airworthiness certificate: Special, Experimental (Special)
- Departed: EPH, EPHRATA, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot, aircraft N17KS; age 61; private; airplane ratings: single-engine land; seat: front; toxicology performed; flight hours: 112 in this make and model
- Pilot, aircraft N919R; age 47; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: front

## Weather

- Conditions: Visual (VMC), Day
- Wind: 210° at 15 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 39 °F
- Altimeter: 29.00 inHg
- Observed at: EPH, 3 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 19840712065262A](https://openairdocs.org/incident/19840712065262A), Jul 12, 1984: Schler ASW20, Ephrata, WA, Minor damage. Was struck from behind by another glider N919R that was attempting to join the gaggle circling in a thermal.
- [Accident 19840712065261A](https://openairdocs.org/incident/19840712065261A), Jul 12, 1984: Sphrth VENTUSA, Ephrata, WA, Destroyed. Overtook and struck another glider N17KS that was circling with 7 gliders in thermal. Was trying to enter thermal.

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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