# NTSB FTW98LA223: AS+ AC-4, N158R, Cedar Fort, UT, May 16, 1998

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: May 16, 1998, 14:15 local (20:15 UTC)
- Place: Cedar Fort, UT
- Coordinates: 40.330375, -112.110206 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.3304&lon=-112.1102&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report June 21, 2000
- Report: Approved by Office Director
- NTSB case key (mKey): 20609
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA223
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20609/pdf
- Page: https://openairdocs.org/ntsb/FTW98LA223

## Probable cause

Failure by the pilot to maintain control of the aircraft.  A factor was lack of experience in make and model.

## Sequence of events

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

- Loss of control - in flight, approach - vfr pattern - downwind
  - aircraft control - not maintained, pilot in command (cause)
  - lack of total experience in type of aircraft, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled
  - airport facilities,runway/landing area condition - open field

## Analysis

While on down wind in the landing pattern, the aircraft was observed to enter a nose low attitude and impact the ground.  Weather at the time was clear skies and calm winds.    Examination of the aircraft provided no evidence of preimpact failure or malfunction. The pilot had accumulated 5 hours experience in aircraft make and model.

## Factual narrative

On May 16, 1998, at 1415 mountain daylight time, an AS+ Ltd. AC-4 glider, N158R, was destroyed while landing at Cedar Valley Airport, near Cedar Fort, Utah.  The private pilot and sole occupant received serious injuries.  The aircraft was being operated by a private individual under Title 14 CFR Part 91.  Visual meteorological conditions prevailed for this local area personal flight which originated approximately 5 minutes before the accident.  No flight plan was filed.

According to available information, the wind was calm.  Witnesses reported that while on down wind, the aircraft assumed a nose low attitude and impacted the ground.

According to FAA records, the aircraft was first registered approximately a month before the accident and the pilot reported he had accumulated 5 hours of flight experience in the accident  aircraft make and model.

Examination of the aircraft by an FAA inspector provided no evidence of preimpact failure or malfunction.

The pilot provided minimal information on NTSB Form 6120.1/2 (Pilot/Operator Report Form) and did not return calls from either the Safety Board IIC or FAA inspector assigned.

## Aircraft

- Registration: [N158R](https://openairdocs.org/deregistered/N158R-1998-08-22), registration cancelled 1998-08-22, S/N 027 (OpenAirDocs)
- Reported make and model: AS+ Ltd AC-4
- Registry model: [AS+ AC 4](https://openairdocs.org/model/as-plus-ac-4) (registry code 05628R1) (OpenAirDocs)
- Category: Glider
- Serial number: 27
- Engines: unknown
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Richard S. Smith
- Registered owner: Russia Sailplanes, Inc.
- Airworthiness certificate: Special, Experimental (Special)
- Departed: UT10, UT
- Airport: UT10, Cedar Valley, runway 35, 5,100 × 100 ft, gravel

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 63; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: front; flight hours: 455 total, 5 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 39 °F
- Altimeter: 29.00 inHg
- Observed at: PVU, 25 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 19980516009559A](https://openairdocs.org/incident/19980516009559A), May 16, 1998: Cedar Fort, UT, Destroyed. While on down wind in the landing pattern, the aircraft was observed enter a nose low attitude and impact the ground. Weather at the time was clearskies and…

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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