# NTSB ATL86LA179: Andrew D. Moore HP-18, N9700P, Chester, SC, June 21, 1986

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: June 21, 1986, 13:05 local (17:05 UTC)
- Place: Chester, SC
- Coordinates: 34.700279, -81.210479 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.7003&lon=-81.2105&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 7136
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL86LA179
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/7136/pdf
- Page: https://openairdocs.org/ntsb/ATL86LA179

## Sequence of events

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

- Airframe/component/system failure/malfunction, approach - vfr pattern - final approach
  - flight control,flap attachment - failure,total (cause)
- Loss of control - in flight, approach - vfr pattern - final approach
  - flt control syst,wing flap control - asymmetrical
  - maintenance,modification - improper, other maintenance personnel (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT RELATED THAT WHILE TURNING FROM BASE TO FINAL HE HEARD A LOUD BANG FROM THE LEFT SIDE OF THE AIRCRAFT. THE AIRCRAFT ENTERED A STEEP LEFT TURN AND CRASHED LEFT OF FINAL APPROACH COURSE. POST CRASH EXAMINATION OF THE AIRCRAFT REVEALED THAT THE FLAP DISENGAGED FROM THE FLAP DRIVE UNIT RESULTING IN A SPLIT FLAP CONDITION. THE FLAPS HAD BEEN MODIFIED WITH THE USE OF POP RIVETS AT THE ATTACH POINTS.

## Aircraft

- Registration: [N9700P](https://openairdocs.org/deregistered/N9700P-2013-06-07), registration cancelled 2013-06-07, S/N 18-162, built 1982 (OpenAirDocs)
- Reported make and model: ANDREW D. MOORE HP-18
- Registry model: [Moore D Andrew HP-18](https://openairdocs.org/model/moore-d-andrew-hp-18) (registry code 05647KG) (OpenAirDocs)
- Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs)
- Category: Glider, amateur-built
- Serial number: 18-162
- Airframe hours: 200
- Engines: unknown UNK unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: William P. Davis
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, April 22, 1986
- Airport: 9A6, Chester Muni, runway 35, 5,000 × 100 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; private; seat: front; flight hours: 127 total, 127 in this make and model, 127 as pilot in command, 10 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 90 °F, dew point -0 °F

## 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 19860621027129A](https://openairdocs.org/incident/19860621027129A), Jun 21, 1986: Amtr HP18, Chester, SC, Substantial damage. Loud bang and aircraft began hard left turn on final approach. Found flap disengaged from flap drive unit.

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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