Szybowcowy Zaklad Do SZD-36A N6SZ

Summary

On 31 March 2007 at about 20:30 local time, a Szybowcowy Zaklad Do SZD-36A registered N6SZ, operated by Robert Obrian Wallace, was involved in an accident near Sylacauga, Alabama, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

31 March 2007 at 20:30

Classification

Accident

Location

Sylacauga, Alabama, United States

Nearest airport

Merkel Field Sylacauga Airport (KSCD)

Coordinates

33.1697, -86.3033

Aircraft

Szybowcowy Zaklad Do SZD-36A

Registration

N6SZ

Category

Glider

Operator

Robert Obrian Wallace

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Sylacauga → Sylacauga

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ATL07LA066

1 person died.

The pilot's improper installation of the left wing attachment pin, which allowed it to disengage during cruise flight, resulting in wing separation.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

Witnesses stated that the glider had been airborne for about 30 minutes when they observed both wings fold up, and the glider descend out of control until impacting into a rock quarry. The wings were located about 1/2-mile north of the impact crater on the upper rim of the quarry. Examination of the wreckage revealed that during assembly, the lower attach pin had failed to enter the lower attachment hole on the left wing. The misalignment allowed the pin to rest on the top surface of the left wing attach lug in a clamping action. Examination of the mechanism that actuates the movement of both pins found that there had been two tabs located above the center pivot, and these two tabs were not found. Examination of the area where the two tabs were missing disclosed that these tabs had been missing for an extended period of time, as the upward motion of the mechanism (center pivot) had machined into the surface above where the upper tabs should have been located. The misalignment of the attach pin in the lower attachment hole allowed the left wing to move upwards to about 45 degrees and separate.

Quoted verbatim from the NTSB record.