Let L-13 N90865

Summary

On 11 August 1996 at about 02:15 local time, a Let L-13 registered N90865 was involved in an accident near Shelton, Washington, 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

11 August 1996 at 02:15

Classification

Accident

Location

Shelton, Washington, United States

Nearest airport

Sanderson Field (SHN)

Coordinates

47.2295, -123.2010

Aircraft

Let L-13

Registration

N90865

Category

Glider

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA96FA186

1 person died.

failure of the operator to provide its pilots with information essential for an accurate determination of the glider's weight and balance, the resultant operation of the glider with a center-or-gravity that exceeded the aft limit, and the pilot's inadvertent entry into a stall/spin. Factors relating to the accident were: an incorrect placard concerning the glider's minimum front seat solo weight limitation, and the pilot's lack of experience in the make and model of aircraft.

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

Read the full NTSB narrative

After receiving a glider certification on 7/24/96, the pilot (plt) logged about 2.1 hrs in a Let L-13 glider, before flying it solo. The initial solo was the accident flight (flt) on 8/10/96. On this flight, the plt planned to be towed to traffic pattern altitude, then release the glider, enter the traffic pattern, & land. Release occurred about 3 mi southwest of the airport at 1,850 ft. Airport elevation was 269 ft. Witnesses said the L-13 entered a right spin about 5 to 10 sec after release & continued spinning until ground impact. To keep the center-of-gravity (CG) from exceeding the aft limit, a placard had been installed in the cockpit, indicating the minimum front seat solo weight to be 150 lbs. The L-13's operating manual contained this & other info based on the L-13's original weight & balance (W/B) configuration. The plt weighed between 128 & 135 lbs, & a single 25 lb ballast bag was found in the wreckage. However, after repainting & modification with a non-standard tailwheel, the glider's revised W/B data indicated the current minimum front seat solo weight was 181 lbs. Based on this info (kept in the operator's maintenance shop), the glider's C.G. was computed to be 1.4 inches behind the aft limit. The plt's personal copy of the L-13 operating manual did not contain the revised W/B data. Copies of the glider's operating manual were being sold to renters without this info.

Quoted verbatim from the NTSB record.