Schweizer SGS-1-30 N3620D

Summary

On 6 April 1991 at about 17:20 local time, a Schweizer SGS-1-30 registered N3620D, operated by Wurtsboro Flight Service, Inc., was involved in an accident near Wurtsboro, New York, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 April 1991 at 17:20

Classification

Accident

Location

Wurtsboro, New York, United States

Coordinates

41.5702, -74.4807

Aircraft

Schweizer SGS-1-30

Registration

N3620D

Category

Glider

Operator

Wurtsboro Flight Service, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

NYC91LA102

1 person died.

AN INFLIGHT FAILURE OF THE LEFT WING SPAR DUE TO OVERLOAD FROM PILOT INDUCED CONTROL INPUTS, WHILE RECOVERING FROM A DIVE. FACTORS RELATED TO THE ACCIDENT WERE, THE PILOT'S DECISION TO FLY WITH THE TRIM SYSTEM DISCONNECTED AND LACK OF RECENT EXPERIENCE IN MAKE AND MODEL OF GLIDER.

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

Read the full NTSB narrative

THE GLIDER WAS OBSERVED IN A STEEP NOSE DOWN PITCH ATTITUDE. JUST ABOVE THE TERRAIN, THE NOSE PITCHED UP AND THE LEFT WING FAILED AT THE WING ROOT. THE GLIDER STRUCK TREES, DESCENDING TO THE GROUND. POST CRASH EXAMINATION SHOWED THE WING HAD FAILED IN OVERLOAD. ACCORDING TO THE MANUFACTURER, THE WING HAD AN ULTIMATE FAILURE LOAD OF 9.72G. EXAMINATION OF THE GLIDER SHOWED TAPE ON THE TRIM DISCONNECT SYSTEM AND CONTROL STICK. THIS IS A TECHNIQUE USED BY COMPETITION PILOTS TO REDUCE THE CONTROL FORCES. THERE IS A FLIGHT MANUAL LIMITATION AGAINST OPERATING WITH SPEEDS IN EXCESS OF 108 MPH WITH THE TRIM DISCONNECTED. FLIGHT TESTING BY THE MANUFACTURER SHOWED THE GLIDER HAD 'NEAR TO NEUTRAL STABILITY' WITH THE TRIM DISCONNECTED.

Quoted verbatim from the NTSB record.