Air Sailing Glider Port Airport
Aircraft Accident/Incident Report

Reno, Nevada 89424
Saturday, May 8, 2004 16:00 PDT

NTSB Narrative Summary Released at Completion of Accident

The glider entered a stall and spin while attempting a return to runway maneuver following an overload failure of the towrope in the takeoff initial climb. During takeoff, the towrope between the tow plane and glider broke while the glider was about 300 feet above ground level. The glider pilot reversed course and attempted to return to the departure runway. The tow plane pilot said that when he looked back the glider was in a left turn with its heading passing through 030 degrees when the right wing suddenly dropped downwards and the glider appeared to descend vertically, nose down. The glider made about 1/2 a clockwise rotation, nose down, before it impacted the desert. The Safety Board Materials Laboratory examination of the towrope and safety link revealed: 1) The towrope was worn by abrasion and sunlight at the glider connection end, which had substantially reduced the strength of the rope at the failure location; 2) the worn end of the rope was about 60 percent weaker than the unworn end; 3) the towrope failed due to overloading at the knot; and 4) the unworn end of the towrope and the safety link met the tensile strength required by 14 CFR 91.309. The rope area around the knot connecting the towrope to the safety link was wrapped in a protective layer of duct tape, and therefore, the rope condition at the failure point could not be easily examined by the pilot during a towrope preflight inspection. Examination of the glider revealed no evidence of preimpact malfunction or failure of the flight control system. The tow plane pilot reported that there were gusty winds and turbulence present at the time. The ASW-20 Flight Manual includes a section titled "Dangerous Flight Attitudes," which contain a number of cautionary statements and warnings pertaining to stalled flight. Full control deflections will result in wing dropping, whereas full-deflected controls in opposite directions with stick pulled completely back will case rapid wing dropping. Initiated from turning flight the wing dropping is more rapid than from level flight. Full deflections of opposite rudder and aileron deflections will lead to a spin. The Federal Aviation Administration produced "Glider Handbook, AC 80-83-14" contained a very brief section about towrope inspection and essentially stated that the rope should be inspected for excessive wear without defining what that means.

NTSB Probable Cause Narrative

the pilot's failure to maintain an adequate airspeed margin while performing a return to runway maneuver, which led to a stall and spin. Factors in the accident were: 1) the deteriorated condition of the glider towrope, which resulted in towrope failure during a critical phase of the tow; 2) the duct tape covering over the abraided portion of the failed rope end that made inspection of the rope difficult; and, 3) the gusty winds and turbulence.

Event Information

Type of Event Accident
Event Date 5/8/2004
Event Day of the Week Saturday
Time of Event 1600
Event Time Zone Pacific Daylight Time
Event City Reno
Event State NEVADA
Event Country --
Zipcode of the event site 89424
Event Date Year 2004
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 395600N
Event Location Longitude 1194100W
Event Location Airport Air Sailing Glider Port
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 0.2
Degrees magnetic from airport 210
Airport Elevation 4300
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1556 Mountain Standard Time
Direction of event from weather observation facility (degrees) 180
Weather Observation Facility ID KRNO
Elevation of weather observation facility 4415
Distance of event from weather observation facility (units?) 21
Time Zone of the weather observation MST
Lighting Conditions Day
Lowest Ceiling Height 25000
Lowest Non-Ceiling Height 18000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 23
Dew Point at event time (in degress fahrenheit) 1
Wind Direction (degrees magnetic) 280
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 17
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 22
Altimeter Setting at event time (in. Hg) 30.03
Density Altitude (feet) 6159
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 19007
NTSB Notification Source FAA
NTSB Notification Date May 8 2004 12:00AM
NTSB Notification Time 1658
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Jan 31 2006 7:35AM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office WP-FSDO-Reno, NV

Aircraft Involved

Aircraft #1

Aircraft Registration Number N126PS
NTSB Number LAX04LA203
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Schleicher
Aircraft Model ASW-20
Aircraft Series Identifier --
Aircraft Serial Number 20014
Certified Max Gross Weight 1000
Aircraft Category Glider
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 1
Number of Engines 0
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Mar 1 2004 12:00AM
Airframe hours since last inspection 0
Airframe Hours 2314.8
ELT Installed --
ELT Activated --
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Ruben Zelwer
Aircraft Owner Street Address --
Aircraft Owner City Berkeley
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 94709
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code --
Departure City Reno
Departure State NV
Departure Country USA
Departure Time 1600
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City Reno
Destination State NV
Destination Country USA
Specific Phase of Flight Takeoff - initial climb
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Oct 18 2005 5:08PM
User who most recently changed record COOS
Since inspection or accident Last Inspection
Event Location Runway Number and Location 21
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --