- Date
- August 2, 2009, 11:39 local (18:39 UTC)
- Place
- Williams, CA
- Injuries
- 1 serious
- Damage
- Substantial damage
- Phase of flight
- Initial climb
- Aircraft
- N7HVSchempp Hirth Discus CS
- Defining event
- Initial climb: Glider tow event
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 15, 2009
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration
- FAA report
- 20090802014629A
- Case key
- 74437
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The pilot's failure to maintain clearance with terrain after intentionally releasing from the tow plane at a low altitude during the initial climb.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
After taking off, the lead pilot in a dual tow elected to perform a precautionary release as a result of a "slack-line" condition. The trail pilot, realizing that his tow rope was now under the lead pilot's right wing, released his tow rope and immediately turned right. Without sufficient altitude or airspeed to return to the airport, the trail pilot tried to level the glider's wings, but could not before the right wing tip impacted terrain. The glider sustained substantial damage to its right wing and empennage.
Factual narrative
On August 2, 2009, about 1139 Pacific daylight time, a Schempp-Hirth Discus CS glider, N7HV, collided with terrain while maneuvering near the Williams Gliderport (CN12), Williams, California. The private pilot, the sole occupant, received serious injuries. The glider sustained substantial damage. Visual meteorological conditions prevailed for the local flight, which was conducted in accordance with Title 14 Code of Federal Regulations (CFR) Part 91, and a flight plan was not filed. The flight was originating at the time of the accident. The pilot reported that his glider, the trail glider, and another glider, the lead glider, were being towed simultaneously by a single tow plane. The lead glider was attached with a 200-foot rope, while his glider was attached to a 300-foot rope. The trail pilot stated that after taking off the lead glider started to descend back to the runway; the lead pilot had elected to release from the tow plane due to a "slack-line" condition. The trail pilot reported that after realizing that his tow rope was under the lead glider's right wing, and that his glider and the tow plane were ascending, released his tow rope. The trail pilot stated that he feared that his tow rope would pull the lead glider's right wing up causing him to ground loop if he did not release the tow rope. The trail pilot further stated, "Instinctively, I turned right immediately after releasing from the tow plane, then realized that I did not have enough airspeed or altitude to return to the airport. I tried to level my wings but my right wing tip struck the ground." The glider came to rest upright in a rice field east of the runway and sustained substantial damage to its right wing and empennage. In a statement submitted to the IIC, the lead glider pilot reported that he was connected to a shorter tow rope, while the accident trail glider was attached to a longer tow rope, positioned aft and to the right of his glider. The lead pilot stated that after taking off he encountered a slack line, which prompted him to perform a precautionary release, followed by clearing to the left and landing uneventfully off of the west side of the runway. The lead pilot further stated that after landing he observed the accident glider strike the ground with its right wing tip heading in a southerly direction, about 100 yards east of the departure runway.
Aircraft
- Registration
- N7HV
- Reported as
- Schempp Hirth Discus CS
- Category
- Glider
- Serial number
- 26SCS
- Airframe hours
- 1,152
- Damage
- Substantial damage
- Flight
- Glider tow · Part 91
- Operator
- Richard M Parker
- Registered owner
- John G Kahrs
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Annual · May 10, 2009
- Departed
- CN12 · Williams, CA
- Destination
- CN12 · Williams, CA
- Airport
- CN12 · Williams Gliderport, runway 34, 2,500 × 40 ft, asphalt
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 55
- Injuries
- Serious
- Certificate
- Private
- Last flight review
- April 6, 2008
- Seat
- Single
- Flight hours
- 1,699 total · 1,072 in this make and model · 1,699 as pilot in command · 194 in the last 90 days · 77 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 200° at 7 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 79 °F, dew point 54 °F
- Altimeter
- 29.94 inHg
- Observed at
- MYV, 33 nm away
Docket · 2
The files NTSB released with the investigation on October 14, 2009, on NTSB’s docket system: statements, records, photos and specialists’ reports. 996 KB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.