- Date
- August 2, 2015, 15:00 local (21:00 UTC)
- Place
- Logan, UT
- Injuries
- 1 serious
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N20YZSchleicher ASW 20B
- Defining event
- Maneuvering: Loss of lift
- Weather
- Visual (VMC) · Day
- Status
- Completed · report November 5, 2015
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- Federal Aviation Administration
- FAA report
- 20150802012549A
- Case key
- 91706
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 NTSB’s determination of the probable cause, and any contributing factors.
The pilot’s failure to maintain glider control when it encountered a strong downdraft while maneuvering near a ridgeline.
Findings · 3
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings.
Analysis
The pilot reported that he was participating in a mountain flying training course when the glider encountered a strong downdraft while maneuvering near a mountain ridge and lost lift. The pilot was unable to arrest the glider's descent rate, and the left wing impacted a tree. The pilot reported no preimpact malfunctions or failures with the glider that would have precluded normal operation.
Factual narrative
On August 2, 2015, about 1500 mountain daylight time, a Schleicher ASW 20B glider, N20YZ, experienced a loss of lift during cruise flight, and impacted terrain near Logan, Utah. The private pilot owned and operated the glider under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. The pilot was seriously injured. The glider sustained substantial damage throughout the fuselage and wings. Visual meteorological conditions prevailed for the local flight that departed the Logan-Cache Airport (LGU), Logan, at 1430. No flight plan had been filed. The pilot reported that he was participating in a mountain flying training course when the glider encountered a strong downdraft while maneuvering near a mountain ridge, and lost lift. The pilot was unable to arrest the glider's rate of descent, and the left wing impacted a tree. The pilot reported no preimpact malfunctions or failures that would have precluded normal operation of the glider. Postaccident examination of the wreckage revealed that the left wing was completely separated from the fuselage, and the right wing partially separated from the fuselage. The empennage forward of the vertical stabilizer was separated from the fuselage.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.
Aircraft
- Registration
- N20YZ
- Reported as
- Schleicher ASW 20B
- Category
- Glider
- Serial number
- 20664
- Built
- 1984
- Airframe hours
- 1,448
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Abbott David H
- Registered owner
- Abbott David H
- Airworthiness certificate
- Special, Experimental (Special); Standard, Utility
- Last inspection
- Annual · March 22, 2015
- Departed
- LGU · Logan, UT
- Destination
- LGU · Logan, UT
- Airport
- LGU · Logan-Cache
- Equipment
- Data recorder, Electronic flight bag or handheld device, Handheld GPS
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
- 63
- Injuries
- Serious
- Last flight review
- July 18, 2015
- Seat
- Center
- Flight hours
- 280 total · 280 in this make and model
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 360° at 6 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 93 °F, dew point 34 °F
- Altimeter
- 29.95 inHg
- Turbulence
- Unknown
- Observed at
- KLGU, 5 nm away
Docket · 3
The files NTSB released with the investigation on October 16, 2015, on NTSB’s docket system: statements, records, photos and specialists’ reports. 736 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.