ERA12CA352

NTSB accident investigation · Schempp-Hirth Ventus 2CT · Duncansville, PA · May 18, 2012

Accident · Serious injuriesData collectionFinal report
Date
May 18, 2012, 15:15 local (19:15 UTC)
Place
Duncansville, PA
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N900BMSchempp-Hirth Ventus 2CT
Defining event
Maneuvering-low-alt flying: Aerodynamic stall/spin
Weather
Visual (VMC) · Day
Status
Completed · report October 15, 2012
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20120518015099A
Case key
83722

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The glider’s encounter with atmospheric lift conditions not sufficient to clear terrain, which resulted in an aerodynamic stall. Contributing to the accident was the pilot's decision to continue turning toward a ridgeline.

Findings · 4

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.

Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Attain/maintain not possibleSchempp-Hirth VENTUS 2CT: 1 caseAll aircraft: 1,681 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · Not specifiedSchempp-Hirth VENTUS 2CT: 1 caseAll aircraft: 9,295 casesProbable cause
Environmental issuesEnvironmental issues › Conditions/weather/phenomena · Effect on equipmentSchempp-Hirth VENTUS 2CT: 1 caseAll aircraft: 57 cases

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

The pilot reported that the glider was towed to an altitude of 2,000 feet above ground level, released, and then flown for more than 2 hours without incident. He was subsequently looking for lift and performing "S" turns, while flying away from a ridgeline. During one of the "S" turns, he encountered a 200- to 300 foot-per-minute increase in lift and elected to continue the left turn. However, when the glider turned back toward the ridgeline, it encountered a large downdraft and loss of airspeed. The glider stalled, spun to the left, and struck trees. The glider's tail boom separated and both wings were substantially damaged. The pilot reported that there were no mechanical malfunctions or failures that would have precluded normal operation. He further stated that he should not have continued the left turn and that standard training techniques called for continuing to perform "S" turns when close to a ridge or mountain until the glider reaches an altitude of at least 200 to 300 feet above the highest point to provide adequate altitude to recover from possible stalls caused by downdrafts.

Factual narrative

The pilot reported that the glider was towed to an altitude of 2,000 feet above ground level, released, and flown for more than 2 hours without incident. He subsequently was looking for lift and performing "S" turns, while flying away from a ridgeline. During one of the "S" turns, he encountered a 200 to 300 foot increase in lift and elected continue turning to the left. As the glider turned directly toward the ridgeline, it encountered a large downdraft and loss of airspeed. The glider stalled, spun to the left, and immediately struck trees. The glider's tail boom separated and both wings were substantially damaged. The pilot reported that he did not experience any mechanical malfunctions or failures during the flight. He further stated that he should not have continued the left turn and that standard training techniques called for continuing to do "S" turns when close to ridges or mountains until at least 200 to 300 feet above the highest point, which would provide for adequate altitude to recover from possible stalls caused by wind gusts.

Aircraft

Registration
N900BM
Reported as
Schempp-Hirth Ventus 2CT
Category
Glider
Serial number
206
Airframe hours
208
Engine
Solo 2350 SER, 22 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · June 5, 2011 · 3 hours before
Departed
RVL · Reedsville, PA
Destination
RVL · Reedsville, PA

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
70
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Unknown
Last flight review
November 24, 2010
Seat
Front
Flight hours
7,215 total · 1,000 in this make and model · 7,000 as pilot in command · 60 in the last 90 days · 40 in the last 30 days · 0 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
50° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
163 °F, dew point 102 °F
Altimeter
30.18 inHg
Observed at
AOO, 13 nm away

Docket · 2

The files NTSB released with the investigation on August 7, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 634 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.