WPR13LA007

NTSB accident investigation · Schleicher ASH25M · Kamuela, HI · October 7, 2012

Accident · Serious injuriesLimited investigationFinal report
Date
October 7, 2012, 10:30 local (20:30 UTC)
Place
Kamuela, HI
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N513WKSchleicher ASH25M
Defining event
Maneuvering: Loss of lift
Weather
Visual (VMC) · Day
Status
Completed · report November 6, 2013
Report
Approved by Office Director
NTSB office
Western Pacific Region
Parties
Federal Aviation Administration
FAA report
20121007021869A
Case key
85298

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 control of the glider after it encountered atmospheric conditions while maneuvering where the lift was not sufficient to maintain flight, which resulted in a stall and impact with terrain during the subsequent approach to land.

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.

Temp/humidity/pressure: thermal liftingEnvironmental issues › Conditions/weather/phenomena · Effect on operationSchleicher ASH25M: 1 caseAll aircraft: 53 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotSchleicher ASH25M: 1 caseAll aircraft: 9,295 casesProbable cause

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 on the day of the accident the weather was marginal, with low clouds and shifting wind. He took off in the motorized glider and then stowed the engine. About 1 mile northwest of the airport, the pilot realized that the wind was not conducive to convective activity, and the glider started to descend. The pilot turned back toward the airport and extended the engine/propeller to restart the engine; however, the engine would not start. The pilot entered the downwind leg of the traffic pattern and lowered the landing gear. As the pilot was turning from the downwind to the base leg of the traffic pattern, the left wing of the glider stalled; the glider subsequently impacted the ground and cart-wheeled before coming to a rest in a field. The pilot reported that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The pilot reported that he believed the accident occurred because "everything happened so fast,” and he was unable to use a checklist.

Factual narrative

On October 7, 2012, about 1030 Hawaiian standard time, a Schleicher ASH-25M glider, N513WK, landed approximately 1 mile short of the runway at the Waimea-Kohala airport (PHMU), Kamuela, Hawaii. The private pilot sustained serious injuries; the glider sustained substantial damage to both wings. The glider was registered to, and operated by, the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight that departed PHMU at approximately 1000. The pilot reported that on the day of the accident the weather was marginal with low clouds. The wind was shifting between a trade wind and a westerly wind. He took off from runway 22, and shortly thereafter stowed the engine. About 1 mile northwest of the airport about 500 feet above the ground, the wind had not changed back to a trade wind and the glider was not getting adequate lift. The pilot turned back towards the airport, and raised the engine pylon to restart the engine, however, the engine would not start. He entered the traffic pattern, and while on the downwind leg, he noted that the glider would not make it to the runway. Given a lack of adequate emergency landing sites around the airport, he elected to still attempt to land on the runway. The pilot lowered the landing gear and turned to base when he felt the left wing stall. The wing subsequently contacted the ground damaging an approximate 4 foot section of the left wing’s outboard leading edge. The glider cartwheeled before coming to a rest in a field. During a telephone conversation with the National Transportation Safety Board Investigator-In-Charge, the pilot reported that there were no mechanical anomalies with the engine as it was running about 5-10 minutes prior to the accident. He mentioned that he believes it was an operational error because everything was happening so fast he was unable to use a checklist. According to the “ASH 25 Mi flight manual”, it states that it is possible to land the glider with the engine/propeller extended; but to expect a higher than normal sink rate. The manual also states that in the event of an engine failure, if a crash landing is imminent that it is best to retract the powerplant to at least the halfway point to increase the glide distance, which will potentially allow for a better emergency landing site.

Aircraft

Registration
N513WK
Reported as
Schleicher ASH25M
Category
Glider
Serial number
25263
Engine
Mid-West AE50R, 50 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Woods Woodson K
Registered owner
Woods Woodson K
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 19, 2012 · 2 hours before
Departed
PHMU · Kamuela, HI
Destination
PHMU · Kamuela, HI
Airport
PHMU · Waimea-Kohala Airport, runway 22, 5,197 × 100 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
80
Injuries
Serious
Certificates
Private, Commercial
Airplane ratings
Single-engine land, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Unknown, With waivers/limitations
Last flight review
August 31, 2011
Seat
Front
Flight hours
7,000 total · 120 in this make and model · 7,000 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 7 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
82 °F, dew point 70 °F
Altimeter
29.92 inHg
Observed at
PHKO, 26 nm away

Docket · 4

The files NTSB released with the investigation on August 21, 2013, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.2 MB 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.