SEA97LA194

NTSB accident investigation · Let Blanik L-13 · Hamilton, MT · August 19, 1997

Accident · No injuriesLimited investigationFinal report
Date
August 19, 1997, 16:30 local (22:30 UTC)
Place
Hamilton, MT
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N52ASLet Blanik L-13
Weather
Visual (VMC) · Day
Status
Completed · report May 4, 1998
Report
Approved by Office Director
FAA report
19970819023189A
Case key
42679

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 excessive speed taxispeed and failure to maintain wing clearance from a taxiway sign.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

On ground/water collision with objectLanding - roll
Taxispeed - excessivePilot in commandCause
Clearance - not maintainedPilot in commandCause
Object - airport sign/marker

Analysis

Eyewitnesses observed the glider turn off the runway at an excessive speed after landing. The glider then impacted a taxiway sign near the turnoff. The pilot stated that a gust of wind 'slammed down' the left wing of the glider onto the sign. The eyewitnesses reported that the winds were light and variable with no gusts or crosswinds.

Factual narrative

On August 19, 1997, about 1630 mountain daylight time, N52AS, a Blanik L-13 glider, operated by the Hellgate Soaring Society, struck a taxiway sign during landing rollout and was substantially damaged near Hamilton, Montana. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed and no flight plan had been filed. The personal flight departed Hamilton and was conducted under 14 CFR 91.

According to an eyewitness (statement attached) who is a representative of Hamilton Aviation, Inc., the glider turned off of "...runway 34 at the A-1 exit at high speeds, estimated at thirty miles an hour. The winds favored [runway 34] at light and variable. At that time the wing of the glider missed the runway lights, but impacted with the exit A-1 sign...."

According to a certified flight instructor (statement attached) who was in the traffic pattern behind the glider, no corrections were necessary for a cross wind, and there was a "slight breeze...no more than five knots..." from the northeast as indicated by the wind sock. The certified flight instructor also stated that as he observed the glider land on runway 34, he expected the glider pilot to continue his landing roll out to the end of the runway. Instead, he observed that the glider had turned off onto a taxiway well before the end of the runway.

In a written statement to the Safety Board, the pilot stated: "... [I] landed properly and safely. While taxiing to tie down area a wind gust slammed down my left wing which struck down the airport [runway] signs.... " The pilot also reported that there were no preimpact mechanical malfunctions.

Aircraft

Registration
N52AS
Reported as
Let Blanik L-13 (BLANIK L-1)
Category
Glider
Serial number
027056
Airframe hours
90
Engine
unknown
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Hellgate Soaring Society
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 12, 1996 · 90 hours before
Departed
6S5
Airport
6S5 · Ravalli County Airport, runway 34, 4,200 × 75 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
65
Certificate
Private
Medical
Unknown, Unknown
Flight hours
1,000 total · 1,000 in this make and model · 900 as pilot in command

Weather

Conditions
Visual (VMC) · Day
Wind
330° at 8 knots, gusting 12
Visibility
50 statute miles
Lowest ceiling
None
Temperature
81 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N52AS · 1

Matched to the same aircraft by N-number and date.