NYC02LA046

NTSB accident investigation · Let L-23 · Sterling, MA · January 1, 2002

Accident · No injuriesLimited investigationFinal report
Date
January 1, 2002, 14:58 local (18:58 UTC)
Place
Sterling, MA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Emergency descent
Aircraft
N117BBLet L-23
Weather
Visual (VMC) · Day
Status
Completed · report June 25, 2003
Report
Approved by Office Director
Parties
FAA
FAA report
20020101000299A
Case key
53996

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 student pilots inadequate compensation for wind conditions which resulted in an off-field landing, and the CFI's improper decision to allow the student to fly solo. Factors related to the accident were the gusting wind conditions, and the students lack of total experience in gliders.

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.

In flight collision with objectEmergency descent/landing
Compensation for wind conditions - inadequatePilot in commandCause
Lack of total experience in kind of aircraftPilot in commandFactor
Object - fence
Weather condition - gustsFactor
Planning/decision - improperFlight instructor(on ground)Cause

Analysis

As the glider neared the airport, the student pilot entered the downwind leg further out from the runway than she normally would. As the glider was turned on to the base leg, the student realized that she would not make the runway and elected to perform a forced landing to a two-lane highway. The glider touched down on the southbound lane of the elevated roadway, impacted a metal guardrail, and came to rest upright. The student had accumulated about 13 hours of dual instruction in gliders, with 7 or 8 different flight instructors, and about 1.4 hours of solo time. The student added that previous to the accident flight, she had no plans to fly solo due to the wind conditions. After her flight instructor reassured her that the pervious dual flight had been good, and student climbed into the glider alone. The recorded weather at a nearby airport, about the time of the accident, included winds from 250 degrees at 13 knots, gusts to 22 knots.

Factual narrative

On January 1, 2002, about 1458 eastern standard time, a LET L-23 glider, N117BB, was substantially damaged during a forced landing near the Sterling Airport, Sterling, Massachusetts. The student pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight conducted under 14 CFR Part 91.

According to the student pilot, the accident flight was the second flight of the day, which was conducted solo.

The first flight was about 3-1/2 hours earlier, and was conducted with an instructor. The student added that it was windy on the flight, and she had no plans to solo due to the wind conditions. When the flight instructor asked her if she wanted to fly again, she said yes, assuming the flight would be conducted as dual instruction. When the student realized that the flight would be conducted solo, she replied that she did not want to go solo, and that it was still too rough. After the flight instructor reassured her that the pervious dual flight had been good, the student climbed into the glider alone.

On the solo flight, as the glider was towed behind a tow plane, the student observed that the wind was blowing down the favored runway, runway 34. During the tow to altitude, the conditions were rough, with the towline going slack, and then tight, requiring the student to make corrections more often then she had done in the past. As the glider approached 2,500 feet, the towline was released and the student began to practice maneuvers. During the maneuvers, the student stated that she hit her head twice on the canopy due to the turbulent conditions. About 12 minutes into the flight, the student decided to return to the airport. She entered the traffic pattern, on the downwind leg, at 1,500 feet, but further out from the runway than she normally would have flown. While on the downwind leg, the student checked the operation of the airbrake and kept her hand on it as she had been taught. As the glider was turned on to the base leg, the student realized that she would not make the runway and elected to perform a forced landing to a two-lane highway. The glider touched down on the southbound lane of the elevated roadway and impacted a metal guardrail, coming to rest upright on the highway.

The student additionally stated that she might have been moving the speed brake handle inadvertently during the approach due to the turbulence.

The student reported she had accumulated about 13 hours of dual instruction, with 7 or 8 different flight instructors, at the Massachusetts Institute of Technology Soaring Club. She also accumulated about 1.4 hours of solo time. All of her previous flights had been conducted on days with light or calm wind conditions, with some crosswind landings.

The recorded weather at a nearby airport, about the time of the accident, included winds from 250 degrees at 13 knots, gusts to 22 knots.

Aircraft

Registration
N117BB
Reported as
Let L-23
Category
Glider
Serial number
917815
Airframe hours
911
Engine
Damage
Substantial damage
Flight
Instructional · Part 91
Registered owner
M.I.T. Soaring Association
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · August 27, 2001 · 25 hours before
Departed
3B3 · Sterling, MA
Airport
3B3 · Sterling Airport, runway 34, 3,010 × 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
Student pilot
Age
36
Injuries
None
Certificate
Student
Seat
Front
Flight hours
17 total · 17 in this make and model · 2 as pilot in command · 10 in the last 90 days · 4 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
250° at 18 knots, gusting 22
Visibility
10 statute miles
Lowest ceiling
None
Temperature
30 °F, dew point 9 °F
Altimeter
29.93 inHg
Observed at
FIT, 5 nm away

Docket · 3

The files NTSB released with the investigation on May 15, 2003, on NTSB’s docket system: statements, records, photos and specialists’ reports. 674 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.