ATL97LA013

NTSB accident investigation · Let L-13 · Benton, TN · October 30, 1996

Accident · Serious injuriesLimited investigationFinal report
Date
October 30, 1996, 18:00 local (23:00 UTC)
Place
Benton, TN
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N15CBLet L-13
Weather
Visual (VMC) · Dusk
Status
Completed · report August 21, 1997
Report
Approved by Office Director
FAA report
19961030037039A
Case key
3803

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

failure of the flight crew to maintain altitude/clearance above runway obstacles, and inadequate supervision by the flight instructor. Factors relating to the accident were sunglare on the canopy, and the proximity of obstacles (trees) to the runway.

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 objectApproach - vfr pattern - final approach
Light condition - sunglareFactor
Object - tree(s)Factor
Altitude/clearance - not maintainedFlightcrewCause
Supervision - inadequatePilot in command(cfi)Cause

Analysis

The glider collided with a tree during final approach to landing on runway 21. According to the instructor and the student, they did not see the tree because of dusk lighting conditions, which placed the sun low on the horizon and produced glare on the glider canopy. The instructor stated that the tree was about 300 feet from the runway threshold. Runway obstacle information indicated that the threshold for the runway was displaced 200 feet.

Factual narrative

On October 30, 1996, about 1800 eastern standard time, a Let L-13 "Blanik" glider, N15CB, collided with trees during the final approach to the Chilhowee Glider Port, Benton, Tennessee. The glider was operated under the provisions of Title 14 CFR Part 91, and visual flight rules. A flight plan was not filed for the local instructional flight. There were serious injuries to the private pilot under instruction, minor injuries to the airline transport instructor, and substantial damage to the glider. Origination of the flight was Benton, Tennessee, about 1730 on the same day.

The instructor stated that when the glider was turned onto the final approach for landing on runway 21, the sun was directly in their eyes. He stated that the glare on the canopy was causing very poor visibility. He was able to barely see the runway directly in front of the aircraft and side visibility was nil. The pilot under instruction continued the final approach descent and collided with a tree short of the runway. Both pilots stated they did not see the tree until the collision occurred.

The instructor indicated in his report of the accident that the tree was about 300 feet from the end of the runway. Airport information obtained from an Internet file entitled "Airnav" regarding the airport indicated that the runway 21 threshold is displaced 200 feet. A 36 foot tree is listed as an obstacle, located 500 feet from the threshold and 110 feet right of the centerline. The slope to clear the tree is listed as 13:1.

Aircraft

Registration
N15CB
Reported as
Let L-13
Category
Glider
Serial number
174806
Engine
unknown
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Wendylene, Inc
Registered owner
Earl D.Masters/James E. Davis
Airworthiness certificate
Standard, Normal
Last inspection
Annual · August 21, 1996 · 12 hours before
Departed
92A
Airport
92A · Chillhowee Glider Port, runway 21, 2,600 × 200 ft, grass/turf

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
31
Certificate
Airline transport
Airplane ratings
Single-engine land, Multi-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Rear
Flight hours
7,500 total · 7 in this make and model · 5,500 as pilot in command · 200 in the last 90 days · 80 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Dusk
Wind
270° at 4 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
70 °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 N15CB · 1

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