NYC98LA011

NTSB accident investigation · Schweizer SGS1-26A · Fairfield, PA · October 13, 1997

Accident · Serious injuriesLimited investigationFinal report
Date
October 13, 1997, 17:30 local (21:30 UTC)
Place
Fairfield, PA
Injuries
1 serious
Damage
Minor damage
Phase of flight
Initial climb
Aircraft
N1154NSchweizer SGS1-26A
Weather
Visual (VMC) · Day
Status
Completed · report January 28, 2000
Report
Approved by Office Director
FAA report
19971013031199A
Case key
39488

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 improper installation of the elevator cables and elevator control bell-crank by the pilot, and an inadequate annual inspection by the mechanic. Also causal was the pilot's inadequate preflight of the flight controls prior to takeoff.

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.

Loss of control - in flightTakeoff - initial climb
Flt control syst,elevator control cable/rod - reversedCause
Flight control,elevator attachment - reversedCause
Maintenance,installation - improperPilot in commandCause
Maintenance,annual inspection - inadequateOther maintenance personnelCause
Aircraft preflight - inadequatePilot in commandCause
Stall - inadvertentPilot in command
In flight collision with terrain/waterDescent - uncontrolled

Analysis

Before takeoff, the pilot installed the wings and tail on the glider. During the takeoff, just after the glider became airborne, it pitched up vertically. After the tow rope was released the nose dropped, and the glider impacted the ground. Examination of the glider revealed that the control cables were rigged in reverse and the elevator control bell-crank located in the aft end of the fuselage was installed inverted from its normal position. About 8 days prior to the accident an airframe and powerplant mechanic with inspector authorization performed an annual inspection which included a statement, 'AC assembled and rigged.' At that time, the complete elevator assembly was not installed. The pilot completed the elevator installation after the annual inspection. Prior to the flight, the pilot was asked by a witness if he had performed a 'positive control check' of the primary flight controls, which the pilot stated 'yes.'

Factual narrative

On October 13, 1997, about 1730 eastern daylight time, a Schweizer SGS1-26A, N1154N, a glider, was substantially damaged when it entered an uncontrolled descent after takeoff from the Mid-Atlantic Soaring Center, Fairfield, Pennsylvania. The certificated private pilot received serious injuries. Visual meteorological conditions prevailed for the local flight. No flight plan was filed for the personal flight conducted under 14 CFR Part 91.

A witness reported that the glider and towplane departed runway 15, an asphalt runway, on its first flight after maintenance. The glider became airborne after a 20 to 25 foot takeoff roll and began to climb at a high pitch attitude. The tow line was then released, and the glider's pitch attitude increased to about a 75 to 80 degree angle. The nose of the glider then dropped and impacted the ground. The witness stated that just prior to the flight, the wings and tail section of the glider were assembled. The witness had asked the accident pilot if he performed a "positive control check" on the primary flight controls, to which the pilot responded "yes."

Another witness stated he observed the glider takeoff and pitch vertically straight up, then after the tow rope was released, the glider's nose pitched down and impacted the ground. The witness also stated that the pilot had been working on the glider for most of the summer, and recently replaced the flight control cables for the elevator.

Examination of the wreckage by a Federal Aviation Administration Inspector revealed that the elevator controls were rigged backwards, with the right hand elevator cable going through the top fairlead, and the left hand elevator cable going through the bottom fairlead. According to Schweizer Control Surface Installation Chart, Form I-4073, the left hand elevator cable should have been routed through the top fairlead located in the aft fuselage. Further inspection revealed that the elevator bell-crank located in the aft end of the fuselage was installed inverted from its normal position. The elevator control, located in the cockpit, operated in reverse of normal control operation. Forward movement of the control moved the elevator surface in an upward direction.

An airframe and powerplant mechanic with inspector authorization had performed an annual inspection and a flight control check about 8 days prior to accident. The annual write-up included, "AC assembled and rigged." At that time, the complete elevator assembly was not installed. The pilot completed the elevator installation after the annual inspection. No other evidence of pre-impact malfunctions were found with the glider during the examination.

Aircraft

Registration
N1154N
Reported as
Schweizer SGS1-26A
Category
Glider
Serial number
056
Airframe hours
1,725
Engine
unknown
Damage
Minor damage
Flight
Personal · Part 91
Registered owner
Gayle P. Lathrop
Airworthiness certificate
Standard, Normal
Last inspection
Annual · October 5, 1997 · 0 hours before
Airport
W73 · Mid-Atlan. Soaring Center, runway 15, 2,700 × 50 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
44
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Front
Flight hours
686 total · 634 as pilot in command · 15 in the last 90 days · 5 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 8 knots
Visibility
7 statute miles
Lowest ceiling
None
Temperature
73 °F, dew point 57 °F
Altimeter
30.00 inHg
Observed at
HGR, 24 nm away

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 N1154N · 1

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