FTW95LA237

NTSB accident investigation · Stokes Smith DSA-1 · Brookshire, TX · June 8, 1995

Accident · Minor injuriesLimited investigationFinal report
Date
June 8, 1995, 15:15 local (20:15 UTC)
Place
Brookshire, TX
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N33BSStokes Smith DSA-1
Weather
Visual (VMC) · Day
Status
Completed · report November 8, 1995
Report
Approved by Office Director
FAA report
19950608014409A
Case key
19448

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

Owner/builder's inadequate maintenance resulting in a loss of engine power due to corroded magneto coils. A factor was the lack of suitable terrain for the forced landing.

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 engine power(total) - mech failure/malfTakeoff - initial climb
Ignition system,magneto - corrodedCause
Maintenance - inadequateOwner/builderCause
Forced landingDescent - emergency
On ground/water encounter with terrain/waterLanding - roll
Terrain condition - none suitableFactor
Terrain condition - dirt bank/rising embankment

Analysis

The pilot reported that the engine lost power during the initial climb after takeoff and collided with a rice levee during the forced landing. The builder/owner/pilot holds an FAA aircraft repairman certificate and performed the maintenance on the airplane including the last annual inspection the day before the accident. The factory remanufactured magnetos (bendix model S4LN21 p/n 10- 51360-30; s/n 321336 and 321337) had been installed since June 10, 1988. Following a loss of engine power, examination of the magnetos revealed 'heavily corroded coils.' The left magneto coil 'failed the resistance check.' Ground lead to high tension resistance 'read .85 ohm'; according to the manufacturer it should read '12,000 to 16,000 ohms.' This was the pilot's 'third forced landing due to engine failure.' Prior troubleshooting by the builder did not lead to magneto teardown.

Factual narrative

On June 8, 1995, at 1515 central daylight time, a Stokes, SMITH DSA-1, homebuilt airplane, N33BS, sustained substantial damage during a forced landing following a loss of engine power near Brookshire, Texas. The commercial pilot received minor injuries. Visual meteorological conditions prevailed for the local personal flight conducted under Title 14 CFR Part 91.

During interviews, conducted by the Federal Aviation Administration (FAA) inspector, the pilot reported that after refueling, the flight departed a private airstrip near Waller, Texas, at 1525. A witness (statment enclosed) observed the airplane at 300 to 350 feet above the ground and "heard the aircraft mag cross firing." The pilot reported that the engine lost power. During the landing roll, the main gear hit a rice levee, the airplane cartwheeled and came to rest nose down. Horizontal stabilizer, vertical stabilizer, wing spars and engine components were damaged.

A review of FAA records and the airplane maintenance logbooks revealed that the airplane was built by the current pilot/owner. Bendix model S4LN21 (P/N 10-51360-30) factory remanufactured left magneto (S/N 321336) and right magneto (S/N 321337) were installed on June 10, 1988. The airplanes's first flight was conducted on January 2, 1989, and on November 16, 1989, an FAA airworthiness certificate was issued without a geographic operation limitation. The builder holds an aircraft repairman certificate issued by the FAA on December 1, 1988. Records indicate that he performed the maintenance for N33BS including the last annual inspection on June 7, 1995.

The magnetos were examined at C & D Aviation at Waller, Texas, and the FAA inspector reported that the teardown of the Bendix magnetos revealed that both magnetos had "heavily corroded coils." The left magneto coil "failed the resistance check." Ground lead to high tension resistance "read .85 ohm"; according to the manufacturer it should read "12,000 to 16,000 ohms." This was the pilot's "third forced landing due to engine failure" and prior troubleshooting by the builder did not lead to magneto teardown.

Numerous attempts were made by the investigator-in-charge to obtain the Pilot/Operator Report (NTSB Form 6120.1/2). To date this report has not been received.

Aircraft

Registration
N33BS
Reported as
Stokes Smith DSA-1 (SMITH DSA-)
Category
Airplane, amateur-built
Serial number
100
Engine
Lycoming O-320-A2B, 150 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
William G. Stokes
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Annual · June 7, 1995
Departed
NONE · Waller, TX

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
74
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Center
Flight hours
3,300 total

Weather

Conditions
Visual (VMC) · Day
Wind
150° at 15 knots
Visibility
6 statute miles
Lowest ceiling
None
Temperature
93 °F, dew point 73 °F
Altimeter
29.00 inHg
Observed at
DWH, 20 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.