T & T
TRAINING
& TECHNIQUE
18 | AUGUST 2019 FLYINGMAG.COMAFTERMATH Accident Analysis
I
n December 1996, a pilot and his
companion checked out a Beech
T-34 Mentor from the flying club at
the Memphis Naval Air Station in
Millington, Tennessee. They departed
at about 4:15 in the afternoon on a
300-nautical-mile trip to Bay St.
Louis, Mississippi. By the time they
approached the Gulf Coast, it was dark.
Several witnesses reported seeing
the airplane—or at least its naviga-
tion and anti-collision lights—flying
westbound “oscillating both vertically
and laterally” and then “rotating about
the longitudinal axis” before pitching
nose-down. The pitch of the engine
sound was heard rising, then there was
a sound like an explosion, followed by
that of an impact with the ground.
The pilot had not been in contact
with any ground station, but Houston
ATC radar recorded a target that was
most likely the T-34. Squawking 1200,
the target f lew at 3,500 feet for 12 min-
utes then began a gradual descent.
After two minutes, it abruptly climbed
from 3,200 feet to 3,600 feet in 12 sec-
onds, then descended 1,500 feet in
the next 12 seconds before disappear-
ing from radar. During this time, the
direction of f light was generally south-
or southeast-bound, not westbound, as
witnesses reported. The discrepancy
was unexplained.The wreckage of the T-34 was found
about two-tenths of a mile south
of the location of the last recorded
transponder code, in an area with
“minimal ground-reference lights.”
It appeared that the right wing had
separated in f light, followed by the
empennage surfaces.
The National Transportation
Safety Board attributed the accident
to “the noninstrument-rated pilot’s
intentional operation of the airplane
with known...inoperative attitude
indicator and directional gyro...with
an estimated time of arrival after
official twilight.”
This analysis had quite the stink
of bureaucrat about it. There is no
legal requirement that an airplane
be equipped with attitude and direc-
tional gyros to be flown at night. The
pilot knew that the vacuum-dependent
instruments were inoperative. Navy
Flying Club rules required airplanes
to be instrument equipped for night
cross-country f lights, but the nonpilot
desk clerk who released the airplane
may have been unaware of that rule
or its significance, or unaware of the
condition of the particular airplane,
or both. The pilot too may have been
unaware of the rule. At any rate, the
NTSB’s conclusion was tantamount
to saying that the airplane crashedbecause it was in violation of a rule of
the Navy Flying Club.
A few years after this accident,
several wing-spar failures in T-34s
led the FA A to ground the entire
civilian f leet until spars were either
reinforced or replaced. At the time
of this accident, however, concerns
about structural integrity of the
type—which was manufactured from
1953 to 1959—had not been raised.
The accident airplane had f lown
nearly 15,000 hours. The NTSB’s
description of the structural fail-
ures makes no mention of metal
fatigue and the metallurgical exper-
tise of the investigator who reported
“ overload failure” is not recorded.
It is possible that the 38-year-old
pilot, who had almost 500 hours
total time and 164 hours in the T-34,
became spatially disoriented, but it is
not especially likely. It was evidently a
VMC night with a partial moon, there
were towns nearby and the T-34 has
a greenhouse canopy that provides a
clear view of the surroundings in all
directions and minimizes the likeli-
hood of disorientation. The environ-
ment was rural but not unpopulated;
there were towns, roads and highways
below, including Interstate 59 and
U.S. Highway 11. The pilot had been
properly signed off by the f lying club’sUNKNOWNS: KNOWN
AND UNKNOWN
WHAT EVIL LURKS IN THE HEARTS OF MACHINES?By Peter Garrison