This fault tree analysis examines the causes of the Kegworth air disaster in which British Midland Flight BD 92 crashed on landing at East Midlands Airport in 1990. The primary cause was the pilots shutting down the wrong engine (the right engine) due to judgment error likely caused by insufficient protocols for dealing with simultaneous symptoms of vibration and smoke from the engines. Contributing factors included equipment failure, poor aircraft design with no way for pilots to visually confirm the engine status, inadequate training so pilots didn't know about differences in the air conditioning system, and potential flaws in engine design allowing metal fatigue and heavy vibrations.

1. FAULT TREE
ANALYSIS OF
THE KEGWORTH
AIR DISASTER
ROSS APTED

2. British Midland Flight
BD 92 crash landing
Wrong engine
Engine failure
shutdown (right engine)
Fan blade fracture
Judgment error Equipment failure Metal fatigue Heavy vibrations
Other tasks Insufficient protocols Poor aircraft design Inadequate training Engine vibrations
sensor failure Heavy vibrations Flawed engine design
No
protocols in
Pilots did no re- place to No way to Pilots did not High
evaluate engine
switch of
deal with get visual know that the
power In
aircraft had a
decision due to simultaneo conformatio Inadequa adequate
high cabin work us
different air- setting in
n from condition te testing in
load. symptom of cockpit system flight
vibration maintena high
and smoke. nce

3. Engine failure
Fan blade fracture
Metal fatigue Heavy vibrations
Heavy vibrations Flawed engine design
High power
setting in In adequate
flight testing in
high

4. Wrong engine shutdown (right
engine)
Judgment error Equipment failure
Other tasks Insufficient protocols Poor aircraft design Engine vibrations sensor failure
Inadequate training
No protocols
Pilots did no in place to No way to get Pilots did not
re-evaluate deal with visual know that the
engine switch Inadequate
simultaneous conformation aircraft had a
of decision maintenance
symptom of from cockpit different air-
due to high vibration and condition
cabin work smoke. system
load.

5. Wrong engine shutdown (right
engine)
Judgment error Equipment failure
Other tasks Insufficient protocols Poor aircraft design Engine vibrations sensor failure
Inadequate training
No protocols
Pilots did no in place to No way to get Pilots did not
re-evaluate deal with visual know that the
engine switch Inadequate
simultaneous conformation aircraft had a
of decision maintenance
symptom of from cockpit different air-
due to high vibration and condition
cabin work smoke. system
load.