1. 24
www.mcctraining.co.uk
Communication can be:
Verbal/spoken (a single word, phrase or sentence, a grunt)
Written/textual (printed words and/or numbers on paper or on a
screen, hand-written notes)
Non-verbal
Graphic (pictures, diagrams, had-drawn sketches)
Symbolic (‗thumbs-up‘, wave of the hand, nod of the head)
Body language (facial expressions, a pat on the back, posture.
Communication (or more often a breakdown in communication) is often cited
as a contributor to incidents and accidents.
Lack of communication is characterised by the engineer who forgets to pass
on pertinent information to a colleague, or when a written message is mislaid.
Poor communication is typified by the engineer who does not make it clear
what he needs to know and consequently receives inappropriate information, or
a written report in barely legible handwriting.
Both problems can lead to subsequent human error.
Good Communication
Think about what you want to say before speaking or writing
Speak or write clearly
Listen or read carefully
Seek clarification wherever necessary.
“The transmission of something from one location to another. The „thing‟
that is transmitted may be a message, a signal, a meaning etc. In order to
have communication, both the transmitter and the receiver must share a
common code, so that the meaning or interpretation contained in the mes-
sage may be interpreted without error”.
Penguin Dictionary of Psychology
Dissemination of Information
There should normally be someone within an organisation with the responsibil-
ity for disseminating information. Supervisors can play an important role by
ensuring that the engineers within their team have seen and understood any
communicated information.
Poor dissemination of information was judged to have been a contributory
factor to the Eastern Airlines accident in 1983, when the aircraft, en route from
Miami to Nassau in the Bahamas, was forced to return when all three engines
dumped their oil as the result of missing seals.
‗On May 17, 1983, Eastern Airlines issued a revised work card 7204 [master
chip detector installation procedures, including the fitment of O-ring seals]. The
material was posted and all mechanics were expected to comply with the guid-
ance. However, there was no supervisory follow-up to ensure that mechanics
and foremen were incorporating the training material into the work require-
ments. Use of binders and bulletin boards is not an effective means of control-
ling the dissemination of important work procedures, especially when there is
no accountability system in place to enable supervisors to ensure that all me-
chanics had seen the applicable training and procedural information.‘
National Transportation Safety Board accident report
Communication
Martin Coupland
38 Church Meadow
Boverton
Vale of Glamorgan
Wales CF61 2AT
T: +44 (0) 1446 792 382
M: +44 (0) 7796 352 764
martin.coupland@mcctraining.co.uk
The Dirty Dozen
“To err is human”. Alexander Pope (1688-1744), poet
Mr Gordon Dupont (Transport Canada) researched numerous aircraft incidents and accidents where Human Factors
had been the primary cause. He concluded that there were essentially 12 factors that were the most common causes
of human error in maintenance—‖The Dirty Dozen‖.
If we could eliminate or control these, we would eliminate a very high percentage of maintenance-related events.
Lack of Communication Discuss work to be done or what has been
completed. Never assume anything. Try to avoid abbreviations without
explaining them.
Complacency Train yourself to expect to find a fault. Never sign for
something you didn't do. Approach repetitive inspections as if for the first
time.
Lack of Knowledge Get type training. Use only the latest editions of
technical documents. Ask a Technical Representative; someone who knows.
Distraction Mark incomplete work. When you return to the job, go back a
couple of steps. Use a detailed check sheet.
Lack of Teamwork Discuss what is to be done, who by and how. Ensure
that everyone understands and agrees.
Fatigue Be aware of the symptoms and look for them in yourself and
others. Avoid complex tasks at the bottom of your circadian rhythm. Sleep
and exercise regularly. Ask others to check your work.
Lack of Resources Order and stock parts well before they are needed.
Remember; manpower is a resource - insufficient personnel puts pressure
on everyone else.
Pressure Ensure pressure isn't self-induced. Communicate your concerns.
Ask for extra help. Just say ―NO".
Lack of Assertiveness Only sign for what is serviceable. Refuse to
compromise your standards.
Stress Be aware of how stress can affect your work. Stop and look ration-
ally at a problem. Work out a rational course of action and follow it. Take
time off or at least a short break. Discuss it with someone. Ask colleagues
to monitor your work. Exercise your body; fight stress.
Lack of Awareness Think what may happen in the event of an accident.
Check to see if your work will conflict with an existing modification or
repair. Ask others if they can see any potential problem with the work done.
Norms Always work in accordance with instructions or have the instruc-
tions changed. Be aware that "we always do it that way" doesn't make it
right.
1
―Human Factors is about people in their work-
ing and living environments, about their rela-
tionship with equipment, procedures and the
environment. Just as importantly, it is about
their relationships with other people. Human
Factors involves the overall performance of
human beings within the aviation system; it
seeks to optimise people‘s performance through
the systematic application of the human scienc-
es, often integrated within the framework of
system engineering. Its twin objectives can be
seen as safety and efficiency.―
International Civil Aviation Organisation (ICAO)
More examples of „Ramp Rash‟ inside.
―The [Part 145] organisation shall establish and
control the competence of personnel involved
in any maintenance, management and/or quality
audits in accordance with a procedure and to a
standard agreed by the competent authority. In
addition to the necessary expertise related to the
job function, competence must include an un-
derstanding of the application of human factors
and human performance issues appropriate to
that person‘s function in the organisation.
‗Human Factors‘ means principles which apply
to aeronautical design, certification, training,
operations and maintenance and which seek
safe interface between the human and other
system components by proper consideration of
human performance. ‗Human performance‘
means human capabilities and limitations which
have an impact on the safety and efficiency of
aeronautical operations.‖
European Aviation Safety Agency Part 145.A.30(e)
Personnel Requirements
―Human factors continuation training should
be of an appropriate duration in each two-year
period in relation to relevant quality audit find-
ings and other internal/external sources of in-
formation available to the organisation on hu-
man errors in maintenance.‖
European Aviation Safety Agency AMC Part 145.A.30(e)
Why have Human Factors training?
A brief history ...
In April 1988, an Aloha Airlines Boeing 737-200
suffered a near-catastrophic incident when a
large section of the cabin roof separated from
the aircraft at 24,000’. Despite this (and one
engine failing as it approached touchdown
coupled with a cockpit indication that the nose
undercarriage leg was not locked down), the
aircraft landed safely, with the loss of only one
life.
Although Human Factors had been an intrinsic
part of the aviation world before this point, the
authorities found many human factors-related
failings that led up to this incident, and there-
fore Human Factors training was treated much
more seriously as a result.
mcctraining.co.uk
Issue 2: June 2010
Human
Factors
Ramp Rash
It was once estimated that
the annual bill to the airlines
industry worldwide for „ramp
rash‟ (damage to aircraft by
ground contacts) was $1bn.
Recently, doubt was cast on
this figure, so calculations
were re-checked. It was
discovered that the figure
arrived at was inaccurate; in
fact, certain variables had
not been included (lost
revenue due to aircraft
unavailability (not just repair
costs), insurance claims etc).
The true figure is more like
$10bn.
Ramp damage occurs about
once every 1000 flights but
personal injury on the ramp
occurs every 100 flights.
Personal injury costs
account for $4.4bn of the
total figure.
Average aircraft downtime is
3.5 days at an average cost
of $225,000.
Flight International Nov 2005

2. 2
On December 26 2005, a McDonnell
Douglas MD-83, N979AS, operated by
Alaska Airlines, was substantially dam-
aged when the aircraft experienced a rap-
id cabin depressurisation during climb out
from Seattle, Washington.
The airline transport pilot captain and
first officer, the three flight crew mem-
bers and the 137 passengers were unin-
jured.
A new ground baggage handler
(approximately one week on the job),
who was driving a tug towing a train of
baggage carts, said that he waited for a
belt loader to be correctly positioned on
the right side at the middle cargo door of
the aircraft.
He said that he approached the aircraft
from aft to forward, but had to manoeu-
vre around another train of carts to get
close to the belt loader.
Once in position, he said the front of his
tug was 4-5 feet away from the aircraft.
After loading the carts with baggage, he
attempted to drive away. He said that he
turned the tug's wheels as far as possible.
He stated, "I was hoping to make it out,
but I felt my tug going against something.
I immediately set my foot on the brakes
and glanced at the body of the aircraft to
see if there was any damage. It was a
quick glance and I did not see any dam-
age."
He said two other ground personnel came
to assist him in manoeuvring his tug away
from the aircraft. He did not report the
incident to anyone.
The pilot said that the take-off was nor-
mal. During the climb out, at approxi-
mately 26,000 feet, they heard a loud
bang, and the cabin depressurised. He
said that they put their oxygen masks on,
and coordinated a descent to a lower alti-
tude with Seattle Centre. An uneventful
landing was performed at Seattle-Tacoma
International Airport, Seattle, Washing-
ton.
Post landing examination of the fuselage
revealed a 12‖x6‖ hole between the mid-
dle and forward cargo doors on the right
side of the aircraft. After the occurrence,
the ground baggage handler confessed
that he had "grazed the aircraft" with a
tug, while attempting to depart the vicini-
ty of the aircraft.
Alaska Airlines: Cabin Depressurised
CHIRP - Confidential Human Factors Incident Reporting Programme www.chirp.co.uk
Some accidents are difficult to hide.
In the Alaska Airlines MD-83 incident (top of page), the baggage handler obviously
had little idea of how fragile aircraft are and the potentially disastrous consequences of
his ―grazing‖ the fuselage.
The UK Civil Aviation Authority has stressed that it ―seeks to provide an environment
in which errors may be openly investigated in order that the contributing factors and
root causes of maintenance errors can be addressed‖.
―To facilitate this, it is considered that an unpremeditated or inadvertent lapse should not incur any punitive action, but a breach
of professionalism may do so (eg where an engineer causes deliberate harm or damage, has been involved previously in similar
lapses, attempted to hide their lapse or part in a mishap, etc).‖ (Airworthiness Notice 71)
Don’t hide a mistake. You will (probably) keep your job, and others can learn valuable lessons.
Report your mistakes anonymously through CHIRP, the Confidential Human Factors Incident Reporting Programme at www.chirp.co.uk.
23
For more information on stress, visit www.hse.gov.uk/stress
Stress
Stress now accounts for the majority of
lost workdays in the United Kingdom.
Modern lifestyles contribute to stress, and
pressure (both at home and work) raises
stress levels.
Stress is unavoidable (indeed, a certain
amount of stress is beneficial). However,
too much stress can seriously affect your
health.
Recognising that you are becoming over-
stressed and dealing with it are crucial.
What can you do at work?
Talk to your employer: if they don‘t
know there‘s a problem, they can‘t
help. If you don‘t feel able to talk di-
rectly to your employer or manager, ask
an employee representative to raise the
issue on your behalf.
Support your colleagues if they are ex-
periencing work-related stress.
Speak to your doctor if you are worried
about your health.
Discuss with your manager whether it is
possible to alter your job to make it less
stressful for you, recognising your and
your colleagues‘ needs.
Try to channel your energy into solving
the problem rather than just worrying
about it. Think about what would make
you happier at work, and discuss this
with your employer.
What can you do out of work?
Eat healthily.
Stop smoking – it doesn‘t help you to
stay healthy, even though you might
think it relaxes you.
Try to keep within Government recom-
mendations for alcohol consumption –
alcohol acts as depressant and will not
help you tackle the problem.
Watch your caffeine intake – tea, coffee
and some soft drinks (eg cola drinks)
may contribute to making you feel more
anxious.
Be physically active – it stimulates you
and gives you more energy.
Try learning relaxation techniques –
some people find it helps them cope
with pressures in the short term.
Talk to family or friends about what
you‘re feeling – they may be able to
help you and provide the support you
need to raise your concerns at work.
Have a laugh! Laughter releases hor-
mones into your system that combat the
harmful stress hormones.
Health and Safety Executive
Age Related Macular Degeneration http://www.eyesight.nu
ARMD (Aged Related Macular Degener-
ation) is a condition that can normally
affect you as you get older. In fact, alt-
hough it is the leading cause of sight loss
in the over 50s, it is now appearing in
much younger people (some as young as
20 years of age).
It is basically caused by the huge amount
of free radical damage inflicted by sun-
light, wrong foods, toxins and the lack of
nutrients reaching the macula (the small
part of the eye responsible for the
central vision, that allows you to see de-
tail and colours) to protect it from this
free radical damage.
ARMD usually starts in one eye and is
highly likely to affect the other at a later
stage.
The two specific nutrients responsible for
protecting the macula are Lutein and Ze-
axanthin. These Carotenoids are powerful
antioxidants that are known to be missing
in the eyes of sufferers.
Lutein and Zeaxanthin are found in most
fruit and vegetables, and in super quanti-
ties in some vegetables. It is well worth
including these super veggies in your
everyday diet, especially in soups, stir-
fry, oven roast veggies and salads.
This is critical to stop and reverse eye
disease.
Kale 21,900 mcg
Collard Greens 16,300 mcg
Spinach - raw 12,600 mcg
Spinach - cooked 10,200 mcg
Mustard Greens 9,900 mcg
Okra 6,800 mcg
Red Pepper 6,800 mcg
Romaine Lettuce 5,700 mcg
Endive 4,000 mcg
Cooked Broccoli 1,800 mcg
Green Peas 1,700 mcg
Pumpkin 1,500 mcg
Brussel Sprouts 1,300 mcg
Summer Squash 1,200 mcg
Sight-saving treatment currently being
carried out on ARMD sufferers involves
daily injections of a drug called Lucentis
directly into the eyeball. Nice.
Normal Vision
Early ARMD
Advanced ARMD

3. 22
The Control of Noise at Work Regula-
tions 2005 (the Noise Regulations) came
into force for all industry sectors in Great
Britain on 6 April 2006.
The level at which employers must pro-
vide hearing protection and hearing pro-
tection zones (if normal speech cannot be
heard clearly at 1 metre) is now 85
(formerly 90) decibels daily or weekly
average exposure
• and the level at which employers must
assess the risk to workers' health and pro-
vide them with information and training
(if normal speech cannot be heard clearly
at 2 metres) is now 80 (formerly 85) deci-
bels.
“According to the Royal National Institute
for Deaf People (RNID), there are about
nine million people who are deaf or hard
of hearing in the UK. Most of them have
lost their hearing gradually with increasing
age (presbyacusis). Over half of all people
aged over 60 are hard of hearing or deaf.
Hearing loss can also occur at a younger
age. There are about 123,000 people over
16 who were born hearing but have devel-
oped severe or profound deafness.”
Bupa's health information team, March 2007
CAUSES OF HEARING LOSS
There are many possible causes of
hearing loss. These can be divided
into two basic types, called conduc-
tive and sensorineural hearing loss.
Conductive hearing loss is caused
by anything that interferes with the
transmission of sound from the outer
to the inner ear. Some possible caus-
es of conductive hearing loss are:
. Middle ear infections (otitis media).
. Collection of fluid in the middle ear
("glue ear") in children.
. Blockage of the outer ear, most
commonly by wax.
. Otosclerosis, a condition in which
the ossicles of the middle ear harden
and become less mobile.
. Damage to the ossicles, for example
by serious infection or head injury.
. Perforated (pierced) eardrum, which
can be caused by an untreated ear
infection, head injury or a blow to the
ear, or from poking something in your
ear.
Sensorineural hearing loss is due
to damage to the pathway that sound
impulses take from the hair cells of
the inner ear to the auditory nerve
and the brain. Some possible causes
are:
. Age-related hearing loss
(presbycusis). This is the natural de-
cline in hearing that many people ex-
perience as they get older. It's partly
due to the loss of hair cells in the
cochlea.
. Acoustic trauma (injury caused by
loud noise) can damage hair cells.
. Certain viral or bacterial infections
such as mumps or meningitis can
lead to loss of hair cells or other dam-
age to the auditory nerve.
. Ménière's disease, which causes
dizziness, tinnitus and hearing loss.
. Certain drugs, such as some power-
ful antibiotics, can cause permanent
hearing loss. At high doses, aspirin is
thought to cause temporary tinnitus -
a persistent ringing in the ears. The
antimalarial drug quinine can also
cause tinnitus, but it's not thought to
cause permanent damage.
. Acoustic neuroma. This is a benign
(non-cancerous) tumour affecting the
auditory nerve. It needs to be ob-
served and is sometimes treated with
surgery.
. Other neurological (affecting the
brain or nervous system) conditions
such as multiple sclerosis, stroke, or
a brain tumour.
Noise and Hearing Protection
Source: http://hcd2.bupa.co.uk/fact_sheets/Mosby_factsheets/Hearing_Loss.html
3
US investigators have determined that
ground staff covered up an accident in
which a vehicle damaged a McDonnell
Douglas DC-9's fuselage, and allowed the
jet to depart for a flight during which it
depressurised.
The Northwest Airlines jet was being
attended in daylight on the ramp at Syra-
cuse, New York, by Air Wisconsin Air-
lines Corporation personnel ahead of op-
erating a flight to Detroit on 18 May last
year.
As the ground crew were dealing with
baggage, the engine of their belt-loader
stopped operating and a senior ground
agent decided to use a luggage tug to
push the loader away from the aircraft.
The tug drove within the safety-clearance
zone - against regulations - and during the
effort to push the loader away, the tug's
cab contacted the fuselage.
In a probable-cause statement on the
event, the National Transportation Safety
Board says: "The senior ground agent
then advised, 'Don't say anything' to one
of the other ground agents who was
working the flight with him."
The extraordinary decision to allow the
DC-9 to depart led the jet to suffer cabin
depressurisation as it climbed through
20,000ft. It performed an emergency de-
scent to 10,000ft and diverted to Buffalo.
Inspection of the aircraft revealed a 12in-
by-5in (30cm-by-13cm) tear in the right
side of the fuselage, about 6ft (1.8m)
ahead of the forward cargo door. There
was also a crease in the skin ahead of the
tear.
Marks on the tear were consistent with
the damage having been caused by the
tug. The jet, 38 years old at the time, had
passed an airworthiness inspection the
day before.
Two weeks after the accident the ramp-
handling company reminded personnel of
safety-zone regulations and underlined
the importance of reporting immediately
any damage to aircraft. It also issued ad-
ditional training materials.
None of the 95 passengers and four crew
members on board the DC-9 was injured
during the depressurisation and diversion.
Flight International, 15/12/2008
CHIRP - Confidential Human Factors Incident Reporting Programme www.chirp.co.uk
DC-9 depressurised after ramp crew covered up tug strike
BA staff arrested after 'failing to report hit-and-run with
baggage truck and passenger jet'
Two British Airways workers are alleged
to have hit a passenger jet with a bag-
gage truck at Heathrow - and then driven
off without telling anyone.
The damage by the electric-powered vehi-
cle, which pulls bags around the airport,
was done to the side of the Airbus A321.
It was only spotted hours later by ground
staff while it waited to taxi to a Terminal
5 runway with 80 people on board. It was
withdrawn from service and the passen-
gers were taken off.
The danger posed by the hit-and-run, and
the fact it was not reported, was consid-
ered so great that police were called in
and the men were arrested and bailed.
The two British Airways staff, one aged
54 and the other 49, with over 40 years
experience between them, have also been
suspended.
A BA insider said, 'For all they knew the
plane could have suffered fuselage dam-
age, causing it to fall apart mid-air.'
The incident happened on Friday morn-
ing. The damage was noticed at around
8.30pm when the jet was due to fly to
Aberdeen. Bosses have ordered an inves-
tigation.
The two workers could face charges of
criminal damage and endangering safety.
A police spokesman said: 'We were called
in by ground staff at Heathrow after they
became aware of fuselage damage.'
The 54-year-old man has been bailed
until a date the end of February and the
younger man until early March, he add-
ed.
A BA spokesman confirmed: 'Two mem-
bers of our ground staff based at
Heathrow were arrested following an
incident where one of our aircraft was
damaged. They were both questioned by
the police and released on bail pending
further inquiries. It would therefore be
inappropriate to give further details.'
Daily Mail 14th January 2009

4. 4
Nov 2, 2004 A Robinson R44 helicopter was being flown
from Cork, Ireland, to Weston, Ireland.
About 700 feet above ground-level, severe vibrations of
the cyclic control began, and the controls became “stiff
and heavy.” The pilot conducted an emergency landing in
a field two miles (three kilometers) from Cork Airport. Af-
ter exiting the helicopter, the pilot examined the area un-
derneath the auxiliary fuel tank and noticed oil on the fire-
wall.
The pilot, the only occupant, was not injured, and the heli-
copter received minor damage in the incident.
An engineer was called to the scene of the landing to in-
vestigate the problem.
“The engineer confirmed by using a hydraulic ground rig
that the forced landing was caused by loss of hydraulic
fluid in the flight control system, which in turn resulted in
the flying controls functioning without hydraulic servo as-
sistance,” said the report by the Irish Air Accident Investi-
gation Unit.
“The engineer detected that the leak was coming from a
T-piece union on the output side of the hydraulic pump.
He removed the union and noted that the O-ring retainer
had a ring mark around it, indicating that the associated
union nut was tightened too far up the union and distorted
the retainer.”
The helicopter manufacturer said that the retainer, which
seats the O-ring seal, had not been installed properly dur-
ing manufacture, the report said. Because the retainer is
not visible after installation, the manufacturer used a leak
check with normal system pressure to verify that the in-
stallation was correct.
The manufacturer has since revised procedures to pro-
vide for visually inspecting the retainers and O-ring seals
earlier, to verify correct assembly before the fittings are
installed in the final assembly.
At the time of the incident, the helicopter had a total of 24
flight hours since new.
“The incident shows that an improperly installed retainer
may not cause a leak for several flying hours,” said the
report.
Incorrect Installation Produces Delayed Hydraulic Leak
There is currently no requirement for Human Factors training in manufacturing/operating environments.
21
• Norms
• Simplify task
• Save time/effort
• Break rules for “kicks”
• Unrelated to task
• Satisfy personal need
• Time Pressures
• Workload Pressures
• Poor Procedures
• Poor Tooling
• Poor Conditions
Inevitable due
to tasks or
circumstances
Exceptional
Situational
Optimising
Routine
VIOLATIONS
• Norms
• Simplify task
• Save time/effort
• Break rules for “kicks”
• Unrelated to task
• Satisfy personal need
• Time Pressures
• Workload Pressures
• Poor Procedures
• Poor Tooling
• Poor Conditions
Inevitable due
to tasks or
circumstances
Exceptional
Situational
Optimising
Routine
VIOLATIONSExceptional
Situational
Optimising
Routine
VIOLATIONS
Violations in Aircraft Maintenance
It is an unfortunate fact of life that violations occur in aviation maintenance. Most stem from a genuine desire to do a
good job. Seldom are they acts of vandalism or sabotage. However, they represent a significant threat to safety as
systems are designed assuming people will follow the procedures.
There are four types of violations:
R - routine
O - optimising
S - situational
E - exceptional
Routine violations are things which have become ‟the normal way of doing something‟ within the person‟s work
group (eg a maintenance team). They can become routine for a number of reasons: engineers may believe that pro-
cedures may be over-prescriptive and violate them to simplify a task (cutting corners), to save time and effort.
Examples of routine violations are not performing an engine run after a borescope inspection (“it never leaks”), or not
changing the O-ring seals on the engine gearbox drive pad after a borescope inspection (“they are never damaged”).
Optimising violations involve breaking the rules for ‟kicks‟. These are often quite unrelated to the actual task - the
person just uses the opportunity to satisfy a personal need. An example of an optimising violation would be an engi-
neer who has to go across the airfield and drives there faster than permitted.
Situational violations occur due to the particular factors that exist at the time, such as time pressure, high workload,
unworkable procedures, inadequate tooling or poor working conditions. These occur often when, in order to get the
job done, engineers consider that a procedure cannot be followed. An example of a situational violation is an incident
which occurred where the door of a B747 came open in-flight. An engineer with a tight deadline discovered that he
needed a special jig to drill off a new door torque tube. The jig was not available, so the engineer decided to drill the
holes by hand on a pillar drill. If he had complied with the maintenance manual he could not have done the job and
the aircraft would have missed the service.
Exceptional violations are typified by particular tasks or operating circumstances that make violations inevitable, no
matter how well-intentioned the engineer might be.
Error Types: Violations

5. 20
Violations
Mistakes
Lapses
Slips
ERROR
TYPES
Actions not as intended
(skill-based)
Forgetting something
(skill based)
Doing something you believe
was correct (but wasn‟t)
(knowledge based)
Deliberate illegal actions
(rule based)
Violations
Mistakes
Lapses
Slips
ERROR
TYPES
Violations
Mistakes
Lapses
Slips
ERROR
TYPES
Actions not as intended
(skill-based)
Forgetting something
(skill based)
Doing something you believe
was correct (but wasn‟t)
(knowledge based)
Deliberate illegal actions
(rule based)
Error Types
Slips can be thought of as actions not carried
out as intended or planned, eg transposing dig-
its when copying out numbers, or misordering
steps in a procedure.
They typically occur at the task execution stage.
Lapses are missed actions and omissions,
ie when somebody has failed to do some-
thing due to lapses of memory and/or at-
tention or because they have forgotten
something, eg forgetting to replace an en-
gine cowling.
They occur at the storage (memory) stage.Mistakes are a specific type of error brought
about by a faulty plan/intention, ie somebody did
something believing it to be correct when it was, in
fact, wrong, eg an error of judgement such as mis-
selection of bolts when fitting an aircraft wind-
screen.
They occur at the planning stage.
Violations sometimes appear to be human errors,
but they differ from slips, lapses and mistakes be-
cause they are deliberate ‟illegal‟ actions, ie some-
body did something knowing it to be against the
rules (deliberately failing to follow proper
procedures).
Aircraft maintenance engineers may consider that
a violation is well intentioned, ie ‟cutting corners‟ to
get a job done on time. However, procedures must
be followed appropriately to help safeguard safety.
Skill-based behaviours are those that rely on stored routines or motor programmes that have been learned with
practice and may be executed without conscious thought.
Rule-based behaviours are those for which a routine or procedure has been learned. The components of a rule-
based behaviour may comprise a set of discrete skills.
Knowledge-based behaviours are those for which no procedure has been established. These require the aircraft
maintenance engineer to evaluate information, and then use his knowledge and experience to formulate a plan for
dealing with the situation.
5
For more information on this incident, visit http://www.aaib.dft.gov.uk/publications/bulletins
No Torque Figure Specified by Manufacturer
During the cruise, some four minutes into
the flight, the helicopter suffered severe
vibration. The pilot carried out an autoro-
tation and landed safely.
Subsequent investigation revealed that
one of the two tail-rotor trunnion flange
caps had separated, causing damage to a
tail-rotor blade and the vertical fin.
Agusta A109S Grand, G-CGRI
7 April 2006, Liskeard, Cornwall
The metallurgical examination showed
the failure to be due to an initial clock-
wise torsional overload followed by a
final axial tensile overload. It is possible
that the initial clockwise torsional over-
load was applied either during the manu-
facture of the helicopter or during mainte-
nance activity during the night prior to the
incident flight.
The maintenance manual did not contain
the specific torque-loading for the trun-
nion flange caps.
The helicopter manufacturer has since
issued torque loading figures for the
flange caps and has amended the
maintenance manual accordingly.

6. 6
A circadian rhythm is an approximate
daily periodicity, a roughly-24-hour cycle
in the biochemical, physiological or be-
havioural processes of living beings.
Circadian rhythms are important in deter-
mining the sleeping and feeding patterns
of all animals, including human beings.
There are clear patterns of core body tem-
perature, brain wave activity, hormone
production, cell regeneration and other
biological activities linked to this daily cy-
cle.
In addition, photoperiodism, the physio-
logical reaction of organisms to the length
of day or night, is vital to both plants and
animals, and the circadian system plays a
role in the measurement and interpreta-
tion of day length.
The clock affects our level of alertness
over about 24 hours. You can see from
the illustration that we are most alert
around 9 in the morning and around 7 at
night. Our lowest level of alertness is
around 2 in the afternoon and even lower
between 1 and 3 am.
Even if you are working permanent night-
shifts, the clock does not compensate.
You will always be at your lowest level of
alertness in the early hours.
However, it is also worth noting that your
level of alertness mid-afternoon is also
low; you will feel tired.
When you are tired, your decision-making
will be impaired.
Therefore, you should consider the impli-
cations of the Circadian Clock on your
work schedule.
1990: BAC 1-11 Windscreen Blowout
Download the report from: http://www.aaib.gov.uk/publications/rmal_reports/1_1992__g_bjrt.cfm
“This is your Captain
screaming …”
On 10 June 1990, a BAC 1-11 aircraft
(British Airways Flight 5390) departed
Birmingham International Airport for
Malaga, Spain, with 81 passengers, 4
cabin and 2 flight crew.
The co-pilot was the pilot flying during
the take-off and, once established in the
climb, the pilot-in-command handled the
aircraft in accordance with the operator's
normal operating procedures.
At this stage both pilots released their
shoulder harnesses and the pilot-in-
command loosened his lap-strap. As the
aircraft was climbing through 17,300 feet
pressure altitude, there was a loud bang
and the fuselage filled with condensation
mist indicating that a rapid decompres-
sion had occurred.
A cockpit windscreen had blown out and
the pilot-in-command was partially
sucked out of his windscreen aperture.
The flight deck door blew onto the flight
deck where it lay across the radio and
navigation console.
The co-pilot immediately regained con-
trol of the aircraft and initiated a rapid
descent to FL 110.
The cabin crew tried to pull the pilot-in-
command back into the aircraft but the
effect of the slipstream prevented them
from succeeding. They held him by the
ankles until the aircraft landed.
The investigation revealed that the acci-
dent occurred because a replacement
windscreen had been fitted with the
wrong bolts.
Alertness Levels: The Circadian Clock
19
Peer Pressure
In the working environment of aircraft maintenance, there
are many pressures brought to bear on the individual en-
gineer. There is the possibility that the aircraft mainte-
nance engineer will receive pressure at work from those
that work with him. This is known as peer pressure.
Peer pressure is the „actual or perceived pressure which
an individual may feel, to conform to what he believes
that his peers or colleagues expect‟.
For example, an individual engineer may feel that there is
pressure to cut corners in order to get an aircraft out by a
certain time, in the belief that this is what his colleagues
would do under similar circumstances.
There may be no actual pressure from management to
cut corners, but subtle pressure from peers, eg taking the
form of comments such as 'You don't want to bother
checking the manual for that. You do it like this...' would
constitute peer pressure.
Peer pressure thus falls within the area of conformity.
Conformity is the tendency to allow one's opinions, atti-
tudes, actions and even perceptions to be affected by
prevailing opinions, attitudes, actions and perceptions.
The influence of peer pressure and conformity on an indi-
vidual's views can be reduced considerably if the individu-
al airs his views publicly from the outset. However, this
can be very difficult.
Conformity is closely linked with 'culture'. It is highly rele-
vant in the aircraft maintenance environment where it can
work for or against a safety culture, depending on the
attitudes of the existing staff and their influence over new-
comers. In other words, it is important for an organisation
to engender a positive approach to safety throughout
their workforce, so that peer pressure and conformity per-
petuates this. In this instance, peer pressure is clearly a
good thing.
Too often, however, it works in reverse, with safety stand-
ards gradually deteriorating as shift members develop
practices which might appear to them to be more effi-
cient, but which erode safety. These place pressure, al-
beit possibly unwittingly, upon new engineers joining the
shift, to do likewise.
There is probably no industry in the commercial environment that does not impose
some form of deadline, and consequently time pressure, on its employees. Aircraft
maintenance is no exception. One of the potential stressors in maintenance is time
pressure. This might be actual pressure, where clearly specified deadlines are im-
posed by an external source (eg management or supervisors) and passed on to en-
gineers, or perceived, where engineers feel that there are time pressures when car-
rying out tasks, even when no definitive deadlines have been set in stone.
In addition, time pressure may be self imposed, in which case engineers set them-
selves deadlines to complete work (eg completing a task before a break or before
the end of a shift).
Management have contractual pressures associated with ensuring an aircraft is re-
leased to service within the time frame specified by their customers. Striving for
higher aircraft utilisation means that more maintenance must be accomplished in
fewer hours, with these hours frequently being at night. Failure to do so can impact
on flight punctuality and passenger satisfaction.
Thus, aircraft maintenance engineers have two driving forces:
the deadlines handed down to them and
their responsibilities to carry out a safe job.
The potential conflict between these two driving pressures can cause problems.
Time Pressure

7. 18
Phobias
Although not peculiar to aircraft maintenance engineering, working in restricted space and at heights is a feature of
this trade. Problems associated with physical access are not uncommon.
Maintenance engineers and technicians often have to access, and work in
very small spaces (eg in fuel tanks)
cramped conditions (such as beneath flight instrument panels, around rudder pedals)
elevated locations (on cherry-pickers or staging), and
sometimes in uncomfortable climatic or environmental conditions (heat, cold, wind, rain, noise).
This can be aggravated by aspects such as poor lighting or having to wear breathing apparatus.
There are many circumstances where people may experi-
ence various levels of physical or psychological discomfort
when in an enclosed or small space, which is generally
considered to be quite normal. When this discomfort be-
comes extreme, it is known as claustrophobia.
Claustrophobia can be defined as ‘abnormal fear of being
in an enclosed space’.
It is quite possible that susceptibility to claustrophobia is
not apparent at the start of employment. It may come
about for the first time because of an incident when
working within a confined space, eg panic if unable to
extricate oneself from a fuel tank.
If an engineer suffers an attack of claustrophobia, he
should make his colleagues and supervisors aware so that
if tasks likely to generate claustrophobia cannot be avoid-
ed, at least colleagues may be able to assist in extricating
the engineer from the confined space quickly, and sympa-
thetically.
Engineers should work in a team and assist one another if
necessary, making allowances for the fact that people
come in all shapes and sizes and that it may be easier for
one person to access a space than another. However, this
should not be used as an excuse for an engineer who has
put on weight, to excuse himself from jobs which he
would previously have been able to do with greater ease!
Acrophobia
Working at significant heights can also be a problem for
some aircraft maintenance engineers, especially when
doing crown inspections (top of fuselage, etc).
Some engineers may be quite at ease in situations like
these, whereas others may be so uncomfortable that they
are far more concerned about the height, and holding on
to the access equipment, than they are about the job in
hand. In such situations, it is very important that appro-
priate use is made of harnesses and safety ropes. These
will not necessarily remove the fear of heights, but will
certainly help to reassure the engineer and allow him to
concentrate on the task in hand.
Ultimately, if an engineer finds working high up brings on
phobic symptoms (such as severe anxiety and panic),
they should avoid such situations for safety's sake. How-
ever, as with claustrophobia, support from team mem-
bers can be helpful.
Shortly before the Aloha Airlines accident, during mainte-
nance, the inspector needed ropes attached to the rafters
of the hangar to prevent falling from the aircraft when it
was necessary to inspect rivet lines on top of the fuse-
lage. Although unavoidable, this would not have been
conducive to ensuring that the inspection was carried out
meticulously (nor was it, as the subsequent accident in-
vestigation revealed).
Managers and supervisors should attempt to make the
job as comfortable and secure as reasonably possible (eg
providing knee pad rests, ensuring that staging does not
wobble, providing ventilation in enclosed spaces, etc) and
allow for frequent breaks if practicable.
7
24 AUG 2001
Airbus A.330-243 C-GITS
Operator: Air Transat
Year Built: 1999
Total Airframe Hrs: 10433 hours
Cycles: 2390 cycles
Engines: 2 Rolls Royce Trent 772B
Crew: 0 fatalities / 13 on board
Passengers: 0 fatalities / 293 on board
Total: 0 fatalities / 306 on board
Aircraft Damage: Substantial
Location: Terceira-Lajes AFB, Azores
Departure: Toronto-Pearson International
Airport, Canada
Destination: Lisboa Airport, Portugal
Flight number: 236
Air Transat Flight TS236, was en route at
FL390 when, at 05:36 UTC, the crew
became aware of a fuel imbalance be-
tween the left and right-wing main fuel
tanks. Five minutes later the crew, con-
cerned about the lower-that-expected fuel
quantity indication, decided to divert to
Lajes Airport in the Azores.
At 05:48 UTC, when the crew ascertained
that a fuel leak could be the reason for the
possible fuel loss, an emergency was de-
clared to Santa Maria Oceanic Control.
At 06:13, at a calculated distance of 135
miles from Lajes, the right engine flamed
out. At 06:26, when the aircraft was about
85 nm from Lajes and at an altitude of
about FL345, the left engine flamed out.
At 06:39 the aircraft was at 13,000 feet
and 8 miles from the threshold of runway
33. An engines-out visual approach was
carried out and the aircraft landed on run-
way 33.
Eight of the plane's ten tyres burst during
the landing. An investigation determined
that a low-pressure fuel line on the right
engine had failed, probably as the result
of its coming into contact with an adja-
cent hydraulic line.
FINDINGS AS TO CAUSES AND
CONTRIBUTING FACTORS
. The replacement engine was received in
an unexpected pre-SB configuration to
which the operator had not previously
been exposed.
. Neither the engine-receipt nor the en-
gine-change planning process identified
the differences in configuration between
the engine being removed and the engine
being installed, leaving complete reliance
for detecting the differences upon the
technicians doing the engine change.
. The lead technician relied on verbal
advice during the engine change proce-
dure rather than acquiring access to the
relevant SB, which was necessary to
properly complete the installation of the
post-mod hydraulic pump.
. The installation of the post-mod hy-
draulic pump and the post-mod fuel tube
with the pre-mod hydraulic tube assembly
resulted in a mismatch between the fuel
and hydraulic tubes.
. The mismatched installation of the pre-
mod hydraulic tube and the post-mod fuel
tube resulted in the tubes coming into
contact with each other, which resulted in
the fracture of the fuel tube and the fuel
leak, the initiating event that led to fuel
exhaustion.
. Although the existence of the optional
Rolls-Royce SB RB.211-29-C625 be-
came known during the engine change,
the SB was not reviewed during or fol-
lowing the installation of the hydraulic
pump, which negated a safety defence
that should have prevented the mis-
matched installation.
.Although a clearance between the fuel
tube and hydraulic tube was achieved
during installation by applying some
force, the pressurisation of the hydraulic
line forced the hydraulic tube back to its
natural position and eliminated the clear-
ance.
.The flight crew did not detect that a fuel
problem existed until the Fuel ADV advi-
sory was displayed and the fuel imbal-
ance was noted on the Fuel ECAM page.
.The crew did not correctly evaluate the
situation before taking action.
.The flight crew did not recognise that a
fuel leak situation existed and carried out
the fuel imbalance procedure from
memory, which resulted in the fuel from
the left tanks being fed to the leak in the
right engine.
.Conducting the FUEL IMBALANCE
procedure by memory negated the de-
fence of the Caution note in the FUEL
IMBALANCE checklist that may have
caused the crew to consider timely action-
ing of the FUEL LEAK procedure.
.Although there were a number of other
indications that a significant fuel loss was
occurring, the crew did not conclude that
a fuel leak situation existed - not action-
ing the FUEL LEAK procedure was the
key factor that led to the fuel exhaustion.
For more information on this incident, visit http://www.transat.com/en/media_centre
2001: A New World Record (80-mile glide by an airliner)
crack
chafing
8 out of 12 tyres burst

8. 8
From http://www.flightglobal.com 9 Oct 2008 (sourced from Air Transport Intelligence)
Cathay 747 tractor collision enquiry cites aircrew fatigue
Swedish investigators believe pilot fatigue
contributed to a Cathay Pacific Boeing 747
-200 freighter sustaining heavy engine
damage after accidentally taxiing into its
tow-tractor at Stockholm Arlanda last
year.
The pilots had been awake for 18-20
hours by the time of the accident, which
occurred early on 25 June just after the
jet had been pushed back from stand R9
for a service to Dubai.
Investigation commission SHK has con-
cluded that, shortly after the tow-tractor
was disconnected from the nose-gear, the
pilots started to taxi the aircraft before a
ground technician had given an unambig-
uous all-clear signal. The Schopf 356 trac-
tor had been moved a short distance but
was out of the pilots' field of vision.
SHK says that, while the pilots read the
normal checklist after engine start, it "did
not contain any point" concerning a 'clear
signal' - a specific thumb-up gesture
showing that the aircraft is clear to taxi.
Only a supplemental note in the carrier's
expanded checklist informed pilots that
the ground dispatcher would "clearly dis-
play" to them the steering pin removed
from the nose-gear.
“Abandon ship!”
The Arlanda tow-tractor driver, who was
preparing to move the vehicle clear, hasti-
ly abandoned it when he heard the 747's
engines powering up.
Both the driver and the ground technician
"had to run in order to be safe" and the
aircraft struck the tractor with its inboard
left-hand Rolls-Royce RB211 engine. The
rear of the vehicle penetrated the nacelle
by 20-30cm, heavily damaging the cowl-
ing, pumps, fuel lines and control units,
and the engine began leaking fuel.
In its report into the accident, which also
badly damaged the tractor, SHK states
that - despite the fuel leak, close to hot
exhaust and electrical wiring - emergency
services were not summoned for nearly
an hour.
It attributes the collision to "inadequate"
checklists for the crew regarding confir-
mation of an all-clear signal. But SHK also
highlights the length of time the pilots
had been awake and says the time of the
accident, 03:33, was within a biological
window of low activity. Stress and fatigue,
it says, probably limited the crew's con-
centration abilities.
See the „Circadian Clock‟ on Page 6.
It‘s not the first (or probably last) time
this type of collision has happened (see
the picture on the front page and the arti-
cle on next page).
17
(From an article by Anastasia Stephens, Daily Mail 15 Aug 2009)
The £17 eye test that could save your life
Thousands of Britons could be saved
from the devastating effects of seri-
ous illness such as heart disease,
diabetes and brain tumours simply by
attending a regular eye test at their
local High Street opticians, say ex-
perts.
Studies have found that as many as
one in five of us have a health prob-
lem not related to the eye that could
be diagnosed through a routine eye
test. However, only about 20 per cent
of us go for the recommended check-
up every two years.
A 30-minute examination, which
costs as little as £17, can spot the
early signs of a range of life-
threatening health conditions.
Dr Susan Blakeney, fellow of the Col-
lege of Optometrists in London, says:
'An eye test is an integral part of a
general health check-up. Serious
illnesses other than eye disease can
be identified, such as signs of diabe-
tes, high blood pressure, high choles-
terol and even brain tumours.'
According to Brain Tumour UK, an
estimated 16,000 people are diag-
nosed with brain tumours in Britain
each year. And up to 30 per cent of
these tumours could be spotted
through routine eye tests, often at an
early stage.
'Brain tumours may cause swelling of
the optic nerve, which can appear
large and pale,' says Trevor Lawson
of Brian Tumour UK. 'There can be
loss of vision in certain areas and
headaches.
If spotted early, such diagnoses can
be life-saving, catching the tumour
before it spreads or causes perma-
nent damage to brain tissue.
'Sadly, in many cases they are
picked up too late and in these cases
survival rates for malignant brain tu-
mours are 14 per cent.'
Over-60s, who are more at risk,
would benefit from annual check-ups,
but only 47 per cent do so, according
to the Royal National Institute of Blind
People.
Optometrist Carolyn Zweig says:
'Diabetes can cause leakage of blood
and fluid at the back of the eye and
changes to blood vessels, easily
spotted during an eye test.
High blood cholesterol, which leads
to coronary heart disease, stroke and
heart attack, can cause a white ring
to appear around the cornea, the out-
er surface of the eye, early on.
Another indicator of heart disease,
high blood pressure, can cause burst
blood vessels at the back of the eye,
which an optometrist would see.'
Complex neurological conditions
such as multiple sclerosis, thyroid
disease and even cancer can also be
revealed during an eye test.
'Multiple sclerosis can cause swelling
of the optic nerve which can appear
abnormally large and pale,' says
Zweig. 'And an overactive thyroid
gland, or tumour in the neck, can re-
sult in an abnormal bulging of the
cornea.'
During an eye test, optometrists
check eyesight by asking patients to
read letters on a chart. A light is
shone on the front of the eyes to
check how they react, and a magnify-
ing instrument called an ophthalmo-
scope is used to check the back of
the eyes. The optometrist will also
check that the muscles that control
eye movement are working well.

9. 16
Vision
Basic Function of the Eye
The basic structure of the eye is simi-
lar to a simple camera with an aper-
ture (the iris), a lens and a light sen-
sitive surface (the retina).
Light enters the eye through the cor-
nea, then passes through the iris and
the lens and falls on the retina. Here
the light stimulates the light-sensitive
cells on the retina (rods and cones)
and these pass small electrical im-
pulses by way of the optic nerve to
the visual cortex in the brain. Here,
the electrical impulses are interpreted
and an image is perceived.
Cornea
The cornea is a clear 'window' at the
very front of the eye. The cornea acts
as a fixed focusing device. The focus-
ing is achieved by the shape of the
cornea bending the incoming light
rays. The cornea is responsible for
between 70% and 80% of the total
focusing ability (refraction) of the
eye.
Iris and Pupil
The iris (the coloured part of the eye)
controls the amount of light that is
allowed to enter the eye. It does this
by varying the size of the pupil (the
dark area in the centre of the iris).
The size of the pupil can be changed
very rapidly to cater for changing
light levels. The amount of light can
be adjusted by a factor of 5:1.
Lens
After passing through the pupil, the
light passes through the lens. Its
shape is changed by the muscles
(cillary muscles) surrounding it which
results in the final focusing adjust-
ment to place a sharp image onto the
retina. The change of shape of the
lens is called accommodation. In or-
der to focus clearly on a near object,
the lens is thickened. To focus on a
distant point, the lens is flattened.
The degree of accommodation can be
affected by factors such as fatigue or
the ageing process.
When a person is tired, accommoda-
tion is reduced, resulting in less sharp
vision (sharpness of vision is known
as visual acuity).
The retina is located on the rear wall
of the eyeball. It is made up of a
complex layer of nerve cells connect-
ed to the optic nerve. Two types of
light sensitive cells are found in the
retina - rods and cones.
The central area of the retina is
known as the fovea and the receptors
in this area are all cones. It is here
that the visual image is typically fo-
cused. Moving outwards, the cones
become less dense and are progres-
sively replaced by rods, so that in the
periphery of the retina, there are only
rods.
Cones function in good light and are
capable of detecting fine detail and
are colour sensitive. This means the
human eye can distinguish about
1000 different shades of colour.
Rods cannot detect colour. They are
poor at distinguishing fine detail, but
good at detecting movement in the
edge of the visual field (peripheral
vision). They are much more sensi-
tive at lower light levels. As light de-
creases, the sensing task is passed
from the cones to the rods. This
means in poor light levels we see
only in black and white and shades of
grey.
At the point at which the optic nerve
joins the back of the eye, a 'blind
spot' occurs. This is not evident when
viewing things with both eyes
(binocular vision), since it is not pos-
sible for the image of an object to fall
on the blind spots of both eyes at the
same time. Even when viewing with
one eye (monocular vision), the con-
stant rapid movement of the eye
(saccades) means that the image will
not fall on the blind spot all the time.
It is only when viewing a stimulus
that appears very fleetingly (eg a
light flashing), that the blind spot
may result in something not being
seen.
In maintenance engineering, tasks
such as close visual inspection or
crack detection should not cause such
problems, as the eye or eyes move
across and around the area of inter-
est (visual scanning).
Optic
Nerve
To the brain
9
El Al 747 crushes tow tractor at Paris Charles de Gaulle
From http://www.flightglobal.com 16 Apr 2007
Lack of Communication*
French investigators have started an in-
quiry after an El Al Boeing 747-400 suf-
fered severe engine damage at Paris after
it taxied over its pushback tractor.
The Israeli-operated aircraft was prepar-
ing to depart Paris Charles de Gaulle for
Tel Aviv during late morning on 13 April
when the incident occurred. It crushed the
tow tractor under the number three en-
gine, heavily damaging both.
A spokesman for airports operator Aero-
ports de Paris says the pushback tractor
had been disconnected from the aircraft
but was still under the 747 when it started
to taxi.
―During the departure the tractor had
pushed back the aircraft,‖ he says. ―It was
still under the aircraft and the pilot decid-
ed to go without authorisation from the
ground staff. Normally the pilot has to
wait for ground staff authorisation before
moving.‖
The aircraft involved was the youngest
747-400 in El Al‘s fleet, an eight-year old
example registered 4X-ELD.
All of El Al‘s 747-400s are equipped with
Pratt & Whitney PW4056 powerplants.
None of the occupants on board the jet,
including 374 passengers, was injured.
*See back page—The Dirty Dozen.
More ramp rash ...
Madrid, 8 Jan 2004
McDonnell Douglas MD-82 hit by a
tractor in the second forward hold
door (no further information availa-
ble).

10. 10
July 2008: Three planes collide in Baton Rouge
Edited version of the report at: http://www.wafb.com
Three CRJ passenger jets sustained serious damage when a
young mechanic pressed a starter switch to slowly spin jet en-
gine compressor blades for routine washing.
She had successfully performed the same action on the jet's
right engine without difficulty. However, mechanics familiar with
the accident said that when the mechanic repeated the action
on the left engine of the CRJ model 700 jet, a computer control
system known as "FADEC" ignited the engine and immediately
spun up to near take-off power. Someone had left the throttle
setting for the left engine at 85% power, sources said.
The 34 ton passenger jet leapt forward, ploughing into two other
CRJ aircraft in the hangar.
Airport manager Anthony Marino said the pair of model 200
aircraft that were damaged will be repaired at the Baton Rouge
maintenance facility, which employs 120 people. "That's a sign
of the high skill levels over there" at the new ASA hangar. Ma-
rino was instrumental in construction of the $6 million hangar to
lure the ASA maintenance facility to Baton Rouge.
Marino acknowledged that the three-plane smash-up could
have become an explosive disaster. The incident occurred in
the pre-dawn hours of Monday, July 7th. None of the 14 ASA
mechanics and cleaning workers inside the hangar was injured.
ASA spokeswoman Modolo said the investigation of the acci-
dent is still underway. Ordinarily, any damage that renders an
aircraft not flyable requires a report to the National Transporta-
tion Safety Board. However, the NTSB told WAFB News it was
not investigating the ASA incident. The aircraft carried no pas-
sengers, were not in flight, and were damaged in an FAA-
approved maintenance facility.
Together, the three jets are valued at $50 million, according to
Modolo. The young woman who set the multi-million dollar chain
of events in motion is not likely to bear full blame for the event.
"There's plenty of blame to go around," said one airport employ-
ee familiar with the accident.
CRJ 700
CRJ 200
15
Memory
IMPROVING THE MEMORY
The best way to improve memory
seems to be to increase the supply of
oxygen to the brain, which may be
accomplished with aerobic exercises;
walking for three hours each week
suffices, as does swimming or bicycle
riding.
One study found that chewing gum
will supply the brain with enough oxy-
gen to help memorise items simply
because of the muscle movement.
It‟s thought that the process of writing
a working memory into the long-term
memory store is largely controlled by
a seahorse-shaped set of neurons in
the brain called the hippocampus.
TYPES OF MEMORY
A basic and generally accepted clas-
sification of memory is based on the
duration of memory retention, and
identifies 3 distinct types of memory:
sensory memory
short-term memory
long-term memory.
Sensory Memory
The ability to look at an item, and re-
member what it looked like with just a
second of observation, or memorisa-
tion, is an example of sensory
memory.
With very short presentations, partici-
pants often report that they seem to
"see" more than they can actually
report.
Short-Term Memory
Short-term memory allows one to re-
call something from several seconds
to as long as a minute without re-
hearsal.
Its capacity is also very limited: exper-
iments have shown that the store of
short term memory was 7±2 items.
Memory capacity can be increased
through a process called chunking.
For example, if presented with the
string:
FBIPHDTWAIBM
people are able to remember only a
few items. However, if the same infor-
mation is presented in the following
way:
FBI PHD TWA IBM
people can remember a great deal
more letters. This is because they are
able to chunk the information into
meaningful groups of letters.
The ideal size for chunking letters and
numbers is three.
Long-Term Memory
The storage in sensory memory and
short-term memory generally have a
strictly limited capacity and duration,
which means that information is avail-
able for a certain period of time, but is
not retained indefinitely. By contrast,
long-term memory can store much
larger quantities of information for
potentially unlimited duration
(sometimes a whole life span).
For example, given a random seven-
digit number, we may remember it for
only a few seconds before forgetting,
suggesting it was stored in our short-
term memory. On the other hand, we
can remember telephone numbers for
many years through repetition; this
information is said to be stored in long
-term memory.
DEMENTIA
There are over 100 different types of
dementia with Alzheimer's Disease
being perhaps the best known. As
with most forms of dementia, Alzhei-
mer's involves progressive memory
loss (as well as loss of other vital
functions) and at present is irreversi-
ble.
It is not entirely clear what causes
Alzheimer's but there's likely to be
more than one contributing factor. On
a molecular level, it involves chemical
and structural changes to the brain
which start killing off brain cells. In the
Alzheimer brain, the cortex shrivels
up, damaging areas involved in think-
ing, planning and remembering.
Shrinkage is especially severe in the
hippocampus, an area of the cortex
that plays a key role in formation of
new memories. Ventricles (fluid-filled
spaces within the brain) grow larger.

11. 14
Murphy’s Law
There is a tendency among human beings towards compla-
cency. The belief that an accident will 'never happen to me or
to my Company' can be a major problem when attempting to
convince individuals or organisations of the need to look at
human factors issues, recognise risks and implement improve-
ments, rather than merely paying lip-service to human factors.
'Murphy's Law' can be regarded as the notion: 'If something
can go wrong, sooner or later it will.'
If everyone could be persuaded to acknowledge Murphy's
Law, this might help overcome the 'it will never happen to me'
attitude that many people hold. It is not true that accidents
only happen to people who are irresponsible or sloppy. The
incidents and accidents described in this publication show that
errors can be made by experienced, well-respected individuals
and accidents can occur in organisations previously thought to
be 'safe'.
Factors Affecting Performance: Fitness and Health
―What fits your busy schedule better: exercising
20 minutes a day or being dead 24 hours a day?‖
Fitness and health can have a significant affect upon job
performance (both physical and cognitive). Day-to-day
fitness and health can be reduced through illness
(physical or mental) or injury.
Responsibility falls upon the individual aircraft mainte-
nance engineer to determine whether he is not well
enough to work on a particular day. Alternatively, his col-
leagues or supervisor may persuade or advise him to ab-
sent himself until he feels better.
In fact, as the CAA's Air-
worthiness Notice No. 47
points out, it is a legal
requirement for aircraft
maintenance engineers
to make sure they are fit
for work: 'Fitness: In
most professions there is
a duty of care by the indi-
vidual to assess his or
her own fitness to carry
out professional duties.
This has been a legal requirement for some time for doc-
tors, flight crew members and air traffic controllers.
Licensed aircraft maintenance engineers are also now
required by law to take a similar professional attitude.
Cases of subtle physical or mental illness may not always
be apparent to the individual but as engineers often work
as a member of a team any substandard performance or
unusual behaviour should be quickly noticed by col-
leagues or supervisors who should notify management so
that appropriate support and counselling action can be
taken.'
Aircraft maintenance engineers can take common sense
steps to maintain their fitness and health. These include:
Eating regular meals and a well-balanced diet
Taking regular exercise (exercise sufficient to dou-
ble the resting pulse rate for 20 minutes, three
times a week is often recommended)
Stopping smoking
Sensible alcohol intake (for men, this is no more
than 3 - 4 units a day or 28 per week, where a unit
is equivalent to half a pint of beer or a glass of wine
or spirit).
Finally, day-to-day health and fitness can be adversely
influenced by the use of medication, alcohol and illicit
drugs.
11
Pictures from http://www.airliners.net
2004: A320 cowlings - #1 Iberia
May 11, 2004
Some minutes after take-off to Bilbao, the engine covers
flew out and the aircraft returned for an emergency
landing at Madrid (no further information available).
… and #2 AirTran Airways
On July 13, 2004, an Airbus Industrie A320-233, operated by
Ryan International Airlines as AirTran Airways Flight 4, returned
for landing after a portion of the left engine cowling separated
from the aircraft in flight in the vicinity of Atlanta, Georgia.
The captain, first officer, 4 flight attendants and 104 passengers
were not injured, and the aircraft sustained minor damage.
The flight departed Hartsfield-Jackson Atlanta International Air-
port, Atlanta, Georgia, at 1140 on July 13, 2004 en route to
Orlando, Florida.
According to the captain, immediately after take-off, the lead
flight attendant called to inform him that a passenger reported
seeing a cover come off the left engine. The captain received
no cockpit indications of a problem, and he instructed the lead
flight attendant to look out the window and verify. The captain
stated he felt the aircraft "shutter," and he contacted air traffic
control and requested to return for landing. The lead flight at-
tendant confirmed to the captain the left engine cowling was
missing.
The captain stated the No 1 engine oil quantity indicator illumi-
nated amber, and he declared an emergency. The engine con-
tinued to operate normally, and the flight returned for landing
without further incident.
Preliminary examination of the aircraft revealed both sides of
the left engine cowling were separated, the left engine pylon
was bent up, aft, and inboard and the left wing slat outboard of
the engine nacelle displayed an approximate 12-inch area with
dent and puncture damage.
The Union City Police Department retrieved the inboard side of
the left engine cowling from a dirt roadway approximately 7.5
nautical miles west southwest of Hartsfield-Jackson Atlanta
International Airport. Airport authorities found the outboard side
of the left engine cowling in the grass beside runway 27R.
A mechanic later stated he opened the fan cowl for the No 1
engine prior to the flight, and he could not recall if the cowl
doors were fully latched.

12. 12
For more information on this incident, visit http://www.bea-fr.org/anglaise/rapports/rap.htm
2007: $200,000,000 Airbus A340 Written Off
16 November 2007
Airbus confirms an A340-600 was dam-
aged and five people were injured in a
ground test accident at the company‘s
Saint-Martin site in Toulouse.
The aircraft sustained damage when it
somehow broke free of its parking chocks
during engine run-ups around 5 pm, local
time. News photos taken at the scene
show the aircraft's nose rammed through
a blast deflection wall.
―At this time, recovery operations are still
in progress and Airbus staff is working
closely with the emergency services and
local authorities at the site,‖ an Airbus
statement says.
Nine people were aboard the aircraft at
the time of the accident. The condition of
the five injured person was not immedi-
ately available.
―Airbus expresses its sympathy to the
families and friends of the [injured] per-
sons concerned,‖ the company adds.
The aircraft, with tail number MSN 856,
was due to be delivered to Abu Dhabi-
based Etihad Airways, "in the coming
days," Airbus says.
French investigators have determined that
the aircraft, which was undergoing pre-
delivery checks, was being held at stand-
still with the parking brake on and all
four Rolls-Royce Trent 500 powerplants
running with a relatively high engine
pressure ratio of 1.24-1.26.
The aircraft‘s engines were not retarded
to idle until two seconds before the jet
struck its test-pen wall.
The aircraft, which had been performing
an engine and brake test, was travelling at
around 30kt (55km/h) at the time of im-
pact.
Wheel chocks were not inserted under the
aircraft at the time.
The engineers had taken all four engines
to take-off power with a virtually empty
aircraft.
The take-off warning horn was blaring
away in the cockpit because they had all
4 engines at full power. The aircraft com-
puters thought they were trying to take
off but the aircraft had not been config-
ured properly (flaps/slats, etc).
Then one of the crew decided to pull the
circuit breaker on the Ground Proximity
Sensor to silence the alarm. This fools the
aircraft into thinking it is in the air.
The computers automatically released
all the brakes and set the aircraft rocket-
ing forward. The crew had no idea that
this is a safety feature so that pilots can't
land with the brakes on.
“AIRBUS REMINDS ALL OPERATORS TO
STRICTLY ADHERE TO AIRCRAFT
MAINTENANCE MANUAL PROCEDURES
WHEN PERFORMING ENGINE GROUND
RUNS.
ENGINE GROUND RUNS AT HIGH POWER
ARE NORMALLY CONDUCTED ON A SIN-
GLE ENGINE WITH THE ENGINE IN THE
SAME POSITION ON THE OPPOSITE
WING OPERATED AT A LIMITED THRUST
SETTING TO AVOID DAMAGE TO THE
AIFRAME.
WHEEL CHOCKS ARE TO BE INSTALLED
THROUGHOUT THE TEST.”
YANNICK MALINGE
VICE PRESIDENT FLIGHT SAFETY
AIRBUS
20 Nov 2007
13
April 2010: Polish president killed in Tu-154 crash
Polish president Lech Kaczynski is
among some 90 people killed
after a governmental Tupolev Tu-
154 crashed near the Russian city
of Smolensk.
The Polish presidential office con-
firms that Kaczynski, his wife Ma-
ria and dozens of senior Polish
representatives were on board
the aircraft.
It states that preliminary information suggests the air-
craft struck trees at the end of the runway while at-
tempting a go-around. Weather conditions were report-
edly poor, including fog, but meteorological information
from the airport has yet to be confirmed, as is a report
that the Tu-154's crew was offered a diversion.
The main questions that arise relate to the decision to
send so many national leaders on a single flight, and why
the aircraft's crew made the disastrous attempt to carry
out an approach when visibility was well below the mini-
mum for the non-precision approach. Other questions
relate to why the navigation aids available at Smolensk
were not supplemented for a flight carrying such a high-
profile delegation. The aircraft, arriving from Warsaw on
10 April, had been approaching runway 26 at Smolensk
North in fog. Images from the scene show that the jet's
wreckage is displaced to the left of the runway's extend-
ed centreline, and that the direction of the debris trail
bears some 30° to the left.
CIS Interstate Aviation Committee (MAK) leader Tatyana
Anodina has stated that the Soloviev D-30KU engines
were "in working order" until the aircraft collided with an
obstacle. She added that preliminary analysis of the re-
corders showed no evidence of in-flight fire or explosion
or on-board equipment failure.
In addition, communications with the aircraft were nor-
mal, and the pilots did not report any problems to air
traffic control.
Smolensk ATC says it had, however, suggested to the
pilots that they consider diverting to Minsk or Vitebsk in
Belarus, or Moscow Vnukovo.
The problem with those airports is that they are all more
than four hours by road from Katyn, the ultimate destina-
tion for the Polish delegation, where they were to attend
a commemoration of a massacre of Polish officers 70
years ago during the Second World War. Diverting would
have made the officials late for the scheduled ceremony.
The Tu-154M's 35-year-old captain had a total of 3,528h,
of which 2,937h were on Tu-154 aircraft. His co-pilot had
506h on the type from an overall 1,939h. There was also
a navigator on board, who had 59h on the Tu-154 but
had also flown as a Yakovlev Yak-40 pilot, as well as a
senior technician.
Flight International