Inspection of malfunctions and damages of the aircraft
National Aviation
UniversityInstituteMaintenance Department
report
of malfunctions and
damages of the aircraft
Done by: Oleksandr Krasnoshchok,Chelpanova,
Stanislav Pashnyak: FLA-106by: L. Zhuravlova
2012
Content
Introduction1.
Inspected damages
Our visual inspection of the
aircrafts which are present in the hangar of NAU9
.1 Damages of a fuselage
.2 Damages of an engine
.3 Damages of a wing
.4 Damages of a tail unit
.5 Damages of a landing gear
Part
2. What to do while accident?
Emergency landings (on ground
and on water)water landings
Conclusion
INTRODUCTION
are serious problem in aviation. Great amounts of damages
cause improper operation of an aircraft or even to the catastrophes. The
aircraft engineers have to carry out some technical maintenance to get rid of
all the things which may cause the improper operation of an aircraft. Different
types of operations are used to prevent damages formation.damages can be
classified into different classes: dents, nicks, scratches, cracks, holes,
abrasions, gouges, corrosions, notes, delamination, disbonds. Dent is
depressed or hollow deformations without removal of material or change in cross
sectional area. Generally dents are caused by impact from a smoothly
contoured object. One characteristic that all dents should have is a
"pushed in surface" and a relatively smooth bottom where metal is not
displaced, folded or creased. Many Aircraft Structural Repair Manuals specify
that a "crease" be treated as a crack. Generally when evaluating
dents, the width of the dent is the second longest distance across the dent,
measured at 90 degrees to the direction of the length.
Nicks are broken edges without cracks, but with portions of
material removed. Negligible damage limits will vary with structure, material,
and loading.
Scratches are marks penetrating the surface
that reduce the structural cross section of the material but do not penetrate
the complete thickness. The depth of a scratch may be determined by use
of an optical micrometer. Generally, scratches in Alclad aluminum alloy sheet
that do not penetrate the protective Alclad layer are classified as negligible.
Holes are punctures, penetrations or cutouts that
breach the complete thickness of the material and is fully surrounded by
undamaged material. The size, shape, and distance from edges and supporting
structures must be considered when evaluating hole damage.
Abrasion is a damaged area that is the result of scuffing,
rubbing, scraping, or other surface erosion. This type of damage is usually
rough and has an irregular shape.
Gouge is a damaged area where the result is a
cross-sectional change caused by a sharp object and gives a continuous, sharp
or smooth groove in the material
Corrosion is a deterioration of a metal because of an
electrochemical reaction with its environment. Depending on the type of
corrosion, this deterioration may take the form cracking, exfoliation, or erosion
of the corroding material. Corrosion damage is typically classified as
light, moderate, or severe, depending on the extent of the corrosion and the
loading requirements of the corroded part. Aircraft-specific structural manuals
should be consulted for the correct classification of corrosion damage
on a given part.
Not: is an initial accurate determination of the type of
damage encountered can usually be made by the use of a 10X magnifying glass or
an optical micrometer. True crack length determination will generally require
some form of Non Destructive Testing such as Eddy Current or Fluorescent
penetrants.
Delamination is a separation of the layers of
material in a laminate, either local or covering a wide area, that occurs
during manufacturing or in service. Fiber-reinforced and composites may
delaminate when impacted and not exhibit visible damage.
Disbond is an area within a bonded interface between two
adherents in which an adhesion failure or separation has occurred. If the
separation is performed deliberately to referred to as a debond.aviation
accident is defined as an occurrence associated with the operation of an
aircraft which takes place between the time any person boards the aircraft with
the intention of flight until such time as all such persons have disembarked,
in which a person is fatally or seriously injured, the aircraft sustains damage
or structural failure or the aircraft is missing or is completely inaccessible.
There are different types of aviation accidents: aircraft fires, accidents
caused by an air traffic controller error, accidents caused by pilot, accidents
involving controlled flight into terrain, aircraft collisions, accidents caused
by fog or fuel exhaustion, runway incursionsý.
Aircraft maintenance checks are periodic inspections that have to be
done on all commercial/civil aircraft
<#"564687.files/image001.gif">
On the figures 1-4 we can see the damages of a fiberglass
window. The absence of some rivets is shown on the third picture. The traces of
corrosion are shown on the fourth one.
.1 Damages of a fuselage
fuselage is the main structure in the aircraft that holds
crew, passengers and cargo. An aircraft fuselage structure must be capable of
withstanding many types of loads and stresses, and at the same time with low
weight.damage is unexpected physical injury of an aircraft which can lead to
depressurization, loss of power or improper work of an aircraft system and it
is caused by external things, such as birds’ strike, watering (corrosion),
faults of a crew or else.two most frequently types of structural damages in a
fuselage are the longitudinal cracks due the pressurization cycles and
the circumferential cracks due the bending and torsion of the fuselage.
These damages can occur along all the shape of fuselage: in the nose, in the
glass part, at the joints., monocoque, and the semi-monocoque solutions are
found for the design of this structure. Truss or ramework types of construction
have wood, steel or aluminum tube, or other cross sectional shapes which may be
bolted, welded, bonded, pinned, riveted or machined into a rigid
assembly.principal source of the stresses in this structure is the internal
pressure in high altitude caused by difference of cabin pressurization and
reduction of the outside pressure with increase in altitude, but the structure
is subjected to other loads, as bending, torsion, thermal loads, etc.damages of
a fuselage are represented in the following pictures. There are rupture holes
in the nose of a fuselage, scratches, corrosion, and cracks.
5. Minor impact damage
6. Hole in the nose of a fuselage
7. Corrosion
8. Damage caused by hailstone
were some accidents involving the damages of a fuselage:
, August 22 - Far Eastern Air Transport Flight 103, a
Boeing 737, disintegrates during flight and crashed near Taipei, Taiwan; severe
corrosion in the fuselage structure leads to explosive decompression and
disintegration at high altitude; all 110 on board are killed.
, April 1 - Southwest Airlines Flight 812, a Boeing
737, ruptures a hole in the fuselage at 36,000 feet, causing the cabin to lose
pressure after takeoff from Phoenix Sky Harbor. The plane lands safely at Yuma International
Airport, Arizona with all 118 people aboard uninjured.
.2 Damages of an engine
An engine is a machine
<#"564687.files/image009.gif">
One strike can involve up to several dozens of birds, which
can cause damage to more than one part of the aircraft.
Figure 9. The impeller blade damages
10. Birds’ strike
maintenance of an engine requires a very proper exploration.
The vibration in the engine must be checked.the visual inspection of the
aircraft engines we did not notice any damages. But if this inspection was more
precise I think this damage could have been found.
.3 Damages of a wing
wing is a principal structural unit of an airplane. Its
function is to lift and to support the airplane during the flight.maintain its
all-important aerodynamic shape, a wing must be designed and built to hold its
shape even under extreme stress. Basically, the wing is a framework composed
chiefly of spars, ribs, and (possibly) stringers (see figure 1-5). Spars are
the main members of the wing. They extend lengthwise of the wing (crosswise of
the fuselage). All the load carried by the wing is ultimately taken by the
spars. In flight, the force of the air acts against the skin. From the skin,
this force is transmitted to the ribs and then to the spars.wing structures
have two spars, the front spar and the rear spar. The front spar is found near
the leading edge while the rear spar is about two-thirds the distance to the
trailing edge. Depending on the design of the flight loads, some of the
all-metal wings have as many as five spars. In addition to the main spars,
there is a short structural member which is called an aileron spar.ribs are the
parts of a wing which support the covering and provide the airfoil shape. These
ribs are called forming ribs and their primary purpose is to provide shape.
Some may have an additional purpose of bearing flight stress, and these are
called compression ribs.damages of a wing are different: damaged ribs or
bulkheads, broken fastening, broken parts of trailing (or leading) edge.
Figure 11. The rear of the slate is de-laminating Figure
. Broken leading edge
In our hangar there were some airplanes with broken parts of
wings. Particularly, there were troubles with the skin on the wings. Some of
airplanes even did not have a skin cover at all.
.4 Damages of a tail unit
The empennage also known as the tail or tail assembly,
of most aircraft gives stability to the aircraft, in a similar way to the
feathers on an arrow. Most aircraft feature empennage incorporating vertical
and horizontal stabilising surfaces which stabilise the flight dynamics
<#"564687.files/image014.gif">13. Damaged tail unit
the investigation of aircrafts in our
hangar we have found some damages in the tail assemblies. You can see that
damages in the following pictures:
14-15. Damaged tail assembly
damage aircraft accident
landing
1.5 Damages of a landing gear
undercarriage or landing gear is the structure that supports
an aircraft on the ground and allows it to taxi, takeoff and land. Typically
wheels are used, but skids, skis, floats or a combination of these and other
elements can be deployed, depending on the surface. Gear
arrangementstaildragger arrangement was common during the early propeller era,
as it allows more room for propeller clearance. Most modern aircraft have
tricycle undercarriages. Taildraggers are considered harder to land and take off
(because the arrangement is unstable, that is, a small deviation from
straight-line travel is naturally amplified by the greater drag of the
mainwheel which has moved farther away from the plane's centre of gravity due
to the deviation), and usually require special pilot training. Sometimes a
small tail wheel or skid is added to aircraft with tricycle undercarriage, in
case of tail strikes during take-off. The Concorde, for instance, had a
retractable tail "bumper" wheel, as delta winged aircraft need a high
angle when taking off. The Boeing 727 also had a retractable tail bumper. Some
aircraft with retractable conventional landing gear have a fixed tailwheel,
which generates minimal drag (since most of the airflow past the tailwheel has
been blanketed by the fuselage) and even improves yaw stability in some
cases.gear may have such damages as wear, holes, cracks, scratches and others.
In the following picture you can see the landing gear damages of the aircraft
of National Aviation University hangar:
Each of the aircraft's four main landing gear wheels has
electrohydraulic disc brakes and an anti-skid system.
Part 2. What to do while accident?
majority of those involved in plane crashes survive. Here are
some ideas for increasing odds of making it through such an event. A plane
crash is a terrifying experience, and the very idea is enough to make many
people avoid flying altogether. Although much of what's happening will probably
be beyond your control, there are a number of things people can do to increase
their chances of survival. Here are some guidelines.the plane takes off, count
the rows between you and the emergency exits in case power failures or smoke
reduce your visibility. Keep your seat belt on when you're sitting, and don't
wander around unnecessarily. Put your tray up when you don't need it. The
procedures followed during an inflight crisis vary widely depending upon the
situation. Follow the directions given by the airline staff - they've been
trained for these events. If it's obvious that there will be a crash, put your
head between your knees or against the seat. If you have a pillow or a blanket,
put it on your lap. The theory here is that if you're going to be thrown
forward anyway, you'll reduce possible injuries by assuming that position
beforehand. Breathe slowly and deeply and think about where the nearest
emergency exit is located.impact, you will hopefully be able to unbuckle
yourself and move toward the exit. This is a crucial time. Many airplane crash
deaths and injuries occur not because of the actual crash but because of the
fire that erupts afterward. Don't try to bring your carry-on luggage. Stay low,
but don't crawl or you could be trampled. Watch the floor lights; those near
emergency exits will be red. Go through the exit one person at a time.a typical
plane, you'll slide down an inflatable ramp after exiting. These are very
strong, so don't be afraid of punctures. Help at the bottom in whatever way you
can. A flight attendant may ask you to help people off the ramp. If not,
consider joining those already off and moving them as far from the plane as
possible. Look for injured people and assist them. Comfort those who are
panicked, especially children. If possible, look for a place to call 911.planes
crash in remote areas. This compounds fear and confusion. Try to find or make a
clear space away from the wreckage for people to rest and get their bearings.
Emotional trauma can be just as exhausting as physical injuries, so don't
expect people to be up and ready to move. In this situation, think about the
most basic human needs before trying to find help. Assuming you've done what
you can for the injured, your first priority is to find clean water. With that
taken care of you can focus on getting help, finding food, creating shelter,
and salvaging what you can from the wreck.matter what happens, stay calm.
Remembering this statistic might help: almost 60% of people involved in
airplane crashes survive. Following these tips will increase those odds even
more.
landings (on ground and on water)
emergency landing is a landing made by an aircraft in
response to a crisis which either interferes with the operation of the aircraft
or involves sudden medical emergencies necessitating diversion to the nearest airport.
There are several different types of emergency landings for powered aircraft:
planned landing or unplanned landinglanding - the aircraft is forced to make a
landing due to technical problems, or in rare situations with light aircraft,
weather conditions. Landing as soon as possible is a priority, no matter where,
since a major system failure has occurred or is imminent. This means that the
forced landing may even occur when the aircraft is still flyable, in order to
prevent a crash or ditching situation.landing may result from a planned landing
at a location about which information is limited, from unanticipated changes
during the flight, or from abnormal or even emergency situations. This may be
as a result of problems with the aircraft, or a medical or police emergency.
The sooner a pilot locates and inspects a potential landing site, the less the
chance of additional limitations being imposed by worsening aircraft
conditions, deteriorating weather, or other factors.landing is caused by the
failure of or damage to vital systems such as engines, hydraulics, or landing
gear, and so a landing must be attempted where a runway is needed but none is
available. The pilot is essentially trying to get the aircraft on the ground in
a way which minimizes the possibility of injury or death to the people
aboard.is the same as a forced landing, only on water. After the disabled
aircraft makes contact with the surface of the water, the aircraft will most
likely sink if it is not designed to float, although it may well float for
hours, depending on damage.
Emergency water landings
US Airways Flight 1549 after ditching in the Hudson River
passenger and cargo aircraft and helicopter ditchings have
been documented. These intentional emergency water landings are the result of
an in-flight fuel depletion or mechanical malfunction and not an accidental
overshoot of a runway or an uncontrolled crash into a body of water.
The FAA
<http://en.wikipedia.org/wiki/Federal_Aviation_Administration> does not
require commercial pilots
<http://en.wikipedia.org/wiki/Pilot_certification_in_the_United_States>
to train to ditch but airline cabin personnel must train the evacuation
process. In addition, the FAA implemented rules under which circumstances (kind
of operator, number of passengers, weight, route) an aircraft has to carry
emergency equipment including floating devices such as life jackets
<http://en.wikipedia.org/wiki/Life_jacket> and life rafts
<http://en.wikipedia.org/wiki/Life_raft>.aircraft are designed with the
possibility of a water landing in mind. Airbus
<http://en.wikipedia.org/wiki/Airbus> aircraft, for example, feature a
"ditching button" which, if pressed, closes valves and openings
underneath the aircraft, including the outflow valve, the air inlet for the
emergency RAT, the avionics inlet, the extract valve, and the flow control
valve. It is meant to slow flooding in a water landing. While there have been
several 'successful' (survivable) water landings by narrow-body and propeller-driven
airliners, few commercial jets have ever touched down 'perfectly' on water.
There has been a good deal of popular controversy over the efficiency of life
vests and rafts. For example, Ralph Nader
<http://en.wikipedia.org/wiki/Ralph_Nader>'s Aviation Consumer Action
Project
<http://en.wikipedia.org/w/index.php?title=Aviation_Consumer_Action_Project&action=edit&redlink=1>
had been quoted as saying that awide body
<http://en.wikipedia.org/wiki/Wide-body_aircraft> jet would “shatter like
a raw egg dropped on pavement, killing most if not all passengers on impact,
even in calm seas with well-trained pilots and good landing
trajectories.", in December 2002, The Economist had quoted an expert as
claiming that "No large airliner has ever made an emergency landing on
water" in an article that goes on to charge, "So the life jackets ...
have little purpose other than to make passengers feel better." This idea
was repeated in The Economist in September 2006 in an article which reported
that "in the history of aviation the number of wide-bodied aircraft that
have made successful landings on water is zero."
Conclusion
are different types of damages. And those damages prevent the
proper work of an aircraft. The consequences can be different. It can be a loss
of power, depressurization or even worse, up to the breaking of an airplane
part.the result of our practice we have learnt how to carry out visual
inspection, how to conclude the report of condition for each aircraft and how
to work with different types of damages.inspection of aircraft damages is the
one of very important parts of the work of the Aircraft Engineer. So, this
practice gave us some knowledge which is to be used by us when we go to a
job.the next generations, we would advice to be careful during transit visual
inspections. Our carefulness will lead us to the safety flights.
References
1. Testing,
inspection, maintenance and storage procedures
<http://www.globalsecurity.org/military/library/policy/army/accp/al0993/le4.htm>
. Maintenance
and Certification - Torque Paint (Slippage Marks)
<http://www.tc.gc.ca/eng/civilaviation/publications/tp185-3-05-paint-3861.htm>
. “Composite
materials for aircraft structures” Alan A. Baker, Stuart Dutton, Donald W.
Kelly
. <http://en.wikipedia.org>
. <http://civilavia.info>
. <http://www.ehow.com/info_12203115_damages-caused-overheating-engines.html>