National Aviation UniversityInstituteMaintenance Department
of malfunctions and damages of the aircraft
Done by: Oleksandr Krasnoshchok,Chelpanova, Stanislav Pashnyak: FLA-106by: L. Zhuravlova
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
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.
Cracks are fractures that would not separate the material into two parts if the surrounding supports were removed; usually originating at edges, holes, or points where concentrated loads are applied or where abrupt changes in cross-sectional area occur. Cracks cause a significant cross-sectional area change. This damage usually has an irregular line and is often the result of fatigue in the material. The length of cracks that may be tolerated varies widely with material, structure, and application. No crack should be regarded as negligible until the damage limits for the affected structure have been determined
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.
Transit check - is the simplest form of an aircraft maintenance. Its carried out before every flight.
Daily Check is the everyday check of aircraft performance. It must be done in every 24 hour (sometimes in every 36 hour). Usually this check is carried out at night.
Weekly Check is done approximately once a week. It can be done at night and day as well. It doesnt require a special room (like hangar). Its carried out every 3-4 hours as usual.
This is performed approximately every 500 - 800 flight hours. It needs about 20 man-hours and is usually performed overnight at an airport gate. The actual occurrence of this check varies by aircraft type, the cycle count (takeoff and landing is considered an aircraft "cycle"), or the number of hours flown since the last check. The occurrence can be delayed by the airline if certain predetermined conditions are met.
This is performed approximately every 4-6 months. It needs about 150 man-hours and is usually performed wi