This is performed approximately every 15-21 months or a specific amount of actual Flight Hours (FH) as defined by the manufacturer. This maintenance check is much more extensive than a B Check, as pretty much the whole aircraft is inspected. This check puts the aircraft out of service and until it is completed, the aircraft must not leave the maintenance site. It also requires more space than A and B Checks - usually a hangar at a maintenance base. The time needed to complete such a check is generally 1-2 weeks and the effort involved can require up to 6000 man-hours. The schedule of occurrence has many factors and components as has been described, and thus varies by aircraft category and type.
This is - by far - the most comprehensive and demanding check for an airplane. It is also known as a Heavy Maintenance Visit (HMV). This check occurs approximately every 5-6 years. It is a check that, more or less, takes the entire airplane apart for inspection and overhaul. Also, if required, the paint may need to be completely removed for further inspection on the fuselage metal skin. Such a check will usually demand around 40.000 man-hours and it can generally take up to 2 months to complete, depending on the aircraft and the number of technicians involved. It also requires the most space of all maintenance checks, and as such must be performed at a suitable maintenance base. Given the requirements of this check and the tremendous effort involved in it, it is also the most expensive maintenance check of all, with total costs for a single visit being well within the million-dollar range.
%20(MRO)%20shops%20state%20that%20it%20is%20virtually%20impossible%20to%20perform%20a%20D%20Check%20profitably%20at%20a%20shop%20located%20within%20the%20United%20States.%20As%20such,%20only%20few%20of%20these%20shops%20offer%20D%20checks.">Because of the nature and the cost of such a check, most airlines - especially those with a large fleet - have to plan D Checks for their aircraft years in advance. Ofttimes, older aircraft being phased out of a particular airline's fleet are either stored or scrapped upon reaching their next D Check, due to the high costs involved in it in comparison to the aircraft's value. On average, a commercial aircraft undergoes 2-3 D Checks before it is retired. Many Maintenance, Repair and Overhaul <http://en.wikipedia.org/wiki/Maintenance,_repair,_and_operations> (MRO) shops state that it is virtually impossible to perform a D Check profitably at a shop located within the United States. As such, only few of these shops offer D checks.
As pilot in command you are responsible to ascertain that the aircraft is an airworthy condition. As such it is required to check all aircraft papers as weight (mass) and balance, aircraft logbooks, licenses and limitations. Part of any flight is a visual inspection of the aircraft.
Visual inspectioninspection is the most basic and common inspection method, and involves getting the inspector to "see" where one normally couldn't. This is done with the use of tools such as fiberscopes, borescopes, magnifying glasses and mirrors. Successful use of the technique requires good lighting and vision for best sensitivity, as well as training & experience which are vital for accurate interpretation of features.
Advantages of Visual Inspection
-Inspection performed rapidly and at low cost
-Ability to inspect complex sizes and shapes of any material
-Minimum part preparation required
Limitations of Visual Inspection
-Surface to be inspected must somehow be accessible to inspector or visual aids
-Surface finish, roughness and cleanliness can interfere with inspection
-Only surface defects are detectable
Visual inspection or walk around is done by the pilot or mechanic as final airworthiness check. In this section we describe were and what to look for when inspecting your aircraft. The walk around is a visual inspection for the general condition of the aircraft and it is intended to make a final check for its airworthiness. Especially important during the winter season, is to remove even small accumulations of frost, ice or snow from the wings, tail and control surfaces.are a number of items that need to be checked on the exterior of the aircraft during the walk around (this order can be slightly different but this one would work for any high wing aircraft like Cessna's, Murphy's or Pelicans):
·Empennage (French for the tail section)
·Right wing trailing edge, wingtip and leading edge
·Nose and Engine
·Left wing leading edge, wingtip and trailing edge
In the cabin it is needed to check for a number of items, most importantly are aircraft papers like: POH, Weight (mass) and Balance and insurance. At this point It is also checked the movement of the stick/yoke and listened for any odd sounds and check if elevator/ailerons move in the correct direction without problems. After making sure no one is standing near the propeller/engine switch on the master and check fuel level. While we are in the cabin: we check for any sign of mice or other rodent which may have turned the airplane into their house.leaving the cabin and walk, while looking at the fuselage for anything out of the ordinary (missing antenna's, dents, loose bolts, missing rivets, remove any bird droppings), towards the tail feathers (empennage).
PART 1. INSPECTED DAMAGES
visual inspection of the aircrafts which are present in the hangar of NAU
the result of our inspection of the aircrafts fuselages which are hold in the hangar of our university we have found massive scratches, damages of a skin, holes, absence of rivets, traces of corrosion and other different damages. They are shown in the following pictures:
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
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.
, July 13 - Southwest Airlines Flight 2294, a Boeing 737-300 from Nashville to Baltimore makes an emergency landing in Charleston, West Virginia after a 14x17 inch hole opens in the skin of the fuselage at 34,000 feet (10,000 m), causing a loss of cabin pressure; the plane lands safely with no injuries.
, 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%20designed%20to%20convert%20energy%20into%20useful%20mechanical%20motion%20<http://en.wikipedia.org/wiki/Motion_%28physics%29>."> is a machine <http://en.wikipedia.org/wiki/Machine> designed to convert energy into useful mechanical motion <http://en.wikipedia.org/wiki/Motion_%28physics%29>. ,%20including%20internal%20combustion%20engines%20<http://en.wikipedia.org/wiki/Internal_combustion_engine>%20and%20external%20combustion%20engines%20<http://en.wikipedia.org/wiki/External_combustion_engine>%20(such%20as%20steam%20engines%20<http://en.wikipedia.org/wiki/Stea