A company wishes to modify a commercial aircraft to deliver

A company wishes to modify a commercial aircraft to deliver humanitarian supplies into areas of natural disaster. The modifications include removing passenger seats and adding a cargo door in the overhead of the previous passenger area.

What are the mechanical considerations and material options for such a new design aspect? Assume that there is only one aircraft to be modified, see below. (At least 300 words) Thanks!!!

A-321
Door Frame
Mechanical Door Locking

Solution

A321 Door design:

carbon fiber composite material is one which is used, this material is light weight and more tought which is its mechanical properties.in some aeroplanes aluminium alloy 5251is used.As jet engine power required is more as cargo area is increased and twin engine is power by the CFM International CFM56 or International Aero Engines’ V2500 is used for the same twinjet design is more fuel efficien then trijet or four engine aircraft .locktite and double strap revets can be used for joining door body and 25.4 mm is standard overlap area for bonding.carbon fiber composite material has high strength to weight ratio. limitation of carbon fiber composite(CFC) is lack of a fatigue endurance limit. This means that stress cycle failure cannot calculated finely. While steel and many other structural metals and alloys do have estimable fatigue endurance limits,fatigue failure properties of CFC are difficult to predict.It is having good corrosion resistance property.

Door dimension may be like 50”x60”,70”x66”,30”x36” depends upon requirement and space available

Mechanical door locking:

While designing mechanical door locking system door system are like Door swings out, door slides up into crown, door swings down with stairs, problems regarding doors such as inadvertently opening of doors should be considerd and reasons behind this need to investigate some reasons may like doors never closed fully, It was backdriven manually, It was back driven electrically, Fuselage flexing allowed door to spring open, Electrical short to door opening system, Cargo shift into door, Locking pins shearing and releasing door to open.

For mechanical door locking plug doors often open outward and use a locking mechanism with multiple pins or hatch dogs to prevent opening while in flight if the plug doors will open inside then that may be disadvantageous for cargo area. On non- plug type door a soft flap seal around edge that rests against the inside of door surround, as soon as you pressurize the seal is pushed tight against the frame.A non-plug door is held closed by door latches and becomes part of the fuselage structure when closed.They are pretty heavy, but they are also mounted rather cleverly to ensure it doesn\'t take too much force. Doors that go up into the fuse instead of out tend to be motorized and also have counterweights