3 Diff. B/W Cargo & Comm. A/C Structures

.Hello everyone, we all know the basic two types of aircrafts - passenger and cargo.

Airbus Beluga - Comercial cargo carrier

Airbus A380 - Passenger carrier

While considering aircraft structures, we basically classify them on the basis of the structural integrity and materials used for construction.

Now for the purpose of this topic we will classify them on the basis of:-

1.      STRENGTH/WEIGHT RATIO

2.      WING DESIGNS

3.    SERVICE LIFE

 

1)      STRENGTH/WEIGHT RATIO:

This is the most important factor while considering materials, an optimum strength/weight ratio is very crucial to maintain the structural integrity and make it possible for manufacturers to use the same material for most of the applications on airframe.

Strength/weight ratio of various materials.
Note that composites are the most ideal
 materials for a/c use acc. to this chart.

 Most of the commercial planes use materials which have a nominal strength/weight ratio, which is usually around …..

While most of the cargo planes have a high strength/weight ratio as they do not work for profit. So, the strength/weight ratio varies greatly for them based on their applications.

 

2)      WING DESIGNS:

Most of the commercial planes need more maneuverability and control over them so they prefer dihedral wing assembly i.e. wings which lie at a positive angle w.r.t. the horizontal plane. There are some exceptions to these, not exceptions but most of the Russian aircrafts tend to eliminate the use of dihedral wings, due to difficulty to recover from an instable condition or turbulence.

Anhedral wings - Boeing 737-8 Max

Dihedral wings - Antonov AN-225 Mirya
(Also the world's largest commercial cargo carrier)

Now talking about cargo aircrafts, the aircrafts built specifically for cargo have anhedral wings while those modified into cargo keep their dihedral wings if they have them  before the modification.

 

3)      SERVICE LIFE:

This one is going to be easy to understand, commercial aircraft have a less payload capacity as compared to cargo aircraft. Most of the cargo aircraft use extra reinforced fuselages.

 Now by general concept, reinforced assemblies are designed so that they need less service and their operational life is more. So cargo aircraft have more service life than normal commercial passenger aircraft.