In Yang Jie's memory of his previous life, the end of the research and development stage of Da Mao's regional aircraft project was in 2008, and after the transfer to the production stage, Da Mao's domestic PD-14 engine test was far away, and it was decided to use the Pw1400g engine produced by Pratt & Whitney on the first prototype, and at the same time, composite materials and a large number of parts need to be imported from abroad, and the sanctioned Da Mao was forced to postpone its development process because it could not import key spare parts in time, and it took almost 16 or 7 years to start delivering.

And according to media reports, the workmanship of this Z regional airliner is really poor, and it is plagued by engine and reliability problems, which scare away many foreign customers, even Damao domestic airlines are complaining that the aircraft is unreliable, difficult to repair and find spare parts, and it is rarely operated.

Yang Jie never wanted these very bad things to happen to the aircraft jointly developed with the Ilyushin Aviation Group.

He values Damao's domestic pneumatic layout technology and experienced design team, and is not interested in Damao's poor domestic manufacturing process.

In the general design department of the R&D center, Yang Jie also had a detailed understanding of the overall digital prototype design 3D drawing of this heavy transport aircraft.

The overall layout of this heavy-duty transport aircraft adopts the conventional aerodynamic layout of the cantilever upper single Ji and T-shaped tail type, the machine adopts a supercritical airfoil design, the sweep angle is 18 °, and the wing is equipped with 4 Kunlun turbofan engines, the cross-sectional shape of the fuselage is different from the previous transport aircraft, and its fuselage structure is designed as a top circle after computer simulation analysis, and the cross-sectional shape of the two sides is slightly arced and the rounded corners transition to the straight bottom edge, and the cargo compartment is an approximate square cross-sectional shape with four corners rounded.

In the past, the strategic transport planes of the Soviet Union and Eagle Sauce were basically "pear-shaped" with a narrow top and a wide bottom, and a flat bottom, which could reduce the floor height of the cargo compartment and increase the width of the cargo compartment to facilitate the loading and unloading of large-sized heavy equipment.

The design team of Ilyushin Aviation Group originally wanted to continue this fuselage design, but the technical team of Zhonghua Fokker Company did not agree, but invited the huge mathematicians of Huaxing Group itself to conduct mathematical modeling and analysis of the space utilization rate of the cargo room, and finally determined the new fuselage shape.

In this way, the cargo compartment cross-sectional size can be widened and heightened as much as possible under the premise of minimum fuselage size and structural weight to obtain the maximum utilization of cargo space and large equipment loading capacity.

Another advantage of the squarer cross-sectional design is that the ground clearance of the cargo floor can be significantly reduced due to the flat bottom of the fuselage.

When loading and unloading small bulk cargo, flatten the tail large cargo door and cargo bridge, which can just dock with the truck transporting materials, and directly use the conveyor belt, roller rod and in-machine lifting device on the cargo bridge and cargo floor to complete loading and unloading more quickly.

And when loading and unloading large vehicles, because the cargo floor is low from the ground, and the main landing gear has the function of "squatting", the height of the cargo hold floor can be further reduced, so the slope of the cargo bridge is very small, which is particularly beneficial for the loading and unloading of large goods.

Although designing the fuselage to approximate a square cross-sectional shape can maximize the benefits of cargo space utilization, there is also a serious problem - the fuselage stresses are concentrated in the corners on both sides of the bottom, which is a major challenge in the design of structural strength.

In order to solve this problem, Nikolai Tarikov, one of the chief designers, also exerted his ability and came up with a solution, using high-strength titanium alloy to design and process parts in the parts with large fuselage loads, and using computer simulation simulation analysis to round the two corners to reduce the stress concentration, and optimize the design and strengthen the structure according to the direction of stress transmission.

Now the teams on both sides are competing in secret, but the purpose is the same, to see who can come up with a better design solution and who has a better solution.

Bai Yonghui also reflected this situation to Yang Jie, and Yang Jie was happy to see it happen, this kind of benign competition is much stronger than inferior competition such as stumbling and slandering each other.

Nikolai Tarikov's solution has worked well through simulation tests, has a service life of no less than 40,000 hours, has an overload limit of 2.25g when loading 150 tons of cargo, and up to 2.5g when loading 120 tons of cargo, and has a high tolerance for structural damage.

In other words, even if the aircraft is designed to fly 10 hours a day from start to finish every year, it will not be a problem for the aircraft to be used for more than 10 years.

It is precisely this design that makes the fuselage shape of this transport aircraft completely different from that of the An-124.

Although the An-124 was designed by the Antonov Design Bureau, the landing gear was produced in Damao, and naturally there are design drawings in this area, so Da Mao also took it out this time.

The design team of both sides also re-designed the landing gear, and the R&D team of Fokker Landing Gear Company also participated, and also used a lot of electro-hydraulic technology and new material technology, the landing gear is much smaller than the original design scheme of the An-124, reducing a lot of hydraulic circuits, because there is already a design scheme of the An-124 landing gear, so the design scheme in this regard was quickly taken out.

Fokker Landing Gear Company has undertaken the production and manufacturing of landing gear, and has now entered the stage of trial production.

The original An-124 can be installed on the top of the cargo compartment with two overhead cranes with a lifting capacity of 10,000 kg, or one overhead crane with a lifting capacity of 30,000 kg, in addition to two electric winches with a towing capacity of 3,000 kg, and two auxiliary power units in the engine room, which can be loaded and unloaded without relying on external power trucks.

Four P-7 or P-16 parachute platforms can be accommodated in the cargo compartment for airdrop equipment. It is also possible to load 12 containers or other heavy bulky cargo, such as tanks, engineering vehicles, heavy artillery and missile systems. However, due to the low pressurization value of the cargo compartment, the airdrop of paratroopers was limited and could only be carried out by opening the tail hatch.

The R&D team also redesigned the cargo loading, with a crane with a maximum lifting weight of 20 tons installed at the rear of the fuselage, with slide rails extending from the nose to the tail of the tail cargo compartment, which can lift all military pallets and bulk cargo directly from the ground or from trucks of various heights, and the cargo crew can use a hand-held remote control device to control the heavy machine.

At present, only this transport aircraft has the ability to carry cargo outside the cargo compartment without relying on external support machinery.

Of course, the cargo floor is also designed with in-flight self-loading and unloading equipment such as tethered rings, guide rails and roller rod systems, which extend all the way to the cargo bridge, so that the roller rods and tethered ring system can be hidden under the cargo floor when not needed.

Four heavy-duty winches were equipped in the front and rear positions under the floor of the aircraft for towing the loading of heavy supplies.

In addition, in addition to the fixed washbasin designed in the cargo hold, there is also a fixed sheltered toilet module, which is still very thoughtful in terms of humanization.

In order to improve the efficiency of shipment, the R&D center is also developing a set of "autonomous cargo compartment load management system".

The system is designed to accurately measure the change in the center of gravity caused by the loading and unloading of the aircraft, automatically calculate it during the ground loading and unloading phase, and mark the optimal loading position on the display at the cargo operator's workstation.

Combined with the in-hold handling system, the system allows all cargo to be efficiently loaded and unloaded by a single cargo attendant without the need for assistance from ground personnel.

This system has such a system on the Globemaster transport aircraft of Eagle Sauce, and Huaxing Group, as a high-tech company, naturally wants to independently develop such a system.

The development of such a transport aircraft is not only a matter of the R&D and design department, a large number of technical departments of Huaxing Group are responsible for the development of some subsystems, and teamwork has always been the tradition of Huaxing Group.

Huaxing Group now has nearly 200,000 R&D teams from home and abroad, and the group company has accumulated a large number of various technical patents, and the technical department responsible for the research and development of the independent cargo compartment load management system can use a large number of mature technologies to quickly develop this system.