Chapter Ninety-Eight: Perhaps It Would Be Better

The chin intake.

As the name suggests, this newly proposed intake arrangement is a kind of belly intake, but with a difference: the inlet is moved forward from beneath the fuselage to a position farther back, under the radar nose cone. The later and famously successful belly intake of the F-16 was, in fact, originally examined through a more conservative chin-intake design during early concept studies; the belly intake is really a further development of the chin intake. For a useful reference on chin intakes, one can look at the American A-7 attack aircraft, the A-8 fighter, or, domestically, the heavily revised J-7 New Century variant, the J-7 FS.

The chin intake appeared quite early. If one were to count from the beginning, some of the air-cooled intake openings on propeller-driven fighters in the Second World War could be regarded as the earliest prototypes of the chin intake. The first jet fighter to truly make practical use of the chin intake was the American Navy carrier fighter, the F8 Crusader, which entered service in 1957.

By the 1980s, the chin intake had already fallen out of favor, but for a new trainer aircraft, adopting such an intake was in fact quite appropriate.

Why say that? Because the airflow of a chin intake can enter the engine in a smooth, uninterrupted path from nose to tail, much like a nose intake. In a twin-side-intake configuration, if the goal is to train J-7 pilots, then excellent supersonic performance must be ensured, and that means paying attention to the area rule; a wasp-waist fuselage becomes necessary.

That, however, creates a problem. The wasp-waist design means that after the side intakes draw in the airflow, the ducting must immediately bend sharply inward toward the fuselage. This is very unfavorable to smooth airflow. With such a pronounced turn, there is a strong likelihood of small vortices forming, and airflow containing vortices is absolutely detrimental to normal engine operation. If you are interested, you can look up the J-9 Mountain Eagle trainer from below and examine its intakes; then you will understand.

Yang Hui knew why the later J-9 trainer adopted side intakes: first, domestic research into J-7 variants had gone relatively deeply into side-intake arrangements; second, small vortices in the incoming flow could in practice be managed by special methods; and third, the Mountain Eagle’s turbojet 13 engine had a relatively good surge margin and strong tolerance for distortion.

But in 1983, neither side intakes nor chin intakes for improved J-7 variants had yet been studied in depth, so naturally the first advantage seen in later years did not exist yet. Aircraft design should minimize weight wherever possible, and the special methods used by the later J-9 trainer would exact a weight penalty. As for the final point, of course the engine prefers the smoothest possible airflow; who would want to swallow chaotic air? That would be inviting discomfort.

All of these considerations made the chin intake appear, at present, to have rather a large advantage over the side intake.

Yet in Yang Hui’s view, although the chin intake was technically superior to side intakes for the new aircraft, it did not look especially attractive and did not sound all that fashionable. That might be difficult for the style-conscious Saudi tycoons to accept.

Whatever the performance, a handsome exterior is also a very important factor for a trainer intended for large-scale export. Some countries are just that absurd: when buying aircraft, they care less about performance than about fashion. In truth, for manufacturers, those are precisely the customers most beloved.

After a moment’s thought, Yang Hui voiced what he saw as the one, rather unconvincing shortcoming: “Personally, I think the chin intake really is an excellent design. It would be a very good choice for our new aircraft. But our new aircraft has to take Saudi Arabia into account. They are a country that values style, and they will be providing half the funding. If they are dissatisfied, we have to give that serious consideration. And countries like Saudi Arabia are not uncommon. From an appearance standpoint, then, the chin intake has only one flaw.”

The moment Yang Hui said this, it was as if spectacles had shattered all over the room.

Even Chief Designer Yu, who had always held Yang Hui in fairly high regard, was stunned into silence. “Saudi Arabia has such a preference? Can an air force from such a country actually be combat effective?”

That remark really struck the mark. Saudi Arabia’s military combat effectiveness was indeed mediocre, and even that one bit of effectiveness came only from the boost provided by its splendid imported equipment.

The director of the Shuangyang Factory, who had proposed the chin-intake plan, found Yang Hui’s words utterly unbelievable. Was this young man boasting? In the People’s Republic, a procurement officer like that would absolutely have to be dragged out and shot. In the dynasty of the Kim family, he would without question be hauled away for anti-aircraft execution.

Although the chin intake had technical advantages, Yang Hui was one of the very few people who had actually dealt with the Saudi side. If Saudi Arabia truly cared about this sort of thing, then it would be troublesome indeed.

Not knowing what else to do, the factory director handed the matter over to Chief Designer Yu to hear the aircraft designer’s opinion.

“Chief Designer Yu, as things stand, what do you think we should do? You are the chief designer for this base trainer, so now you have to make the decision.”

At this point, Yu’s heart had already tilted toward the chin-intake solution, but Yang Hui’s opinion could not be ignored.

“Then let us hear which way Yang Hui is leaning. Both projects have their own advantages. Yang Hui, say again what you think.”

After going back and forth, the question had somehow come back to him. What kind of situation was this? But since Yang Hui could not simply toss it to someone else, he had no choice but to state his own solution.

“On this matter, I think the choice between the two schemes is not really in our hands. At worst, we can simply develop both. When the report is made, we will have two options. That shows we are thoroughly prepared, which will only help us win the project in the end. As for which one is chosen, let the military, the Saudis, and the Pakistanis worry over it slowly afterward.”

Yu was already well past middle age, but hearing this solution, he could not help slapping his thigh in approval. After a deep breath, he said slowly, “That is a good method. Since it is hard for us to decide, we will submit both schemes. We will present the good points and the bad points alike, and then we shall see which one the higher authorities choose.”

This was, indeed, the only practical course available at the moment, and the factory director of Shuangyang also agreed.

“That is best. Let us first settle the aerodynamic modification scheme in broad outline. The specific data can only be finalized after the project is approved, depending on the wind-tunnel skill of the several designers. For now, let us discuss the other aspects.”

The new aircraft would require sweeping changes. Every system would need surgery; it would not be enough merely to alter the aerodynamics. There had to be substance as well as appearance. Only when every aspect met the design requirements could the new aircraft be considered a technical success.

There were many other modifications. At this point, Yang Hui needed to spell out the Saudi tycoons’ requirements in detail.

“The Saudi side wants to stay in step with the West. The cockpit cannot be packed with gauges the way our current military aircraft are. They want the cockpit layout to move toward Western design, to reduce the pilot’s workload and emphasize ergonomics. They are also particularly strict about the environmental control system. In any case, their requirements are difficult for us to achieve at present.”

It had long been expected that the maximum three hundred million dollars would not be so easy to obtain. Now the shortcomings of domestic technology were coming to light. If these were not handled well, the project could be in danger. Chief Designer Yu had never underestimated the difficulty of the project, and the cockpit and environmental control system were now major issues.

“As for the environmental control system, if the domestic side grits its teeth and devotes itself to research, we may be able to reach the standard with enough funding. But the cockpit requirement for display screens….”

He paused, thought carefully, and then continued, “Even the early Western CRT displays are still very difficult for us to produce under current conditions.”

This was a problem created by the present state of domestic electronics industry. Even CRT displays were high-end items at that time. It was no wonder that the hottest craze of the 1980s was for people to go abroad and bring back a color television set. Think about it: by then, CRT displays were already being used on a large scale in civilian fields overseas, yet the People’s Republic had scarcely made any real progress in military applications in this area.