Messerschmidt said happily: "Philip, if you have the opportunity to return to Germany in the future, you must come to my company." ”

Philip looked at him with a smile and said, "Definitely, definitely." I heard that Dr. Wiley is working on a small transport aircraft, I wonder how it is going? ”

Messerschmitt shook his head and sighed, "It's not going well! There have been several failures in the test flight, the engine always stopped in the air for no reason, but fortunately the plane's gliding performance was good, which saved the danger and made a successful forced landing. ”

Philip said in surprise: "Hey, I heard that this transport plane uses your BMW piston engine, it is said that this engine has good performance, how can it have such a serious failure?" ”

Messerschmitt sighed: "We also looked for the cause, but we haven't solved the problem. Once parked in the air, it can no longer be started. ”

Fei Depu remembered China's Y-5 aircraft, which was a bit similar to the M20, and it is said that the Y-5 also had a lot of problems back then, including the story about the hand-cranked engine of the Y-5 aircraft.

During the Spring Festival in the early 90s, an old ground worker took a hitchhike to his hometown five times for the New Year, carrying large bags of luggage and even half a pig. The aircraft cruises at an altitude of 3000 meters. When flying over the Badaling Mountains, something unexpected suddenly happened. The engine is parked in the air! The consequences of a single-engine plane being stopped are very serious, and this is a mountainous area, and it is difficult to find an open space that can make a forced landing.

The pilots in the cockpit were also a little numb, the air power started several times without success, and the batteries were almost out of power. Seeing that the plane continued to drop in height, the brothers in the rear cabin also panicked, and hurriedly opened the hatch and threw things down to reduce weight, and the precious half of the pig also turned into a flying pig and fell from the sky. Suddenly, the cockpit shouted to the rear cabin: Shake it quickly! This old ground crew is a professional who is very familiar with it, grabbed the rocker and plugged it in, and used all the strength to eat, and when the altitude fell to only 800 meters, the engine roared again.

Maybe it's a nice not to do it. The use of hand crank start can play an important role when electric start is unsuccessful.

Philip asked, "Dr. Wiley, I wonder if you have a hand-cranked actuation design?" I think that's a good solution. The engine power of the M20 should not be large, and the hand crank is completely startable. ”

Messerschmidt was so excited that he grabbed Philip's arm and suddenly realized: "Philip, how did you come up with it!" This is a great solution, I finally have a way to solve the problem with the M20! ”

Philip smiled bitterly and said, "Don't get excited, Dr. Willy! Although this method can solve the problem of air parking, it still cannot solve the lack of reliability caused by a single engine, and if it is other engine failures, there is still only a forced landing. Therefore, I think that it is better to have a twin-engine transport aircraft, and if it is said to be a single engine, it can only improve the reliability of the engine. ”

Messerschmitt shook his head and said, "That's a real problem!" The M20 transport aircraft was designed to be a small passenger aircraft, which required better economy, so a 500-horsepower engine was used. If the twin-engine is adopted, it will be much larger, and the entire aircraft will have to be redesigned. ”

Philip thought for a moment and said, "Then why not put some effort into the engine structure and propeller design?" For example, the use of exhaust gas turbocharging to improve engine efficiency and all-metal torque conversion propellers to improve aerodynamic efficiency are very practical improvement directions. ”

Messerschmidt looked at Philip in surprise, "Mr. Philip, I didn't expect you to be so proficient in aircraft design, although the all-metal torque conversion propeller has been proposed a long time ago, it is technically difficult to implement." ”

Philip laughed and said, "There was some understanding. The different sections of the torque conversion propeller have a moderate angle of attack in the entire flight envelope range, so that it has a high working efficiency, and can control the speed of the engine under different flight speed conditions, which is of equal importance to the work efficiency of the strip engine propeller, using this technology, the propeller can be made from the take-off speed of the aircraft to the maximum flight speed have a high work efficiency, and the engine has a large output power moderately. Use a small pitch when the plane takes off, and a large pitch when cruising. For transport aircraft, if the number of blades is increased to six or even eight blades, then its aerodynamic efficiency will be higher, even more than 50% of the fixed moment propeller, that is to say, it is equivalent to raising the engine power to 750 horsepower! ”

Messerschmitt patted his head and laughed: "Philip, it's a pity that you don't go to be an aircraft designer!" I don't know if the six-bladed propeller you mentioned will work, but you did show me the way, and I think the M20 has hope of resurrection! ”

Philip said: "Dr. Wiley, I am talking on paper, and it is not a simple matter to design and produce a practical all-metal torque conversion multi-blade propeller. First of all, the material development of the propeller is very complex, which requires trial and error, and the torque conversion controller is not relatively complicated. However, once it is successfully developed, then its role is conceivable, enough to make your company the top company in the world in the field of aviation industry. ”

Messerschmidt said happily: "I am so lucky today, my biggest gain from this visit to Stockholm is to meet you, Philip!" Come, let's have another toast, I wish us a successful cooperation and friendship ever! ”

Lucas chimed in, "Hey, you two have said so much, why are you leaving me and Anna alone!" It's not funny, how can we say that we are also Germans! ”

Messerschmidt noticed Lucas and Anna. I didn't expect to discuss the issue of the plane with Philip and ignore the issue of etiquette.

Messerschmidt said embarrassedly: "Are the two of you also friends with Mr. Philip?" What a faux pas! ”

Philip hurriedly introduced: "Dr. Wiley, this is my good friend, Mr. Lucas, who also used to work in design at Krupp, and is now the deputy general manager of Bofors. This one is my girlfriend, Miss Anna. Both of us came to Sweden from Germany. ”

Messerschmidt owes and says, "What a disrespect! Some of them are from Germany. But why not stay in Germany? ”

Philip smiled wryly: "Who doesn't want to stay in their homeland." It's just that at Krupp, we don't have much room for development. You also know that now Germany is limited by the Treaty of Versailles, and a lot of weapons are not allowed to be produced. As those of us who are engaged in artillery, this is indeed a very big limitation! Sweden, on the other hand, is a neutral country that can develop weapons on its own. ”

Several people quickly got acquainted, chatted, and became good friends who cherished each other.