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Post by oldpop2000 on Apr 7, 2023 10:18:42 GMT -6
I decided to start a discussion about twin-engined fighters of WW2. Most discussions are about single-engined fighters but twin-engined fighters were very valuable during the war. The problem with twin-engined fighters is that they were designed by aeronautical engineers that had been given a set of requirements and most were not fighter pilots. In fact, most had never been in a war. The twin-engined aircraft were used in many different missions; missions they had never been designed to execute. Most became fast bombers used for special ground attack missions and close air support during land campaigns. Anyway i have prepared a short list of the most widely known twin-engined fighters of the war. I have not encluded Russia and Italian. I will include those later. Here is the list.
P-38 Westland Whirlwind ME-110 P-61 Black Widow Night fighter Nakajima J1N1-S gekko Heinkel He-219 Uhu Kawasaki Ki-45 Toryu Bristol Beaufighter Junkers Ju-88 Ke Havilland KH 98 Mosquito
In the list above, I would remove the Heinkel He-219 and the Junkers Ju-88, they were actually light bombers or twin engined bombers. Personally, I would also remove the KH-98 Mosquito, it was a light bomber but fast. It was almost always used as a light bomber. Here is my final list: Let's understand that most of the below, were used as bombers or at least fighter-bombers.
P-38 Westland Whirlwind Ki-45 gekko Beaufighter P-61 Black Widow Night Fighter Ki-45 Toryu
So, there it is, my list.
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Post by oldpop2000 on Apr 7, 2023 10:32:38 GMT -6
Here are some pro's and Con's for twin-engined fighters.
Pros: Redundancy: Having two engines meant that you could still fly home if one engine was lost to damage or reliability issues. Range: Twin engined fighters were typically larger and had room for larger fuel tanks, which could mean longer range. Some twin engined aircraft were also easier to fly than their single engined counterparts, owing to factors such as contra-rotating props to minimize torque. In certain cases, twin engined layouts also allowed aircraft to carry heavier payloads (this is what allowed the de Havilland Mosquito to double as a light bomber.
Cons: Maneuverability: With some exceptions (such as the P-38 Lightning, which was sized similar to single-engined fighters of the time), the larger size and weight of twin engined fighters made them much bulkier than their single engined counterparts (just ask the Me 410 and Bf 110 how they held up against P-51s, Spitfires and Tempests). Speed: Once again, there are exceptions (the de Havilland Mosquito is a great example). Twin engined designs were typically draggier. Towards the end of the war, the increasing engine performance of piston engines (and later, the advent of jet engines) meant that twin-engined designs were less popular than before. However, they would still be found on later aircraft like jet bombers
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Post by zederfflinger on Apr 7, 2023 11:41:08 GMT -6
You mention jet fighters in your posts, but don't include them. How come?
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Post by oldpop2000 on Apr 7, 2023 12:42:55 GMT -6
You mention jet fighters in your posts, but don't include them. How come? The jet fighters of WW2 only occurred near the end of the war. I just don't feel that they contributed much to its total missions.
Here is a complete list of Jet/rocket fighters. Notice the entered service date on them.
Note: In an airshow at Gillespie Field in El Cajon, I had an opportunity to talk to a former Me-262 pilot. He was an old man and he had some interesting comments to make. I was able to verify his statements later. He said that you could not accelerate the plane quickly or you would get compressor stall. You had to ease both throttles forward gentily. This meant that your take-off was slow and long as was the landing. This made you susceptible to Allied fighters who were waiting for you. Once you reached the attack altitude, you had only enough fuel for maybe one pass or two, then you had to return to base. The bases were bombed frequently. He also said that the engines were high maintenance and were not reliable.
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Post by oldpop2000 on Apr 7, 2023 16:38:58 GMT -6
Ok, so the War department or what ever a nation calls their military department, puts out a set of specifications for a pursuit aircraft. Its mission is the interception and attack of aircraft at high altitude; essentially a bomber killer. Max speed is 360 mph at 20,000 ft and max speed at sea level of 290 mph. It must be able to sustain its full power for one hour at its altitude of 20,000 feet. It has to be able to climb to 20,000 feet in six minutes from its takeoff roll. Another specifications is that is has to be able to land and takeoff within 2200 feet and clearing a 50 foot obstacle at the runway's end.
This is the specification for the Lockheed P-38 as of January 1937 . This was an overwhelming specification for any aircraft company. All the twin-engined aircraft of the time were probably designed around similar specifcations. But I want to stress that aircraft specifications originated from air warfare doctrine. In the 1930's it was " the bomber will always get through". This guided many nations in their design specifications and requirements. However, once the war started, all bets were off. Many of the birds did not execute their primary design missions well or the war required these birds for more, differrent missions such as anti-shipping,, night fighting, close-support for land campaigns and photo-recon. This is normal.
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Post by oldpop2000 on Apr 8, 2023 6:53:05 GMT -6
Here is a unique twin-engine fighter that did not enter service until after the war.
Here is one for the record. The flight manual for the Me-110
Here is information for the Ki-45, commonly referred to as the Nick 1
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Post by oldpop2000 on Apr 8, 2023 9:09:23 GMT -6
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Post by oldpop2000 on Apr 8, 2023 10:03:57 GMT -6
BF-110 Zerstorer (Destroyer) In the first few months of 1934, the German Air Ministry issued a requirement for a twin-engined heavy fighter. It's primary mission was to attack and blow through bomber formations. It was a bomber destroyer. However, the specifications were also for strategic reconnaissance and bomber missions. The first flight was on 12 May 1936 from Augsburg. This was Messerschmitt's main plant, but construction was to be in the Gotha Factory. The BF-110 B-1 entered production in April 1938. It was not the main version, it was withdrawn in the summer of 1939. The primary model was the C variant. It would have its first combat missions in the Polish campaign. Unfortunately, the plane became involved in air combat with Polish fighters, where it suffered very unacceptable losses. This was a portent of things to come for the BF-110.
The first three campaigns of WW2: Poland, Norway, France did not test the true capabilities of the BF-110 aircraft. These campaigns were not static, and the opponent aircraft were not really organized and capable of engaging the 110's to test their capability.
This changed with the Battle of Britain, which was a static front, with an effective air defense system based on radar, observers, and fightet control centers. The fighters were much better and the pilots had better training. This was to prove the undoing of the BF-110 fighter. It performed adequately against the shipping in the Channel and against the RDF stations initially, but as they moved inland against the fighter fields and London, this was when their ability to escort bombers failed and losses began to mount. Norwegian units were eventually returned to Germany and converted to night fighter units. In this they were effective.
The other campaigns such as Russia and North Africa, the BF-110 when used in anti-shipping missions and for providing close-air support, proved effective as long as enemy fighters were not present. It was never a good bomber escort but then, it was never meant to perform that mission. It was a bomber killer.
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Post by oldpop2000 on Apr 9, 2023 6:50:45 GMT -6
In order to simplify this discussion, here is a good article on the P-38 lightning. It explains the compressibility issue and Operation Vengence. The latter was the operation where Admiral Yamamoto was shot down and killed. I managed to talk to one of the pilots in the escort group of the mission and I have a signed copy of his book.
The Luftwaffe had four twin-engined fighters: BF-110, Me-210, Me-410 and the Do-335 Pfeil. The latter is interesting as it was a twin-engine pusher/puller fighter. It had an engine in front and one in the tail. en.wikipedia.org/wiki/Dornier_Do_335
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Post by oldpop2000 on Apr 9, 2023 12:20:32 GMT -6
The problem of compressibility and the loss of control began to rear its ugly head in the 1940's as aircraft began to be heavier and have more powerful engines. It continued to be a problem into the jet age and in fact, it is still and issue. It takes a high speed wind tunnel to try to get some actual factual data to solve the issues. Wing design did help and for the P-38, a dive flap gave the pilots the ability to pull out of dive before they lost control.
If you are interested to understand this and the history of aviation, here is a good link to a free book.
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Post by oldpop2000 on Apr 10, 2023 7:28:03 GMT -6
The best twin-engined heavy fighter for the Japanese was the Kawasaki Ki-45 Toryu, nicknamed the Nick. It was, as was normal, designed as a bomber killer but eventually turned out to be a very good night fighter. There was another version of this aircaft, the Ki-45 KAlb which was designed as a close-air suppport and anti-shipping version. The A model was armed with one 20 mm cannone and two 12.7 mm or .50 caliber mg's and a single 7.92 mm self-defense gun. The B version had 37mm cannon plus the 20mm and included the sefl-defense mg. Evenually a search radar was installed and it was used as a night fighter.
The other Japanese twin-engine aircraft was the Nakajima J1N and it was used in a reconnaissance role. Eventually 20mm cannons firing at 30 degrees upward were installed to attack US bombers. It was no a high-altitude fighter and as such, was not effective against the B-29. It was an IJN aircraft, requested in about 1938.
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Post by oldpop2000 on Apr 10, 2023 9:08:17 GMT -6
Soviet twin-engine fighters
The Petlyakov Pe-2 was a twin-engine dive bomber and was very successful as a heavy fighter, night fighter, and recon aircraft. It was the most numerous and best soviet bomber in the war. Development began in 1937, it was armed with two 12.7 mm heavy machine guns and could carry about six 100 kg bombs.
Another twin-engined fighter was the Tu-2. It could carry up to 3 tons of bombs and had two 20mm cannons and three 12.7 mm machine guns. it came late in the war but was very successful in the destruction of Army Group Center in Operation Bagration.
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Post by oldpop2000 on Apr 10, 2023 9:20:45 GMT -6
The Italian air force developed the Savoia-Marchetti SM-88 but it was designed for export. When the war started, the German's forbid its export due to the DB 601 engine from Germany. The fighter never entered production that I know of.
The only true twin-engine fighter for the British was the Westland Whirlwind. It was a fighter and ground-attack aircraft. It was withdrawn from service in 1943. It was reported that it was a good fighter and served well. Only about 114 were actually built.
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Post by oldpop2000 on Apr 11, 2023 7:41:39 GMT -6
To summarize, the twin-engine fighters designed in the late 1930's were all originally meant to be bomber killers. Bombers were now getting bigger, faster and much better armed. The twin-engine fighters were armed with larger cannons, could stay aloft longer, and were tougher than the single-engined fighters. However, they were not maneuverable and as such, were vulnerable to the single-engine fighters. Almost all the twin-engined fighters were eventually used as night fighters, close-support aircraft, anti-shipping and reconnaissance aircraft. On these missions, they were very successful. The only twin-engine fighter to be a good fighter was the P-38 but even she was removed from escort in Europe, and served as a close-air support and reconnaissance aircraft. She was very valuable in the Pacific as a fighter because of range and durability plus firepower.
However, almost all the fighters, including the P-51 and P-47, began to experience compressibility which hindered their recovery from dives. There was also the issue of tail flutter. The two problems were different. Flutter almost always destroyed the tail but compressibility would sometimes destroy the tail or tear the wing off or just hammer the fuselage from the rest of the plane. The compressibility problem took longer to understand and fix. The P-38J solved the issue with a dive flap that was extended to provide lift in a dive. The problem continued into the jet age. The flutter issue was solved rather quickly by installing wing fillets and making tailplane changes. The compressibility problem caused severe tail buffeting, uncontrollable shaking with severe yawing motion then the controls would freeze. There were numerous issues with compressibility including tuck under of the tail when the controls became immobile. The plane then went into an outside loop. This would scare the dickens out of any pilot.
On the whole, twin-engine fighters served a useful purpose for air forces.
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Post by oldpop2000 on Apr 11, 2023 12:15:52 GMT -6
One last comment. If you are in a twin-engine fighter and get jumped by a single engine fighter, your safest defensive maneuver is to split-S and dive away. You are heavier and possibly faster in a dive than the single-engine fighter. But there is a problem; you might enter the transonic region of flight and begin to get compression. This shaking will empede your ability to pull out of the dive and might just shake your plane to pieces. So, once in a dive, if you sense the shaking, then it is time to pull out.... quickly or you will be come a smoking hole in the ground. It happened. It also happened to single-engine fighters.
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