Very similar to the Do.17 in appearance, but nevertheless a completely different plane. Developed according to separate terms of reference for a long-range bomber that can throw bombs from a dive. What to do, there was such a fashion in the late 30s: everything should be able to dive, even four-engine giants.
So the Do.217, which seems to be similar to its predecessor, differed from it, primarily in size.
The appearance of the 217th in a form close to the ideal allowed the appearance of the BMW 801 engine. The very compact BMW 801 had a small diameter and developed 1580 hp at takeoff. Such power and light weight allowed the Dornier designers not only to make the aircraft fly better than its predecessor, but also to significantly strengthen the frankly weak defensive armament of the 17th.
And everyone should feel good.
Compared to the Do.17, the new aircraft had a lot of modifications. The main design change for the Do.217 was an increase in the height of the fuselage along its entire length. Inside the noticeably enlarged fuselage, a horizontal bulkhead appeared immediately after the cockpit, dividing the fuselage in half. The lower half formed a bomb bay, where bomb racks were mounted on the bulkhead itself, and a 915-liter gas tank and various equipment such as an armored box with an inflatable liferaft were located on the upper part.
The bomb bay had a length of more than six meters and was completely closed by three sections of flaps. In such a bomb bay, 1000-kilogram bombs or one torpedo could be freely placed.
Do.217 tests were more than successful. In the spring of 1940, preparations began for serial production. In the fall, the plane went into production.
However, the first serial Do.217s, contrary to the terms of reference, could not dive. They were not even equipped with air brakes due to unavailability. So the new bombers were designed for level bombing.
But by that time, the hysteria for dive bombers had already passed, and new Lotfe tachometric sights appeared in service with the Luftwaffe. The use of this sight made it possible, even with horizontal bombing, to hit stationary targets with almost the same accuracy as with a dive attack. Therefore, the Luftwaffe began to be more tolerant of such a disadvantage of the Do.217 as the inability of the aircraft to dive bombing.
The Do.217E-1 bomb bay could accommodate eight 250 kg bombs, four 500 kg bombs or two 1000 kg bombs. Or any German torpedo of that time, starting with an F5B weighing 725 kg and a caliber of 450 mm.
For assault operations, one fixed 15-mm MG.151 cannon with 250 rounds of ammunition was installed at the bottom left of the nose of the fuselage.
Defensive armament consisted of five 7, 92 mm MG.15 machine guns. One (like the Do.17) fired through the nose glazing, two were located above and below in the rear of the cockpit, and two more - on the sides of the cockpit canopy.
Already better than Do.17, but in modifications they went even further. In the E-3 modification, the machine gun in the nose was replaced with a 20 mm MG-FF cannon, and the installation was not rigid, but so that it was possible to fire forward and downward.
The number of 7, 92 mm MG.15 machine guns on the sides of the cockpit canopy increased from two to four.
In general, a strange move, since the firepower seemed to have increased, but … one shooter could not shoot from two machine guns at the same time. Of the four, even more so. So the number of machine guns did not greatly affect the power of the salvo, the point of installing such a number of MG.15s was to ensure constant combat readiness and the fastest use of weapons from either side. And the shooter simply moved to the machine gun from which it was more profitable to fire.
Unlike the Do.17, the Do.217E-3 now has armor. Armor plates with a thickness of 5 to 8.5 mm were installed in the rear of the cockpit, in the upper part of the fuselage just behind the cockpit and in the lower part of the cockpit under the position of the lower gunner. Armor also protected the pilot's seat and side machine-gun mounts.
Naturally, the field kits for aircraft retrofitting, the so-called Rustsatze, were also not ignored. These were kits for tuning in the field, but produced at the manufacturing plant.
The list of kits for the Do.217 was quite long.
R1 - special bomb rack for one 1800 kg SC 1800 bomb with an annular stabilizer;
R2 - two bomb racks for hanging two 250 kg SC 250 bombs under the wing;
R4 - PVC 1006 suspension unit for one L.5 torpedo;
R5 - one fixed 30-mm MK 101 cannon in the forward fuselage, bottom left;
R6 - camera for installation in a bomb bay;
R7 - four-seater inflatable lifeboat in an armored box at the top of the fuselage behind the wing;
R8 - an additional 750-liter fuel tank for placement in the front of the bomb bay;
R9 - additional 750-liter fuel tank for placement in the rear of the bomb bay;
R10 - two ETC 2000 / HP bomb racks for placement under the wing, on the outside of the engine nacelles, two radio-controlled Henschel Hs.293A gliding bombs;
R13 - another additional fuel tank in the front of the bomb bay;
R14 - another additional fuel tank in the rear of the bomb bay;
R15 - two ETC 2000 / HN suspension assemblies for placing two HS.293 radio-controlled gliding bombs under the wing between the engine nacelles and the fuselage;
R17 - additional 1160 liter fuel tank for installation in the front of the bomb bay;
R20 - two coaxial 7, 92 mm MG.81Z machine guns mounted in the tail fairing;
R21 - Equipment for external disposable fuel tanks;
R25 tail brake parachute.
Since the kits could be installed as many as fit, one can imagine how much it was possible to plan the alteration of the aircraft for a specific task.
On the Do.217E-2 modification, which appeared after the E-3, an improved tail air brake was installed to limit the dive speed. The E-2 was supposed to be used precisely as a dive bomber.
In general, the brake drive mechanism was on all Do.217s without exception, but was not used. Obviously, everyone was waiting for him to be brought to mind so that he could dive without fear of crashing.
It should be noted that the mechanism that actuates the air brake was also on the Do 217 E-1 and E-3. But he was inactive. Apparently, they left it just in case in the hope that when the brake itself was brought to perfection, these bombers could be quickly turned into dive bombers.
There was an innovation on the plane. Quite, say, difficult, and given the love of the Germans for complex methods …
The rear upper lens (armored glass with a mechanism for turning the machine gun) installation of the MG.15 machine gun was replaced with an electromechanical turret (actually a turret) with a 13 mm MG.131 machine gun.
The turret was a very complex mechanism and had an electric and manual horizontal rotation drive. That is, it could work even in conditions of a power failure. The horizontal shelling was circular, and the vertical shelling was from 0 to 85 degrees.
The MG.131 machine gun has already used cartridges with an electric primer igniter. This increased the rate of fire and simplified synchronization, because an electrical interlocking system had to be used to prevent parts of the aircraft from being shot through in the heat of battle. 13mm bullets could easily pierce your plane, which was not a positive thing.
The 500 rounds of ammunition were well placed inside the turret's movable ring. Therefore, the usually bulky machine gun supply sleeve was absent.
This replacement significantly increased the defensive capabilities of the aircraft. There were, of course, drawbacks in the form of a rather rather large (under 100 kg) weight and the inability to fire in the event of a failure or damage to the electrical system, but the second issue was solved by installing batteries, which made it possible to fire for some time, but we had to put up with the weight. Still, a 13-mm bullet weighing 38 grams with an initial flight speed of 750 m / s pierced 20 mm armor from 100 meters, and 11 mm from 300 meters.
By the way, a feature of the machine gun ammunition was the presence of a leading belt on the shells, which, according to the currently accepted classification, would rank this weapon not as machine guns, but as small-caliber artillery. And the head part of the 13x64B cartridge was, in fact, not a bullet, but a small-caliber artillery projectile with a head or bottom fuse and an explosive charge. But a machine gun is a machine gun.
I liked the idea very much, and soon the lower MG.15 machine gun also gave way to the 13 mm MG.131c machine gun, a version with a mechanical escapement. The ammunition capacity was also 500 rounds.
Well, there were two 7, 92 mm MG.15 on the sides of the canopy, one MG.15 through the right half of the nose glazing and a fixed 15 mm MG.151 cannon at the bottom left of the bow.
The usual bomb load inside the fuselage was 2500 kg, and the maximum, using external hardpoints, could reach 4000 kg.
Actually, that's how the BMW 801ML engine changed the plane. Despite such weights, the engines perfectly accelerated the bomber to 514 km / h at an altitude of 5200 m, which was a very, very decent result in 1941.
True, the plane never learned to dive. The air brake mechanism itself worked just fine, but the tail section simply could not withstand such loads. Excessive overloads often led to a distortion of the brake actuator rod, and it wedged in the open position. The emergency release mechanism of the air brake helped out, but the one-time VT mechanism on the plane is overkill in all respects.
In general, it was easier not to try to dive, but to bomb from level flight. As a result, having suffered from attempts to teach the Do.217 to dive, the Luftwaffe and the Dornier firm resigned themselves and stopped this senseless work. The aircraft remained a horizontal bomber.
Here I must say a few words about the pedantry of the Germans. According to the plane's specification, it was supposed to have an air brake. But the VT, crippling the tail section, did not work as expected, that is, it was not needed. The Dornier decided this paradox in a very original way: the factory began to produce a field kit without a number, which consisted of a conventional tail fairing, which was placed in the bomb bay at the factories. The air force personnel quickly replaced the unused air brake with a conventional fairing, and the problem was solved.
It so happened that mainly Do.217 operated against ships, and therefore were considered a kind of naval strike aircraft.
It is not surprising that in 1943 it was on the Do.217 that the newest anti-ship weapons began to be tested: the Henschel Hs.293A and FX 1400 Fritz-X radio-controlled bombs.
Hs.293A would be more correctly called a gliding bomb. She was the prototype of modern cruise missiles and looked like a small plane or glider with an inverted tail. In the bow there was a warhead weighing 500 kg, in the tail there was a radio equipment. There was a rocket booster under the fuselage. A special sleeve inside the wing of the aircraft supplied warm air to the bomb, maintaining a constant temperature inside it, which is necessary for the normal operation of all devices.
Hs.293A was suspended under the wing of a bomber. After dropping, the rocket booster accelerated the bomb to a speed of 600 km / h, after which it switched to a controlled gliding flight. The Hs.293A was aimed at the target by the navigator-bombardier by radio using the ancestor of the modern joystick on the radio transmitter panel. To prevent the navigator from losing sight of the bomb, a signal flash was installed on the tail section.
The Henschel FX 1400 Fritz-X bomb was also radio-controlled, but had neither a wing nor a rocket booster. A ring-shaped stabilizer of an increased area with horizontal and vertical rudders was installed on the tail of this bomb.
This allowed the FX 1400 to fall fairly slowly and therefore manageable. The bomb was dropped from a great height. Firstly, because it was necessary to have a margin of time to aim it at the target, and secondly, the bomb had to accelerate to a certain speed in order to accumulate the necessary amount of energy with which to try to pierce the deck of the ship. The Fritz-X also had a bright signal flash on its tail.
This modification was numbered E-5 and differed, apart from suspensions for guided bombs ETC 2000 / XII (2 pcs.), By the installation of a special FuG 203b "Kehl" III control transmitter. The bombs were equipped with a FuG.230b Strasbourg command receiver.
It is to this model Do.217 that the most striking victories belong.
September 9, 1943 saw the first and more than successful use of the FX-1400 radio-controlled bomb in the Bonifacio Strait between Corsica and Sardinia.
A group of 11 Do-217E-5s attacked the Italian battleships Roma and Italia (formerly Littorio), which were heading for Malta to surrender to the British.
From a very high altitude, being outside the effective zone of the ship's air defense, the Dornier dropped their Fritzes.
The first "Fritz-X" hit the forecastle deck on the starboard side, went through the compartments of the structural underwater protection and exploded in the water under the ship's hull. The explosion led to huge destruction of the underwater part of the battleship, and outboard water began to flow there.
The aft engine room, the third power plant, the seventh and eighth boiler rooms were flooded. Plus broken cables, pipelines and other damage.
"Roma" sharply slowed down and left the formation of ships. And then the second bomb hit him.
"Fritz-X" passed through all decks and exploded in the forward engine room. A fire started, which caused an explosion of gunpowder and further detonation of ammunition in the bow group of artillery cellars.
After a series of internal explosions, the hull broke in the area of the bow superstructure. The battleship, heeling to the starboard side, capsized and went to the bottom. Of the 1,849 crew members, only 596 were saved.
Another bomb hit the battleship of the same type, Italy, roughly according to the scenario of the first bomb that Roma got. The Fritz punctured the decks and exploded underneath, causing flooding. In reality, one bomb was not enough for such a ship as a battleship, and "Italia" limped to Malta, where it surrendered to the British.
Literally a few days later, the same Do-217E-5 unit worked on the ships covering the Allied landings near Salerno.
The battleship "Worspeight", the cruisers "Savannah" and "Uganda" were damaged, all remained afloat, but were forced to go for repairs.
In principle, the use of "Fritz-X" by Do-217E-5 bombers can be considered more than effective. One battleship was sunk, two were sent for repairs (in fact, "Italia" was not repaired, but was dismantled for metal, that is, it is like sunk), two cruisers also needed repair.
A new aircraft was born from the Do-217E. Another modernization, but, in fact, it is so deep that it can be called another aircraft.
The modification was named Do-217K, production began in the fall of 1942.
The aircraft received a completely different nose. The nose glazing and the top of the cockpit canopy were one piece, which significantly improved visibility. The cabin has become more spacious.
The plane was equipped with new engines from the Bavarian engine builders: BMW 80ID, which produced 1700 hp each. on takeoff and 1440 hp. at an altitude of 5700 meters.
The maximum speed of the bomber was 515 km / h at an altitude of 4000 m, which was quite at the level for 1942. Our Pe-2F in 1942 with 1300 hp M-105F engines. gave out 470 km / h at the ground and 540 km / h at altitude.
The armament of the Do-217K differed from that of its predecessor. The guns were removed, the crew operated 5 (later - 7) machine guns. Ahead was a coaxial 7, 92 mm MG.81Z machine gun with an ammunition capacity of 1000 rounds.
All in the same electrically driven turret, a 13-mm MG.131 machine gun with an ammunition of 500 rounds, another MG.131 with an ammunition of 1000 rounds in the lower stage, as well as two 7, 92-mm MG.81 machine guns on the sides of the cockpit stood at the top. with 750 rounds of ammunition per barrel.
The maximum bomb load of the Do-217K was 4000 kg. And here interesting options began.
Calculations were made on the suspension of FOUR L5 torpedoes at once, which would definitely make the plane simply the quintessence of anti-ship aircraft.
If such an aircraft confidently went out to the distance and made an accurate launch, any ship would have catastrophically little chance of surviving.
But in real combat use, the Do-217K never carried four torpedoes. Two is a completely normal load.
The next modification, the K-2, was also anti-ship, but it was "sharpened" for the use of guided bombs. The wingspan of the aircraft was increased from 19 to 25 meters and, accordingly, the wing area increased from 56.7 to 67 square meters. As expected, the altitude characteristics improved, the aircraft could climb to a high altitude, from which it could launch guided bombs with impunity and give the bombs a tremendous acceleration.
The defensive armament of the Do 217 K-2 remained the same as on the K-1, but there were field improvements, and quite original ones. Using the R19 kit, two MG.81Z coaxial machine guns were installed in the tail section, and two of the same machine guns were installed in the tail sections of the engine nacelles. The ammunition, frankly, was small, only 250 rounds per barrel.
It is interesting that the pilot was firing from all this abundance of barrels! He was fitted with an RF.2C periscope and a P. VIB sight, with which he tried to aim.
It is difficult to say how effective the use of this battery was, but I think that eight barrels, albeit 7.92 mm, could scare the pilot with the strongest nerves, since eight tracer fire jets are serious.
In January 1944, the Do.217K-2 from III / KG.100 sank the British cruiser Spartan and the destroyer Janus.
The last serial modification of the bomber was the Do.217M. This aircraft was created and began to be mass-produced all in the same year 1942.
The reason for the appearance of the Do 217M was the lack of BMW 801D engines, which all went to the needs of Focke-Wulf. To keep the production of Do 217K bombers from interruption, Dornier engineers quickly and easily adapted the Do.217K-1 design to the DB.603 liquid-cooled engine. This is how the Do 217M-1 modification appeared.
Both aircraft, Do-217K and Do-217M, were produced at the same time, and the Luftwaffe began to enter service at the same time. But by the beginning of 1943, in connection with the intensification of air raids by the Anglo-American aviation, the Luftwaffe began to experience an urgent need for night fighters.
Since the DB.603 was slightly more powerful and provided a speed increase of almost 50 km / h at all indicators, it was decided to convert the Do-217M bombers into night fighters. But the Dornier night fighters are a topic for a separate article.
Despite the fact that the aircraft was really very good, one might say, it was consistently good, at the end of 1943 the serial production of the Do.217 began to decline, and in June 1944 it was discontinued.
A total of 1,541 Do.217 bomber aircraft of various modifications were produced.
First of all, the reason for this attitude towards a very good aircraft in general was its narrow specialization. Still, possessing even good flight characteristics, the aircraft was, as it were, attributed to anti-ship aviation, that is, not essential.
The work with guided bombs was good, the sunken ships are the best confirmation of this. But alas, the reality is that the Luftwaffe favored more versatile aircraft such as the Ju.88, which could be used in anything from a fighter to an attack aircraft to a dive bomber.
This is not to say that the 88th was better in all respects. It was more versatile, because the Dornier aircraft failed to provide adequate resistance and make a great contribution to the war.
Although what they did at sea was a pretty decent result.
LTH Do.217m-1:
Wingspan, m: 19, 00.
Length, m: 17, 00.
Height, m: 4, 95.
Wing area, sq. m: 55, 10.
Weight, kg:
- empty aircraft: 9 100;
- normal takeoff: 16 700.
Engine: 2 x Daimler-Benz DB-603A x 1750 hp
Maximum speed, km / h:
- near the ground: 470;
- at the height: 560.
Cruising speed, km / h: 500.
Practical range, km: 2,480.
Maximum rate of climb, m / min: 210.
Practical ceiling, m: 9 500.
Crew, pers.: 4.
Armament:
- one 7, 92-mm spark MG.81Z in the nose with 500 rounds per barrel;
- one 13 mm MG.131 machine gun with 500 rounds in the upper turret;
- one MG.131 machine gun in the lower installation with 1000 rounds;
- two MG.81 machine guns in side mounts with 750 rounds per barrel;
- up to 4000 kg of bombs (2500 kg in the bomb bay).
