Heinkel H-111 Luftwaffe Bomber Aviation Art Collectible Wrist Watch

Heinkel He 111
A Heinkel He 111H of Kampfgeschwader 53
Role	Medium bomber
Manufacturer	Heinkel Flugzeugwerke
Designer	Siegfried and Walter Günter
First flight	24 February 1935
Introduction	1935
Retired	1945 (Luftwaffe) 1958 (Spain)[1]
Primary user	Luftwaffe
Produced	1935–44
Number built	32 prototype aircraft 12 civilian airliners 808 pre war aircraft 5,656 aircraft (1939–44) Total: 6,508.[2]
Variants	CASA 2.111

The Heinkel He 111 was a German aircraft designed bySiegfried and Walter Günter at Heinkel Flugzeugwerke in 1934. Through development it was described as a "wolf in sheep's clothing"^[3] because the project masqueraded the machine as civilian transport, though from conception the Heinkel was intended to provide the nascent Luftwaffe with a fast medium bomber.

Perhaps the best-recognised German bomber due to the distinctive, extensively glazed "greenhouse" nose of later versions, the Heinkel He 111 was the most numerous Luftwaffe bomber during the early stages of World War II. The bomber fared well until the Battle of Britain, when its weak defensive armament was exposed.^[3] Nevertheless, it proved capable of sustaining heavy damage and remaining airborne. As the war progressed, the He 111 was used in a variety of roles on every front in the European theatre. It was used as a strategic bomber during the Battle of Britain, atorpedo bomber in the Atlantic and Arctic, and a medium bomber and a transport aircraft on the Western, Eastern,Mediterranean, Middle Eastern, and North African Front theatres.

The He 111 was constantly upgraded and modified, but became obsolete during the latter part of the war. The German Bomber B project was not realised which forced the Luftwaffe to continue operating the He 111 in combat roles until the end of the war. Manufacture of the He 111 ceased in September 1944, at which point, piston-engine bomber production was largely halted in favour of fighter aircraft. With the German bomber force virtually defunct, the He 111 was used forlogistics.^[3]

Production of the Heinkel continued after the war as the Spanish-built CASA 2.111. Spain received a batch of He 111H-16s in 1943 along with an agreement to licence-build Spanish versions. Its airframe was produced in Spain under licence by Construcciones Aeronáuticas SA. The design differed significantly in powerplant only, eventually being equipped with Rolls-Royce Merlin engines. The Heinkel's descendant continued in service until 1973.

Design and development

Ernst Heinkel (right) withSiegfried Günter

Design conception

After its defeat in World War I, Germany was banned from operating an air force by the Treaty of Versailles. German re-armament began earnestly in the 1930s and was initially kept secret because it violated the treaty. Consequently, the early development of military bombers was disguised as a development program for civilian transport aircraft.^[4]

Among those designers seeking to benefit from German re-armament was Ernst Heinkel. Heinkel decided to create the world's fastest passenger aircraft, a goal met with scepticism by Germany's aircraft industry and political leadership. Heinkel entrusted development toSiegfried and Walter Günter, both fairly new to the company and untested.^[4]

In June 1933 Albert Kesselring visited Heinkel's offices.^[4] Kesselring was head of the Luftwaffe Administration Office: at that point Germany did not have a State Aviation Ministry but only an aviation commissariat, the Luftfahrtkommissariat.^[4] Kesselring was hoping to build a new air force out of the Flying Corps being constructed in the Reichswehr and required a modern force of aircraft.^[4] Kesselring convinced Heinkel to move his factory from Warnemünde to Rostock and turn it over to mass production with a force of 3,000 employees. Heinkel began work on the new design, which garnered urgency as the American Lockheed 12, Boeing 247 and Douglas DC-2 began to appear.^[4]

Features of the He 111 were apparent in the Heinkel He 70. The first single-engined He 70 Blitz("Lightning") rolled off the line in 1932 and the type immediately started breaking records. In the normal four-passenger version its speed reached 380 km/h (230 mph), when powered by a 447 kW (600 hp) BMW VI engine.^[5] The He 70 was designed with an elliptical wing, which the Günther brothers had already incorporated into the Bäumer Sausewind before they joined Heinkel. This wing design became a feature in this and many subsequent designs they developed. The He 70 drew the interest of the Luftwaffe, which was looking for an aircraft with dual bomber and transport capabilities.^[6]

The He 111 was a twin-engine version of the Blitz, preserving the elliptical inverted gull wing, small rounded control surfaces and BMW engines, so that the new design was often called the Doppel-Blitz("Double Lightning"). When the Dornier Do 17 displaced the He 70, Heinkel needed a twin-engine design to match its competitors.^[5] Heinkel spent 200,000 man hours designing the He 111.^[7] The fuselagelength was extended to just over 17.4 m/57 ft (from 11.7 m/38 ft 4½ in) and wingspan to 22.6 m/74 ft (from 14.6 m/48 ft).^[5]

First flight

The first He 111 flew on 24 February 1935, piloted by chief test pilot Gerhard Nitschke, who was ordered not to land at the company's factory airfield at Rostock-Marienehe (today's Rostock-Schmarl neighbourhood), as this was considered too short, but at the central Erprobungstelle Rechlin test facility. He ignored these orders and landed back at Marienehe. He said that the He 111 performed slow manoeuvres well and that there was no danger of overshooting the runway.^[8][9] Nitschke also praised its high speed "for the period" and "very good-natured flight and landing characteristics", stable during cruising, gradual descent and single-engined flight and having no nose-drop when the undercarriage was operated.^[10] During the second test flight Nitschke revealed there was insufficient longitudinal stability during climb and flight at full power and the aileron controls required an unsatisfactory amount of force.^[10]

By the end of 1935, prototypes V2 V4 had been produced under civilian registrations D-ALIX, D-ALES and D-AHAO. D-ALES became the first prototype of the He 111 A-1 on 10 January 1936 and received recognition as the "fastest passenger aircraft in the world", as its speed exceeded 402 km/h (250 mph).^[11] The design would have achieved a greater total speed had the 1,000 hp DB 600 engine that powered the Messerschitt Bf 109s tenth through thirteenth prototypes been available.^[6] Heinkel was forced initially to use the 650 hp BMW VI liquid-cooled engine.^[9]

During the war, British test pilot Eric Brown evaluated many Luftwaffe aircraft. Among them was a He 111 H-1 of Kampfgeschwader 26 which was forced to land at the Firth of Forth on 9 February 1940. Brown described his impression of the He 111s unique greenhouse nose,

The overall impression of space within the cockpit area and the great degree of visual sighting afforded by the Plexiglas panelling were regarded as positive factors, with one important provision in relation to weather conditions. Should either bright sunshine or rainstorms be encountered, the pilot's visibility could be dangerously compromised either by glare throwback or lack of good sighting.|Brown^[12]

Taxiing was easy and was only complicated by rain, when the pilot needed to slide back the window panel and look out to establish direction. On take off, Brown reported very little "swing" and the aircraft was well balanced. On landing, Brown noted that approach speed should be above 145 km/h (90 mph) and should be held until touch down. This was to avoid a tendency by the He 111 to drop a wing, especially on the port side.^[12]

Competition

In the mid-1930s, Dornier Flugzeugwerke and Junkers competed with Heinkel for Ministry of Aviation(German: Reichsluftfahrtministerium, abbreviated RLM) contracts. The main competitor to the Heinkel was the Junkers Ju 86. In 1935, comparison trials were undertaken with the He 111. At this point, the Heinkel was equipped with two BMW VI engines while Ju 86A was equipped with two Jumo 205Cs, both of which had 492 kW (660 hp). The He 111 had a slightly heavier takeoff weight of 8,220 kg (18,120 lb) compared to the Ju 86's 8,000 kg (17,640 lb) and the maximum speed of both aircraft was 311 km/h (193 mph).^[10] However the Ju 86 had a higher cruising speed of 177 mph (285 km/h), 9 mph (14 km/h) faster than the He 111. This stalemate was altered drastically by the appearance of the DB 600C, which increased the He 111's power by 164 kW (220 hp).^[10] The Ministry of Aviation awarded both contracts, and Junkers sped up development and production at a breathtaking pace, but the financial expenditure for the Junkers was huge. In 1934-1935, 3,800,000 RM (4½% of annual turnover) was spent. The Ju 86 appeared at many flight displays all over the world which helped sales to the Ministry of Aviation and abroad. Dornier, which was also competing with their Do 17, and Heinkel were not as successful. However, in production terms, the He 111 was more prominent with 8,000 examples produced^[10] against just 846 Ju 86s^[7] and was therefore the Luftwaffe's most numerous type at the beginning of the Second World War.^[10]

Basic design

The Norway-restored He 111P-2's nose

The design of the He 111 A-L initially had a conventional steppedcockpit, with a pair of windscreen-like panels for the pilot and co-pilot. The He 111P and subsequent production variants were fitted with a fully glazed cockpits, laterally asymmetric nose, with the port side having the greater curvature for the pilot, offsetting the bombardier to starboard. The resulting stepless cockpit, which was a feature on a number of German bomber designs during the war years in varying shapes and formats, no longer had the separate windscreen panels for the pilot. Pilots had to look outside through the same bullet-like glazing that was used by the bombardier and navigator. The pilot was seated on the left and the navigator/bomb aimer on the right. The navigator went forward to the prone bomb-aiming position or could tilt his chair to one side, to move into the rear of the aircraft. There was no cockpit floor below the pilot's feet—the rudder pedals being on arms—giving very good visibility below.^[13] Sliding and removable panels were manufactured into the nose glazing to allow the pilot, navigator and or bomb aimer to exit the aircraft quickly, without a time-consuming retreat into the fuselage.^[14]

Inside Wk Nr 701152 He 111 H-20. Looking forward to the first bulkhead from theventral gunner's position. The control column and cockpitglazing is visible in the central background.

The fuselage contained two major bulkheads, with the cockpit at the front of the first bulkhead. The nose was fitted with a rotating machine gun mount, offset to allow the pilot a better field of forward vision. The cockpit was fully glazed, with the exception of the lower right section, which acted as a platform for the bombardier-gunner to be positioned. The commonly-used Lotfernrohr-series bombsight penetrated through the cockpit floor into a protective housing on the external side of the cockpit.^[13]

Between the forward and rear bulkhead was the bomb bay, which was constructed with a double-frame to strengthen it for carrying the bomb load. The space between the bomb bay and rear bulkhead was used up by Funkgerät radio equipment and contained the dorsal and flexible casemate ventral gunner positions. The rear bulkhead contained a hatch which allowed access into the rest of the fuselage which was held together by a series of stringers. The wing was a two spar design. The fuselage was formed of stringers to which the fuselage skin was riveted. Internally the frames were fixed only to the stringers which made for simpler construction but at the loss of some rigidity.^[13]

The wing leading edges were swept back to a point inline with the engine nacelles, while the trailing edges were angled forward slightly. The wing contained two 700 L (190 US gal) fuel tanks between the inner wing main spars, while at the head of the main spar the oil coolers were fitted. Between the outer spars, a second pair of reserve fuel tanks were located carrying an individual capacity of 910 L (240 US gal) of fuel.^[13] The outer trailing edges were formed by the ailerons and flaps, which were met by smooth wing tips which curved forward into the leading edge. The outer leading edge sections were installed in the shape of a curved "strip nosed" rib, which was positioned ahead of the main spar. Most of the interior ribs were not solid, with the exception of the ribs located between the rear main spar and theflaps and ailerons. This was of solid construction, though even they had lightening holes.^[13]

Heinkel He 111 H-1

The control systems also had some innovations. The control column was centrally placed and the pilot sat on the port side of the cockpit. The column had an extension arm fitted and had the ability to be swung over to the starboard side in case the pilot was incapacitated. The control instruments were located above the pilot's head in the ceiling which allowed viewing and did not block the pilot's vision.^[15] The fuel instruments were electrical. The He 111 used the inner fuel tanks closest to the wing root. The outer tanks acted as reserve tanks. The pilot was alerted to the fuel level when the tank had 100 L (26 US gal) left. A manual pump was available in case of electrical or power failure but the delivery rate of just 4½ L (1.2 US gal) per minute demanded that the pilot fly at the lowest possible speed and just below 3,048 m (10,000 ft). Fortunately, the He 111 handled well at low speeds.^[15]

The defensive machine gun positions were located in the glass nose, the flexible ventral, dorsal and lateral positions in the fuselage and all offered a significant field of fire.^[16] The design of the nose allowed the machine gun position to be moved 10° upwards from the horizontal and 15° downwards.^[16] The gun could traverse some 30° laterally. Both the dorsal and ventral machine guns could move up and downwards by 65°. The dorsal position could move the 13 mm (.51 in) MG 131 machine gun 40° laterally, but the ventral Bola-mount 7.92 mm (.312 in) twinned-up MG 81Z machine guns could be moved 45° laterally. Each MG 81 single machine gun mounted in the side of the fuselage in "waist" positions, could move laterally by 40° and could move upwards from the horizontal by 30° and downwards by 40°.^[16]

Early civilian variants

He 111C

The first prototype, He 111 V1 (W.Nr. 713, D-ADAP), first flew from Rostock-Marienehe on 24 February 1935.^[17] It was followed by the civilian-equipped V2 and V4 in May 1935. The V2 (W.Nr. 715, D-ALIX) used the bomb bay as a four-seat "smoking compartment", with another six seats behind it in the rear fuselage. V2 entered service with Deutsche Luft Hansa in 1936, along with six other newly built versions known as the He 111C.^[18] The He 111 V4 was unveiled to the foreign press on 10 January 1936.^[18]Nazi propaganda inflated the performance of the He 111C, announcing its maximum speed as 400 km/h (249 mph), in reality its performance standing at 360 km/h (224 mph).^[19] The He 111 C-0 was a commercial version and took the form of the V4 prototype design. The first machine, designated D-AHAO "Dresden". It was powered by the BMW VI engine and could manage a range (depending on the fuel capacity) of 1,000 km (621 mi) to 2,200 km (1,367 mi)^[19] and a maximum speed of 310 km/h (193 mph).^[20] The wing span on the C series was 22.6 m (74 ft 1¾in).^[20] The fuselage dimensions stood at 17.1 m (56 ft 1¾in) in the He 111 V1, but changed in the C to 17.5 m (57 ft 5 in). The Jumo 205 diesel-type powerplant engine replaced the BMW VI. Nevertheless, the maximum speed remained in the 220–240 km/h (137–149 mph) bracket. This was increased slightly when the BMW 132 engines were introduced.^[20]

A general problem existed in powerplants. The He 111 was equipped with BMW VI glycol-cooled engines. The German aviation industry lacked powerplants that could produce more than 600 hp.^[9]Engines of suitable quality were kept for military use, frustrating German airline Luft Hansa and forcing it to rely on the BMW VI or 132s.^[20]

He 111G

The He 111G was an upgraded variant and had a number of differences to its predecessors. To simplify production the leading edge of the wing was straightened, like the bomber version. Quite a few different engine types were used, among them the BMW 132, BMW VI, DB 600 and DB601A. Some C variants had been upgraded with the new wing modifications. A new BMW 132H engine was also used in a so-called Einheitstriebwerk (unitary powerplant). These radial engines were used in the Junkers Ju 90 and the Focke-Wulf Fw 200. The wing units and engines were packed together as complete operating systems, allowing for a quick change of engine.^[21] The He 111G was the most powerful as well as the fastest commercial version.^[21] The G-0 was given the BMW VI 6.0 ZU. Later variants had their powerplants vary. The G-3 for example was equipped with the BMW 132. The G-4 was powered by DB600G inverted-vee 950 hp (710 kW) engines and the G-5 was given the DB601B with a top speed of 410 km/h (255 mph). By early 1937, eight G variants were in Lufthansa service. The maximum number of He 111s in Lufthansa service was 12. The He 111 operated all over Europe and flew flights as far away as South Africa. Commercial development ended with the He 111G.^[21]

Military variants

He 111 A - D

A Chinese He 111A re-engined with Wright Cyclone radial engines

The initial reports from the test pilot, Gerhard Nitschke, were favourable. The He 111's flight performance and handling were impressive although it dropped its wing in the stall. As a result, the passenger variants had their wings reduced from 25 m (82 ft) to 23 m (75 ft). The military aircraft - V1, V3 and V5 - spanned just 22.6 m (74.1 ft).^[17] The prototypes were equipped with 431 kW (578 hp) BMW VI 6.0 V12 in-line engines, succeeded by745 kW (999 hp) DB 600 engines.^[17]

The first prototypes were underpowered, as they were equipped with 431 kW (578 hp) BMW VI 6.0 V12 in-line engines. This was eventually increased to 745 kW (999 hp) with the fitting of the DB (Daimler-Benz) 600 engines into the V5, which became the prototype of the "B" series.^[17]

Only 10 He 111 A-0 models based on the V3 were built, but they proved to be underpowered and were eventually sold to China. The type had been lengthened by 1.2 m (3.9 ft) due to the added 7.92 mm (.312 in) MG 15 machine gun in the nose. Another gun position was installed on top of the fuselage, and another in a ventral position as a "dustbin" exposed turret, which could retract. The bomb bay was divided into two compartments and could carry 680 kg (1,500 lb) of bombs. The problem with these additions was that the weight of the aircraft reached 8,200 kg (18,080 lb). The He 111's performance was seriously reduced; in particular, the BMW VI 6.0 Z engines were not now powerful enough. The increased length also altered the 111's aerodynamic strengths and reduced its excellent handling on takeoffs and landings.^[22]

The crews found the aircraft difficult to fly, and its top speed was reduced significantly. Production was shut down after the pilots reports reached the Ministry of Aviation. However, a Chinese delegation was visiting Germany and they considered the He 111 A-0 fit for their needs and purchased seven machines.^[23]

The first He 111B made its maiden flight in the autumn of 1936. The first production batch rolled off the production lines that summer, at Rostock.^[24] Seven B-0 pre-production aircraft were built, bearing theWerknummern (Works numbers) 1431 to 1437. The B-0s were powered by DB 600C engines fitted with variable pitch airscrews.^[24] The screws increased output by 149 kW (200 hp). The B-0 had a MG 15 machine gun installed in the nose. The B-0 could also carry 1,500 kg (3,310 lb) in their vertical cells.^[24]The B-1 had some minor improvements. The installation of the revolving gun-mount in the nose and a flexible Ikaria turret under the fuselage.^[24] After improvements, the RLM ordered 300 He 111 B-1s; the first were delivered in January 1937. In the B-2 variant, engines were upgraded to the supercharged634 kW (850 hp) DB 600C, or in some cases, the 690 kW (925 hp) 600G. The B-2 began to roll off the production lines at Oranienburg in 1937.^[25] The He 111 B-3 was a modified trainer. Some 255 B-1s were ordered.^[24] However, the production orders were impossible to fulfill and only 28 B-1s were built.^[24] Owing to the production of the new He 111E, only a handful of He 111 B-3s were produced. Due to insufficient capacity, Dornier, Arado and Junkers built the He 111B series at their plants inWismar, Brandenburg and Dessau, respectively.^[24] The B series compared favourably with the capacity of the A series. The bomb load increased to 1,500 kg (3,300 lb), while there was also an increase in maximum speed and altitude to 215 mph (344 km/h) and 22,000 ft (6,700 m)^[11][23]

In late 1937, the D-1 series entered production. However, the DB 600Ga engine with 781 kW (1,047 hp) planned for this variant was instead allocated to Messerschmitt Bf 109 and Bf 110 production lines. Heinkel then opted to use Junkers Jumo engines, and the He 111 V6 was tested with Jumo 210 G engines, but was judged underpowered. However, the improved 745 kW (999 hp) Jumo 211 A-1 powerplant prompted the cancellation of the D series altogether and concentration on the design of the E series.^[26]

He 111 E

A He 111E in Luftwaffe service, 1940. The early variants had a conventional, stepped cockpit.

The pre-production E-0 series were built in small numbers. Fitted with Jumo 211 A-1 engines loaded with retractable radiators and exhaust systems. The variant could carry 1,700 kg (3,748 lb) of bombs giving it a take off weight of 10.300 kg (22,707 lbs). The development team for the Jumo 211 A-1 engines managed to increase engine power to 930 hp (690 kW), subsequently the He 111 E-1s bomb load capacity increased to 2,000 kg (4,410 lb) and a top speed of 242 mph (390 km/h).^[27]

The E-1 variant with Jumo 211A-1 engines was developed in 1937, the He 111 V6 being the first production variant. The E-1 had its original powerplant, the DB 600 replaced with the Jumo 210 Ga engines.^[28] The more powerful Jumo 211 A-1 engines desired by the Ministry of Aviation were not yet ready for installation. Another trial aircraft, He 111 V10 (D-ALEQ) was to be fitted with two oil coolers necessary for the Jumo 211 A-1 installation.^[28]

He 111E of the Legion Condor

The E-1s came off the production line in February 1938, in time for a number of these aircraft to serve in the Condor Legion during theSpanish Civil War in March 1938.^[29] The RLM thought that because the E variant could outrun enemy fighters in Spain, there was no need to upgrade the defensive weaponry, which would prove to be a mistake in later years.^[28]

The fuselage bomb bay used four bomb racks, in later versions eight modular standard bomb racks designed to carry one SC 250 kg (550 lb) bomb or four SC 50 kg (110 lb) bombs each in nose up orientation. These modular standard bomb racks were a common feature on the first generation of Luftwaffe bombers, but it turned out that they limited the ordnance selection to bombs of only two sizes. These racks were abandoned in later designs.^[28]

The E-2 series was not produced, and was dropped in favour of producing the E-3 with only a few modifications, such as external bomb racks.^[27] Its design features were distinguished by improved FuG radio systems.^[29] The E-3 series was equipped with the Jumo 211 A-3 for the duration of the series which packed 1,100 hp (820 kW).^[29]

The E-4 variant was fitted with external bomb racks also and the empty bomb bay space was filled with an 835 L (221 US gal) tank for aviation fuel and a further 115 L (30 US gal) oil tank. This increased the loaded weight but increased range to 1,800 km (1,130 mi). The modifications allowed the He 111 to perform both long- and short-range missions.^[30] The E-4s eight internal vertically aligned bomb racks could each carry a 250 kg (550 lb) bomb.^[31] The last E Variant, the He 111 E-5, was powered by the Jumo 211 A-3, and retained the 835 L (221 US gal) fuel tank on the port side of the bomb bay. Only a few of the E-4 and E-5 were built.^[29]

The RLM had acquired an interest in rocket boosters fitted for the sake of simplicity below the wings of a heavily loaded bomber to cut down the length of runway needed for takeoff. Once in the air the booster canisters would be jettisoned by parachute for reuse. The firm of Hellmuth Walter, at Kiel, handled this development.^[32] The first standing trials and tests flights of the Walter HWK 109-500 Starthilfe liquid-fueled boosters were held in 1937 at Neuhardenberg with test pilot Erich Warsitz at the controls of Heinkel He 111E bearing civil registration D-AMUE.^[33]

He 111 F

The He 111 design quickly ran through a series of minor design revisions. One of the more obvious changes started with the He 111F models, which moved from the elliptical wing to one with straight leading and trailing edges, which could be manufactured more efficiently.^[29] The dimensions of the new design had a wing span of 22.6m (74 ft 1¾in) and an area of 87.60m² (942.90 ft).^[29]

Heinkel's industrial capacity was limited and production was delayed. Nevertheless, 24 machines of the F-1 series were exported to Turkey.^[29] Another 20 of the F-2 variant were built.^[34] The Turkish interest, prompted by the fact the tests of the next prototype, He 111 V8, was some way off, prompted the Ministry of Aviation to order 40 F-4s with Jumo 211 A-3 engines. These machines were built and entered service in early 1938.^[26] This fleet was used as a transport group during the Demyansk Pocket andBattle of Stalingrad.^[35] At this time, development began on the He 111J. It was powered by the DB 600 and was intended as a torpedo bomber. As a result, it lacked an internal bomb bay and carried two external torpedo racks. The Ministry of Aviation gave an order for the bomb bay to be retrofitted; this variant became known as the J-1. In all but the powerplant, it was identical to the F-4.^[26]

The final variant of the F series was the F-5, with bombsight and powerplants identical to the E-5.^[34]The F-5 was rejected as a production variant owing to the superior performance of the He 111 P-1.^[34]

He 111 J

The He 111's low-level performance attracted the interest of the Kriegsmarine. The result was the He 111J, capable of carrying torpedoes and mines. However, the navy eventually dropped the program as they deemed the four-man crew too expensive in terms of manpower. The RLM nevertheless continued production of the He 111 J-0. Some 90 (other sources claim 60)^[36] were built in 1938 and were then sent to Küstenfliegergruppe 806 (Coastal Flying Group).^[37] Powered by the DB 600G engines, it could carry a 2,000 kg (4,410 lb) payload. But few of the pre-production J-0s were fitted with the powerplant. Instead, the DB 600 was used, performance deteriorated and the torpedo bomber was not pursued. The J variants were used in training schools until 1944.^[34] Some J-1s were utilised used as test beds forBlohm & Voss L 10 (de) radio-guided air-to-ground torpedo missiles.^[38]

He 111 P

He 111P dropping bombs over Poland, September 1939

The He 111P incorporated the updated Daimler-Benz DB 601A-1 liquid-cooled engine and featured a newly designed nose section, including an asymmetric mounting for an MG 15 machine gun that replaced the 'stepped' cockpit with a roomier and more aerodynamic glazed stepless cockpit over the entire front of the aircraft. This smooth glazed nose was first tested on the He 111 V8 in January 1938. These improvements allowed the aircraft to reach 475 km/h (295 mph) at 5,000 m (16,400 ft) and a cruise speed of 370 km/h (230 mph), although a full bomb load reduced this figure to 300 km/h (190 mph).^[26] The design was implemented in 1937 because pilot reports indicated problems with visibility.^[26] The pilot's seat could actually be elevated, with the pilot's eyes above the level of the upper glazing, complete with a small pivoted windscreen panel, to get the pilot's head above the level of the top of the "glass tunnel" for a better forward view for takeoffs and landings. The rear-facing dorsal gun position, enclosed with a sliding, near-clear view canopy, and for the first time, the ventral Bodenlafetterear-facing gun position, immediately aft of the bomb bay, that replaced the draggy "dustbin" retractable emplacement became standard, having been first flown on the He 111 V23, bearing civil registration D-ACBH.^[39]

One of Heinkel's rivals, Junkers, built 40 He 111Ps at Dessau. In October 1938, the Junkers Central Administration commented:

Apparent are the externally poor, less carefully designed components at various locations, especially at the junction between the empennage and the rear fuselage. All parts have an impression of being very weak.... The visible flexing in the wing must also be very high. The left and right powerplants are interchangeable. Each motor has an exhaust-gas heater on one side, but it is not connected to the fuselage since it is probable that ... the warm air in the fuselage is not free of carbon monoxide (CO). The fuselage is not subdivided into individual segments, but is attached over its entire length, after completion, to the wing centre section. Outboard of the powerplants, the wings are attached by universal joints. The latter can in no way be satisfactory and have been the cause of several failures.^[40]

The new design was powered by the DB 601 Ba engine with 1,175 PS^[26] The first production aircraft reached Luftwaffe units in Fall 1938. In May 1939, the P-1 and P-2 went into service with improved radio equipment. The P-1 variant was produced with two DB 601Aa powerplants of 1,150 hp (860 kW). It had self-sealing fuel tanks.^[41] The P-1 featured a semi-retractable tail wheel to decrease drag.<sup id="cite_ref-Regnat_2004.2C_p._35._4