Mitsubishi G3M, part three

 

The Mitsubishi G3M was a land-based medium bomber that was used for the first during the Second Sino-Japanese War of 1937 where it made great use of its long range. On 14th August 1937 forty-two G3M2 together with seven Hiro G2H and escorted by twelve Nakajima A4Ns and twelve Mitsubishi A5M fighters belonging to the 2. Rengo Kokutai (formed itself by the 12th and 13th kokutais) took off from their bases on western Japan, crossed the East China Sea and bombed the cities of Hangchow and Kwanteh, in China and performed, among other actions, terror bombings on coastal and inland targets in China, including bombings during the Battles of Shanghai and Nanjing. 

The bombers and their escorts were often engaged in combat by Curtiss Hawk III and Boeing P-26 fighters of the Chinese Air Force in the early periods of the war. As the war kept going on, the Japanese set up airfields in occupied China, where many bomber kokutais operated from in the strategic carpet bombardment campaigns of the Chinese mainland, taking advantage of its long range (4.400 km - 2.700 milles) as the distances in that war were considerably longer. Most notably, it was involved in the round-the-clock bombing of the city of Chongqing where the type took part from February 1938 until 1941 when the Pacific War started as that city was used for operative bomber training and testing of new types.

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_G3M

2. https://en.wikipedia.org/wiki/Bombing_of_Chongqing

3. http://all-aero.com/index.php/contactus/53-planes-l-m-n-o/6919-mitsubishi-g3m--ka-15--l3y

Mitsubishi G3M, part two.

 

The Mitsubishi G3M Model 11 had a crew of five, could carry up to 800 Kg (1763.7 lb) of bombs carried externally under the fuselage or a single torpedo (as the specification made by the Imperial Japanese Navy - IJN - requested) capable of sinking an armoured battleship.

Just like the Ka-15 its defensive armament consisted on two retractable dorsal turrets equipped with a single 0.303in Type 92 machine gun plus another retractable ventral one. These turrets were initially "flat topped", however, in later versions, some of them were retroactively fitted with a "cupola shaped" one, typical of the G3M2. 

It was powered by two Mitsubishi Kinsei 3 engines, rated at 898 hp each. 

Although it flew for the first time, as the Ka-15 (see our previous post) in 1935, in a flight taking off from Mitsubishi's private airfield in Nagasaki and landing at Haneda airport, close to Tokyo, it wasn't until 1937 that the G3M was employed in combat. It was employed, albeit in smaller numbers than its successor the G3M2, in the Japanese expansionists campaigns on the Chinese mainland, known as the Second Sino-Japanese War. During this campaign, the G3M1 exploited their long-range capabilities when aircraft belonging to the 1. Rengo Kokutai (a special unit) was set up together with Kanoya and Kisarazu Kokutais based at Taipei in Formosa and Omura, Kyushu and Jeju islands in western Japan, though Jeju nowadays belongs to south Korea. 

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_G3M

2. http://all-aero.com/index.php/contactus/53-planes-l-m-n-o/6919-mitsubishi-g3m--ka-15--l3y

3. https://www.valka.cz/Micubisi-G3M1c-11C-Nell-t1283

Mitsubishi G3M, part one, Mitsubishi Ka-15

 

Back in 1935 the Imperial Japanese Navy (IJN) issued a requirement for a land-based twin-engine reconnaissance airplane. Mitsubishi presented the Ka-15, a development of their previous Ka-9/G1M1 recon airplane. The Ka-15 prototype presented some room for improvement to be used as a land-based long-range medium bomber. 

The original prototype, flew for the first time in July 1935 powered by two Hiro Type 91 radial engines which could deliver up to 750 hp of power mounted on the mid-set wings, just like in the Ka-9. 

Twenty more prototypes and pre-production Ka-15 were completed, of which three were powered by the Hiro engine and remaining 17 by either the Mitsubishi Kinsei 2 (which could deliver up to 830 hp of power) or the Mitsubishi Kinsei 3 (whose power output could reach up to 910 hp), engines which greatly boosted the bomber's performance. 

These aircraft were assigned to the IJN and received the unofficial designation of G3M1a, comprising the three original prototypes with Hiro engines and solid nose, G3M1b, to designate two prototypes powered with the Kinsei 2 engine, having solid noses and one of them having been tested with ski undercarriage for winter operations, and G3M1c for the remaining machines featuring a redesigned cockpit and a glazed nose. 

They could carry up to 800 kg of bombs externally or a single torpedo. The versions featuring a solid nose were armed with two 0.303 in Type 92 machine guns (a Japanese copy of the famous Lewis machine gun) placed inside retractable dorsal turrets. These pre-production bombers were assigned to various Kokutais (IJN's basic combat group) which used them for various service trials, however, before the completion of the first batch, the IJN ordered the much promising G3M1 Model 11, being itself a more elaborate development of the Ka-15/G3M1a-b-c.

Sources:

1. http://all-aero.com/index.php/contactus/53-planes-l-m-n-o/6919-mitsubishi-g3m--ka-15--l3y

2. https://en.wikipedia.org/wiki/Mitsubishi_G3M

3. https://www.armedconflicts.com/Mitsbishi-Ka-15-1st-2nd-5th-and-6th-prototype-20061-15-1-2-5-a-6-t33046

Junkers Ju.52, part ten

 

On this part, which the last of the ones dedicated to the Junkers Ju.52, we write about the latest versions of this venerable airplane.

The Ju.52/3mg7e was an improved variant which included various improvements. It was developed from the previous g5e version and had an enlarged starboard cargo loading hatch in order to load and unload heavier and bulkier items. The roof hatch was deleted on this variant and a Siemens K4ü autopilot was installed to ease pilots' workload on longer flights. It was developed in 1941 and was armed with two 7.92 mm MG 15 machine guns, one placed in an opened aft dorsal position, another one placed inside a Condor-Haube (Condor Hood) turret in the cockpit's overhead glazing, plus two additional MG 15s in the windows at the sides (which, in some earlier variants were ad-hoc installed in the windows). 

The Ju.52/3mg8e was also began to be developed in 1941. Overall it was similar to the previous g7e, but it had the Condor-Haube removed and was powered by three more powerful BMW 132Z radial engines. In some machines, the dorsal machine gun was replaced by the 13 mm MG 131. Both the g7e and the g8e were the most produced variant from 1941 until late 1942. 

The g9e was a tropicalized variant of the g4e. It was equipped with dust filters and other equipment for desert operations, along with a cabin air inlet. This variant was also known as Ju.52/3mg4e (trop). 

The Ju.52/3mg10e superseded the previous g8e in 1942. It was equipped with the smaller starboard cargo door seen already on the g4e. The narrower hatch allowed Junkers to revert to five cabin windows from the g8e's three. This version lacked de-icing equipment.

The Ju.52/3mg11e reinstated the de-icing equipment. Otherwise, it was identical to the g10e. 

The Ju.52/3mg12e was built in very small numbers and featured extra armour to protect the flight crew. 

The Ju.52/3mg13e was purposely omitted due to the association of that number with bad luck.

Ju.52/3mg14e  was the last production variant of the German Ju.52. It featured armour plating all around the cockpit to protect both pilot and co-pilot, was armed with a single 13 mm MG 131 and two 7,92 mm MG 15 in the beam positions. This variant entered production in late 1943 and continued until late 1944. It was powered by three BMW 132L radial engines, delivering each of them up to 830 hp of power with an extra air inlet added under each engine to increase the airflow into the carburetor. Exhausts were also different as its upper one was located behind the cowling and the lower one was extended aft. Most of them had also a small antenna on the upper fuselage, but lacked a direction finding loop-one. Landing gear struts, untouched since the g3e, were also reinforced. 

The Ju.52/3mMS were various g4e to g7e converted into mine sweepers. They were mounted with a 14 meters (45.93 ft) diameter duraluminium Gauss ring which was energised by a 270 ampere electrical generator, powered itself by a 55 hp Mercedes engine mounted inside the fuselage and cooled by an extra inlet, placed in front of the main landing gear struts. As we wrote, this variant was used for the first time in November 1940 off the coast of Holland and was used all along the Atlantic, Baltic and North Adriatic coasts. Seventy-four machines of this variant were assigned to the Minensuchgruppe 1 in November 1943, six of which were deployed to Hungary in April 1944, to detonate mines dropped into the Danube river. By the beginning of 1945 most Ju.52/3m MS were grounded by the lack of fuel. 

One of the many last operations the Ju.52 was involved on, which if often overlooked, was the Operation Hannibal, the evacuation of the Courland Peninsula, in May 1945 which lasted until the very VE-Day on 8th May 1945.

Nowadays, Lufthansa has one restored operational Ju.52, though powered by Pratt & Whitney engines, which in 1984 received the registration of D-AQUI.

 

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. https://en.wikipedia.org/wiki/List_of_airworthy_Ju_52s

3. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

4. https://www.youtube.com/watch?v=iZCsTUP6-A8

Junkers Ju.52/3m, part nine

 

As World War 2 kept going on, the Junkers Ju.52/3m saw itself involved in most operations executed by the German Army in the Eastern Front. This way, the Ju.52/3m took part in the evacuation of the 17th Army from the Kuban area, located north of the Caucasus region in the spring 1943. From 19th April 1943 Ju.52/3m-s aided in suppressing the Jewish revolt in the Warsaw Ghetto, as they dropped leaflets and bombs against the resistants. This was effectively, the last time the Ju.52/3m was used as a bomber, albeit in a much smaller scale.

The final large-scale operation of World War 2 the Ju.52/3m was involved in was the attempt to resupply the besieged German troops at the city of Breslau (nowadays Wroclaw, in Poland). Those aircraft began their missions to Breslau in mid-February 1945 and the last three Ju.52/3m landed in the city on 7th April 1945. Most of the 165 Luftwaffe aircraft destroyed during the relief attempt were Ju.52/3m. After that, sporadic flights were made to Berlin while it was surrounded by the Soviet Army. In fact, the last supply mission into the German capital took place on 29th April 1945 by Ju.52/3m of the Transportgeschwader 3 (TG.3), just the day before Hitler committed suicide in his bunker. The airplanes dropped supplies over the Tiergarten near the Reichskanzlei (Reich Chancellery).

Luftwaffe's main transport units, Transportgeschwader 1, 2 and 3 plus Transportgruppe 20 (an unit formed in 1943 in Norway from elements of KGrzbV 108) had in total 190 Ju.52/3m on strength on 25th April 1945. Those machines were taken over by various countries after V-E Day on 8th May 1945. Very few of the original 3.400 Ju.52/3m survived the conflict.

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

Junkers Ju.52/3m, part eight

 

After the heavy losses sustained in Operation Merkur (Mercury), and commitments elsewhere, meant that only 150 Ju.52 were available for Operation Barbarossa, German invasion of the Soviet Union, on 22nd June 1941. Those transports were hard pressed into service, flying supplies to the rapidly advancing Wehrmacht troops and, therefore, other Ju.52/3m were redeployed to the east. 

Later, in early 1942, the Ju.52/3m of various Luftwaffe units were key in resupplying the surrounded German troops of the II Army Corps at Demyansk in the USSR. The Ju.52/3m flew on a daily basis to deliver up to 330.7 tons of supplies to the trapped German troops. This took place in spite of temperatures plummeting to -45ºC (-49 Fahrenheit), causing great difficulties for the aircraft and their crews. Nevertheless, between 21st February and 18th May 1942, the Germans managed to fly 71.51.2 tons of supplies plus 30.000 troops to the Demyansk pocket and managed to evacuate over 35.000 wounded troops to German rear areas. During this operation, Soviet fighters, anti-air fire and various accidents made for the loss of 265 German aircraft, most of them being Ju.52/3m.

Thanks to the success of this airlift, the Luftwaffe was prompted to attempt a large scale airlift in Stalingrad after the encirclement of the German Sixth Army on 19th November 1942. Therefore approximately 375 Ju.52/3m-s were deployed to Morzovskaya and Tatsinskaya airfields, at 241 km  (149.8 milles ) west of Stalingrad. Those airfields were the main hub for the airlift which began on 25th November. The Sixth Army required a daily amount of 826.7 tons of supplies, but that proved to be beyond Luftwaffe's means. The harsh winter conditions took a heavy toll on the Ju.52/3m-s and their crews, many of whom lacked proper winter clothing. By mid-December the transports delivered an average of 93 tons per day of supplies, well below the requirements of the Sixth Army. As the Operation Uranus (the Soviet encirclement of Stalingrad) continued on, the number of proper airfields to operate from was reducing and aerial operations were moved to Pitomnik airfield, closer to Stalingrad. These airlifts were becoming more and more difficult as steadily improved Soviet fighters and anti-air fire, made the flights in and out of that airfield very risky. The Soviets pushed the Gemrans further West of the city and tigthened the encirclement, which further hampered Luftwaffe's resupply efforts. On 2nd February 1942, when the Sixth Army surrendered, the Luftwaffe lost 266 Ju.52/3m-s and more than 1.000 airmen. The Soviet VVS (Soviet Air Force) captured over 100 lightly damaged Ju.52/3m-s, which were repaired and put into service.  

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

Junkers Ju.52/3m, part seven

 

Those Ju.52/3m equipped with floats for water-based operations were designated as Ju.52/3m See (Sea). They had their tailwheel removed and the main landing gear was replaced by two floaters. The floats were designed by Junkers. They were made out of metal and had a displacement of 9.500 L (2.509,6 gal), but they were soon replaced by  larger, Heinkel-designed ones as they were 11,34 m (37 ft 2,4 in) long and displaced 11.000 L (2.905,9 gal). Four V-shaped struts attached each float to the wing undersurface, with wire bracing giving additional support.

An access ladder linked the rear entrance door to the port float's upper rear section and no ladder was mounted at the other side. Handhold rails were also mounted under the windows on both sides of the Ju.52/3m See. Rails which were retained on those which were later converted for land operations.

Its gross weight on floats was 11.500 kg (25.352,7 pounds), 500 kg heavier than a regular Ju.52/3mg8e landplane, due to its floaters. It had a water take off run of 845 m (2.772,3 ft) which could accomplish it in 53 seconds, during type's evaluation trials. It could also reach an altitude of 3.000 m (9.842,5 ft) in 21 minutes and had a maximum speed of 231 km/h (143,5 mph), which was 55 km/h (34.2 mph) slower than its land-based counterpart, given the aerodynamic drag produced by the floaters and their struts. Its cruising speed at low altitude was 173 km/h (107,5 mph), 42 km/h (26,1 mph) slower than the regular Ju.52/3mg8e, which made the type very vulnerable to fighter attacks.

As we wrote in a previous post, many Ju.52/3m See were assigned to the KGrzbV 108 in early 1940 to take part in invasion of Norway and later, they were redeployed to eastern Mediterranean theatre. In October 1943 an unit entirely composed of Ju.52/3m See was formed, the Seetransportstaffel 1, with base in Athens-Phaleron, from where they performed various patrol flights over the Aegean Sea and kept connections with Crete. This island was turned into a Festung (fortress) by the Germans and was partitioned in two, with most of the island under German occupation, with headquarters in the city of Chania, and the Easternmost part of the island under Italian control, with headquarters at the city of Lasithi. From October 1943 many resupply flights were flown to Heraklion from Athens, which were kept until October 1944 when the Germans retreated from Greece, although Crete was kept. The last resupply flight to Crete took place in that month, October 1944. After that, the Seetransportstaffel 1 was redesigned as 17/TG.4 and was disbanded shortly before the end of the war.

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

3. https://en.wikipedia.org/wiki/Fortress_Crete

4. http://www.ww2.dk/air/transport/trspsee1.html

5. https://www.asisbiz.com/Luftwaffe/trspsee1.html

Junkers Ju.52/3m, part six

 

The Luftwaffe began to decrease its use of the Junkers Ju.52/3m from 1943 onwards, as interest on the type waned and the Reich Air Ministry started to show interest on the Junkers Ju.352 (a larger transport aircraft, somewhat resembling the Ju.52/3m) as the official successor. Actions were taken to switch Ju.52/3m's production lines into the Ju.352, but the end of the conflict in Europe in May 1945 made the effort worthless and the Ju.352 was left unfinished. Therefore the German production of the Ju.52 was terminated in late 1944 with 3.234 aircraft of various models having being built during wartime alone.

The Junkers Ju.52/3m was also employed thoroughly in the North African theatre of war. In fact, during this campaign the Ju.52 constituted the main reinforcement and supply aircraft for the Germans there. From February 1941, when the first resupplying flights took place, many Ju.52/3m began to airlift troops and supplies to the German Afrika Korps stationed in Libya. One Gruppe (group - squadron) of KgzbV1 flew these missions from Comiso, in Sicily, across the Mediterranean Sea, sometimes, flying up to three missions per day, with crews spending up to 12 hours in the air. During the period from February 1941 until November 1942, the transports flew up to 1.000 troops and 27.6 tons of supplies to North Africa each day. From November 1942, those flights were increased to 20-50 per day to Tunisia from Sicily, reaching up to 150 landings a day in early April 1943 as the Axis situation in Africa became more desperate and the Heeresgruppe Afrika/Gruppo d'Armate Africa (Army Group Africa) was set for evacuation to Italy. It was in this context that the Allied launched a counter-air operation over a two-month period, codenamed Operation Flax, on 5th April 1943, which lead to the destruction of 11 Ju.52/3m in the air near Cap Bon, Tunisia, and many more during aerial raids on Sicilian airfields, leaving only 29 serviceable in the North African continent. That was the starting point of two catastrophic weeks where more than 140 Ju.52/3m were lost in aerial interceptions, mainly because their slow speed made them very vulnerable to Allied fighters. On 18th April 1943, the "Palm Sunday Massacre" took place on which more than 24 Ju.52 were shot down, and another 35 staggered back to Sicily and crash-landed.

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

3. https://en.wikipedia.org/wiki/Operation_Flax

Junkers Ju.52/3m, part five

 

The Junkers Ju.52/3m was massively used also during the Balkans Campaign. Thanks to the Ju.52, Axis forces could be rapidly deployed through the whole theatre.

It was during this campaign that a special variant of the Ju.52 was introduced as up to twelve Ju.52/3mg4e were modified to carry an extra rotating tower equipped with a 20 mm MG 151 to serve as escort gunships. However, they were not very successful and were limited to operations over the Mediterranean.

Fifteen Ju.52 took part in the not so famous Operation Hannibal, the airborne assault on the Corinth Canal, in order to secure it. Original plan was for Fallschirmjäger (German paratroops) assault engineers to seize both sides of the canal (which links both Ionian and Aegean Seas) on a surprise glider assault, while both battallions of the 2nd Fallschirmjäger regiment parachuted both North and South of the bridge to neutralize any Allied forces at the canal.

The assault took place on 26th April 1941 and was a success as the Fallschirmjägers managed to hold the bridges and deactivate the demolition charges set by the Allied forces.

Shortly later, the Wehrmacht launched Operation Mercury, the invasion of the island of Crete, on 20th May 1941. The Luftwaffe sent a massive formation of 493 Ju.52/3m to fly a total force of 8.500 paratroopers and tow gliders to the Greek island, which was defended by Greek and British Commonwealth forces. Eleven days later, on 31st May, the Fallschirmjägers captured the island, but at the high cost of 4.000 paratroopers killed and 151 Ju.52/3m destroyed or damaged beyond repair (according to other sources, 4.500 killed and 170 Ju.52/3m destroyed). This was the first battle in military history where airborne troops were used massively, and also the first one where the German troops found heavy local resistance. Given the high casualty rate and the belief that the airborne forces had no longer the surprise factor, Adolf Hitler became reluctant to authorise further large airborne operations, preferring to employ paratroopers as ground troops. 

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. https://en.wikipedia.org/wiki/Battle_of_the_Corinth_Canal

3. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

4. Osprey - Combat Aircraft 120 - Ju 52/3m Bomber and Transport units 1936-1941

Junkers Ju.52/3m part four

 

The two wing-mounted radial engines of the Ju.52/3m had half-chord cowlings and in planform view (from above or below), they seemed to be splayed outwards, being mounted at an almost perpendicular angle to the tapered wing's sweptback leading edge, in a similar way other airplane of the time had like the Mitsubishi G3M or the Short Sunderland. In the case of the Ju.52 this was to make straight flight easier, in the case one of the engines failed. 

The three engines had NACA cowling or Townend ring to reduce drag from the engine cylinders, however, a mixture of both was the most common set-up, with deeper-chord NACA cowlings on the wing engines and a narrow Townend ring on the central engine as a NACA cowling was harder to fit there because of the widening fuselage behind the engine. 

Production models flown by Lufthansa before World War 2 as well as those flown by Luftwaffe during the war, used an air-start system to turn over to their trio of engines, using a common compressed air supply that operated wheel's brakes too.

Used in a military role, the Ju.52 could carry up to 18 fully-equipped soldiers, or 12 stretchers when used as an air ambulance. Transported materials was loaded and unloaded via a side door which also contained a ramp. Air dropped supplies were jettisoned through two double chutes. Supply containers were dropped by parachute through the bomb-bay doors and paratroopers jumped using the side doors. Small vehicles like a Sdkfz.2 Kettenkrafträder and supply canisters for parachute drops were secured under the fuselage at the bomb bay exits and could be dropped with four parachutes. A tow coupling was built into the tail-skid for towing freight gliders, of which, could tow up to two DFS.230.

Another major military campaign the Ju.52 was involved was the Operation Fall Gelb (Plan Yellow), the German invasion of Western Europe, on 10th May 1940. On that day, many transports, some of them towing the DFS.230 glider, successfully performed an airborne assault on the Belgian fortress of Eben Emael, while others were employed in the first massive airborne operation of history, the Battle for The Hague. During this battle, around 500 Ju.52 took part. They acted not only deploying paratroopers, but also landing straight into enemy territory, like it happened at Ypenburg airport and on public highways around The Hague. It was during this battle that Dutch anti-aircraft defenses took their serious toll on the Ju.52 shooting down a total of 125 and damaging 47 of them. 

Although Fall Gelb was a success, in the entire operation almost half of the Ju.52/3m assigned to the invasion were lost forcing the Luftwaffe to curtail aerial transport operations, though the type kept on supplying forward ground troops. Due to those heavy losses, the Luftwaffe was forced to replace them with new Ju.52s or taking them from Lufthansa. 

During August 1940 several Ju.52 were stationed in the Lyon, Lille and Arras areas of France, where they were held at an state of readiness for Operation Sealion, the German invasion of England, that never took place, because Germany couldn't secure aerial supremacy over the Royal Air Force.

After 1940 the Ju.52/3m MS (a mine sweeping variant) was the only Ju.52 that saw service in the Western Front. The first MS missions were flown in September 1940 off the coast of Holland and later, as war kept going on, they were also deployed on airfields along the Atlantic Ocean coast. All of them belonged to the Minensuchgruppe 1, which had also detachments in other theatres of the war and was created in November 1943 and was disbanded in May 1945, almost at the end of the war.

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

3. Osprey - Combat Aircraft 120 - Ju 52/3m Bomber and Transport units 1936-1941

4. https://www.ww2.dk/air/seefl/msgr1.html

Junkers Ju.52/3m, part three

 

As the Ju.52 was originally conceived, the Ju.52/1m, it was powered by a single engine, either a BMW IV or a liquid-cooled Junkers V-12. This model, however, was deemed as seriously underpowered and, after seven prototypes having been built, every subsequent Ju.52 was built in the three engine configuration, being denominated as Ju.52/3m (drei motoren - three engines). Those engines were ,at first, three Pratt & Whitney R-1690 Hornet, but later production models were powered by three BMW 132 which delivered up to 770 hp each and were themselves, a licensed copy and refinement, of Pratt & Whitney's design. Some export models were built with Pratt & Whitney R-1340 Wasp engine (delivering up to 600 hp) and Bristol Pegasus VI (delivering up to 775 hp).

Thanks to its excellent reputation as an airlines with Lufthansa, the Luftwaffe adopted the type as its standard transport airplane. In 1938, the 7. Flieger-Division alone had five transport groups with a total of 250 Ju.52. At the outbreak of World War 2, the whole Luftwaffe had a total of 552 Ju.52, although the aircraft was already considered being obsolete. Between 1939 and 1944, when German production ceased, a total of 2.804 machines were delivered to the Luftwaffe, 145 in 1939, 388 in 1940, 502 in 1941, 503 in 1942, 887 in 1943 and 379 in 1944, however, by the end of the War, there were only 100 to 200 serviceable. 

The first major operation the type was involved in, after the bombing of Warsaw, was in Operation Wesserübung, the German invasion on Denmark and Norway, on 9th April 1940. Fifty-two Ju.52 belonging to 1. and 8. Staffels of Kampfgeschwader 1 transported a company of Fallschirmjäger (paratroopers), plus an infantry battalion to the northern part of Jutland peninsula to capture the airfield in Aalborg, a key objective tu support operations in southern Norway. Many hundreds Ju.52 were also used to transport troops to Norway during the first days of the invasion, including the difficult, yet successful airborne assault on the Norwegian airports of Oslo-Fornebu, Stavanger-Sola and the bridge at Vordingborg. In the late stages some Ju.52/3m of the KGzbV 102 flew artillery to the German forces at Narvik, having to land on the frozen ice of Hartvigann lake. As those lacked the fuel to make the return trip, they were abandoned by their crews and the machines sank to the lake's bottom when the ice melted next spring. 

During this operation, the Ju.52 of the Luftwaffe, performed a total of 3.018 sorties, 1.830 of which were to carry troops and remainder to carry cargo and supplies. By the end of the operation, a total of 150 Ju.52 were recorded as lost with a total of 29.280 personnel, 2.376 tons of supplies and 259.300 imp. gallons (1.179L) of fuel transported. 

Many Ju.52/3mg4e (see), the floatplane variant, were assigned to KGzbV 108 See in early 1940 to be employed in the invasion of Scandinavia. These were used mainly to deliver troops and supplies to various islands and fjords which were, otherwise, inaccesible for German forces. 

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52#Military_use_1932–1945

2. https://www.axishistory.com/books/151-germany-luftwaffe/luftwaffe-ground-units/5604-7-flieger-division

3. https://www.valka.cz/Junkers-Ju-52-t16146 (translated)

4. Signal Squadron - Aircraft In action 186 - Junkers Ju-52 in Action

5. Osprey - Combat Aircraft 120 - Ju 52/3m Bomber and Transport units 1936-1941

Junkers Ju.52/3m, part two

 

Many improved models were made before and during World War 2. The main production model was the Ju.52/3mg7e, with advances such like autopilot, enlarged doors to the cabin and other general enhancements. It was configured to serve as a pure transport aircraft, capable of carrying up to 18 fully-equipped troops. Defensive weaponry consisted on a dorsal-mounted 13mm MG 131 and two sideways mounted 7.9mm MG 15 machine guns. Further models were improved in many different ways, such as revised glazing, newer engines, reinforced undercarriage, and increased take-off weight. 

The Ju.52 had a low cantilever wing , whose mid section was built into the fuselage, shaping its underside. It was formed around four pairs of circular cross-section duraluminium spars with a corrugated surface that provided torsional stiffening. A thin control surface, with its outer section acting as the aileron, while the inner section functioned as a flap. These sections ran along the whole trailing edge of each wing panel, well split from it. The inner flap section lowered the stalling speed and the arrangement was known as the "Doppelflügel" ("Double wing in German).

Outer sections operated diferentially as ailerons, projecting slightly beyond the wingtips with control horns. The strutted horizontal stabiliser featured horn-balanced elevators which projected and showed a significant gap between them and the stabiliser itself, which could be adjusted in-flight. All stabiliser surfaces were corrugated too. 

The Ju.52/3m featured an unusual, for the time, corrugated skin made out of duraluminium, pioneered by Junkers during World War 1. The purpose of the corrugation was to strengthen the whole structure over a smoother approach. The fuselage was of rectangular section with a domed decking, comprising a tubular steel tube that was completely covered by the corrugated metal skin. A port-sided passenger door was placed just aft the wings, which also acted as a loading hatch for freight, with the lower half acting as a platform to ease cargo movements. The cabin was lined with numerous windows stretching forward to the pilots' cockpit. The main undercarriage was fixed and divided, with some of them with wheel fairings, while others not, as many crew decided to remove them to ease maintenance duties. A fixed tailskid, or tailwheel in later models, was also used. Some aircraft were fitted with floats of skis instead of wheels. 

The type saw action as a bomber for the last time during World War 2 during the Invasion of Poland, as the type took part in the bombing campaign against Warsaw in September 1939, during the course of which only two Ju.52/3m bombers were lost. After the end of the Spanish Civil War, no further bomber versions were made and the Luftwaffe relied on the type entirely for transport and paratroop drops.

Sources:

1. https://en.wikipedia.org/wiki/Junkers_Ju_52

2. https://en.wikipedia.org/wiki/Bombing_of_Warsaw_in_World_War_II

3. Osprey - Combat Aircraft 120 - Ju 52/3m Bomber and Transport units 1936-1941

Bristol Bombay

 

The Bristol Bombay was a British transport which could also serve as a medium bomber.

It was designed to an Air Ministry specification (C.26/31) which sought for a transport monoplane which could also act as a bomber to replace the outdated Vickers Valentia biplane which was in active service in the Middle East and India. The specification required the aircraft to be capable of carrying 24 troops, or an equivalent amount of cargo as a transport, while mounting defensive gun turrets and bombs to be used as a bomber. This versatile design was common in British designs of the era. Another designs presented for the specification were the Armstrong Whitworth A.W.23, Handley Page H.P.51 and the Vickers Type 230, though this last one was eventually never built. 

Bristol's design, named by the company as the 'Type 130', was a high-wing cantilever monoplane made entirely out of metal. Given that Bristol's previous monoplane design, the Bristol Bagshot of 1927, suffered from lack of torsional rigidity in the wings which caused aileron reversals, an extensive research program was founded at Bristol which eventually led to a new wing design with a stressed metal skin riveted to an internal framework of multiple spars and ribs. This was the basics of the Bombay's wing, which consisted on 7 spars with high-tensile flanges and alclad webs. The aircraft had also a twin-tail and a fixed tailwheel undercarriage.

The crew consisted of a pilot, sat in an enclosed cockpit, a navigator/bomb-aimer who sat in the nose and a radio operator/gunner who divided his time between the radio post behind the cockpit and the gun turret in the nose. When acting as a bomber, an additional crew member was carried to the tail turret.

In the prototype, the tail gun was equipped with a single Lewis gun mounted on a scarf ring, but in production aircraft both gun positions were armed with single Vickers K machine guns. A total of eight 250 pounds (110 kg) bombs could be carried externally under the fuselage on racks.

A prototype, the Type 130, was ordered in March 1933 and flew for the first time on 23rd June 1935. The Type 130 was powered by two Bristol Pegasus III engines which delivered a total of 750 hp of power and drove two-bladed propellers. Testings were carried out successfully and an initial order for 80 machine was placed as the Bombay in July 1937. Unlike the prototype, these were powered by the more powerful Bristol Pegasus XXII which delivered 1.010 hp of power and drove three-bladed propellers. Wheel spats which were present on the prototype were also discarded in the production version, called Bombay Mk.I. 

Production run was set for early 1939 but, considering that Bristol's production lines were full with the more urgent Bristol Blenheim, manufacturing was taken by Short & Harland, in Belfast, where a total of 50 machines were made from March 1939 until June 1940. Given the complex nature of the Bombay's wing, production was delayed, and the last 30 left were cancelled.

The first production Bombay flew in March 1939 and were delivered to the No.216 Squadron RAF , based in Egypt in September that year. Although obsolete as a bomber, for the European theatre, it saw action with the No.271 Squadron which was based at RAF Doncaster, in Yorkshire, transporting supplies to the British Expeditionary Force in June 1940. That same month, French pilot Jean-François Demozay borrowed an abandoned Bombay to ferry himself and 15 more soldiers from France to England, where he became an ace for the Royal Air Force (RAF).

The Middle-East is where the Bombay was more extensively used, specially with the No.216 Squadron which operated most of the Bombays that had been built. When Italy waged war on Britain in June 1940, in the absence of more modern aircraft, No.216 Squadron's Bombays were used as night bombers as well as transports. Its payload of eight bombs was supplemented by improvised bombs thrown out the cargo door by hand. This way the aircraft flew bombing sorties against targets in the Western Desert region, such as Benghazi and Tobruk and the Italian Somaliland. Until the Vickers Wellington arrived in significant numbers to that theatre, the Bombay was British main transport and bomber.

Serving as a transport, they ferried supplies and evacuated wounded soldiers during the Siege of Tobruk of 1941. On 2nd May 1941 Bombays of No.216 Squadron, evacuated the Greek Royal Family from Crete to Egypt. Later that month, Bombays played a significant role transporting troops during the Anglo-Iraqi War. It was also used by the Special Air Service (SAS) in their first special operation in the Middle East when, five Bombays performed five raids against German forward airfields on 17th November 1941.

Lieutnant General William Gott, the highest ranking British general killed in the war, dies when the Bombay he was being carried on was shot down in the Western Desert on 7th August 1942. He was about to assume command from General Claude Auchinleck, but his death opened way for General Bernard Montgomery to take over.

Bombays were also employed by the No.1 Air Ambulance Unit of the Royal Australian Air Force (RAAF), where they evacuated over 2.000 wounded troops during the Sicily Campaign in July 1943. One crew of this unit was credited with having evacuated more than 6.000 casualties from Sicily and Italy before the type was finally withdrawn from use service in 1944.

Sources:

1. https://en.wikipedia.org/wiki/Bristol_Bombay

2. https://en.wikipedia.org/wiki/No._271_Squadron_RAF

3. https://en.wikipedia.org/wiki/No._1_Air_Ambulance_Unit_RAAF

4. https://www.valka.cz/Bristol-Bombay-t6615