Curtiss Hawk 75A/Mohawk. Part Seven. The Hawk 75 in Thailand

 

During the early 1930s Curtiss and the Royal Siamese Air Force (RSAF) held contacts and, in 1934 twelve Hawk II biplanes were sold, together with a production license. One year later, additional Hawk III biplanes were sold and delivered. 
As the situation in the region deteriorated with the turn of the decade, the Thai government sought to bolster their country's combat strength so, to that end they bought a number of warplanes, among them twelve Hawk 75Ns, a export variant with a fixed landing gear, to the United States. 
When designing the aircraft for Siam, Curtiss took advantage of its experience with the Chinese H-75H, skipping this way the need for a new prototype. However, several changes were made. The airframe was closer to the Y1P-36 than the Hawk 75B, just like the Chinese demonstrator. 
This new variant, however, featured glass panels behind the cockpit canopy and a number of minor modifications. The landing gear also modified as it was moved slightly forward and was enclosed by larger cowlings. 
The armament was changed too, although fuselage machine guns remained unchanged, wing armament was completely redesigned. 
It was considered the installation of two 8mm machine guns or 23mm Madsen cannons under the wings, in special aerodynamic pods. Eventually the decision was made to install cannons that could be detached at any time and, in their place bomb racks could be placed. 
This sub-variant was designated as "Hawk 75N" and its first exemplar flew for the first time on 1st November 1938. By 9th December all twelve ordered aircraft were delivered at a price of $ 31.074,50 each. On 22nd March 1939 one of the aircraft crashed and the remaining eleven were transferred to a squadron based at Don Muang airfield, close to Bangkok. 
They were employed in the Franco-Thai War achieving some limited success and during the short-lived Thai-Japanese War which lasted for just 5 hours. 
During this time the 12.7mm Browning machine guns of the Siamese Hawks were replaced with Danish Madsens of 11.35mm.
Nowadays only one Hawk 75N survives, located at the Royal Thai Air Force Museum.
The RSAF also ordered a specific two-seat version of the Hawk 75N, intended for training purposes, capable of carrying 450kg of bombs, to replace their ageing Vought V-93S Corsair biplanes. 
Curtiss rejected this proposal, as it was impossible to adapt the aircraft to carry such heavy payload and so few machines. Moreover, like any single-unit production, it would have been too expensive, so Curtiss offered some SBC-4 Helldivers instead, but this was rejected by te RSAF, which preferred the North American NA-69. This order, however, never reached Thai land as the shipment was intercepted by the Japanese after December 1941 and "sold" the RSAF some Mitsubishi Ki-30 of their own.

Sources:
1st  AJ-Press - Monografie Lotnicze 61 - Curtiss P-36 Hawk Part 1 (translated)
2nd https://en.wikipedia.org/wiki/Curtiss_P-36_Hawk

Mitsubishi Ki-21, foreign users

 

The Mitsubishi Ki-21 was a Japanese twin-engined bomber which took part in the World War II. Its main user was Japan, however, it was used by some other users:

• France: After the War, some few Ki-21 were used in Indochina by the French Armée de l'Air (French Air Force) during the First Indochina War. They were originally Ki-21-IIb bombers converted ad-hoc into transports with their defensive armament removed. These machines were very worn out so their usage through that conflict wasn't very prolonged and they were most likely, replaced. 
• Manchukuo: The Manchukuo Imperial Air Force had 6 Ki-21-Ia bombers in strength in the year 1941. They were assigned to 2nd Air Unit, based in Fengtian, but, most probably, they were not used very much and were either destroyed on ground or left to rot. 
• Thailand: Nine Ki-21-IIa bombers were sold to the Kingdom of Thailand in 1940 to be used by the Royal Thai Air Force against the Vichy French forces in Indochina. However they couldn't take part in the Franco-Thai War as crews didn't complete training in time. They were part of the 62nd Squadron and were based at Don Muang, in Bangkok. In 1942, when the Japanese Army invaded Burma, the Thai Army invaded the Shan States, using their Ki-21 extensively against the defending Chinese forces. Two Thai Ki-21s were lost on air raids on 2nd May 1943 and 30th November 1944 when they were based in Lampang, North-West of Thailand. The remaining seven were kept in active after the war and it wasn't until 1949 that they were written off service and were immediately scrapped.

Sources:

1. https://en.wikipedia.org/wiki/Mitsubishi_Ki-21

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

3. https://www.traditions-air.fr

4. http://wings-aviation.ch/51-Profiles/M/M-Basis-en.htm (translated)

Martin Type 139 - Various Foreign Users

 

The Martin Type 139 was an all-metal monoplane bomber that was used by the United States Army Air Corps and by many other countries:

• China: The National Revolutionary Army, (Kuomingtan's Armed Forces) ordered six 139s which Martin called them 'Type 139WC' (the letter 'C' standing for 'China'). This version was powered by two Wright R-1820 Cyclone engines which could deliver up to 850 hp of power each. 
  They arrived in China in February 1937 and were used in August against the Japanese in the Battle of Shanghai, where the Chinese Nationalist Air Force (CNAF) launched a major strike with a formation of various types of aircraft. One of such attacks took place on 14th October 1937 when three 139WC, two Heinkel He.111A, five Douglas O-2MCs, five Northrop Gammas and three Curtiss Hawk IIIs, based in Nanjing, bombed Japanese positions.
  Later, on 19th May 1938, the Type 139WC has the honour of being the first aircraft to conduct a raid into Japanese mainland. On that day, two 139WC belonging to the 2nd Bomber Group, 14th Squadron, commanded by Cpt. Hsu Huan-Sheng and Lt. Teng Yen-bo successfully flew a nighttime raid over Japan. However, instead of dropping bombs, they dropped propaganda leaflets over the cities of Nagasaki, Fukuoka, Kurume, Saga and some others, while making reconnaissance duties over ports, airports, warships and factories. 
  Most of the 139WC were destroyed during the course of the war.
• Japan: After the fall of the Dutch East Indies, three Type 139WH (the export version made for the Dutch colony) and Type 166 were captured intact by the Nippons and shipped to Haneda, Tokyo to be evaluated by the Testing Division of the Army Aircraft Authority. Their ultimate fate is unknown, but they were most likely destroyed during an air raid.
• Philippines: Apparently, some few B-10B (regular production variant) were leased to the Philippine Army Air Corps (PAAC) by the 4th Composite Group. They were most likely, destroyed during the Japanese invasion of the Philippines. As we couldn't find graphical evidence of a B-10B serving with the PAAC, the drawing should be considered as speculative.
• Thailand: Six Type 139WS (the 'S' standing for 'Siam') were sold to Thailand in April 1937. They saw action against the French in the Franco-Thai War in late 1940 and January 1941 and later they were used to support Japanese troops in their advance towards Burma in early 1942. They were complemented by an amount of ex-Dutch airplanes given by the Japanese later that same year. They were kept in active service until 1949.
• Turkey: When fascist Italy sought to expand their empire in the Mediterranean, the Turkish Government, decided to equip their air force with a long-range bomber. Therefore Cpt. Enver Akoglu was sent in a mission to the United States to purchase 20 Type 139WT ('T' standing for 'Turkey'). This variant was powered with uprated engines which could, theoretically, deliver up to 1.000 hp of power instead of the regular 750 hp. They arrived to Turkey in September 1937 and were assigned to 55 and 56th Tayyare Bölügü (Flying detachment, a squadron-sized unit) based at the city of Çorlu, in the Marmara region. Those were part of the higher 9th Tayyare Taburu unit. During 1941 and 1942 they were employed extensively in reconnaissance patrols over the Black Sea. When the type was showing its obsolescence, they were reassigned to other secondary and transport units. They were in active until 1946 with four of them crashing in 1945.

Sources:

1. en.wikipedia.org/wiki/Martin_B-10

2. http://www.joebaugher.com/usaf_bombers/b10.html

3. http://www.tayyareci.com/digerucaklar/turkiye/1923ve50/martin139wt.asp

Mitsubishi Ki-30 - Foreign users, part two - Thai users

Due to the American embargo, the Royal Thai Air Force (RTAF) switched to Japan for their new suppliers in October 1940. They sent a purchasing commision to Japan where they were shown both the Mitsubishi Ki-21 and the Mitsubishi Ki-30. They were greatly impressed by the performance of the Ki-30 so they ordered nine Ki-21s and 24 Ki-30s. Apparently an unknown number of fighters were ordered too, but were never delivered.
The Ki-30 filled the void that the North American NA-69 (a light attack plane) would've filled if it had been delivered. The Ki-30 was found to be easy to fly and maintain and it performed notably much better than the obsolete Vought O2U Corsair. It had a much better bombload and twice the range, compared to the Corsair and its fixed landing gear allowed the type to operate in the rough airfields located specially in the Northern and Eastern parts of the country. They received the nickname of Nagoya by their Thai pilots.
All 24 of them were delivered in November 1940 and, to operate them, two squadrons were formed at the city of Don Muang. Thai crews completed their training quickly and on 7th January 1941, in the context of Franco-Thai War, twenty-three Ki-30s attacked French targets in Cambodia. The next day, 9 Nagoyas, escorted by three Curtiss Hawk 75Ns attacked the airfield at the city of Siem Reap and two days later, they sustained their first casualty as one Ki-30 was shot down by a Morane-Saulnier M.S.406. The Ki-30s took part also in the last air raid of the conflict ,on 24th January, as nine Ki-30s and three Martin 139WS medium bombers, raided the same airfield of Siem Reap, hoping to destroy the M.S.406 fighters. During that raid, one Ki-30 was attacked by two M.S.406s but the Ki-30 managed to scape.
On 22nd December 1941, the RTAF underwent reforms and shortly later, in January 1942 they were rebased to Lampang, to become part of the Northern Air Wing. They were extensively used in the Burmese front, flying both attack and reconnaissance missions without, surprisingly, no Chinese fighter opposition at all. However, the occasional anti-air fire and hazardous weather and terrain conditions, made those missions dangerous.
One of those raids, took place on 29th January 1943 when a mixed force of Ki-21s and Ki-30s raided the Chinese base at Mong Sae, managing to inflict severe damage at the cost of just some damaged bombers. That was the last Thai raid of the Northern campaign because, technically, Thailand wasn't at war with China and a truce was arranged. Thailand had invaded the Burmese Shan States, following orders coming from Japan, and fought Chinese forces present there but, when Thailand signed the declaration of war against the Allies, China didn't respond.
In spite of the efforts to obatin more Japanese bombers, like the Ki-21 and the Ki-30, no more aircraft of either was supplied.
 In April 1945 there were still 21 Ki-30s in active service of which 14 of them were in flying conditions. The last Ki-30 was written off active service in 1950.

Sources:
1. http://www.j-aircraft.com/research/jan_forsgren/j-aircraft_royal_thai.htm
2. https://en.wikipedia.org/wiki/Mitsubishi_Ki-30
3. https://www.valka.cz/Micubisi-Ki-30-Ann-t1289

Aichi E13A - Thai & French users

In this post we cover two users of this Japanese floatplane.

• Thailand: Back in 1942 three Aichi E13A were handed over to the Royal Thai Navy. Those were followed by three more in 1943. They were employed in coastal defence, patrol and search & rescue missions. They operated from the Royal Naval Aero Base Sattahip, located at the Southern part of the country. They served through the inmediate postwar, until 1948 when they were written off and replaced.
• France: When the Imperial Japanese Army left the French Colony of Indochina, they left many equipment behind, among them, eight Aichi E13A that were taken over by the local French Authorities and pushed over into service by the Aéronavale (French's Naval Air Arm) and also, at least one, by the Armée de l'Air which was probably given to the Aéronavale's 8S squadron that was the one that employed them in the reconnaissance role during the First Indochina War. They operated mainly from the B.A.N. Cat-Lai, close to Saigon, that was also the same base that they operated when serving with the Japanese.

Sources:

1. https://en.wikipedia.org/wiki/Aichi_E13A

2. http://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=443

3. http://www.combinedfleet.com/ijna/e13a.htm